Inorganic Chemistry Communications (v.10, #12)

Contents List (iii-xiv).

A novel Keggin unit supported transition metal complex [Cu(4,4′-bipy)]2[SiW12O40 {Cu(4,4′-bipy)}4] · (OH)2  · H2O (1) has been prepared by hydrothermal methods. The title compound represents the first saturated Keggin-type polyoxoanions which are covalently linked by four Cu (I) complexes into an interesting 1D fourfold structure.A novel Keggin unit supported transition metal complex [Cu(4,4′-bipy)]2[SiW12O40{Cu(4,4′-bipy)}4] · (OH)2  · H2O (1) (4,4′-bipy = 4,4′-bipydine) has been hydrothermally synthesized and structurally characterized by IR spectroscopy, TG analyses and single-crystal X-ray diffraction. The result of the X-ray crystallography analysis exhibits that four { Cu ( 4 , 4 ′ -bipy ) } n n + chains simultaneously connect with the [SiW12O40]4− units via W–Ot–Cu bridges constructing an infinitely one-dimensional fourfold-chain structure.
Keywords: Polyoxometalate; Hydrothermal synthesis; Crystal structure;

Self-assembly of organometallic Pd(II) complexes via CH3⋯π interactions: The first example of a cyclopalladated compound with herringbone stacking pattern by E.T. de Almeida; A.E. Mauro; A.M. Santana; S.R. Ananias; A.V.G. Netto; J.G. Ferreira; R.H.A. Santos (1394-1398).
The synthesis, structural and spectroscopic characterization of the cyclometallated compounds [Pd(C 2,N-dmba)(μ-N3)]2 (1) and [Pd2(C 2,N-dmba)2(μ-N3)(μ-Cl)] (2) (dmba =  N,N-dimethylbenzylamine) have been described. The C(sp3)―H⋯π interactions are responsible for the self-assembly within the crystals. Compound 1 crystallizes as 1D supramolecular chains whereas the crystal packing of 2 consists of herringbone of sandwiches.Two binuclear cyclometallated compounds [Pd(C 2,N-dmba)(μ-N3)]2 (1) and [Pd2(C 2,N-dmba)2(μ-N3)(μ-Cl)] (2) (dmba =  N,N-dimethylbenzylamine) have been synthesized and characterized by elemental analysis, IR and NMR spectroscopies and single crystal X-ray diffraction crystallography. The ability of CH3 groups to form C(sp3)―H⋯π hydrogen bonds with phenyl rings is responsible for the molecular self-assembly within the crystals of 1 and 2. Compound 1 crystallizes as one-dimensional supramolecular chains whereas the crystal packing of 2 consists of a herringbone of sandwiches composed by two inversely related [Pd2(C 2,N-dmba)2(μ-N3)(μ-Cl)] molecules.
Keywords: Supramolecular chemistry; C(sp3)―H⋯π interactions; Cyclopalladated compounds; Self-assembly;

3D Ln–Ag (Ln = Nd; Eu) coordination polymers based on N- and O-donor ligands: Synthesis, crystal structures and luminescence by Yongcai Qiu; Hanguo Liu; Yun Ling; Hong Deng; Ronghua Zeng; Guoyong Zhou; Matthias Zeller (1399-1403).
Two isostructural 3D 4d–4f coordination polymers, Ln2Ag4(OX)(IN)6(H2O)1.5  · 2(ClO4) [Ln = Nd (1); Eu (2), OX = oxalic acid, IN = isonicotinic acid] have been synthesized under hydrothermal conditions. Compounds 1 and 2 are 3D coordination frameworks via 2D layers built by carboxylate groups of isonicotinic acid and oxalate ligands coordinating to metal centers and completing the linear linker by silver ions.The self-assembly of isonicotinic acid with metal salts under hydrothermal conditions gave two isostructural 3D 4d–4f coordination polymers, Ln2Ag4(OX)(IN)6(H2O)1.5  · 2(ClO4) [Ln = Nd (1); Eu (2), OX = oxalic acid, IN = isonicotinic acid]. Compounds 1 and 2 are 3D coordination frameworks via 2D layers built by carboxylate groups of isonicotinic acid and oxalate ligands coordinating to metal centers and completing the linear linker by silver ions. Furthermore, the luminescent properties of complex 2 have also been investigated.
Keywords: Hydrothermal synthesis; Isostructural; Ln/Ag heterometallic complexes; Luminescence;

The 3D framework containing 1D left-handed helix: the wave-like two-dimensional networks linked through {ZnO2N2} building blocks and bpp ligands, highlighting the helical chain (purple).The hydrothermal reaction of Zn(NO3)2  · 6H2O, bpp and NH4VO3 in water at 140 °C for 80 h yields an unprecedented chiral three-dimensional vanadium oxide complex, [Zn(bpp)V2O6] (1). The structure of 1 consists of wave-like two-dimensional networks, linked through {ZnO2N2} building blocks and bpp ligands into a three-dimensional covalently linked assembly. Furthermore, the title compound consists of infinite helical chains and all helical chains are left-handed.
Keywords: Hydrothermal synthesis; Zinc vanadate; Helix; Chiral structures;

Novel ether-containing ligands as potential 99mtechnetium(I) heart agents by Kevin P. Maresca; James F. Kronauge; Jon Zubieta; John W. Babich (1409-1412).
A novel pair of lipophilic cationic technetium(I) tricarbonyl complexes were developed and evaluated for cardiac uptake. The ether functionalized compounds, di(pyridylmethyl)amine (DPA) and di(imidazolymethyl)amine (DIA), formed symmetric tridentate chelates for both {Re(CO)3}+ and {99mTc(CO)3}+ cores. The stable {99mTc(CO)3}+ complexes were prepared in excellent yields (>90%) and injected into normal rats. The DIA Tc-99m-complex (8) demonstrated 1.8% ID/g in the heart and a 90:1 heart to blood ratio at 120 min post-injection.A novel pair of lipophilic cationic technetium complexes utilizing the 99mTc-tricarbonyl core have been developed and evaluated for cardiac uptake. Di-(pyridyl-2-methyl)amine (DPA) and di-(imidazol-2-ylmethyl)amine (DIA) ligands were functionalized using aliphatic or aromatic ether substituents to provide the ligands 3 and 4. Octahedral complexes with the fac { 99mTc(CO)3(ligand)}+ configuration were readily formed by reaction of 99m[Tc(CO)3(H2O)3]+ with the ether-containing tridentate ligands. The 99mTc-tricarbonyl complexes, formed in >90% RCY and >90% RCP, were stable to transchelation in vitro against molar excesses of cysteine and histidine. Preliminary evaluation in rats after intravenous administration showed that the complexes concentrated in the heart muscle to an extent greater than surrounding tissue and blood. The 99mTc-complex with derivatized DIA, {99mTc(CO)3(4)}+ (8), demonstrated 1.8% ID/g in the heart and a 90:1 heart to blood ratio at 120 min post-injection. These initial results provide support for an expanded evaluation of novel cationic 99mTc-complexes for cardiac imaging.
Keywords: Tc(I)-tricarbonyl complexes; Heart imaging agents; Radiopharmaceuticals; Re(I)-tricarbonyl complexes;

