Inorganic Chemistry Communications (v.11, #8)

Contents List (iii-xi).

2H-Azirines as ligands: Synthesis and structural characterization of (2H-3-arene-azirine)ReI(CO)3Br complexes by J. Nicolas Roedel; Xaver Wurzenberger; Ingo-Peter Lorenz (829-831).
The synthesis and structural characterization of four 2H-azirine rhenium(I) complexes are described. The reaction of [Re(CO)3(THF)2Br] with 3-arene-2H-azirine ligands (az) in THF at −20 °C in a 1:2 molar ratio afforded the neutral bis-azirine complexes [Re(CO)3(az)2Br] (az = NCH2CC6H4R; R = –H, –Me, –Cl, –Br). The molecular structures of the novel rhenium(I) complexes exhibit slightly distorted octahedral coordination geometries around the metal centers with cis-bonded az ligands.The synthesis and structural characterization of four 2H-azirine rhenium(I) complexes are described. Stabilization of the highly reactive and strained 3-arene-2H-azirine ligand through N-coordination to the transition metal is observed. The reaction of [Re(CO)3(THF)2Br] with 3-arene-2H-azirine ligands (az) in THF at −20 °C in a 1:2 molar ratio afforded the neutral bis-azirine complexes [Re(CO)3(az)2Br] (az = NCH2CC6H4R; R = –H, –Me, –Cl, –Br). After purification, all complexes have been fully characterized. The molecular structures of the novel rhenium(I) complexes exhibit slightly distorted octahedral coordination geometries around the metal centers with cis-bonded az ligands.
Keywords: Rhenium; CO complexes; Azirine; Pi stacking; X-ray crystallography;

The novel 3D coordination polymer, [Zn35-PTC)22-H2O)2] (1), displays the unusual (5,6)-connected topological network and strong blue fluorescence in the solid state at room temperature.The novel 3D coordination polymer, [Zn35-PTC)22-H2O)2] n (1), has been synthesized by hydrothermal reaction of ZnI2  · 4H2O with H3PTC and triethylamine (H3PTC = pyridine-2,4,6-tricarboxylatic acid). Single crystal X-ray structural analysis reveals that complex 1 crystallizes in an orthorhombic space group Pbcn, holding the unusual (5,6)-connected 3D topological network. Fluorescent measurement of 1 exhibits strong blue emission in the solid state at room temperature, and its framework shows remarkable thermal stability.
Keywords: Hydrothermal reaction; Coordination polymer; Topological structure;

Synthesis and structure of dititanium-containing 10-tungstogermanate [{γ-GeTi2W10O36(OH)2}2(μ-O)2]8− by Rongxin Tan; Dongliu Li; Hongbo Wu; Chunli Zhang; Xiaohong Wang (835-836).
Compound 1 [{γ-GeTi2W10O36(OH)2}2(μ-O)2]8− exhibits a dimeric structure composed of two [γ-GeTi2W10O38]4− units which are linked by two Ti–O–Ti bonds.Dititanium-substituted dimeric tungstogermanate K8[{γ-GeTi2W10O36(OH)2}2(μ-O)2] · 32H2O (1) has been prepared and characterized by elemental analysis, IR spectroscopy and 183W NMR spectroscopy. Single-crystal X-ray analysis has been carried out on K8[{γ-GeTi2W10O36(OH)2}2(μ-O)2] · 32H2O which polyanion comprises two (γ-GeTi2W10O36) Keggin moieties linked by oxygen atoms, and leads to a sandwich-type structure with C 2 v symmetry.
Keywords: Polyoxometalates (POMs); Tungstogermanate; Titanium; Dimeric; Substituted;

Solvent-induced mono- and diplatinum(II) complexes of O3S2-macrocycle by Joobeom Seo; Ki-Min Park; Il Yoon; Hyun Jee Kim; Shim Sung Lee (837-839).
The reactions of O3S2-macrocycle L with K2PtCl4 afforded mono- (1) or dinuclear (2) complexes depending on the solvent used. From the X-ray crystal structures, it is confirmed that one water molecule stabilizes the diplatinum complex 2 via hydrogen bond.The reactions of O3S2-macrocycle L with K2PtCl4 afforded mono- (1) or dinuclear (2) complexes depending on the solvent used. From the X-ray crystal structures, it is confirmed that one water molecule stabilizes the diplatinum complex 2 via hydrogen bond.
Keywords: O3S2-Macrocycle; Platinum(II); Cyclic dimer complex; Entrapped water; Hydrogen bond;

