Three New Polyoxometalates Derivatives Decorated by Phenanthroline and Transition-metal Cations(M=Zn~ⅡI,Co~Ⅱ , Ni~Ⅱ)

Three new Keggin polyoxometalates, [Zn(phen) 3 ] 2 [SiW 12 O 40 ]·5H 2 O(1), [Co(phen) 3 ] 2 [SiW 12 O 40 ](2) and [Ni(phen) 3 ] 2 [SiW 12 O 40 ]·2H 2 O(3)(phen=1,10′-phenanthroline) have been hydrothermally synthesized and characterized by elemental analysis, IR, crystal X-ray diffraction, thermogravimetric analyses(TGA) and fluorescence techniques. Complex 1, crystallized in the triclinic space group P1, consists of one [SiW 12 O 40 ] 4– anion, two discrete [Zn(phen) 3 ] 2+ cations and five crystal water molecules. Complexes 2 and 3 have the similar configuration to complex 1, but they crystallized in the monoclinic space group C2/c. Variable-temperature magnetic susceptibilities of complexess 2 and 3 reveal antiferromagnetism and ferromagnetism, respectively.     

Two New Copper Complexes by H_4AQTC(Anthraquinone-1,4,5,8-tetracarboxylic Acid):Syntheses,Structures and Properties

Two new complexes[Cu(AQTC)_0.5(H₂O)₃]·3H₂O}_n (1,H₄AQTC=anthraquinone-1,4,5,8-tetracarboxylic acid) and Cu[(Py)₂C(OH)₂]₂(H₂AQTC)·2H₂O (2,(Py)₂CO=di-2-pyridyl ketone) have been prepared and characterized by elemental analyses and IR spectroscopy.X-ray crystallographic studies show that complex 1crystallizes in monoclinic space group C2/m and complex 2 in monoclinic space group P2_1/c.Complex 1 features a1D chain structure by carboxyl oxygen atoms.Complex 2 displays a mononuclear structure and anions and cations are separated.What's interesting is that the ligand of H₄AQTC with eight carboxyl oxygen atoms and two quinone oxygen atoms does not directly coordinate with metals,and only exist as a counter-anion in complex 2.Three-dimensional structures of two complexes are formed by intermolecular interactions.The thermogravimetric analyses of two complexes are investigated.The luminescent properties of complex 1 are investigated as well.     

Hydrothermal Syntheses,Crystal Structures and Luminescence Properties of Cu(Ⅱ) and Cd(Ⅱ) Complexes Assembled by 6-Hydroxypicolinic Acid and 1,10-Phenanthroline

Two new complexes based on 6-hydroxypicolinic acid(H_2picO) and 1,10-phenanthroline(phen), such as [Cu_4(picO)_4(phen)_4]·12 H_2O(1) and {[Cd_4(picO)_4(phen)_4(H_2O)_2]·5H_2O}_n(2), have been synthesized and characterized by IR, elemental analyses, thermogravimetric analyses and X-ray diffraction technique. Single-crystal X-ray diffraction analyses revealed that the two complexes both crystallize in the triclinic system, space group P(16)-. For complex 1, the picO ligands adopt a tridentate coordination mode to link copper(Ⅱ) ions into dimmers. PicO ligands also adopt a tridentate mode in complex 2, which connects the cadmium(Ⅱ) to form a one-dimensional chain. Moreover, luminescent properties of 1 and 2 were also investigated.     

Three Nickel/maleonitriledithiolate Complexes Accompanied by Different Organic Molecules: Syntheses,Crystal Structures and Properties

Three complexes [AMP][Ni(mnt)2]·CH3CN(1, AMP = 1-(9-anthrylmethyl)pyridinium), [DPI]2[Ni(mnt)2]I(2, DPI = diphenyliodonium) and [DD][Ni(mnt)2]2·2H2O(3, DD = dimethylenediamine) have been prepared and characterized by elemental analyses and IR spectroscopy. X-ray diffraction studies show that three complexes crystallize in the same triclinic space group P1, and anionic accumulations are formed in a column shape. The results show that different counter-cations could induce versatile anionic stacks. The structures of three complexes exhibit rich hydrogen bonding interactions. In addition, UV-VIS properties of them are also investigated.     