A ratiometric fluorescent sensor for zinc(II) with high selectivity by Huili Chen; Yanbo Wu; Yunfei Cheng; Hong Yang; Fuyou Li; Pin Yang; Chunhui Huang (1413-1415).
A schiff base compound was synthesized and exhibited a rather high selectivity toward Zn2+ over other metal ions, even Cd2+.Spectroscopic studies revealed that the compound [N,N′-di(quinoline-2-methylene) -1,2-phenylenediimine] (1) exhibited a rather high selectivity toward Zn2+ over other metal ions, even Cd2+. In acetonitrile, the red shift of fluorescent emission from 396 nm to 426 nm upon zinc binding is due to the formation of a 1:1 metal/ligand complex.
Keywords: Ratiometric; Fluorescence; Zn2+ sensor; Schiff base;

Organic–inorganic hybrid material as zwitterion: Synthesis and structure of terminal ammonium ions-containing organosilyl species supported on mono-lacunary Dawson polyoxometalate by Takeshi Hasegawa; Yuhki Kasahara; Shoko Yoshida; Takayuki Kurashina; Shotaro Aoki; Kenji Yoza; Kenji Nomiya (1416-1419).
The novel organic–inorganic hybrid polyoxometalate (POM) (Bu4N)42-P2W17O61{Me3N+(CH2)3Si}2O] · CH3CN 1 was synthesized by the reaction of the mono-lacunary Dawson POM with an organosilyl precursor [Me3N(CH2)3Si(OMe)3]Cl. This compound is a first example of the free and bound counterions-containing POM.The title compound 1 with a formula of (Bu4N)42-P2W17O61{Me3N+(CH2)3Si}2O] · CH3CN was obtained in 77.1% (4.21 g scale) yield by a 1:2 molar-ratio reaction of the mono-lacunary Dawson polyoxometalate (POM) [P2W17O61]10− with N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride ([Me3N(CH2)3Si(OMe)3]Cl) in mixed water/acetonitrile solution under acidic conditions and unequivocally characterized with complete elemental analysis, thermogravimetric and differential thermal analyses (TG/DTA), FTIR, solution (31P, 1H, 13C and 29Si) NMR and X-ray crystallography. Compound 1 contained two types of the ammonium cations, i.e., the counterions Bu4N+ (free cations) and the terminal quaternary ammonium ions (bound cations) which are connected to the POM through the organosilyl groups.
Keywords: Organic–inorganic hybrid; Dawson polyoxometalate; Organosilyl group; Free and bound ammonium cations; Zwitterion;

The thermal reaction of Ru3(CO)12 with malonic acid, followed by the addition of the corresponding ligand, yields to the tetranuclear ruthenium complexes [{Ru2(CO)4L2}2(O2CCH2CO2)2] (L = PPh3: 1, L = 3,5-(CH3)2-NC5H3: 2), while the reaction of Ru3(CO)12 with terephthalic acid, followed by the addition of the corresponding ligand, gives rise to the formation of the hexanuclear ruthenium complexes [{Ru2(CO)4L2}3(O2CC6H4CO2)3] (L = PMe3: 3, L = 3,5-(CH3)2-NC5H3: 4). The single-crystal X-ray structure analyses for 1 and 3, reveal both cages to consist of Ru2(CO)4 sawhorse units, 1 being a molecular loop, while 3 is a molecular triangle.The thermal reaction of Ru3(CO)12 with malonic acid, followed by the addition of the corresponding ligand, yields the tetranuclear ruthenium complexes [{Ru2(CO)4L2}2(O2CCH2CO2)2] (L = PPh3: 1, L = 3,5-Me2NC5H3: 2), while the reaction of Ru3(CO)12 with terephthalic acid, followed by the addition of the corresponding ligand, gives rise to the formation of the hexanuclear ruthenium complexes [{Ru2(CO)4L2}3(O2CC6H4CO2)3] (L = PMe3: 3, L = 3,5-Me2NC5H3: 4). The single-crystal X-ray structure analyses for 1 and 3, reveal both cages to consist of Ru2(CO)4 sawhorse units, 1 being a molecular loop, while 3 is a molecular triangle.
Keywords: Cages; Sawhorse-type complexes; Carboxylato bridges; Macromolecular systems; Molecular triangle; Molecular loop;

First dicadmium(II) complex of tripodal amide ligand with one edge-sharing monocapped octahedral geometry by Donghyun Kang; Joobeom Seo; So Young Lee; Jai Young Lee; Kyu Seong Choi; Shim Sung Lee (1425-1428).
A new dicadmium(II) complex [Cd2(L)2(H2O)2](NO3)4  · 8H2O (1) with the tripodal amide ligand L (tris[3-aza-2-oxo-4-(2-pyridyl)butyl]amine) was synthesized and structurally characterized. Complex 1 is revealed as a dinuclear 2:2 (Cd:L) complex, in which each cadmium(II) ion is hepta-coordinated with the coordination surrounding of distorted monocapped octahedral geometry.A new dicadmium(II) complex [Cd2(L)2(H2O)2](NO3)4  · 8H2O (1) with the tripodal amide ligand L (tris[3-aza-2-oxo-4-(2-pyridyl)butyl]amine) was synthesized and structurally characterized. Complex 1 is revealed as a dinuclear 2:2 (Cd:L) complex, in which each cadmium(II) ion is hepta-coordinated with the coordination surrounding of distorted monocapped octahedral geometry. Two cadmium(II) ions are dibridged by two carbonyl μ-O atoms forming a Cd2(μ-O)2 parallelogram-type moiety. Interestingly, the dinuclear coordination sphere can be seen as resulting from the fusion of two distorted monocapped octahedral [Cd(L)(H2O)]2+ units through sharing one edge originated from the two carbonyl μ-O atoms as a first example. Comparative NMR, IR and FAB-mass data of 1 are also discussed.
Keywords: Tripodal amide ligand; Dicadmium(II) complex; Bridging carbonyl group; Edge-sharing; Monocapped octahedral geometry;