Twofold interpenetration corrugated brick wall frameworks of 3d−4f heterometallic coordination polymers by You-Gui Huang; Min-Yan Wu; Fen-Yan Lian; Fei-Long Jiang; Mao-Chun Hong (840-842).
Two 3d−4f heterometallic coordination polymers [EuCo(pydc)3(H2O)3] n  · 2nH2O (1) [YbCo(pydc)3(H2O)3] n  ·  nH2O (2) have been hydrothermally synthesized from pyridine-2,4-dicarboxylic acid (H2pydc). Compounds 1 and 2 possess isostructural twofold interpenetration corrugated brick wall layer structures with (6,3) topology.Two 3d−4f heterometallic coordination polymers [EuCo(pydc)3(H2O)3] n  · 2nH2O (1) [YbCo(pydc)3(H2O)3] n  ·  nH2O (2) have been hydrothermally synthesized from pyridine-2,4-dicarboxylic acid (H2pydc). Compounds 1 and 2 possess isostructural twofold interpenetration corrugated brick wall layer structures with (6,3) topology.
Keywords: Heterometallic; Coordination polymer; Brick wall;

A novel silver(І) coordination polymer based on mixed ligands bpp and 2,2′-bipyridine-4,4′-dicarboxylate by Cui-Juan Wang; Yao-Yu Wang; Hong Wang; Guo-Ping Yang; Gui-Lin Wen; Mei Zhang; Qi-Zhen Shi (843-846).
A novel coordination polymer based on silver(І) and mixed ligands [Ag2(bpdc)(bpp) · H2O] n  · 2H2O (1), has been prepared by hydrothermal method. Compound 1 is the 2D polymeric structure extended with subunits tetranuclear silver, which are linked by ligand-unsupported AgAg contacts. The compound 1 can be simplified as binodal (9, 10) nets with total Schläfli symbol {3^12;4^9;5^6;6^9}{3^18;4^22;5^5}.A novel coordination polymer based on silver(І) and mixed ligands {[Ag2(bpdc)(bpp)(H2O)] · 2H2O} n (1) (H2bpdc = 2,2′-bipyridyl-4,4′-dicarboxylic acid, bpp = 1,3-bis(4-pyridyl)propane), has been prepared by hydrothermal method. Compound 1 has a 2D polymeric structure extended with subunits tetranuclear silver with Schläfli symbol {3^12;4^9;5^6;6^9}{3^18;4^22;5^5}. Compound 1 represents an Ag-containing polymeric compound possessing room-temperature luminescence.
Keywords: Coordination polymer; Ag–Ag contacts; Tetranuclear silver;

Self-assembly of zinc and cobalt complexes mimicking active site of alcohol dehydrogenase by Anna Dołęga; Agnieszka Pladzyk; Katarzyna Baranowska; Monika Wieczerzak (847-850).
Molecules of water are trapped in a neutral zinc and cobalt complexes mimicking resting state of alcohol dehydrogenase. The quality of the crystals allowed comparison of intramolecular hydrogen bonds in the studied zinc and cobalt compounds. The conclusions are confirmed by solid state FT-IR spectroscopy.For the first time molecules of water were trapped in a neutral zinc and cobalt complexes mimicking resting state of alcohol dehydrogenase. The quality of crystals allowed detailed comparison of intramolecular hydrogen bonds in the studied zinc and cobalt compounds. The conclusions were confirmed by solid state FT-IR spectroscopy.
Keywords: Zinc; Cobalt; S-ligands; N-ligands; Structure elucidation; Hydrogen bonds; Enzyme modelling;

Two coordination polymers, [M(HSIP)(H2O)] n (M = Sr (1) and Ba (2)), are obtained from hydrothermal method and characterized by X-ray crystallography, fluorescence spectroscopy and IR spectra. The [M(HSIP)(H2O)] n compound displays a 3D pillared framework featuring a 2D metal sulfonate–carboxylate layer, and has two kinds of topologically nonequivalent six-connected nodes with a unique (411·64)(410·65) topology.The hydrothermal reactions of Sr(NO3)2 or BaCl2 with 5-sulfoisophthalic acid (H3SIP) in the presence of triethylamine yielded two novel 3D coordination polymers [M(HSIP)(H2O)] n (M = Sr (1) and Ba (2)). Single-crystal X-ray analyses revealed that the two compounds are isostructural. The [M(HSIP)(H2O)] n compound displays a 3D pillared framework featuring a 2D metal sulfonate–carboxylate layer, and has two kinds of topologically nonequivalent six-connected nodes based on Sr ions and HSIP ligands with a rare (411·64)(410·65) topology. In the solid state, both 1 and 2 show blue photoluminescence with the maximum emission intensities at 445 and 439 nm upon excitation at 325 and 328 nm, respectively.
Keywords: Alkaline earth metal complexes; Crystal structures; Pillared framework; Topology; Photoluminescence;

