Inorganic Chemistry Communications (v.12, #8)

Contents List (iii-x).

Synthesis and X-ray crystal structure of a bis-cyclometalated phosphorescent red-emitting iridium(III) complex by Marion Graf; Manuel Thesen; Hartmut Krüger; Peter Mayer; Karlheinz Sünkel (701-703).
A convenient synthesis of [{Ir(μ-Cl(ccpz)2}2] (1, ccpz = 1-chlor-4-(4-chlorphenyl)-phthalazine) is described. The crystal and molecular structure of 1 was determined by X-ray crystallography.The synthesis of the bis-cyclometalated complex [{Ir(μ-Cl)(ccpz)2}2] (1, cppz = 1-chloro-4-(4-chlorophenyl)-phthalazine) from hydrated iridium(III) chloride and the ligand ccpz in refluxing ethoxyethanol is described. Compound 1 was characterized by spectroscopic means and the crystal structure was determined by X-ray crystallography. The absorption and emission spectra exhibit the new compound as a red-emitting phosphorescent complex.
Keywords: Iridium; Bis-cyclometalated complex; Photoluminescence; Crystal structure;

The nine-coordination crystal structure of binucleae [NdL1(NO3)(DMF)2]2 complex with 1:1 metal-to-ligand stoichiometry. Dimerization of this monomeric unit occurs through the phenolate oxygen atoms leading to a central planar four-membered (NdO)2 ring.Nd(III) and four Schiff-base ligands can form binuclear nine-coordination [NdL1–4(NO3)(DMF)2]2 complexes with 1:1 metal-to-ligand stoichiometry at Nd(III) center. All the ligands and Nd(III) complexes may be used as potential anticancer drugs, binding to Calf thymus DNA through intercalations with the binding constants at the order of magnitude 105–106  M−1. In addition, Nd(III) complexes present stronger affinities to DNA than ligands. All the ligands and Nd(III) complexes have strong scavenging effects for hydroxyl radicals and superoxide radicals.
Keywords: Rare earth; Schiff-base; X-ray crystallography; Calf thymus DNA binding properties; Antioxidation;

A CdSO4-like 3-D framework constructed from monosodium substituted Keggin arsenotungstates and copper(II)-ethylenediamine complexes by Junwei Zhao; Qiuxia Han; Pengtao Ma; Lijuan Chen; Jingping Wang; Jingyang Niu (707-710).
A 65·8 CdSO4-like 3-D framework [Cu(en)2]3[α-AsW11NaO39]·2H2O constructed by monosodium-substituted Keggin arsenotungstates and copper(II)-ethylenediamine complexes has been synthesized, representing the first 65·8 CdSO4-like 3-D monovacant Keggin POM derivative in POM chemistry.A 65·8 CdSO4-like 3-D framework [Cu(en)2]3[α-AsW11NaO39]·2H2O (1) constructed by monosodium-substituted Keggin arsenotungstates and copper(II)-ethylenediamine complexes (en = ethylenediamine) has been synthesized by reaction of Na8[α-HAsW9O34]·11H2O, CuCl2·2H2O and ethylenediamine under hydrothermal conditions and structurally characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. Crystal data for 1: C12H52AsCu3N12NaO41W11, monoclinic, Cc, a  = 20.409(9) Å, b  = 16.737(8) Å, c  = 16.561(7) Å, β  = 104.607(7)°, V  = 5474(4) Å3, T  = 296(2) K; Z  = 4, μ  = 24.860 mm−1, GOOF  = 1.086, R 1  = 0.0284, wR 2  = 0.0759. To the best of our knowledge, 1 represents the first 65·8 CdSO4-like 3-D monovacant Keggin arsenotungstate derivative in polyoxometalate chemistry.
Keywords: Polyoxometalate; Arsenotungstate; CdSO4-like topology; Keggin structure; Ethylenediamine;

Rare monomeric structure of CpRh(III) dithiolene complex: Combined ESR and electronic absorption studies on electrochemically generated Rh(II) species by Mitsushiro Nomura; Chikako Fujita-Takayama; Toru Sugiyama; Akira Sugimori; Masatsugu Kajitani (711-715).
The rare monomeric structure of [CpRhIII(mnt)] (1) was determined by X-ray diffraction study, and the ESR spectra of electrochemically generated anion radical 1 (Rh(II) species) were obtained with the Rh hyperfine splitting in solution at r.t. (g iso  = 2.045, A iso  = 1.15 mT) and in frozen solution (g 1  = 2.173, a 1  = 1.85 mT, g 2  = 1.982, a 2  = 0.98 mT) at −150 °C.The [CpRhIII(mnt)] (1) (Cp = η5-cyclopentadienyl, mnt = maleonitrile-1,2-dithiolate) was characterized as a rare monomeric structure. The CV of 1 showed a reversible reduction wave which attributed to Rh(II)/Rh(III) couple. UV–Vis spectral measurement during electrolysis using an OTTLE cell indicated that lifetime of electrochemically generated 1 (Rh(II) species) was only a few seconds. Isotropic (g iso  = 2.045, A iso  = 1.15 mT) and anisotropic ESR (g 1  = 2.173, a 1  = 1.85 mT, g 2  = 1.982, a 2  = 0.98 mT) spectra of 1 were observed while electrochemical reduction of 1. Both ESR spectra showed hyperfine splittings due to the central Rh (I  = 1/2).
Keywords: Rhodium; Dithiolene; ESR; Monomeric structure; Electrochemistry;