A metal-free hexaaza macropentacyclic compound (1) and a dinuclear copper(II) complex (2  · 2H2O) have been prepared in high yield from the reaction of bis(3-aminopropyl)amine (BAPA) and formaldehyde in the presence of Ni2+ or Cu2+ ion. Interestingly, 2  · 2H2O exhibits uncommon magnetic behaviors.The reaction of bis(3-aminopropyl)amine with excess formaldehyde in the presence of Ni2+ ion produces the macropentacyclic compound L1(ClO4)2 (1) L1  = 1,3,7,11,13,17- hexaazapentacyclo[15.3.1.13.7.17.13.113.17]tetracosane). The dinuclear complex [Cu2(L2)2(H2O)2](ClO4)2 (2) (HL1  = 1-(3-aminopropyl)-3-(hydroxymethyl)-1,3-diazacyclohexane) as well as 1 can be prepared by the condensation reaction in the presence of Cu2+ ion. Interestingly, 2  · 2H2O exhibits uncommon magnetic behavior.
Keywords: Template synthesis; Macrocycle; Dinuclear complex; Copper(II) complex; Crystal structure; Magnetism;

Two novel lanthanide–sulfate coordination polymers based on inorganic lanthanide–sulfate skeletons and chelidamic acid (H3CAM): {[Ln2(HCAM)2(H2O)2SO4] · 2.5H2O} n (Ln = Dy (1) and Tb (2)) have been synthesized under hydrothermal condition, which are 1D chains constructed by an intriguing bowl-like structure as the repeating unit.Two novel lanthanide–sulfate coordination polymers with chelidamic acid (H3CAM): {[Ln2(HCAM)2(H2O)2SO4] · 2.5H2O} n (Ln = Dy (1) and Tb (2)) have been synthesized under hydrothermal condition. 1 and 2 crystallize in the monoclinic space group P21/c. An intriguing bowl-like structure was constructed by three Ln3+ ions, one SO 4 2 - anion and carboxylate O bridges, in which the pentadente mode of SO 4 2 - anion are observed, and the structure as a repeating unit was assembled into a 1D chain. The luminescent properties of 1 and 2 are studied and exhibit the characteristic bands of the corresponding lanthanide ions.
Keywords: Lanthanide; Sulfate; Bowl-like structure; Luminescent properties;

Solvothermal in situ formation and crystal structure of an unexpected hexanuclear copper(I) complex with 2-thiolate-N,N′-dimethylnicotinamide is described.Solvothermal reaction of 2-mercaptonicotinic acid (HL 1) with copper(II) nitrate in DMF/methanol medium leads to the production of a novel hexanuclear complex [Cu(L 2)]6  · (H2O)2 (1), in which in situ formation of an anionic ligand 2-thiolate-N,N′-dimethylnicotinamide (L 2) and reduction of copper(II) to copper(I) are observed. X-ray single-crystal structure of 1 reveals that each copper(I) center adopts a trigonal geometry provided by two thiolate and one pyridyl groups from three separated L 2 ligands. As a result, six copper(I) ions are interconnected by six μ3L 2 bridges to afford a hexanuclear cluster, in which the octahedral Cu6 core is stabilized by significant cuprophilic interactions.
Keywords: Solvothermal preparation; In situ metal/ligand reaction; Hexanuclear copper(I) complex; Crystal structure; Cuprophilic interaction;

The title compound is the Re3 core complex with iodo bridges. This compound was synthesized by thermal reaction.The Re3 cluster compound (4,4′-bipyH2) Re3Cl8I3H2O · 2H2O was obtained by thermal reaction of (NH4)4[Re2OCl10] with 4,4′-bipirydine triiodide. The structure of this compound has been established by X-ray measurement. This is the three-centre rhenium cluster with Re centres bonded by iodide bridges. The cations and anions positions are stabilized by hydrogen bonding network.
Keywords: Rhenium cluster; Crystal structure; Synthesis;

A novel lead(II) complex [Pb(NIT2Py)2(NO3)2] has been prepared and characterized. The lead(II) ion is coordinated with two bidentate nitronyl nitroxide and two nitrate anions. There is antiferromagnetic interaction between the coordinated nitronyl nitroxides (J  = −19.35 cm−1). We observe the sixth periodic IVA group metal element Pb(II) ion providing an effective pathway for the magnetic exchange interaction between nitronyl nitroxide radicals.The lead(II) complex with nitronyl nitroxide, [Pb(NIT2Py)2(NO3)2] [NIT2Py = 2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide], has been prepared and characterized by magnetic and single-crystal X-ray diffraction studies. In the complex, the lead(II) ion is coordinated with two bidentate nitronyl nitroxide and two nitrate anions. The lead(II) ion shows seven-coordinate geometry. Magnetic susceptibility data for the title complex has been measured in the range 5–300 K. There are antiferromagnetic interaction between the coordinated nitronyl nitroxides (J  = −19.35 cm−1) and intermolecular ferromagnetic interactions. Thus, we observe the sixth periodic IVA group metal element Pb(II) ion providing an effective pathway for the magnetic exchange interaction between nitronyl nitroxide radicals.
Keywords: Nitronyl nitroxide; Lead; Magnetic properties; Crystal structure;

A novel polyoxometalate, which displays 2D layer structure constructed from four vanadium-capped pseudo-Keggin tungstates, has been hydrothermally synthesized and characterized by elemental analysis, IR spectrum, XPS spectrum and single crystal X-ray diffraction analysis.A novel polyoxometalate [Cu(en)2(H2O)]2[Cu(en)2]2 [AsW9V7O44] · 2H2O (1) has been hydrothermally synthesized and characterized by elemental analysis, IR spectrum, XPS spectrum and single crystal X-ray diffraction analysis. It is the first example of two-dimensional layer structure constructed from four vanadium-capped pseudo-Keggin tungstates. The study of the magnetic susceptibility of 1 demonstrates the presence of ferromagnetic interactions.
Keywords: Polyoxometalate; Hydrothermal synthesis; Crystal structure; Magnetic susceptibility;

A new pillar-layered 3D open framework with bi-supporting Anderson-type polyoxometalate clusters as pillars, namely, {[(ala)2Cu]2[Cr(OH)6Mo6O18]}{[(H2O)2Na]2[Cr(OH)6Mo6O18]} · 23.5H2O (1) (ala = alanine), was synthesized and characterized for the first time. Magnetic measurements show weak ferromagnetic interactions for compound 1.A new pillar-layered 3D open framework, {[(ala)2Cu]2[Cr(OH)6Mo6O18]}{[(H2O)2Na]2[Cr(OH)6Mo6O18]} · 23.5H2O (1) (ala = alanine) has been synthesized and characterized for the first time. Compound 1 is constructed from the hybrid two-dimensional cationic layers {[(ala)2Cu]2[Cr(OH)6Mo6O18]}+, and anionic bi-supporting {[(H2O)2Na]2[Cr(OH)6Mo6O18]} clusters as pillars to form a 3D channel framework. Furthermore, magnetic measurements show weak ferromagnetic interactions for compound 1.
Keywords: Polyoxometalate; Open framework; Pillar-layered structure; Magnetic property;