An acentric luminescent cadmium dimethylsuccinate/bipyridine coordination polymer with an uncommon three-dimensional CdSO4 topology by Elena M. Lyons; Maxwell A. Braverman; Ronald M. Supkowski; Robert L. LaDuca (855-858).
The acentric luminescent coordination polymer {[Cd(dms)(4,4′-bpy)(H2O)2] · H2O} n (dms = 2,2-dimethylsuccinate, 4,4′-bpy = 4,4′-bipyridine) exhibits fourfold one-dimensional (1-D) homochiral right-handed helical chain motifs conjoined through tethering 4,4′-bpy ligands to construct a 3-D network with uncommon 658 topology.The acentric coordination polymer {[Cd(dms)(4,4′-bpy)(H2O)2] · H2O} n (1, dms = 2,2-dimethylsuccinate, 4,4′-bpy = 4,4′-bipyridine) has been prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. Fourfold one-dimensional (1-D) homochiral right-handed helical [Cd(dms)] n chain motifs are conjoined through tethering 4,4′-bpy ligands to construct a three-dimensional (3-D) network with uncommon CdSO4 (658) topology. Irradition of 1 with ultraviolet light results in blue–violet luminescence.
Keywords: Coordination polymer; Cadmium; Dimethylsuccinate; Bipyridine; Crystal structure; Luminescent;

Two novel 3-D chiral coordination polymers with helical chains assembled from L(D)-tartrate: [Cd2(L(D)–C4H4O6)(H2O)5(SO4)] · 3H2O by Hongxu Guo; Qingyan Liu; Liguo Yang; Wen Weng; Qinghua Wang; Caiqing Zheng (859-861).
Two unprecedented three-dimensional chiral coordination polymers with left(right)-handed helicate assembled from L(D)-tartrate, [Cd2(L(D)–C4H4O6)(H2O)5(SO4)] · 3H2O, have been prepared and characterized by X-ray diffraction, IR, TGA and vibrational circular dichroism (VCD).Two novel three-dimensional chiral coordination polymers with left(right)-handed helicate assembled from L(D)-tartrate, [Cd2(L(D)–C4H4O6)(H2O)5(SO4)] · 3H2O, have been prepared and characterized by X-ray diffraction, IR, TGA and vibrational circular dichroism (VCD).
Keywords: L(D)-tartrate; 3-D chiral coordination polymers; Crystal structure; Vibrational circular dichroism;

Novel lanthanide–iminodiacetate frameworks with hexagonal pores by Carlos Kremer; Paula Morales; Julia Torres; Jorge Castiglioni; Javier González-Platas; Markus Hummert; Herbert Schumann; Sixto Domínguez (862-864).
The polymeric complexes [Ln(Hida)3] ·  xH2O (H2ida = iminodiacetic acid) have been prepared and fully characterized. The solid state structure presents large hexagonal channels (more than 11 Ǻ diameter). This is the first example of this kind of structure with ida as bridging ligand.A new family of lanthanide complexes with open-framework structures has been prepared and characterized by X-ray diffraction. The structure of the polymers with general formula [Ln(Hida)3] ·  xH2O (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb; H2ida = iminodiacetic acid) presents large hexagonal channels with more than 11 Ǻ diameter, and houses the crystallization water molecules. These molecules can be reversibly removed upon heating. This is the first example of this kind of structure with ida as bridging ligand.
Keywords: Lanthanide; Iminodiacetate; Coordination polymer; Crystal structure;

Two zinc complexes with ammonium groups were synthesized and used for the cleavage of plasmid DNA under hydrolytic conditions. Results showed that both complexes can effectively cleave supercoiled plasmid DNA to nicked form, showing quite high nuclease activities.Two novel zinc complexes of disubstituted 2,2′-bipyridine with ammonium groups, [Zn(L1)3](ClO4)8·3H2O (1) and [Zn(L2)3](ClO4)8 (2) (L1  = [4,4′-(Me2NHCH2)2-bpy]2+, L2  = [5,5′-(Me2NHCH2)2-bpy]2+, bpy = 2,2′-bipyridiyl) were synthesized as artificial nucleases. The outside electrostatic binding interaction between these complexes and calf thymus DNA was confirmed by UV and CD spectroscopies. Even at low concentration (2.0 × 10−4  M), both complexes can effectively cleave supercoiled plasmid DNA to nicked form, giving hydrolysis rate constants of 1.84 × 10−5 and 2.16 × 10−5  s−1, respectively.
Keywords: Artificial nucleases; Zinc complexes; Disubstituted 2,2-bipyridine; Ammonium groups; DNA cleavage;

Two new coordination polymers [Eu2(TFSA)3(phen)2] n (1) and [Tb2(TFSA)3(phen)4(H2O)2] n (2) (TFSA = tetrafluorosuccinate, phen = 1,10-phenanthroline) have 2-D network structures with (4, 4) and (6, 3) topology, respectively.Two new coordination polymers [Eu2(TFSA)3(phen)2] n (1) and [Tb2(TFSA)3(phen)4(H2O)2] n (2) (TFSA = tetrafluorosuccinate, phen = 1,10-phenanthroline) have been synthesized and structurally characterized. The 1 has a 2-D grid-like network structure with (4, 4) topology and the 2 has a 2-D honeycomb-like network structure with (6, 3) topology. The two complexes exhibit strong photoluminescence of the Eu(III) for 1 and Tb(III) for 2, respectively.
Keywords: Lanthanide coordination polymer; Tetrafluorosuccinate; Hydrothermal synthesis; Crystal structure; Luminescence;