First (G1)- and second-generation (G2) poly(propyleneimine) (PPI) dendrimers were reacted with 2-(diphenylphosphino)benzaldehyde, to form iminophosphine-functionalised dendritic ligands (1,  2). The reaction of the dimeric precursor [RhCl(CO)2]2 with the heterobidentate dendritic ligands 1,  2 gave the corresponding rhodium(I) complexes (3,  4).First (G1)- and second-generation (G2) poly(propyleneimine) (PPI) dendrimers were reacted with 2-(diphenylphosphino)benzaldehyde, to form iminophosphine-functionalised dendritic ligands (1,  2). The reaction of the dimeric precursor [RhCl(CO)2]2 with the heterobidentate dendritic ligands 1,  2 gave the corresponding rhodium(I) complexes (3,  4).
Keywords: Dendrimers; Rhodium complexes; Poly(propyleneimine); Iminophosphine; P,N-heterobidentate;

The whole set of the nickel(II) complexes with no derivatized edta-type hexadentate ligands has been investigated from their structural and electronic properties. Two more complexes have been prepared in order to complete the whole set: trans(O5)-[Ni(ED3AP)]2− and trans(O5O6)-[Ni(EDA3P)]2− complexes. trans(O5) geometry has been verified crystallographically and trans(O5O6) geometry of the second complex has been predicted by the DFT theory and spectral analysis. Mutual dependance has been established between: the number of the five-membered carboxylate rings, octahedral/tetrahedral deviation of metal-ligand/nitrogen-neighbour-atom angles and charge-transfer energies (CTE) calculated by the Morokuma’s energetic decomposition analysis; energy of the absorption bands and HOMO–LUMO gap.The whole set of the nickel(II) complexes with no derivatized edta-type hexadentate ligands has been investigated from their structural and electronic properties. Two more complexes have been prepared in order to complete the whole set: trans(O5)-Mg[Ni(ed3ap)]·8H2O and trans(O5O6)-Ba[Ni(eda3p)]·4H2O complexes. trans(O5) geometry has been verified crystallographicaly and trans(O5O6) geometry of the second complex has been predicted by the DFT theory and spectral analysis. Mutual dependance has been established between: the number of the five-membered carboxylate rings, octahedral/tetrahedral deviation of metal-ligand/nitrogen-neighbour-atom angles, charge-transfer energies (CTE) calculated by the Morokuma’s energetic decomposition analysis and energy of the absorption bands and HOMO–LUMO gap.
Keywords: Nickel(II) complexes; Aminopolycarboxylates; Crystal structure; Hexadentates; DFT; MO analysis;

Uncommon coordination modes of 4-methylimidazole in [Zn(4-Meim)2(5-Meim)2]sq·3H2O by Okan Zafer Yeşilel; Hakan Erer; Orhan Büyükgüngör (724-727).
A novel Zn(II)-squarate complex, [Zn(4-Meim)2(5-Meim)2]sq·3H2O have been synthesized and characterized. The Zn(II) ion center accommodates two binding types of the 4(5)-Meim ligand in same coordination sphere, which is a very unique example of the linkage isomers.A novel Zn(II) complex, [Zn(4-Meim)2(5-Meim)2]sq·3H2O (1), (H2sq = squaric acid, 4-Meim = 4-methylimidazole and 5-Meim = 5-methylimidazole) has been synthesized and characterized by elemental, spectral (IR), thermal analyses and single crystal X-ray diffraction techniques. The Zn(II) ion center accommodates two binding types of the 4(5)-Meim ligand in same coordination sphere, which is a very unique example of the linkage isomers. The sq counterion interacts each other though water bridges by strong hydrogen bonds forming a zig-zag chain along the b-axis and generate R 4 4 ( 14 ) motif. The adjacent chains are connected by the water molecule forming a R 8 8 ( 22 ) aperture.
Keywords: 4-Methylimidazole complex; 5-Methylimidazole complex; Squarate complex; Zinc(II) Complex; Linkage isomerism;

Synthesis, spectroscopic, and electrochemical properties of one novel hexanuclear Ru(II) polypyridyl complex by Feixiang Cheng; Longhai Chen; Jie Zhang; Jiangbing Wang; Ning Tang (728-730).
One novel hexapodal ligand based on diazafluorene and corresponding Ru(II) polypyridyl complex have been synthesized. The complex shows MLCT band at 438 nm and emission at 579 nm. Cyclic voltammetry of the complex comprises one Ru(II)-centered quasi-reversible oxidation and three ligand-centered reductions.One novel hexapodal ligand 1,2,3,4,5,6-hexakis[(4,5-diazafluoren-9-yliminoxy)methyl]benzene (L) and corresponding Ru(II) polypyridyl complex [(bpy)12(RuII)6L](PF6)12 have been synthesized. Spectroscopic properties of the complex are investigated by UV–Vis absorption and fluorescence spectrometry. The complex shows metal-to-ligand charge transfer absorption at 438 nm and emission at 579 nm. Cyclic voltammetry of the complex comprises one Ru(II)-centered quasi-reversible oxidation at 1.31 V and three ligand-centered reductions.
Keywords: Hexanuclear Ru(II) complex; UV–Vis absorption; Emission; Electrochemistry;