A novel 3D 2-fold interpenetrated framework assembled via mixed bridging ligands by Li-Juan Chen; Xiao-Yuan Wu; Quan-Guo Zhai; Zhen-Guo Zhao; Qi-Sheng Zhang; Can-Zhong Lu (1457-1460).
A 2-fold parallel interpenetrated 3D → 3D entanglement architecture based on the connectivity of cadmium(II) cations, the 5-sulfoisophthalate and the rigid pyrazine ligands.Hydrothermal reaction of Cd(NO3)2, NaH2SIPA (5-sulfoisophthalalic acid monosodium salt) and pyrazine (Pz) resulted in a new polymeric complex {[Cd3(SIPA)2(pyrazine)(H2O)6] · 2H2O} n . X-ray structure analysis reveals that this complex features a 2-fold parallel interpenetrated 3D → 3D entanglement architecture, in which the single 3D network is constructed from {[Cd3(SIPA)2(H2O)6]} n 2D neutral layers interconnected by pyrazine ligands.
Keywords: Coordination polymers; 2-Fold interpenetrated; Cadmium; Mixed ligands;

Formations of nitrilotriacetato oxomolybdenum(V) dinuclear complex (NH4)4[cis-Mo2O4(nta)2] · 7H2O and its incomplete cubane-type trinuclear molybdenum(IV) complex [Mo3O(OH)3(Hnta)3] · Cl · 3H2O show a pH dependent reaction pattern.Nitrilotriacetato oxomolybdenum(V) dinuclear complex (NH4)4[cis-Mo2O4(nta)2] · 7H2O (1) (H3nta = nitrilotriacetic acid) and its incomplete cubane-type trinuclear molybdenum(IV) complex [Mo3O(OH)3(Hnta)3] · Cl · 3H2O (2) are isolated in a weak acidic and an acidic solutions, respectively (pH 4.5 and 1.0). The nitrilotriacetate ligand in the anion 1 or the cation 2 displays tridentate mode through the nitrogen atom and the oxygen atoms of β-carboxy groups. Unusual protonations of bridged oxygen atoms in 2 have not effect on the skeleton of molybdenum(IV) cap Mo3O unit. There are obvious dissociations of molybdenum(V) complexes based on 13C NMR observations in solution.
Keywords: Molybdate; Nitrilotriacetate; Incomplete cubane cluster; Crystal structure;

Two novel isomeric complexes supported by vanadates {V4O12}: [{Cu(dpa)2}2V4O12] (dpa = 2,2′-dipyridylamine) by Qi Wang; Xiao-li Yu; Wan-sheng You; Yi Zhao; Cui-Ying Huang; Zhen-gang Sun (1465-1468).
Two isomeric Cu(II) complexes supported by chair-like and boat-like configurations [ V 4 O 12 ] 4 - anions, [{Cu(dpa)2}2V4O12] · (1 and 2), have been synthesized under hydrothermal reactions. [ V 4 O 12 ] 4 - anions are coordinated to each Cu(II) ions through a single terminal trans- and cis-oxygen atom of two cross vanadium sites.Two Cu(II) complexes supported by tetravanadates, [{Cu(dpa)2}2V4O12] (1 and 2), have been synthesized under hydrothermal reactions. Structural analysis indicates that complexes 1 and 2 are isomeric and consist of a cyclic [ V 4 O 12 ] 4 - anion bridged to two [ Cu ( dpa ) 2 ] 2 + moieties. Close inspection of complexes 1 and 2 reveals that the [ V 4 O 12 ] 4 - anions adopt chair-like and boat-like configurations respectively, and are coordinated to each Cu(II) ions through a single terminal oxygen atom of two cross vanadium sites. Moreover, Complexes 1 and 2 exhibit trans- and cis-configurations, respectively.
Keywords: Vanadates; Transition metal complexes; Polyoxometalates; Hydrothermal synthesis;

An unprecedented 2D isopolymolybdate with (32·4)(32·53·8)(3·42·54·6·82)(34·43·54·64) topology by Jingquan Sha; Cheng Wang; Jun Peng; Aixiang Tian; Jing Chen; Pengpeng Zhang (1469-1472).
[Mo4O13] n  · 2nH3O: the first (3, 4, 5, 6)-connected two-dimensional framework constructed from isopolymolybdate with (32·4)(32·53·8)(3·42·54·6·82)(34·43·54·64) topology.A novel two-dimensional molybdenum oxide polymer, [Mo4O13] n  · 2nH3O, has been synthesized and represents the first example of 2D layer structure with (32·4)(32·53·8) (3·42·54·6·82)(34·43·54·64) topology, in which two parallel molybdenum oxide dimeric chains (Mo2O10) n are bound together by the dimer of Mo2O9 subunits via the sharing of corners.A novel two-dimensional molybdenum oxide polymer, [Mo4O13] n  · 2nH3O, has been prepared under specific hydrothermal conditions and characterized by IR spectroscopy and TG analysis. Single-crystal X-ray diffraction analysis reveals that compound 1 exhibits a (3, 4, 5, 6)-connected 2D layer structure with (32·4)(32·53·8)(3·42·54·6·82)(34·43·54·64) topology, which is constructed by two parallel molybdenum oxide dimeric chains (Mo2O10) n bound together by the dimer of Mo2O9 subunits via the sharing of corners. Additionally, the electrochemistry activity of compound 1 is also reported.
Keywords: Isopolymolybdate; Hydrothermal synthesis; Topology; Electrochemical property;

Two 1,8-naphthyridine (nap) metal complexes (nap)ReI(CO)3Cl (1) and [(nap)CuI(DPEPhos)]PF6 (2) (DPEPhos = bis[2-(diphenylphosphino)phenyl]ether) were synthesized and characterized by NMR, emission, and absorption spectroscopies, elemental analysis, mass spectrometry, and X-ray structural analysis. In both complexes, the nap ligand coordinates with both N atoms to the metal centre in a bidentate manner. Complexes 1 and 2 exhibit a broad phosphorescence in solid state at T  = 300 K, which is completely quenched in solution at r.t.Two 1,8-naphthyridine (nap) metal complexes (nap)ReI(CO)3Cl (1) and [(nap)CuI(DPEPhos)]PF6 (2) were synthesized and characterized by NMR-, emission, and absorption spectroscopy, elemental analysis, mass spectrometry, and X-ray structural analysis. In both complexes, the nap ligand coordinates with both N atoms to the metal centre in a bidentate manner. 1 and 2 exhibit a broad phosphorescence in solid state at T  = 300 K, which is completely quenched in solution at r.t. In addition, the gas-phase structures of both complexes were optimized at the B3LYP/6-31G(d,p) level of theory.
Keywords: Naphthyridine; Rhenium; Copper; Electronic spectra; Photoluminescence;