咪唑配合物[Co(C3H4N2)6](PhCHCHCOO)2的合成及晶体结构

The complex [Co(Im)6](Cin)2 (Im=imidazole,Cin=cinnamate) was prepared by reaction of Co(PhCHCHCOO)2 with imidazole in ethanol. It has been determined by single crystal X-ray analyses. The crystals are triclinic, space group P, with a=9.7601(3),b=10.5935(3),c=11.3269(2)(A),α =69.948(1),β =71.027(1),γ =62.803(1)°, and Z=1. The crystal structure of the title complex consists of monomeric [Co(Im)6]2+ cations and cinnamate anions in which the cobalt(Ⅱ) ion assumes a centrosymmetric octahedral geometry with the CoN6 chromophore. In the solid state, the complex forms a three dimensional network through N-H… O hydrogen bonds, the intermolecular hydrogen bonds connect the [Co(Im)6]2+ cations and cinnamate anions.The cinnamate anions are nearly planar.     

Synthesis,Crystal Structure and Electrochemistry of Two Complexes （YLn）3＋[PW12O40]3-（L=Me2SO,Me2NCHO）

The reaction of α-H3[PW12O40] with Y（NO3）3 in the presence of DMF or DMSO leads to two complexes with the formulae {Y（DMSO）7}·PW12O40（1） and {[Y（DMF）7]2PW12O40}·PW12O40（2）. The crystal structures indicate that complex 1 consists of discrete [YLn]3＋ cations and α-Keggin heteropolyanions [PW12O40]3-, whereas, in complex 2, donor-acceptor interaction results in a cation-anion-cation triplet. In addition, the electrochemical behavior of the two complexes indicates the usual successive reduction processes of the W atoms in the anions.     

Weak Interactions and 2D Layer Structure of a New Ion-pair Complex Bis（1-benzyl-4-methylquinolinium）-bis（maleonitriledithiolato）nickel（Ⅱ）

A new ion-pair complex,[BzMeQl]2[Ni(mnt)2] 1 ([BzMeQl] =1-benzyl-4-methylquino-linium,mnt2-= maleonitriledithiolate) has been synthesized and structurally characterized by IR,ESI-MS and X-ray diffraction methods. Complex 1 is of triclinic,space group P1,with a=9.079(2),b=10.154(2),c=11.243(2),α=81.58(1),β=69.63(1),γ=68.02(1)°,V=940.1(3)3,Dc=1.427 g/cm3,Z=1,F(000)=418 and R=0.0442. A 2D layer structure is formed via the cation-cation π…π and C–H…π interactions observed in the solid state of the complex.     

Syntheses,Crystal Structures and Intermolecular Interactions of Cu（II） Complexes with Methyl- benzoic Acid （MBA） and 1,10-Phenanthroline

Two cupric complexes containing methylbenzoic acid have been prepared and crystallized by solvent evaporation method in DMF. The single-crystal X-ray crystallographic analysis reveals that they are dicaryon complexes. Complex I with formula of [Cu2（m- MBA）4DMF2] crystallizes in monoclinic with space group of P21/c and complex 2 with formula of [Cuz（o-MBA）ffo-phen）2]·NO3·H2O crystallizes in triclinic with space group of P I. The weak interactions including C-H...O hydrogen bonds, C-H…π interactions and π-π stacking in the structures of two complexes are observed from the X-ray crystallographic data. In addition, there are still classical hydrogen bonds in 2. The different strength of intermolecular interaction in the structure is reflected on their different thermal stability measured by thermal gravimetric analysis and 2D-1R correlation spectroscopy of two complexes. The study of weak interactions is meaningful to provide supporting data for supramolecular chemistry theory and potential applications in molecular biology.     

Syntheses,Structures,Fluorescence and Heterogeneous Catalysis of Coordination Polymers with 4-Benzoimidazol-1-yl-methyl Benzoic Acid and 2,2′-Dipyridine

Two coordination polymers called [Ni(L)_2]_n(1) and [Ni(2,2?-bpy)_22(H_2O)]n (2)(HL = 4-benzoimidazol-1-yl-methyl benzoic acid, 2,2?-bpy = 2,2?-dipyridine) were synthesized by solvothermal reaction simultaneously and characterized by elemental analyses, thermogravimetric analysis, X-ray powder diffraction, IR spectroscopy and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic system, space group P2_1/c with a = 14.673(3), b = 10.773(2), c = 16.566(3) ?, V = 2559.2(8) ?~3, Z = 4 and F(000) = 1160. 2 also crystallizes in monoclinic system, space group C2/c with a = 15.404(3), b = 12.652(3), c = 6.5362(13) ?, V = 1246.2(5) ?~3, Z = 4 and F(000) = 712. The bridging L ligand connects the Ni~Ⅱ cations into a 2D network in complex 1, while 2 shows a 1D structure formed through the two O atoms of SO_4~(2-) ions connecting the molecule. The catalytic properties indicate that complex 1 shows good catalytic activities for the cyanosilylation of 4-chlorobenzaldehyde. In addition, fluorescence property of complex 1 which quenches the excitation intensity in solid state was investigated at room temperature.     