Synthesis and determination of the electron transfer numbers of alkynyl bridged multiferrocenyl derivatives by Li-Min Han; Quan-Ling Suo; Mei-hua Luo; Ning Zhu; Yan-Qiang Ma (873-875).
Ferrocenyl derivatives FcC(CH3)2Fc′–CC–Fc (A) and FcC(CH3)2Fc′–CC–CC–Fc′C(CH3)2Fc (B) (Fc = C5H5FeC5H4, Fc′ = C5H5FeC5H3) were synthesized and characterized by MS, NMR and FT-IR, and the structure of A was identified by single crystal X-ray diffraction. The electron transfer number of each redox peaks in cyclic voltammograms of A and B were determined by chronoamperometry at a microelectrode.Multiferrocenyl derivatives FcC(CH3)2Fc′–CC–Fc(A) (Fc = C5H5FeC5H4, Fc′ = C5H5FeC5H3) and FcC(CH3)2Fc′–CC–CC–Fc′C(CH3)2Fc (B) have been synthesized and characterized by MS, NMR, FT-IR and elemental analysis. The molecular structure of compound A was given by single crystal X-ray diffraction. The electron transfer numbers of two compounds were determined by cyclic voltammetry and chronoamperomeric technique.
Keywords: Ferrocenylacetylene derivatives; Electron transfer; Chronoamperometry; Cyclic voltammogram; Cottrell plot;

A new 1D ladder-like chain, [Ag(aptr)]2(SiF6) · 5H2O (aptr = 4-amino-3-(pyrid-4-yl)-1,2,4-triazole), was synthesized with structure and fluorescence characterized. The skeleton chain comprises of 6- and 14-membered rings. The overlapping of two sets of ladders along the a  +  b and a  −  b vectors produces a 3D supramolecular architecture with the linkage of hydrogen bondings.A new 1D ladder-like chain, {[Ag2(aptr)2](SiF6)} n  · 5nH2O (aptr = 4-amino-3-(pyrid-4-yl)-1,2,4-triazole), was synthesized with structure and fluorescence characterized. The skeleton chain based on a fundamental repeating unit [Ag(aptr)] comprises of two kinds of 6- and 14-membered rings. The overlapping of two sets of ladders along the a  +  b and a  −  b vectors produces elliptic channels with SiF 6 2 - anchoring in. A 3D supramolecular architecture is formed by hydrogen bondings between SiF 6 2 - and aptr. Three lattice water molecules are connected into a water chain through the hydrogen bondings among them.
Keywords: Crystal structure; Fluorescence; Silver(I); 1,2,4-Triazole;

Two-dimensional (3, 6)-topological inorganic aggregate based on the sandwich-type polyoxometalate and lanthanide linkers by Zhiming Zhang; Yangguang Li; Weilin Chen; Enbo Wang; Xinlong Wang (879-882).
A new compound K3Na3{Nd2(H2O)12Cu4(H2O)2(SiW9O34)2} · 21H2O (1) has been prepared, representing the first two-dimensional inorganic aggregate composed of sandwich-type polyoxoanion and lanthanide linkers. The two-dimensional layers are further connected by K+ and Na+ ions into a three-dimensional open framework.A new two-dimensional (2-D) inorganic aggregate, K3Na3{Nd2(H2O)12Cu4(H2 O)2(SiW9O34)2} · 21H2O (1), has been obtained by the reaction of divacant polyoxoanion [γ-SiW10O36], Cu2+, Nd3+ and Al3+ in the aqueous solution. X-ray diffraction analysis reveals that compound 1 represents the first 2-D inorganic aggregate composed of sandwich-type polyoxoanions and Ln cation linkers, and the first (3, 6)-topological network in the sandwich polyoxometalate chemistry. The 2-D layers in 1 are further connected into a three-dimensional (3-D) open framework by the potassium and sodium cations.
Keywords: Polyoxometalate; Inorganic aggregate; Lanthanide; (3, 6)-Topological; Sandwich-type;

A contrastive study for the coordination chemistry of benzimidazole-5-carboxylate (HL1) and 5-methylbenzimidazole-6-carboxylic acid (HL2) based on two MOFs was reported. Both complexes exhibit blue fluorescent emission bands in the solid state.Benzimidazole-5-carboxylate (HL1) and 5-methylbenzimidazole-6-carboxylic acid (HL2) have been employed to assemble with Cd(II) ions under hydrothermal conditions, leading to the generation of 1D (1) and 2D (2) metal-organic frameworks. The two coordinated water molecules of cadmium in 1 restrain the carboxylic moiety from adopting a bidentate chelating coordination mode, which seems to be an important factor in the dramatic structural change from 1D to 2D. Both complexes display blue emission in the solid state and the luminescent properties relate to their structures.
Keywords: Cadmium(II); Crystal structure; Metal-organic frameworks; Luminescent property;