A self-assembled supramolecular solid for catalytic application by Guo-Qiang Kong; Chuan-De Wu (731-734).
A 1,8-naphthalenecarboxylic anhydride-4,5-dicarboxylate (L) bridged copper(II) dimeric molecule [Cu2L2(DMF)2(H2O)2] (1) self-assembled into a supramolecular solid, which can be used as a heterogeneous catalyst for the cross-coupling of arylboronic acids with imidazole to generate the corresponding coupling products in excellent yields.A 1,8-naphthalenecarboxylic anhydride-4,5-dicarboxylate (L) bridged copper(II) dimeric molecular module [Cu2 L 2(DMF)2(H2O)2] (1) can self-organize into a solid-state supramolecular architecture. The combination of the multitopic contact sites of hydrogen bonds coupled with two bulky aromatic cores promoted the molecule to self-link into a solid-state supramolecular architecture, which was almost insoluble in water and common organic solvents. Solid 1 can heterogeneously catalyze the cross-coupling of arylboronic acids with imidazole in the absence of a base or additive to generate the corresponding coupling products in excellent yields in methanol at 50 °C, which can be recovered and recycled by a simple filtration and was used for six consecutive cycles with consistent activity.
Keywords: Catalysis; Crystal structure; Coordination; Heterogeneous; Supramolecular solid;

An intertwined double chain constructed by [SiMo12O40]4− clusters and unusual [Cu2(DF)2H2O] dimers by Hai-jun Pang; Jing-quan Sha; Jun Peng; Ai-xiang Tian; Chun-jing Zhang; Peng-peng Zhang; Yuan Chen; Min Zhu; Yong-hui Wang (735-738).
A new compound has been synthesized, in which all the DF only adopt the unusual bidentate coordination mode for the first time coordinating to Cu atoms to form copper-dimers that link [SiMo12O40]4− clusters obtaining an intertwined double chain.A new compound, {[Cu2(DF)2H2O]2SiMo12O40} (1) (DF = 4,5-diazafluoren-9-one), has been hydrothermally synthesized and characterized by routine methods and single crystal X-ray diffraction. In 1, all the DF only adopt the unusual bidentate coordination mode for the first time coordinating to Cu atoms to form copper-dimers which link [SiMo12O40]4− clusters obtaining an intertwined double chain. Furthermore, the luminescent and electrochemical properties of the title compound have been studied.
Keywords: 4,5-Diazafluoren-9-one; Bidentate coordination mode; Polyoxometalates; Luminescent and electrochemical properties;

Novel magnesium and metal-free porphyrazines (4 and 5) containing four peripheral tetrathiacrown ether-linked tetrathiafulvalene moieties have been synthesized and studied their electron donating properties.Novel magnesium and metal-free porphyrazines (4 and 5) containing four peripheral tetrathiacrown ether-linked tetrathiafulvalene moieties have been synthesized and characterized. Their solution electrochemical data showed two reductive and three oxidative processes within a −1500 mV to +1500 mV potential window. UV/Vis spectroscopy and electron paramagnetic resonance (EPR) measurements reveal the formation of a charge-transfer complex between porphyrazine 4 with F4TCNQ. The single-crystal structure of the TTF-dicyanocrown ether 3 is presented.
Keywords: Porphyrazine; Tetrathiafulvalene; Crown ether; CT complex;

Cyclometalated platinum(II) complex with C^N^N tridentate ligand as sensitizer for lanthanide luminescence by Kun-Jiao Chen; Hai-Bing Xu; Li-Yi Zhang; Zhong-Ning Chen (744-746).
Three heterobinuclear complexes {Pt(C^N^N)(CCbpy)}Ln(hfac)3 (C^N^N = 2-(6-(naphthalen-3-yl)-4-phenylpyridin-2-yl)pyridine; bpy = 2,2′-bipyridine; Ln = Nd, Eu, Yb; hfac = hexafluoroacetylacetonate) have been prepared and investigated. Irradiation of MLCT absorption of the (C^N^N)Pt(CCbpy), lights up the NIR lanthanide luminescence through an antenna effect or energy transfer from PtII-chromophore to the lanthanide center.The preparation, characterization and photophysical properties of heterobinuclear complexes {Pt(C^N^N)(CCbpy)}Ln(hfac)3 (C^N^N = 2-(6-(naphthalen-3-yl)-4-phenylpyridin-2-yl)pyridine; HCCbpy = 5-ethynyl-2,2′-bipyridine; Ln = Nd, Eu, Yb; hfac = hexafluoroacetylacetonate) are described. With excitation at 390 ⩽  λ ex  ⩽ 500 nm which is the MLCT/LLCT absorption region of the Pt(C^N^N)(CCbpy) chromophore, lanthanide luminescence is successfully attained by Pt → Ln energy transfer from the platinum(II) antenna chromophore to the lanthanide center across the bridging CCbpy ligand.
Keywords: Energy transfer; Lanthanide; Luminescence; Platinum; Sensitizer;