New Zn（Ⅱ）/M（I） （M = Na,K and Rb） Metal-organic Frameworks Based on 5-Methylisophthalic Acid Ligand： Syntheses,Structures and Fluorescent Property

Reactions of Zn（NO3）E＇6H20 and MNO3 （M = Na, K and Rb） with HEmip （HEmip = 5-methylisophthalic acid） in DMF （DMF = N,N＇-dimethylformamide） resulted in the formation of novel heterometallic metal-organic frameworks （MeENHE）[ZnM（mip）2] （1： M = Na; 2： M = K; 3： M = Rb, mip = 5-methylisophthalate dianion for 1-3）. These complexes belong to the monoclinic system, space group PE/c and have been fully characterized by satisfactory elemental analysis, FT-IR spectra, TGA and single-crystal X-ray diffraction. Single-crystal X-ray diffraction studies reveal that 1-3 are 3D isomorphic structures based on a trinuclear unit {ZD.ME（/d2-COO）E（μ3- COO）E} and exhibitpcu topological net and blue fluorescence.     

Biferrocene-M(mnt)2 charge-transfer complexes (M = Ni, Co; mnt = maleonitriledithiolate). structure, valence states, and magnetic properties

Charge-transfer salts of branched-alkyl biferrocenes, (1',1' '-R2-1,1' '-biferrocene)[Ni(mnt)2] (1a, R = isopropyl; 2a, R = dineopentyl) and (1',1' '-R2-1,1' '-biferrocene)2[Co(mnt)2]2 (1b, R = isopropyl; 2b, R = dineopentyl), were prepared. Their valence states were investigated using X-ray crystallography and M?ssbauer spectroscopy. Complexes 1a and 1b show segregated-stack crystal structures that contain columns of acceptors, whereas structures of 2a and 2b, which contain bulky donors, are rather discrete. All of the complexes contain mixed-valent biferrocenium monocations. A two-step valence transition was found in complex 1a. The crystal contains two crystallographically independent cations: one undergoes valence localization below room temperature; the other undergoes valence localization below ca. 130 K. The former transition is derived from asymmetry of the crystal environment around the cation, whereas the latter one is caused by symmetry lowering coupled with a spin-Peierls transition (T(C) = 133.2 K) associated with the dimerization of the acceptors. This compound was found to exhibit a dielectric response based on valence tautomerization. Other complexes (1b, 2a, and 2b) show a valence-trapped state. In all complexes, charge localization was found to occur through local electrostatic interactions between the donor's cationic moiety and the acceptor's electronegative moieties.     

Thermal decomposition kinetics of M (mnt) (5-NO2-phen) (M=Co, Cu, Zn) complexes

Studies of the non-isothermal decomposition of M (mnt) (5-NO₂-phen) (M=Co^II, Cu^II, Zn^II) were carried out by thermogravimetry. The thermal decomposition mechanisms and associated kinetics have been investigated. The kinetic parameters were obtained from an analysis of the TG–DTG curves by integral and differential methods. The most probable kinetic model functions were suggested by comparison of the kinetic parameters. Mathematical expressions for the kinetic compensation effect were derived.     

Probing the intrinsic electronic structure of the bis(dithiolene) anions [M(mnt)2]2- and [M(mnt)2]1- (M = Ni, Pd, Pt; mnt = 1,2-S2C2(CN)2) in the gas phase by photoelectron spectroscopy