Silver nitrate reacts with the 2-(1-Methyl-1H-pyrazol-5-yl)pyridine (1-mpp) to produce a supramolecular material comprising three different types of one-dimensional coordination polymers resulting from two nitrate lattice positions.Reaction of silver nitrate with the ligand 2-(1-Methyl-1H-pyrazol-5-yl)pyridine (1-mpp) produces a supramolecular material comprising three different types of one-dimensional coordination polymers as a result of two distinct orientations of the nitrate anions (with a 50/50 ratio) in the crystal lattice.
Keywords: Silver; Coordination polymer; Bidirectional ligands; N-donor ligands; Spatial arrangement;

A ruthenium(II) complex with bis(3,5-dimethylpyrazol-1-yl)dithioacetate built layer-by-layer on silver and gold surfaces by Alicia Díaz-García; Smith Gutiérrez; Mayreli Ortiz; Iliana Sánchez; Roberto Cao; Antonio Otero (1482-1484).
A ruthenium(II) complex with bis(3,5-dimethylpyrazol-1-yl)dithioacetate was self-assembled layer-by-layer on silver and gold surfaces and the ability of the complex to scavenge nitric oxide was studied.A ruthenium(II) complex with bis(3,5-dimethylpyrazol-1-yl)dithioacetate was self-assembled layer-by-layer on silver and gold surfaces. The two-step process and the ability of the complex to scavenge nitric oxide were studied by cyclic voltammetry.
Keywords: Bis(3,5-dimethylpyrazol-1-yl) derivative; Ruthenium complex; AFM; Self-assembly; Nitric oxide;

Voltammetric metal cation sensors based on ferrocenylthiosemicarbazone by Wei Liu; Xia Li; Zhiyuan Li; Maolin Zhang; Maoping Song (1485-1488).
Electrochemical studies on redox-active ferrocenylthiosemicarbazone L 14 were carried out in acetonitrile in the presence of various metal cations. Electrochemical investigation have demonstrated that the binding of Cu2+, Hg2+ and Ni2+ guest cations by L 14 results in large shifts of respective Fc/Fc+ redox couple to more positive potentials. Moreover, for compound L 4 , significant fluorescence enhancement was found in the presence of the Cu2+, and this suggests it can act as a biresponsive fluorescent and electrochemical chemosensor for Cu2+.Electrochemical studies on redox-active ferrocenylthiosemicarbazone L 14 were carried out in acetonitrile in the presence of various metal cations. Electrochemical investigation have demonstrated that the binding of Cu2+, Hg2+ and Ni2+ guest cations by L 14 results in large shifts of respective Fc/Fc+ redox couple to more positive potentials. Moreover, for compound L 4 , significant fluorescence enhancement was found in the presence of the Cu2+, and this suggests it can act as a biresponsive fluorescent and electrochemical chemosensor for Cu2+.
Keywords: Ferrocene; Electrochemistry; Fluorescence; Cation sensing;

Two cationic pentamethylcyclopentadienyl metal-based hexanuclear complexes with trigonal prismatic structure have been synthesised through a two-step strategy. Addition of silver triflate to the trinuclear complexes [Rh35-C5Me5)33-tpt)Cl6] or [Ir35-C5Me5)33-tpt)Cl6] in dichloromethane affords the hexanuclear metallo-prismatic cations [Rh65-C5Me5)63-tpt)2(μ-Cl)6]6+ and [Ir65-C5Me5)63-tpt)2(μ-Cl)6]6+, respectively.Two cationic pentamethylcyclopentadienyl metal-based hexanuclear complexes with trigonal prismatic architecture have been synthesised through a two-step strategy. The dinuclear complexes [M(η5- C5Me5)(μ-Cl)Cl]2 (M = rhodium and iridium) react with 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine (tpt) in dichloromethane to give the trinuclear complexes [Rh35-C5Me5)33-tpt)Cl6] (1) and [Ir35-C5Me5)33-tpt)Cl6] (2), respectively. Addition of silver triflate to 1 and 2 in dichloromethane connects two identical triangular panels to form the hexanuclear metallo-prismatic cations [Rh65-C5Me5)63-tpt)2(μ-Cl)6]6+ (3) and [Ir65-C5Me5)63-tpt)2(μ-Cl)6]6+ (4), respectively. Cations 3 and 4 have been isolated as their triflate salts and characterised by 1H NMR, IR and UV/visible spectroscopy.
Keywords: Bridging ligands; Pentamethylcyclopentadienyl ligands; N ligands; Iridium; Rhodium; Supramolecular chemistry;

A novel and efficient catalyst of binuclear complex [Co2L2(C2H5OH)2Cl2] in conjunction with phenyltrimethylammonium tribromide (PTAT) was used for the coupling reaction of carbon dioxide and epoxides.A novel bicobalt complex [Co2L2(C2H5OH)2Cl2] supported by 2-hydroxyisophthalaldehyde oxime was synthesized. This complex is an efficient catalyst for the coupling reaction of carbon dioxide and epoxides in presence of phenyltrimethylammonium tribromide (PTAT).
Keywords: Bicobalt complex; Catalyst;

Mono- and dinuclear silver(I) complexes of benzene- and pyridine-bearing 20-membered thiaoxaaza macrocycles by Kaniz Fatima Sultana; So Young Lee; Ji-Eun Lee; Joobeom Seo; Shim Sung Lee (1496-1500).
Two 20-membered penta- and hexadentate macrocycles containing one or two pyridine subunits, namely [20]aneNO2S2 (L 1) and [20]aneN2O2S2 (L 2), have been synthesized. Reaction of L 1 with silver(I) nitrate afforded a unique 2:2 (M:L) disilver(I) complex [μ2-Ag2(L 1)2](NO3)2 (1) in which two four-coordinate Ag atoms bridge two ligands to form a cyclic dimer. In contrast, an endo-dentate 1:1 monosilver(I) complexes [AgL 2]X; [X = ClO4 (2) or PF6 (3)] which show isomorphous structures were obtained from the reactions of L 2 with silver(I) salts.Two 20-membered penta- and hexadentate macrocycles containing one or two pyridine subunits, namely [20]aneNO2S2 (L 1) and [20]aneN2O2S2 (L 2), have been synthesized. Reaction of L 1 with silver(I) nitrate afforded a unique 2:2 (M:L) disilver(I) complex [μ2-Ag2(L 1)2](NO3)2 (1) in which two four-coordinate Ag atoms bridge two ligands to form a cyclic dimer. In contrast, an endo-dentate 1:1 monosilver(I) complexes [AgL 2]X; [X = ClO4 (2) or PF6 (3)] which show isomorphous structures were obtained from the reactions of L 2 with silver(I) salts.
Keywords: Thiaoxaaza macrocycle; Pyridine subunit; Mono- and disilver(I) complexes; NMR;