An oxide chain constructed from octamolybdate, a Keggin anion and a copper (II) – Tetrapyridylpyrazine binuclear unit by N. Gabriel Armatas; Wayne Ouellette; Joshua Pelcher; Jon Zubieta (747-749).
The hydrothermal reaction of MoO3, CuSO4·5H2O, tetra-4-pyridylpyrazine and diphenyldiarsonic acid yields a one-dimensional oxide, constructed from β-molybdate and Keggin clusters and a {Cu2(tpyprz)(H2O)3}4+ binuclear linker.The hydrothermal reaction of MoO3, CuSO4·5H2O, tetra-4-pyridylpyrazine (tpyprz), and diphenyldiarsonic acid in water at 140 °C for 48 h yielded the one-dimensional material [{Cu2(tpyprz)(H2O)3}2{Mo8O26}{Mo12O36(AsO4)}]·8H2O (1·8H2O). The chain structure of 1·8H2O is constructed from alternating β-octamolybdate clusters and molybdoarsonate Keggin clusters linked through {Cu2(tpyprz)(H2O)3}4+ binuclear subunits. The Cu(II) sites are inequivalent with one copper bonding to two pyridyl donors and a pyrazine nitrogen of one terminus of the tpyprz ligand, two aqua ligands and an oxo-group of the β - Mo 8 O 26 4 - cluster while the second copper site coordinates to the nitrogen donors of the other terminus of the tpyprz ligand, an aqua group, a terminal oxo-group of the β - Mo 8 O 26 4 - cluster and a terminal oxo-group of the mixed valence {Mo11 VIMoVO36(AsO4)}4− cluster. Crystal data: C48H60AsCu4Mo20N12O80: FW = 4332.96 Triclinic P 1 ¯ , a  = 12.5087(5) Å, b  = 13.6681(6) Å, c  = 14.8980(6) Å, α  = 92.196(1)°, β  = 97.046(1)°, γ  = 97.751(1)°, Z  = 1, D calc  = 2.877 g cm−3; structure solution and refinement based on 12,333 reflections (Mo Kα, λ  = 0.71073 Å) converged at R 1  = 0.0540 and wR 2  = 0.1115.
Keywords: Hydrothermal chemistry; Organic/inorganic oxide; Bimetallic oxide; Polyoxomolybdate cluster building blocks;

Design and construction of two new polymers featuring macrocyclic subunits based on a rigid clamp-like ligand by Jie Wu; Fangfang Pan; Hongwei Hou; Jin’an Zhao; Yaofei Zhao; Yaoting Fan (750-754).
Reaction of a rigid clamp-like ligand N,N′-bis(pyridin-3-yl)-2,6-pyridinedicarboxamide (bppdca) with ZnSO4·7H2O or CoSO4·7H2O resulted in two new polymers, namely, {[Zn2(bppdca)(SO4)2(DMF)2]·DMF} n (1) and {[Co(bppdca)(SO4)(CH3OH)(DMF)]·H2O} n (2). Single-crystal X-ray diffraction reveals that both structures were one-dimensional double chain connected by weak interactions generating higher dimension with macrocycles. Their fluorescence properties were reported in this article.Reaction of a rigid conjugated clamp-like ligand N,N′-bis(pyridin-3-yl)-2,6-pyridinedicarboxamide (bppdca) with ZnSO4·7H2O or CoSO4·7H2O resulted in the formation of two new polymers, namely, {[Zn2(bppdca)(SO4)2(DMF)2]·(DMF)} n (1) and {[Co(bppdca)(SO4)(CH3OH)(DMF)]·H2O} n (2). Both 1 and 2 feature one-dimensional double-chain structures with macrocyclic subunits, and the chains further self-assemble into a higher-dimensional framework via the hydrogen-bonding and π–π stacking interactions. Fluorescence studies show that the free ligand displays a strong fluorescence emission in solid state at room temperature, but in 1 and 2, the complexation of the ligand with metal ions and weak intermolecular interactions make the fluorescence emission partial quenching.
Keywords: Multipyridine; Zinc complex; Cobalt complex; Crystal structure; Fluorescence properties;

Solvent-induced assembly of two supramolecular isomers of MnII thiophenedicarboxylate coordination polymers by Hong-Bo Yuan; Shi-Yao Yang; Zhao-Xiong Xie; Rong-Bing Huang; Stuart R. Batten (755-757).
Two supramolecular isomers of MnII thiophenedicarboxylate coordination polymers, namely, [Mn2(tdc)2(dmf)2] n and [Mn3(tdc)3(dmf)3] n have been synthesized as solvent-induced products. Magnetic susceptibility measurements show antiferromagnetic interactions between the MnII ions.Two supramolecular isomers of MnII thiophenedicarboxylate coordination polymers, namely, [Mn2(tdc)2(dmf)2] n (1) and [Mn3(tdc)3(dmf)3] n (2) (H2tdc = 2,5-thiophenedicarboxylic acid, dmf =  N,N-dimethylformamide), were synthesized with solvent-induced assembly method and the antiferromagnetic interactions between the MnII ions in their solid phase were measured.
Keywords: Supramolecular isomerism; Coordination polymers; Crystal structure; Solvent-induced; Anti-ferromagnetic;