A detailed understanding of the electronic structure of transition metal bis(dithiolene) complexes is important because of their interesting redox, magnetic, optical, and conducting properties and their relevance to enzymes containing molybdenum and tungsten bis(dithiolene) centers. The electronic structures of the bis(dithiolene) anions [M(mnt)(2)](n-) (M = Ni, Pd, Pt; mnt = 1,2-S(2)C(2)(CN)(2); n = 0-2) were examined by a combination of photodetachment photoelectron spectroscopy (PES) and density functional theory calculations. The combined experimental and theoretical data provide insight into the molecular orbital energy levels of [M(mnt)(2)](2-) and the ground and excited states of [M(mnt)(2)](1-) and [M(mnt)(2)]. Detachment features from ligand-based orbitals of [M(mnt)(2)](2-) occur at similar energies for each species, independent of the metal center, while those arising from metal-based orbitals occur at higher energies for the heavier congeners. Electronic excitation energies inferred for [M(mnt)(2)](1-) from the PES experiments agree well with those obtained in optical absorption experiments in solution, with the PES experiments providing additional insight into the changes in energy of these transitions as a function of metal. The singly charged anions [M(mnt)(2)](1-) were also prepared and studied independently. Electron detachment from the ground states of these doublet anions accessed the lowest singlet and triplet states of neutral [M(mnt)(2)], thereby providing a direct experimental measure of their singlet-triplet splitting.     

Quasi-one-dimensional molecular magnets based on derivatives of (fluorobenzyl)pyridinium with the [M(mnt)2] monoanion (M = Ni, Pd or Pt; mnt2- = maleonitriledithiolate): syntheses, crystal structures and magnetic properties

The syntheses, structural characterizations and magnetic behaviors of three new complexes, 1-(3',4',5'-trifluorobenzyl)pyridinium [M(mnt)2]- [M = Ni (1), Pd (2) or Pt (3)], are reported. These complexes are isomorphous and their prominent structural character is that the [M(mnt)2]- anions form columnar stacks, in which the dimerization was observed. Complexes 2 and 3 are diamagnetic, while 1 possesses an energy gap of 2474 K. For crystal 4, 1-(4'-fluorobenzyl)pyridinium [Ni(mnt)2] (its structure and magnetic susceptibility were briefly reported earlier), the magnetic behavior can be divided into two regimes, namely, weakly ferromagnetic coupling above 93 K and strongly antiferromagnetic coupling below 93 K. A transition occurs at 93 K which switches the magnetic exchange nature from ferromagnetic to antiferromagnetic. A sharp thermal abnormality with lambda-shape, associated with the transition, appears from its heat capacity measurement to indicate that the transition is first order. The temperature dependences of the superlattice diffractions revealed the existence of the pretransitional phenomena up to at least 140 K. The unusual magnetic behavior of 4, such as the origin of the ferromagnetic interaction in the high temperature phase and what causes the spin transition, are discussed further.     

18-冠-6与Na2[M(mnt)2](M=Cu,Ni)配合物的合成与结构

研究了18-冠-6分别与Na2[M(mnt)2][M=Cu,Ni;mnt=丁二腈烯二硫醇阴离子,C2S2(CN)^2^-~2]的反应,得到的配合物{[Na(18-C-6)][Na(18-C-6)(H2O)]}[Cu(mnt)2](1),[Na(18-C-6)(H2O)]2[Ni(mnt)2].(18-C-6)(2)通过元素分析、红外光谱、X射线单晶衍射进行了表征。两个配合物均为三斜晶系,空间群P1。1的晶体学结构数据：a=1.22697(19)nm,b=1.22780(19)nm,c=1.5665(3)nm,α=95.083(3)°,β=101.534(3)°,Υ=91.007(3)°,V=2.3016(6)nm^3,Z=2,Dcalcd=1.350g/cm^3,F(000)=976,R1=0.0726,wR2=0.1843.2的晶体学结构数据：a=1.11620(17)nm,b=1.22054(18)nm,c=1.27939(18)nm,α=111.647(2)°,β=29.792(3)°,Υ=103.201(2)°,V=2.5461(4)nm^3,Z=1,Dcalcd=1.304g/cm^3,F(000)=642,R1=0.0459,wR2=0.1003.1中的[Cu(mnt)2]^2^-通过mnt的氮原子与[Na(18-C-6)]^+中的钠原子成键,形成了一维链状结构;[Na(18-C-6)(H2O)]^+只起平衡电荷的作用。2中的[Ni(mnt)2]^2^-也通过配体的mnt氮原子与两个[Na(18-C-6)(H2O)]^+中的钠原子成键,形成稳定的中性配合物。     

Synthesis and Characterization of One-dimensional Dicyclohexyl-18-crown-6 Complexes with M2[Cd(mnt)2] (M = Na, K)

Two supramolecular crown ether complexes [Na(DC18C6-A)(H₂O)]{[Na(DC18C6-A)][Cd(mnt)₂]} (1) and [K(DC18C6-A)]₂[Cd(mnt)₂] (2) (DC18C6-A = cis-syn-cis-dicyclohexyl-18-crown-6, isomer A; mnt = maleonitriledithiolate) have been synthesized and characterized by elemental analysis, FT-IR spectroscopy and X-ray single crystal diffraction. Complex 1 is composed of one [Na(DC18C6-A)(H₂O)]⁺ complex cation and one {[Na(DC18C6-A)][Cd(mnt)₂]}⁻ complex anion and displays an infinite chain-like structure through N–Na–N interactions. In complex 2, [K(DC18C6-A)]⁺ complex cation and [Cd(mnt)₂]²⁻ complex anion afford a novel 1D ladder-like structure by N–K–N, N–K–S interactions.     