Molecular structures and vibrational frequencies for cis-[PdCl2(tmen)] and cis-[Pd(N3)2(tmen)]: A DFT study by Oswaldo Treu-Filho; José C. Pinheiro; Rodrigo A. de Souza; Rogério T. Kondo; Raimundo D. de Paula Ferreira; Antônio F. de Figueiredo; Antonio E. Mauro (1501-1504).
Theoretical molecular structures of the complexes cis-[PdCl2(tmen)] and cis-[Pd(N3)2(tmen)] (tmen =  N,N,N,N′-tetramethylethylenediamine) were investigated using B3LYP/DFT method.Theoretical molecular structures of the complexes cis-[PdCl2(tmen)] and cis-[Pd(N3)2(tmen)] (tmen =  N,N,N,N′-tetramethylethylenediamine) were investigated using B3LYP/DFT method. The calculated molecular parameters, bond distances and angles, revealed a square-planar geometry around the metallic center for both compounds with the azide being linear. The theoretical infrared spectra of C 1 symmetry (electronic state 1A) of the compounds are in agreement with the experimental data.
Keywords: Palladium(II); N,N,N,N′-Tetramethylethylenediamine; Infrared spectrum; Molecular structure; DFT;

A luminescent one-dimensional zig-zag coordination polymer has been rationally assembled by the reaction of europium nitrate and a new amide type semirigid bridging podand 1,4-bis{[(2′-m-picolylaminoformyl)phenoxyl]methyl}naphthalene.One-dimensional zig-zag coordination polymer has been rationally assembled by the reaction of europium nitrate and a new amide type semirigid bridging podand 1,4-bis{[(2′-m-picolylaminoformyl)phenoxyl]methyl}naphthalene (L). The coordination chains are further linked by the intermolecular hydrogen bonds to form two-dimensional supramolecular layer structure. At the same time, the luminescent properties of the Eu(III) complex were also investigated. Under the excitation, the complex exhibited characteristic emissions of europium ion.
Keywords: Coordination polymer; Europium nitrate; Bridging podand; Luminescent properties;

Switching on the photochemical reactivity in heterodimetallic OsII–RuII bipyridyl complexes containing a bis(bidentate) phosphine by Rene Gutmann; Sylvia Eller; Markus Fessler; Wytze E. van der Veer; Alexander Dumfort; Holger Kopacka; Thomas Müller; Peter Brüggeller (1510-1514).
The combination of the bis(bidentate) phosphine cis,trans,cis-1,2,3,4-tetrakis(diphenylphosphino)cyclobutane (dppcb) with the chromophores [M(bpy)2]2+ (M = RuII, OsII) leads to the novel homo- or heterodimetallic species meso-(ΔΛ/ΛΔ)-[Os2(dppcb)(bpy)4](PF6)4 (1), rac-(ΔΔ/ΛΛ)-[Os2(dppcb)(bpy)4](PF6)4 (2),ΔΛ/ΛΔ-[Os(bpy)2(dppcb)Ru(bpy)2](PF6)4 (3), and ΔΔ/ΛΛ-[Os(bpy)2(dppcb)Ru(bpy)2](PF6)4 (4). The presence of “steric pressure”in these compounds switches on the photochemical reactivity in 3 and 4. The X-ray structures of 13 explain this effect.For the first time the excited states of the RuP2N4 moiety belonging to a new heterodimetallic OsII–RuII bipyridyl complex are successfully designed in order to introduce photochemical reactivity. This dramatic effect is achieved via the use of the sterically demanding bis(bidentate) phosphine cis, trans, cis-1,2,3,4-tetrakis(diphenylphosphino)cyclobutane (dppcb). Thus, the temperature dependence of the luminescence lifetimes ranging from 77 to 298 K for the novel homodimetallic species meso-(ΔΛ/ΛΔ)-[Os2(dppcb)(bpy)4](PF6)4 (1) and rac-(ΔΔ/ΛΛ)-[Os2(dppcb)(bpy)4](PF6)4 (2) clearly indicates that the d–d state responsible for photochemistry is not populated. By contrast, the analogous temperature dependence for the new heterodimetallic species ΔΛ/ΛΔ-[Os(bpy)2(dppcb)Ru(bpy)2](PF6)4 (3) and ΔΔ/ΛΛ-[Os(bpy)2(dppcb)Ru(bpy)2](PF6)4 (4) unequivocally shows that as a consequence of the population of the d–d state the photochemical reactivity is switched on. Since single crystal X-ray structure analyses are a major clue to the understanding of photophysical and photochemical properties, also the X-ray structures of 13 are given.
Keywords: Dinuclear Os and Ru complexes; Luminescence; Bis(bidentate) phosphine; Antenna effect; Energy transfer;

Synthesis, characterization and crystal structure of a novel thiocyanate–ruthenium(II) complex by Régia Maria Cordeiro Brito; Alzir Azevedo Batista; Javier Ellena; Eduardo E. Castellano; Izaura Cirino Nogueira Diógenes; Luiz Gonzaga de França Lopes; Jackson Rodrigues de Sousa; Ícaro de Sousa Moreira (1515-1517).
A new thiocyanate–ruthenium complex was synthesized and characterized by spectroscopic and electrochemical techniques and its structure was determined by crystal X-ray analysis.The cis-[Ru(dppb)(Me-bipy)(NCS)2], dppb = 1,4-bis (diphenylphosphino)butane, Me-bipy = 4,4′-dimethyl-2,2′-bipyridine, and NCS = thiocyanate, was synthesized and characterized by spectroscopic and electrochemical techniques and its structure was determined by crystal X-ray analysis. The crystal structure reveals that the coordination geometry around the Ru(II) center is distorted octahedron where two molecules of thiocyanate are bonded to the ruthenium through nitrogen atom in cis orientation. The half-wave formal potential value E 1/2  = 0.8 V (versus Ag/AgCl) observed is considerable higher than that for the cis-[RuCl2(dppb)(Me-bipy)] complex, E 1/2  = 0.6 V (versus Ag/AgCl), well illustrating the strong π-acceptor effect the NCS ligand toward the backbonding interaction with the Ru(II) metal center. The MLCT absorption bands of the thiocyanate complex present a higher molar absorptivity (about 12%) compared with the cis-[RuCl2(dppb)(Me-bipy)] complex, in the same experimental conditions. These properties make the complex potentially promising for the photosensitization process.
Keywords: Thiocyanate complex; dppb; Ruthenium complex;