A polyoxoanion with an unusual [Sb6O16(OH)12] cluster skeleton and S 4 molecular symmetry [Mo4Sb6(OH)12O24]6− by Yanzhong Zhen; Qiang Shen; Lili Li; Ganglin Xue; Huaimin Hu; Feng Fu; Jiwu Wang (886-888).
A novel molybdoantimonate, K6[Mo4Sb6(OH)12O24] · 6H2O, was synthesized in neutral aqueous solution. The ellipsoid-shape polyanion [Mo4Sb6(OH)12O24]6− has S 4 molecular symmetry and is built of an unusual [Sb6O16(OH)12] framework capped with four segregated {MoO2} group.A rich antimony polyoxoanion [Mo4Sb6(OH)12O24]6− was crystallized as potassium salt in neutral aqueous solution and characterized by IR, UV–vis spectra, CVs and single crystal X-ray diffraction. X-ray structural analysis shows that the polyanion [Mo4Sb6(OH)12O24]6− has S 4 molecular symmetry and a ellipsoid-shape structure built of an unusual [Sb6O16(OH)12] framework capped with four segregated {MoO2} groups.
Keywords: Polyoxanion; Antimony; Molybdenum; Crystal structure;

A photoluminescent three-dimensional (3D) AgI coordination polymer {[Ag8(L)34-hmt)2(H2O)6](ClO4)2} with unusually binodal 4-connected (43·63)2(42·62·82)3 topology has been successfully constructed based on mixed ligands anthracene-9,10-dicarboxylate (L) and hexamethylenetetramine (hmt). The relevant results reveal that the anthracene skeleton of L with a large π-conjugated ring system plays an important role in the formation of the final structure.The reaction of AgClO4 with anthracene-9,10-dicarboxylic acid (H2 L) and hexamethylenetetramine (hmt) in the presence of 2,6-dimethylpyridine afforded a photoluminescent three-dimensional (3D) AgI coordination polymer {[Ag8(L)34-hmt)2(H2O)6](ClO4)2} (L  = anthracene-9,10-dicarboxylate) exhibiting binodal 4-connected (43·63)2(42·62·82)3 topological network. The relevant result reveals that the anthracene skeleton of L ligand bearing a large π-conjugated ring system plays an important role in the formation of the final structure.
Keywords: Silver(I) complex; Anthracene-based ligand; Crystal structure; Topology; Luminescence;

A novel hydrated lithium borate, Li8[B16O26(OH)4] · 6H2O, has been hydrothermally synthesized. It possesses the layered structure constructed by the unprecedented [B16O26(OH)4]8− unit. The layered networks are stacked by ABAB fashion and each sheet contains the largest odd 13-membered boron rings.A novel hydrated lithium borate, Li8[B16O26(OH)4] · 6H2O, has been hydrothermally synthesized and characterized by single crystal X-ray diffraction, FT-IR spectroscopy, and simultaneous TGA–DTA. Its crystal structure consists of Li–O polyhedra and polyborate anionic layers constructed by the unprecedented [B16O26(OH)4]8− unit. The layered networks are stacked by ABAB fashion and each sheet contains the largest odd 13-membered boron rings.
Keywords: Lithium borate; Hydrothermal synthesis; Layered structure;

A three-dimensional network constructed from the assembly of 1,3-diaminopropane-copper(II) and tetracyanopalladate(II) moieties by Alexandre de Oliveira Legendre; Antonio Eduardo Mauro; Milene Aparecida Rodrigues de Oliveira; Maria Teresa do Prado Gambardella (896-898).
A Cu–Pd heterobimetallic coordination polymer, [Cu{Pd(CN)4}(pn)] n (pn = 1,3-diaminopropane), assembled by bridging cyano groups and bifurcated hydrogen bonds generating supramolecular rings and chains along the crystal lattice.The coordination polymer [Cu{Pd(CN)4}(pn)] n (pn = 1,3-diaminopropane) has been synthesized and characterized by elemental analysis, infrared spectroscopy and single-crystal X-ray diffraction. The crystal structure showed that three cyano groups of each [Pd(CN)4] unit bridge Cu(II) centers leading to the formation of a three-dimensional network. A series of bifurcated hydrogen bonds between the amino groups of the diamine and the nonbridging cyano groups of the cyanometallate result in the organization of supramolecular chains and rings along the polymer.
Keywords: Copper(II); Coordination polymers; Tetracyanopalladate(II); 1,3-Diaminopropane; Supramolecular chemistry; Hydrogen bonds;