Cyclometallated iridium(III) complexes with dicyanamide or tricyanomethanide by Xu Zhang; Li-Yi Zhang; Lin-Xi Shi; Zhong-Ning Chen (758-760).
Substitution of chloride in the precursor Ir(ppy)2(PPh3)Cl (ppy = 2-phenylpyridine) with dicyanamide or tricyanomethanide improved significantly the luminescence properties with 2.2 to 9.3-fold enhancements of emission quantum yields.Reaction of cyclometallated iridium(III) complex Ir(ppy)2(PPh3)Cl (2, ppy = 2-phenylpyridine) with dicyanamide or tricyanomethanide gave neutral mononuclear complexes Ir(ppy)2(PPh3)N(CN)2 (3a) or Ir(ppy)2(PPh3)C(CN)3 (3b), and dicyanamide/tricyanomethanide-linked binuclear iridium(III) complexes [{Ir(ppy)2(PPh3)}2N(CN)2]+ (4a) or [{Ir(ppy)2(PPh3)}2C(CN)3]+ (4b). Substitution of coordinated chloride in the precursor 2 with dicyanamide or tricyanomethanide improved significantly the luminescence properties of 3a4b. Compared with that in the precursor 2 (1.6%), 2.2 to 9.3-fold enhancement of emission quantum yields was detected in 3a4b.
Keywords: Dicyanamide; Luminescence; Iridium; 2-Phenylpyridine; Tricyanomethanide;

Synthesis, crystal structures and photoluminescence of Zn–Ln heterometallic polymers based on pyridine-2,3-dicarboxylic acid by Li Chen; Xiao-Ming Lin; Yin Ying; Qing-Guang Zhan; Ze-Hong Hong; Jun-Yong Li; Ng Seik Weng; Yue-Peng Cai (761-765).
Three new two-dimensional 3d–4f isostructural heterometallic coordination polymers, namely [Ln2Zn(2,3-pydc)4(H2O)4·4H2O] n (Ln = Sm (1), Eu (2), Gd (3), 2,3-pydcH2  = pyridine-2,3-dicarboxylic acid) have been successfully synthesized by the hydrothermal reactions of Ln2O3, Zn(NO3)2·6H2O, H2pydc and H2O. X-ray diffraction analyses reveal that they possess a 2D heterometallic framework containing 1D lanthanide chains based on dimeric [Ln(2,3-pydc)2(H2O)2]2 unit. The Zn(II) ion, which is six-coordinated by four oxygen and two nitrogen atoms from four 2,3-pydc2− ligands, as a inter-chain spacer, links the lanthanide chains to make the 1D chains further extend into 2D layer framework. Furthermore, the neighboring layers are assembled into three-dimensional supramolecular network through inter-layer O–H⋯O and C–H⋯O hydrogen-bond interactions. In addition, the solid-state luminescent property of complex 2 was investigated.Three new two-dimensional 3d–4f isostructural heterometallic coordination polymers, namely [Ln2Zn(2,3-pydc)4(H2O)4·4H2O] n (Ln = Sm (1), Eu (2), Gd (3), 2,3-pydcH2  = pyridine-2,3-dicarboxylic acid) have been successfully synthesized by the hydrothermal reactions of Ln2O3, Zn(NO3)2·6H2O, H2pydc and H2O. X-ray diffraction analyses reveal that they possess a 2D heterometallic framework containing 1D lanthanide chains based on dimeric [Ln(2,3-pydc)2(H2O)2]2 unit. The Zn(II) ion, which is six-coordinated by four oxygen and two nitrogen atoms from four 2,3-pydc2− ligands, as a bridge, links the lanthanide chains to make the 1D chains further extend into 2D layer framework. Furthermore, the neighboring layers are assembled into three-dimensional supramolecular network through inter-layer O–H⋯O and C–H⋯O hydrogen-bond interactions. In addition, the solid-state luminescent property of complex 2 was investigated.
Keywords: 3d–4f heterometallic complex; Pyridine-2,3-dicarboxylic acid; Synthesis and characterization; Crystal structures; Luminescence;

Bridge-splitting of trans-[PtCl2(η 2-CH2 =CH2)]2 by L in dichloromethane yields trans-[PtCl2(η 2-CH2 =CH2)(L)] (L = THF, 2, or MeCN, 3) with bridge-splitting equilibrium constants of 0.0289 ± 0.0007 and 3601 ± 215 mol−1  dm3, respectively, as determined by UV/Vis measurements. The reaction of 3 in MeCN with Cl is essentially quantitative. The crystal structures of trans-[PtCl2(η 2-CH2 =CH2)(CH3CN)] is reported.Bridge-splitting of trans-[PtCl2(η 2-CH2 =CH2)]2, 1, by L in dichloromethane yields trans-[PtCl2(η 2-CH2 =CH2)(L)] (L = THF, 2, or MeCN, 3) with bridge-splitting equilibrium constants of 0.0289 ± 0.0007 and 3601 ± 215 mol−1  dm3, respectively, as determined by UV/Vis measurements. The reaction of 3 in MeCN with Cl is essentially quantitative. The crystal structure of trans-[PtCl2(η 2-CH2 =CH2)(CH3CN)] is reported.
Keywords: Platinum; Zeise; Ethene; Equilibrium constants; Crystal structure;