The 2-D coordination polymer {[Cu2(malonate)2(dpa)(H2O)2] · H2O} (dpa = 4,4′-dipyridylamine) is composed of alternating syn–anti and antianti copper malonate 1-D chains linked into a (6,3) herringbone layer motif through tethering dpa ligands. Variable temperature magnetic studies indicate weak ferromagnetic coupling through the 1-D copper malonate chains with J  = 0.64(1) cm−1 and g  = 2.033(4).The novel 2-D copper metal–organic layered coordination polymer {[Cu2(malonate)2(dpa)(H2O)2] · H2O} (1, dpa = 4,4′-dipyridylamine) has been prepared and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. The structure of compound 1 consists of alternating synanti and anti–anti copper malonate 1-D chains linked into a (6,3) herringbone layer motif through tethering dpa ligands. Variable temperature magnetic studies indicate weak ferromagnetic coupling through the 1-D copper malonate chains with J  = 0.64(1) cm−1 and g  = 2.033(4).
Keywords: Coordination polymer; Copper; Malonate; Crystal structure; Ferromagnetism;

Hexanuclear 4d–4f heterometallic complexes, [Ln2Ag4(ina)8(H2O)10][NO3]2  · 4H2O [Ln = Sm (1), Eu (2), Dy (3) and Hina = isonicotinic acid], have been synthesized. These 4d–4f complexes consist of extended 1D zigzag chains structure built upon [Sm2Ag4(ina)8(H2O)10] subunits connected by Ag–Ag interactions.Hexanuclear 4d–4f heterometallic complexes, [Ln2Ag4(ina)8(H2O)10][NO3] 2  · 4H2O [Ln = Sm (1), Eu (2), Dy (3) and Hina = isonicotinic acid], have been synthesized by the hydrothermal reaction of lanthanide oxides, AgI, and isonicotinic acid at a suitable temperature. Single-crystal X-ray diffraction studies indicate that these 4d–4f complexes consist of extended 1D zigzag chains structure built upon [Sm2Ag4(ina)8(H2O)10] subunits connected by Ag–Ag interactions. Furthermore, the photoluminescent properties of the complex 2 were studied.
Keywords: Hexanuclear; Synthesis; Structure; Photoluminescent properties;

Synthesis and X-ray crystal structure determination of monomeric cis-Pd(2,2′-bipyridine)(NO3)2 by Rafael A. Adrian; Shourong Zhu; Kevin K. Klausmeyer; Judith A. Walmsley (1527-1530).
Complex cis-Pd(2,2′-bipyridine)(NO3)2 was synthesized and characterized by IR and 1H NMR spectroscopy. Its crystal structure was determined by X-ray crystallography. The structure obtained shows that each of the two nitrate ligands are coordinated through oxygen atoms to the Pd(2,2′-bipyridine)2+ center in unidentate fashion.Complex cis-Pd(2,2′-bipyridine)(NO3)2 was synthesized by the reaction of cis-Pd(2,2′-bipyridine)Cl2 with AgNO3 in water and crystallized by vapor diffusion of diethyl ether into an acetonitrile solution of the complex. The crystal structure obtained shows that each of the two nitrate ligands are coordinated through oxygen atoms to the Pd(2,2′-bipyridine)2+ center in unidentate fashion. IR and 1H NMR spectral data were also obtained.
Keywords: Palladium; Nitrato complex; Bipyridine; Monomer; 2,2′-Bipyridine;

The title complex, Co4(phen)4{5-(NO2)sal}4 (1) (5-(NO2)sal = 5-nitrosalicylate anion, phen = 1,10-phenanthroline), have been prepared by hydrothermal synthesis and characterized by single crystal X-ray analysis. It displays a neutral metallamacrocyclic structure containing [Co(phen)]2+ corner units and 5-(NO2)sal bridging ligands.A novel complex, Co4(phen)4{5-(NO2)sal}4 (1) (5-(NO2)sal = 5-nitrosalicylate anion, phen = 1,10-phenanthroline), have been prepared by hydrothermal synthesis and characterized by single crystal X-ray analysis, IR, TG, cyclic voltammogram and elemental analyses. This complex displays a neutral metallamacrocyclic structure containing [Co(phen)]2+ corner units and 5-(NO2)sal bridging ligands.
Keywords: Metallamacrocycle; Hydrothermal synthesis; 5-Nitrosalicylate; Cobalt(II);

A hemidirected 1-D coordination polymer [Pb2(H2O)2(HBTC)2] · 3H2O extended in holodirected 3-D by weak Pb–O interactions by Jing Shi; Jun-Wei Ye; Tian-You Song; Dao-Jun Zhang; Kui-Rong Ma; Jing Ha; Jia-Ning Xu; Ping Zhang (1534-1536).
The complex [Pb2(H2O)2(HBTC)2] · 3H2O (H3BTC = 1,3,5-Benzenetricarboxylic acid) has been synthesized and structurally characterized which consists of 1-D double-chains. When the Pb–O bonding limit extends to 2.90 Å, the potential weak bonds can be found and an infinite 3-D framework is obtained with the coordination geometry of Pb(II) transforming from hemidirected to holodirected.A new complex, [Pb2(H2O)2(HBTC)2] · 3H2O (H3BTC = 1,3,5-Benzenetricarboxylic acid) (1), has been synthesized under hydrothermal condition. The single-crystal analysis shows that 1 consists of 1-D double-chains with Pb(II) six-coordinated by three H3BTC and one H2O molecule with the Pb–O bond distances in the range of 2.56–2.76 Å. When the Pb–O bonding limit extends from 2.76 to 2.90 Å, the potential weak bonds of Pb–O can be found and the coordination number of Pb will increase from six to nine. As a result, the coordination geometry of Pb(II) transforms from hemidirected to holodirected and an infinite 3-D framework is obtained by the connection of the double-chains. The IR spectrum and the TGA–DTA curve of 1 are also reported in this paper.
Keywords: Pb(II); 1,3,5-Benzenetricarboxylic acid; Double-chain; Hemidirected; Holodirected;