Synthesis, crystal structure and properties of [Er(C6H5NO2)3(H2O)2] n (1.5nZnCl4) · (2nH2O) with strong luminescence by Wen-Tong Chen; Qiu-Yan Luo; Dong-Sheng Liu; Hua-Long Chen; Ya-Ping Xu (899-902).
A novel complex [Er(C6NO2H5)3(H2O)2] n (1.5nZnCl4) · (2nH2O) was synthesized via hydrothermal reaction. The crystal structure is characteristic of a novel one-dimensional polycationic chain-like structure. Optical absorption spectrum shows that the title complex may be a candidate for potential photoelectric material. The title complex shows interesting emission bands in green and red regions, which are attributed to the characteristic emissions of 4F7/2, 2H11/2, 4S3/2, 4F9/24I15/2 of Er3+ ions.A novel bimetallic 4f–3d complex [Er(C6H5NO2)3(H2O)2] n (1.5nZnCl4) · (2nH2O) (1) has been synthesized via hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. Complex 1 is characteristic of a novel one-dimensional polycationic chain-like structure. Photoluminescent investigation reveals that the title complex displays interesting emissions in green and red regions. The luminescence spectra show that the green emission is stronger than the red emission. The green and red emission bands are attributed to the characteristic emissions of 4F7/2, 2H11/2, 4S3/2, 4F9/2  →  4I15/2 of Er3+ ions. Optical absorption spectra of 1 reveal the presence of an optical gap of 3.85 eV.
Keywords: Crystal structure; Erbium; Hydrothermal reaction; Lanthanide; Photoluminescence;

In situ hydrothermal decarboxylation reactions play an important role to form two novel (3D) lanthanide–organic frameworks Ln(2,5-PyDC)(3-Py-C)(H2O) (Ln = Nd, Sm; 2,5-H2PyDC = 2,5-pyridinedicarboxylic acid, 3-HPyC = 3-pyridinecarboxylic acid), which can be specified by the Schläfli symbol (42638) as a 3D {4,4}-connected net. In situ hydrothermal decarboxylation was observed during preparing two novel three-dimensional (3D) lanthanide–organic frameworks Ln(2,5-PyDC)(3-PyC)(H2O) (Ln = Nd, Sm; 2,5-H2PyDC = 2,5-pyridinedicarboxylic acid, 3-HPyC = 3-pyridinecarboxylic acid). X-ray crystallographic analyses revealed that both complexes are isomorphous and show an interesting topology. Magnetic study indicated the coupling interaction between Ln3+ ions in both complexes is weak.
Keywords: Lanthanide–organic framework; Coordination polymer; Hydrothermal in situ ligand reaction; Crystal structure; Magnetic property;

Synthesis and characterization of the highest connected 3D Wells-Dawson POM/TMC hybrid by Jingquan Sha; Jun Peng; Yangguang Li; Pengpeng Zhang; Haijun Pang (907-910).
A novel 3D POM/TMC hybrid based on the highest connected Wells-Dawson POMs is reported for the first time. The rich coordination fashions of Ag+ ions and the nature of Wells-Dawson POMs and phnz molecules together lead to the formation of the high-connected Wells-Dawon POMs.A novel 3D hybrid compound based on TMCs modified Wells-Dawson polyoxometalate, [{Ag(H2O)(phnz)}{Ag(phnz)}5(P2W18O62)][phnz]0.5  · 4H2O (1) (phnz = phenazine), has been synthesized and characterized. X-ray diffraction analysis reveals that the periphery of the Wells-Dawson POMs contains nine Ag-phnz units, which represents the highest connection of the Wells-Dawson POMs up to now. In the crystal engineering point of view, Ag atoms exhibit rich and novel coordination geometries, which facilitate the formation of the highest coordination number of the Wells-Dawson POMs. Additionally, the electrochemical behavior of 1 modified CPE (1-CPE) has been studied.
Keywords: Hydrothermal synthesis; Inorganic–organic hybrid; Wells-Dawson polyoxometalate; Electrochemical properties; Silver;

The reaction of AlMe3 with (dme)2Ca(NPh2)2 in a mixture of toluene and THF yields the addition product [(thf)6Ca] [Me3Al–NPh2]2 (1). The anion (see picture) exhibits an interesting bonding situation. One phenyl group is coplanarily oriented to the amide moiety whereas the other phenyl substituent shows strong hyperconjugation to an Al–Me fragment.The reaction of AlMe3 with (dme)2Ca(NPh2)2 in a solvent mixture of toluene and THF yields the addition product [(thf)6Ca] [Me3Al–NPh2]2 (1). In solution the anion of this solvent-separated complex 1 [δ(27Al) = 153] partly dismutates into ([AlMe2(NPh2)2] [δ(27Al) = 179] and [AlMe4] [δ(27Al) = 155]. The [Me3Al–NPh2] anion shows a strong backdonation of negative charge from the nitrogen atom into one phenyl ring whereas the other phenyl group forms hyperconjugative bonds between the p-orbital of the ipso-carbon atom and the σ∗(Al–C) orbital leading to a slight elongation of one of the Al–C bonds.
Keywords: Calcium; Alanates; Addition reactions; Amides; Trimethylalane;