Photochromic nanocomposite films of mononitrosyl complexes embedded in polymer matrices by Benoit Cormary; Isabelle Malfant; Lydie Valade; Shigekazu Kawai; Tsuyoshi Kawai (769-772).
New photochromic nanocomposite films based on mononitrosyl ruthenium complex [ RuCl ( NO ) py 4 ] 2 + have been synthesized by dispersion in polymer matrices. Infrared study under irradiation reveals that composites present very high population of metastable state. Nanoparticles of the molecular complex stabilized in different matrices have been observed by transmission electron microscopy.New photochromic nanocomposite films based on mononitrosyl ruthenium complex [ RuCl ( NO ) py 4 ] 2 + have been synthesized by dispersion in polymer matrices. Infrared study under irradiation reveals that the composites present very high population of metastable state (≈45%). Nanoparticles of molecular complex stabilized in different matrices have been observed by transmission electron microscopy.
Keywords: Photochromism; Polymer matrices; Composite films; Mononitrosyl ruthenium complex;

A cis-directing effect towards diols by an exocyclic P-NHR moiety in cyclotriphosphazenes by Serap Beşli; Simon J. Coles; David B. Davies; Adem Kılıç; Elif Okutan; Robert A. Shaw; Esra Tanrıverdi; Gönül Yenilmez Çiftçi (773-777).
Reactions of diols with cyclophosphazenes containing a P-NHR moiety in an exocyclic spiro ring lead to ansa derivatives that are exclusively cis rather than trans to the NH group.Cyclophosphazenes containing the P-NHR moiety in an exocyclic spiro ring, N3P3Cl4[NH(CH2)3O], (1), and N3P3Cl4[NH(CH2)3NMe], (2), were used to investigate a possible directing effect of the P-NHR moiety on the formation of products in the nucleophilic substitution reactions with diols such as tetraethyleneglycol, 1,3-propanediol and 2,2-dimethyl-1,3-propanediol. The 31P NMR spectra of the reaction mixtures showed that only one kind of ansa product is formed in each of these reactions. X-ray crystallographic studies of the ansa products [(4a), (5a), (6a) and (7a)] have provided definitive proof of the cis-directing effect of the P-NHR moiety in cyclotriphosphazenes. It is likely that hydrogen-bond interaction between the incoming nucleophile and the P-NHR moiety of the reactant accounts for the preference for products with the substituents cis to the NH group.
Keywords: Cyclophosphazene derivatives; cis-Directing effect; NMR; X-ray crystallography;

A chain-like coordination polymer, [Na2(CH3CN)2(Et2O)2Fe2(C24H20N2O2S3)2]n, was synthesized and structurally characterized. The units of square-pyramidal FeIII dimer are linked by two bridging four-coordinate Na+ cations. Each FeIII atom is equatorially chelated by two deprotonated carboxamido N and S atoms of the ligand. The bridging S atom occupies the axial position.A one-dimensional stair-like coordination polymer, [Fe2 L 2Na2(CH3CN)2(Et2O)2]n {1, where L4  =  N,N’-bis-(2-mercaptophenyl)-2-methyl-2-[(2-methylthio)phenylmethyl] malonyl diamide}, was produced from the one-pot reaction of iron(III) chloride with 2-methyl-2-[(2-methylthio)phenylmethyl] malonyl chloride, 2-aminobenzenethiol and sodium hydride in DMF solution, and was structurally characterized. The dimeric pentacoordinate Fe(III) anionic units are linked by two bridging four-coordinate Na+ cations. Each trivalent iron atom is equatorially coordinated by two deprotonated carboxamido N and S atoms of the ligand. The bridging S atom, occupying the axial position, accomplishes the square-pyramidal geometry of iron center. The coordination environment is very similar to the unmodified active site of Fe-containing nitrile hydratase. In addition, the electronic and magnetic properties of this dimeric complex are included in this report.
Keywords: Iron complex; Nitrile hydratase; Thiols; Amide; Square pyramidal; Coordination polymer;

A novel lamella 2D Ag(I) coordination polymer of graphite-like structure featuring short interlayer distance by Di Sun; Geng-Geng Luo; Qin-Juan Xu; Na Zhang; Yi-Chang Jin; Hai-Xia Zhao; Li-Rong Lin; Rong-Bin Huang; Lan-Sun Zheng (782-784).
The reaction of Ag2O with a mixture of benzene-1,3,5-tricarboxylic acid (H3BTC) and 2-aminopyrazine (APYZ) under the ammoniacal conditions gives rise to a novel metal–organic coordination polymer Ag6(BTC)2(APYZ)6·9H2O (1). The structure of 1 possesses a high ordered lamella 2D structure with an interesting graphite-like 63 net which is comprised of Ag4 and Ag6 fused hexagonal rings. 1 exhibits blue photoluminescence at 416 nm (λ ex  = 330 nm) at room temperature which may be mainly ascribed to ligand-to-ligand charge transfer (LLCT). Semiconducting behavior was also measured at ambient temperature with σ values of 5.56 × 10−7  S cm−1 based on the π–π stacking and Ag(I)–π interactions.The reaction of Ag2O with a mixture of benzene-1,3,5-tricarboxylic acid (H3BTC) and 2-aminopyrazine (APYZ) under the ammoniacal conditions gives rise to a novel metal–organic coordination polymer Ag6(BTC)2(APYZ)6·9H2O (1). The structure of 1 possesses a high ordered lamella 2D structure with an interesting graphite-like 63 net which is comprised of Ag4 and Ag6 fused hexagonal rings respectively. 1 exhibits photoluminescence maximized at 416 nm upon 330 nm excitation at room temperature, which may be mainly ascribed to ligand-to-ligand charge transfer (LLCT). Semiconducting behavior was also measured at ambient temperature with σ values of 5.56 × 10−7  S cm−1 based on the π–π stacking and Ag(I)–π interactions.
Keywords: Silver; 2-Aminopyrazine; Benzene-1,3,5-tricarboxylic acid; Metal–organic polymer; Ag⋯π interactions; Photoluminescence; Semiconductivity;