Catalytic oxidation of olefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl] complex covalently linked to polyoxometalate by Valiollah Mirkhani; Majid Moghadam; Shahram Tangestaninejad; Iraj Mohammadpoor-Baltork; Nahid Rasouli (1537-1540).
The catalytic activity of Fe(salen) covalently linked to a Keggin type polyoxometalate K 8 SiW 11 O 39 (POM) was studied in the oxidation of various olefins in acetonitrile, using hydrogen peroxide as oxygen source. While, [Fe(salen)-POM] catalyst showed moderate to good catalytic activity and product selectivity in the oxidation reactions, the complex Fe(III)(salen)Cl remained catalytically inactive in these reactions.The catalytic activity of a hybrid compound [Fe(salen)-POM] (1) consisting of Fe(III)(salen)Cl [H2salen =  N,N′-bis(salicylidene)ethylenediamine] complex covalently linked to a Keggin type polyoxometalate, K 8 SiW 11 O 39 , (POM) was studied in the oxidation of various olefins in acetonitrile, using hydrogen peroxide as oxygen source. While, [Fe(salen)-POM] catalyst showed moderate to good catalytic activity and product selectivity in the oxidation reactions, the complex Fe(III)(salen)Cl showed poor catalytic activity in these reactions. The effect of other parameters such solvent, oxidant, temperature and the metal type in Schiff base complex were also investigated.
Keywords: Iron(III)-salen; Polyoxometalate; Oxidation; Hydrogen peroxide;

Functional mesoporous carbon built from the 1,10-phenanthroline building block: A new class of catalyst support by Yongsoon Shin; Glen E. Fryxell; Mark H. Engelhard; Gregory J. Exarhos (1541-1544).
A simple synthesis of a high surface area catalyst support composed of a nanoporous carbon architecture built from a 1,10-phenanthroline precursor is described.A simple synthesis of a high surface area catalyst support composed of a nanoporous carbon architecture built from a 1,10-phenanthroline precursor is described.
Keywords: Mesoporous carbon; Synthesis; 1,10-Phenanthroline; Heteroaromatic; Catalyst support; Sorbent; Chelation;

Vanadium(V) complex of a tridentate Schiff base ligand has been synthesized and characterized by elemental analyses, infrared and 1H NMR spectroscopy and single-crystal X-ray diffraction analysis. This complex can catalyze the oxidation of cyclooctene to cyclooctene oxide with tert-buthylhydroperoxide (TBHP) selectively.New dioxovanadium(V) complex bearing tridentate ligand of 1:1 condensation of 1,2-propylenediamine and 2′-hydroxy-4′-methoxyacetophenone has been synthesized and characterized by IR and 1H NMR spectroscopy and elemental analysis. The single-crystal structure of the complex shows that each vanadium(V) ion is six-coordinate through three bonds to oxo groups and through bonds to the tridentate Schiff base ligand. The title complex is used as catalyst for the selective epoxidation of cyclooctene. The catalytic system described here is an efficient and inexpensive method for the oxidation of olefins, with the advantages of high activity, selectivity, and short reaction time.
Keywords: Vanadium complex; Schiff base; Oxidation; Crystal structure;

Investigations on the electronic and the electrochemical properties of four ferric complexes based on substituted hexadentate Schiff base ligands were carried out. The occurrence of spin equilibria in solution was demonstrated and the formation of phenoxyl radicals was characterised in this family of ferric complexes for the first time.Electronic and electrochemical properties of four ferric [Fe(R-Sal)2Trien]+ complexes with R = 5-OMe, 5-Cl, 5-Br and 3,5-Cl2 were studied. The occurrence of thermally-induced spin equilibria in solution was demonstrated by optical spectroscopy. Electrochemical properties of these complexes revealed interesting behaviour in oxidation, and the formation of phenoxyl radicals within these compounds was evidenced by spectro-electrolysis.
Keywords: Schiff base; Iron(III); Spin cross-over; Phenoxyl radical;

Preparation and structural characterisation of a Cd(II) complex with unusual geometry by Josefina Pons; Jordi García-Antón; Rubén Jiménez; Xavier Solans; Mercè Font-Bardia; Josep Ros (1554-1556).
Reaction of Cd(NO3)2  · 4H2O with Ethyl picolinate in a 1:2 metal to ligand molar ratio leads to complex [Cd(NO3)2(C5H4NCOOEt)2]. The structure of the complex was unequivocally determined by single crystal X-ray diffraction. The structure consists of monomeric units. Ethyl picolinate ligands act as N1,O1-bidentate chelates. Moreover, the nitrate anions are also bidentate bonded to the metal centre, giving a four-membered chelate ring.Reaction of Cd(NO3)2  · 4H2O with ethyl-2-pyridinecarboxylate yields [Cd(NO3)2(C5H4NCOOEt)2]. Elemental analyses, conductivity measurements, infrared, 1H and 13C{1H} NMR spectroscopies and single-crystal X-ray diffraction enabled us to characterise this complex. The crystal structure consists of monomeric units in which the cadmium atom is eight-coordinated.
Keywords: Cadmium complexes; Pyridinecarboxylate; Chelate complexes; Crystal structure;

One new metal-organic complex formulated as {[Co(bipy)3][Co22–ox)3]} n 1 (bipy = 2,2′-bipyridyl; ox = oxalate) has been synthesized by low-temperature solid-state reaction and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and UV–visible spectra. The complex 1 contains helical chains composed of left-handed and right-handed helices interlaced in pairs. The third-order non-linear optical (NLO) properties of the 1 were also investigated and they exhibit the reverse saturable absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 5.75 × 10−30  esu for 1 in a 2.36 × 10−4 mol dm−3 DMF solution.One new metal-organic complex formulated as {[Co(bipy)3][Co22–ox)3]} n 1 (bipy = 2,2′-bipyridyl; ox = oxalate) has been synthesized by low-temperature solid-state reaction and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and UV–visible spectra. The complex 1 contains helical chains composed of left-handed and right-handed helices interlaced in pairs. The third-order non-linear optical (NLO) properties of the 1 were also investigated and they exhibit the reverse saturable absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 5.75 × 10−30  esu for 1 in a 2.36 × 10−4 mol dm−3 DMF solution.
Keywords: Metal-organic complex; Double helix; Third-order NLO behavior;

A complex that is the first example in which the Cu+ center being charge-compensated by a coordinating acac anion, was obtained by solution reactions and structurally characterized. X-ray structure analysis shows that acac and (PPh3)2O behave as chelating ligands. Photoluminescent investigation reveals that the title complex displays a strong blue-light emission.A complex Cu[(PPh3)2O](acac)[(PPh3)2O = Bis(2-diphenyl-phosphinophenyl) ether; acac = acetylacetone] was obtained by solution reactions and structurally characterized. The title complex is characterized by an isolated structure. X-ray structure analysis of the title complex shows that acac and (PPh3)2O behave as chelating ligands. Photoluminescent investigation reveals that the title complex displays a strong blue-light emission.
Keywords: Copper; Crystal structure; Diketone; Photoluminescence;