Self-assembly of polyoxometalate clusters and metal–organic coordination fragments into 1D homochiral chains by Haiyan An; Zhengbo Han; Tieqi Xu; Changgong Meng; Enbo Wang (914-917).
A pair of enantiomer, originated from achiral Anderson-type polyoxometalate building units and chiral metal–organic coordination complex fragments, are reported, which represent the first examples of 1D homochiral polyoxometalate compounds featuring single helix.A pair of enantiomerically pure polyoxometalates, (C4NH7O4)[Na2(l-C4H8N2O3)2(H2O)9Zn]2[CrMo6H6O24]2  · 7H2O (l-1), and (C4NH7O4)[Na2(d-C4H8N2O3)2(H2O)9Zn]2[CrMo6H6O24]2  · 7H2O (d-1), have been synthesized for the first time and characterized by elemental analyses, IR, TG, UV and single crystal X-ray diffraction. l-1 and d-1 are enantiomers and crystallize in the chiral space group P21212. To our best knowledge, they represent the first examples of 1D homochiral polyoxometalate compounds constructed from Anderson-type polyoxoanions.
Keywords: Chirality; Polyoxometalate; Helical chain;

A dichloro oxovanadium(V) alkoxide complex [VOCl2(OCH2CH2OCH2CH2O n Bu)] was synthesised by reaction of VOCl3 and 2-(2-butoxyethoxy)ethanol in pentane. It was characterised by infrared, 1H, 13C and 51V NMR spectroscopy, mass spectrometry, elemental and single-crystal X-ray diffraction analysis. This complex catalyses the polymerisation of ethene and the oxidation of cyclooctene with tert-butyl hydroperoxide.A dichloro oxovanadium(V) alkoxide complex [VOCl2(OCH2CH2OCH2CH2O n Bu)] was synthesised by reaction of VOCl3 and 2-(2-butoxyethoxy)ethanol in pentane. It was characterised by IR, 1H, 13C and 51V NMR spectroscopy, mass spectrometry and elemental analysis. Single-crystal X-ray diffraction reveals a monomeric complex with all oxygen atoms of the ligand attached to the overall octahedrally coordinated vanadium atom. This complex exhibits remarkably higher activity than VOCl3 towards ethene polymerisation with diethyl aluminium chloride as co-catalyst and methyl trichloroacetate as promoter. The complex also catalyses the epoxidation of cyclooctene to cyclooctene oxide with tert-butyl hydroperoxide.
Keywords: Vanadium; Oxo ligand; Alkoxide; Chelate; Polymerisation; Epoxidation;

New planar polynitrile dianion and its first coordination polymer with unexpected short M⋯M contacts (tcno2−  = [(NC)2CC(O)C(CN)2]2−) by Chahlae Atmani; Fatima Setifi; Samia Benmansour; Smail Triki; Mathieu Marchivie; Jean-Yves Salaün; Carlos J. Gómez-García (921-924).
A new planar polynitrile dianion ([tcno]2−  = [(NC)2CC(O)C(CN)2]2−) has been synthesized and characterized. Its combination with Cu(II) metal ion led to the coordination complex [Cu(tcno)2(H2O)2], which was characterized as the first example in which this anion acts as a ligand. The monodimensional structure in which the organic dianion acts as a μ3-bridging ligand showed very short Cu⋯Cu contacts (3.644 Å) compared to those reported for several polynitrile metal complexes (>6 Å).A new planar polynitrile dianion ([tcno]2−  = [(NC)2CC(O)C(CN)2]2−) has been synthesized as its potassium salt, K2[tcno] (1). The crystallization of 1 by the slow evaporation of an aqueous solution at room temperature gave two types of colourless crystals having two different shapes [1-A: fine plates and 1-B: needles] for which the crystal structure determinations showed similar geometries for the polynitrile anion in both the structures. The combination of this novel dianion with Cu(II) led to the coordination complex [Cu(tcno)2(H2O)2] (2), which constitutes the first coordination complex of this dianion. The structure of 2 can be described as a coordination polymer in which the organic dianion acts as a μ3-bridging ligand. Despite the fact that the Cu⋯Cu bridges have a large number of atoms, the Cu⋯Cu distance observed through this ligand is relatively short (Cu⋯Cu 3.644 Å) compared to those reported for several polynitrile metal complexes (>6 Å).
Keywords: Coordination polymer; Bridging ligand; Planar polynitrile anion; Copper(II) complexes;

Synthesis, crystal structures and selective oxygenation of dinuclear copper(II) complexes of N,N,N′,N′-xylylenediamine tetraacetate by Yongmei Zhao; Shourong Zhu; Min Shao; Tiantian Jia; Mingxing Li; Wencong Lu; Weijiang He (925-928).
A structural comparison of two flexible dinuclear copper complexes in which the copper(II) centers situate the meta- or para-position suggests that the regulation of the geometry of the polynuclear copper centers may lead to construction of different supramolecular architecture and the former can react with H2O2 to hydroxylate ligand due to proximity effect.Two dinuclear copper(II) complexes, [Cu2L1(imH)2(H2O)2] · 4H2O (1) and [Cu2L2(imH)2(H2O)2] · 2H2O (2) (L1H4  =  N,N,N′,N′-m-xylylenediamine tetraacetic acid, L2H4  =  N,N,N′,N′-p-xylylenediamine tetraacetic acid, imH = imidazole), were synthesized aiming at exploring the geometry of the flexible ligands on their complex structures and reactions with H2O2. In complex 1, both Cu(II) ions are five-coordinated with square-pyramidal geometry and water molecules occupy the apical position. The Cu···Cu distance is 5.344(7) Å. Complex 2 adopts the same coordination geometry as that in 1. The Cu···Cu distance is 7.812(5) Å. Complex 1 exhibits hydroxylation of the xylyl linker of the supporting ligand in the presence of H2O2 in aqueous solution. No observable reaction took place under the identical conditions for complex 2. Proximity effect of the metal center is responsible for the hydroxylation.
Keywords: Copper; Polycarboxylate; Imidazole; H2O2; Hydroxylation;