Synthesis, crystal structure and photophysical properties of a series of new neutral iridium(III) complexes with 2-phenylpyridine by Xuan Shen; Hao Yang; Xiu-Hua Hu; Yan Xu; Feng-Ling Wang; Su Chen; Dun-Ru Zhu (785-788).
Neutral iridium(III) complexes Ir(ppy)2(PPh3)L (L = NCS, 1; N3 , 2; NCO, 3) have been synthesized and characterized. Crystal structure of 1 has been determined. The photoluminescence spectra of 13 show emission maxima at 477, 489 and 485 nm, respectively. Photoluminescence quantum yields of 13 are 0.39, 0.13 and 0.43, respectively.A series of new neutral iridium(III) complexes containing strong-field ancillary ligands, [Ir(ppy)2(PPh3)L] (ppy = 2-phenylpyridine, PPh3  = triphenylphosphine, L = NCS, 1; N 3 - , 2; NCO, 3), have been synthesized and fully characterized by 1H NMR, IR, ESI mass spectral and elemental analysis. The crystal structure of 1 has been determined by X-ray analysis. The photoluminescence (PL) spectra of 13 show emission maxima at 477, 489 and 485 nm, respectively, corresponding to blue light-emitting of 1 and blue-green light-emitting of 2 and 3. PL quantum yields (PLQYs) of 13 are 0.39, 0.13 and 0.43, respectively.
Keywords: Neutral iridium(III) complexes; Strong-field ligands; Crystal structure; Photoluminescence; Blue–green light emitting; PL quantum yields;

The reaction of the [ReOBr3(PPh3)2] complex with 1-isoquinolinyl phenyl ketone in acetone has been examined and the novel [ReOBr2(iquinpk-OH)(PPh3)] complex – has been obtained. It has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The electronic structure of [ReOBr2(iquinpk-OH)(PPh3)] has been calculated with the density functional theory (DFT) method. The spin-allowed electronic transitions of [ReOBr2(iquinpk-OH)(PPh3)] have been calculated with the time-dependent DFT method and the UV–Vis spectrum has been discussed on this basis.The reaction of [ReOBr3(PPh3)2] with 1-isoquinolinyl phenyl ketone in acetone has been examined and the novel complex [ReOBr2(iquinpk-OH)(PPh3)] has been obtained. The complex has been characterised by IR, UV–Vis spectroscopy and X-ray crystallography. The electronic structure of [ReOBr2(iquinpk-OH)(PPh3)] has been calculated with the density functional theory (DFT) method. The spin-allowed electronic transitions of [ReOBr2(iquinpk-OH)(PPh3)] have been calculated with the time-dependent DFT method and the UV–Vis spectrum has been discussed on this basis.
Keywords: Rhenium(V) complexes; 1-isoquinolinyl phenyl ketone; Gem-diol form; X-ray structure; Electronic structure; DFT calculations;

A novel 2D coordination polymer, formulated as [Cd2(Hpimdc)2(bpp)(H2O)] n (bpp = 1,3-bis(4-pyridyl)propane, H3pimdc = 2-propyl-4,5-imidazoledicarboxylate), has been hydro-thermally synthesized and structurally characterized, which shows unusual multifarious helical structures and (3,4)-connected network with (4.82)2(42.83.10) topology. The photoluminescent property and thermal stability of 1 were also discussed.A novel 2D coordination polymer, formulated as [Cd2(Hpimdc)2(bpp)(H2O)] n (bpp = 1,3-bis(4-pyridyl)propane, H3pimdc = 2-propyl-4,5-imidazoledicarboxylate), has been hydro-thermally synthesized and structurally characterized, which shows unusual multifarious helical structures and (3,4)-connected network with (4.82)2(42.83.10) topology. The photoluminescent property and thermal stability of 1 were also discussed.
Keywords: CdII coordination polymer; Helical structure; Network topology; Luminescent property;

Four novel titanium complexes with two β-ketoiminate ligands containing fluorine or alkyl substituent groups have been synthesized, in which the substituents have significant influences upon molecular structures and catalytic activities. Three different isomeric structures have been found as different substituents in ligands. The catalytic activity for ethylene polymerization can be enhanced greatly by introduction fluorine atoms into ligands, owing to electron withdrawing effect.Four titanium complexes having β-ketoiminate chelate ligands with fluorine or alkyl groups [(Ar)NC(CH3)C(H)C(CH3)O]2TiCl2 (3a: Ar = 2.6-F2C6H3; 3b: Ar = C6F5; 3c: Ar = 2.6-Me2C6H3; 3d: Ar = 2.6- i Pr2C6H3) have been synthesized and characterized by 1H NMR and EA. Complexes 3a, 3c and 3d were further characterized by X-ray diffraction analysis and demonstrated distorted octahedral coordination structure around the titanium center. The substituents in ligands greatly affect the coordination mode, resulting in three different isomeric structures. These complexes are active catalysts for polymerization of ethylene with MMAO as cocatalyst. The substituents in ligands have also great influences on catalytic activity. The complexes with alkyl groups have lower activity, while the complexes with fluorine atoms have middle or high catalytic activity.
Keywords: Ethylene polymerization; Titanium complexes; β-Ketoiminate; Electron-withdrawing effect; Isomeric structures;