Carbon dioxide fixation by zinc(II) complexes with macrocyclic ligand by Zhao-Peng Qi; Shu-An Li; Yong-Qing Huang; Guan-Cheng Xu; Guang-Xiang Liu; Ling-Yan Kong; Wei-Yin Sun (929-934).
Two novel zinc(II) coordination complexes [Zn2(L)(CO3)]Br2  · 7H2O (1) and [Zn2(L)(CO3)]Br2  · 0.5CH3COCH3  · 5H2O (2) with 1D chain structure linked by carbonate anions were obtained by reactions of new macrocyclic ligand 3, 6, 9, 12, 20, 23, 26, 29-octaazatricyclo[29.3.1.114,18]hexatriaconta-1(34), 14, 16, 18(36), 31(35), 32-hexaene (L) with zinc salt at an initial pH of ca. 9.5. The results show that carbon dioxide from air was absorbed and converted to carbonate anion during the formation of 1 and 2.Two novel zinc(II) coordination complexes [Zn2(L)(CO3)]Br2  · 7H2O (1) and [Zn2(L)(CO3)]Br2  · 0. 5CH3COCH3  · 5H2O (2) with new macrocyclic ligand 3, 6, 9, 12, 20, 23, 26, 29-octaazatricyclo[29.3.1.114,18] hexatriaconta-1(34), 14, 16, 18(36), 31(35), 32-hexaene (L) were synthesized at an initial pH of ca. 9.5 with evaporation and diffusion methods, respectively. The dinuclear units of [Zn2(L)]4+ in both complexes are linked together by carbonate anions to form 1D infinite chain structure. The results show that carbon dioxide from air was absorbed and converted to carbonate anion in the formation of complexes 1 and 2. To the best of our knowledge, this is the first example of absorption and hydration of atmosphere carbon dioxide to form the 1D chain structure in the zinc(II) macrocyclic complexes.
Keywords: Carbon dioxide; Zinc(II) complex; 1D chain;

Targeted binding of a platinum(II)–methionine complex to the disulfide linkage of a nonapeptide oxytocin by Tingting Chen; Xiaoyong Wang; Jiafei Mao; Haiying Wei; Zijian Guo (935-938).
Platinum(II)–methionine complex [Pt(Met)Cl2] preferentially binds to the disulfide bond between Cys1 and Cys6 residues of oxytocin, forming five- or six-membered chelates [Pt(Met)(OT)]Cl2 as the major products.The electrospray mass spectrometry and NMR spectroscopy techniques reveal that the platinum(II)–methionine complex [Pt(Met)Cl2] binds to the disulfide bond between Cys1 and Cys6 residues of oxytocin (OT). The major adducts identified are [Pt(Met)(OT)]Cl2 species where OT forms five- or six-membered chelates with Pt(II) center. The study suggests that even the oxidized disulfide in oligopeptide still shows a high affinity for platinum complexes, which may be associated with the ubiquity of sulfur-related side effects in platinum anticancer chemotherapy.
Keywords: Disulfide bond; Methionine; Oxytocin; Platinum(II) complex;

Three novel bis(bidentate) ligands derived from dibenzo-14-crown-4, and corresponding bimetallic Ru(II) complexes have been synthesized. These complexes exhibit one Ru(II)-centered reversible oxidation and three ligand-centered reductions, show characteristic MLCT absorption band at 445–454 nm and emission at 575–592 nm.Three bis(bidentate) ligands cis-di(4,5-diazafluoren-9-ylimino)dibenzo-14-crown-4 (BL1), trans-di(4,5-diazafluoren-9-ylimino)dibenzo-14-crown-4 (BL2), and 1,4,8,11-tetraoxacyclotetradecyl[2,3:9,10]bis-dipyrido[3,2-a:2′3′-c]phenazine (BL3), and corresponding bimetallic Ru(II) complexes [(bpy)2RuBL1−3Ru(bpy)2](PF6)4 (Ru–BL1−3) have been synthesized. Cyclic voltammetry of these complexes are consistent with one Ru(II)-centered reversible oxidation and three ligand-centered reductions. These complexes show metal-to-ligand charge transfer absorption at 445–454 nm and emission at 575–592 nm.
Keywords: Ru(II) Complex; Dibenzo-14-crown-4; UV–vis absorption; Emission; Electrochemistry;