Two- and three-dimensional uranyl–organic assemblies were obtained with pyridine-monocarboxylates as ligands. A uranyl–copper heterometallic species could be isolated with nicotinate, in which bonding of Cu(II) to one uranyl oxo group is present (cation–cation interaction).Reaction of uranyl nitrate with pyridine-2-carboxylic acid (HL1) under hydrothermal conditions gives the complex [(UO2)3(L1)4(NO3)2], 1, which differs from the previously reported molecular complex, obtained at room temperature, by the absence of water, coordinated and free, and the extended carboxylate bridging. Although the trimetallic basic unit is similar in both cases, 1 crystallizes as a two-dimensional assembly. A heterometallic complex results from the reaction of uranyl nitrate and copper(II) trifluoromethanesulfonate with nicotinic acid (pyridine-3-carboxylic acid, HL2), [UO2Cu(L2)2(NO3)2], 2, in which copper nicotinate two-dimensional subunits are bridged by uranyl nitrate groups to give a three-dimensional framework. The copper atom environment geometry is elongated octahedral, with one of the axial donors being a uranyl oxo group (cation–cation interaction).
Keywords: Uranyl ion; Copper(II) ion; Cation–cation interaction; Uranyl–organic framework; Nicotinic acid; Hydrothermal synthesis; Crystal structure;

The preparation and X-ray structure of heptasulfurimidostearate by Catherine J. Bromley; Alexandra M.Z. Slawin; Paul G. Waddell; J. Derek Woollins (804-805).
The synthesis and X-ray crystal structure of the stearic acid derivative of S7NH, (S7N)C(O)(CH2)16CH3, is reported. The S–N bond lengths are significantly longer (average 1.704 Å) than those in heptasulfur imide from which it is derived. However, the nitrogen atom environment is not tetrahedral but essentially planar and there is some S–S bond length alternation suggesting that the ring has some multiple bonding character. The three independent molecules pack with alkyl chains over alkyl chains and S–N rings over S–N rings. This arrangement is probably due to favourable intermolecular contacts between sulfur atoms which range from 3.35 to 3.63 Å.The S–N ring in (S7N)C(O)(CH2)16CH3 displays long S–N bonds but planar nitrogen environment and S–S bond length alternation suggesting that it has some multiple bond character.
Keywords: Heterocycle; Sulfur imide; X-ray structure; Stearate;

Pentamethylcyclopentadienyl rhodium and iridium complexes containing oxinato ligands by Trieu-Tien Thai; Bruno Therrien; Georg Süss-Fink (806-807).
The neutral chloro complexes [(η5-C5Me5)M(η2-NC9H6O)Cl] as well as the cationic aqua complexes [(η5-C5Me5)M(η2-NC9H6O)(H2O)]+ (M  = Rh, Ir) have been synthesized from the reaction of the dinuclear precursors [(η5-C5Me5)MCl2]2 and 8-hydroxyquinoline.The neutral chloro complexes [(η5-C5Me5)M(η2-NC9H6O)Cl] as well as the cationic aqua complexes [(η5-C5Me5)M(η2-NC9H6O)(H2O)]+ (M = Rh, Ir) have been synthesized from the reaction of the dinuclear precursors [(η5-C5Me5)MCl2]2 and 8-hydroxyquinoline. The single crystal X-ray structure analysis of [(η5-C5Me5)Ir(η2-NC9H6O)Cl] reveals for these complexes a piano-stool arrangement with the aromatic ligand, the chelating oxinato ligand and the terminal chloro or aqua ligand surrounding the metal center in a pseudo-tetrahedral fashion.
Keywords: Rhodium; Iridium; Pentamethylcyclopentadienyl; Oxinato;

A series of hydrothermal reactions of ZnX2 ( X = NO 3 - , ClO 4 - , and CH3COO) with 3-(1,2,4-triazolyl-4-yl)-1H-1,2,4-triazole (Htrtr) with various Zn–Htrtr ratios led to the same 2D metal–organic coordination polymer [Zn(trtr)2] n (1), which exhibits a fluorescent emission at 424 nm assigned to intra-ligand π–π transition of trtr.A series of hydrothermal reactions of ZnX2 ( X = NO 3 - , ClO 4 - , and CH3COO) with 3-(1,2,4-triazolyl-4-yl)-1H-1,2,4-triazole (Htrtr) with various Zn–Htrtr ratios led to the same 2D metal–organic coordination polymer [Zn(trtr)2] n (1), which features a 2D grid. Four trtr ligands adopting μ2-1κN: 1′κN mode alternately connect four Zn1 centers to form a 28-membered ring. The growth of the 28-membered rings fuses into the 2D grid, thus, to be further fabricated into a supramolecular framework by hydrogen bondings. The fluorescence of 1 shows an emission peak at 424 nm, which can be assigned to intra-ligand π–π transition of trtr.
Keywords: Coordination polymer; Crystal structure; Fluorescence; 1,2,4-Triazole; Zinc(II);