Photoelectron spectroscopy of the doubly-charged anions [MIVO(mnt)2]2- (M = Mo, W; mnt = S2C2(CN)2(2-): access to the ground and excited states of the [MVO(mnt)2]- anion

Photodetachment photoelectron spectroscopy was used to investigate the electronic structure of the doubly charged complexes [MIVO(mnt)2]2- (M = Mo, W; mnt = 1,2-dicyanoethenedithiolato). These dianions are stable in the gas phase and are minimal models for the active sites of the dimethyl sulfoxide reductase family of molybdenum enzymes and of related tungsten enzymes. Adiabatic and vertical electron binding energies for both species were measured, providing detailed information about molecular orbital energy levels of the parent dianions as well as the ground and excited states of the product anions [MVO(mnt)2]-. Density functional theory calculations were used to assist assignment of the detachment features. Differences in energy between these features provided the energies of ligand-to-metal charge-transfer transitions from S(pi) and S(sigma) molecular orbitals to the singly occupied metal-based orbital of the products [MVO(mnt)2]-. These unique data for the M(V) species were obtained at the C(2)(v)() geometry of the parent M(IV) dianions. However, theoretical calculations and available condensed phase data suggested that a geometry featuring differentially folded dithiolene ligands (Cs point symmetry) was slightly lower in energy. The driving force for ligand folding is a favorable covalent interaction between the singly occupied metal-based molecular orbital (a1 in C2v) point symmetry; highest occupied molecular orbital (HOMO)) and the least stable of the occupied sulfur-based molecular orbitals (b1 in C2v point symmetry, HOMO-1) that is only possible upon reduction to the lower symmetry. This ligand folding induces a large increase in the intensity predicted for the a' S(pi) --> a' dx2 - y2 charge-transfer transition originating from the HOMO-2 of [MVO(mnt)2](-) under Cs point symmetry. Electronic absorption spectra are available for the related species [MoVO(bdt)2]- (bdt = 1,2-benzenedithiolato) and for the oxidized form of dimethyl sulfoxide reductase. The intense absorptions at approximately 1.7 eV have been assigned previously to S(sigma) --> Mo transitions, assuming C2v geometry. The present work indicates that the alternative a' S(pi) --> a' dx2 - y2 of Cs geometry must be considered. Overall, this study confirms that the electronic structure of the M-dithiolene units are exquisitely sensitive to dithiolene ligand folding, reinforcing the proposal that these units are tunable conduits for electron transfer in enzyme systems.     

Synthesis and Crystal Structure of One-dimensional Chain Complexes [K(18-C-6)]2[M(mnt)2](M=Zn, Hg)

IntroductionThe 1 ,2 - dicyanoethene- 1 ,2 - dithiolato anion isa bidentate ligand.It can form square- coplanarcomplexes with many transition metal ions and hasfound a lot of application in analytical chemistry,catalyst and biochemistry.In recent years,metalcomplexes containing mnt and its dithiolate analogligands have been extensively studied and have re-ceived considerable attention due to their potentialapplication in charge transfer and storage,molecu-lar metals,magnetic materials,supercon…     

[M(N)X2]-(M=Ru, Os; X=S2C6H4, mnt)的电子结构和光谱性质的理论研究

利用密度泛函理论(DFT)中的B3LYP方法优化了氮化钌和氮化锇配合物[M(N)X2]-[M=Ru, Os; X=S2C6H4, mnt(maleonitriledithiolate)]的基态几何结构, 得到的几何参数与实验结果吻合得很好. 采用TD-DFT方法, 得到了配合物在CH3CN溶液中的激发态电子结构和电子吸收光谱. 利用SCRF方法中的CPCM模型来模拟溶剂化效应. 研究结果表明, 配合物1~4在CH3CN溶液中的吸收跃迁性质相似, 低能吸收均被指认为LMCT和LLCT的混合跃迁, 高能吸收均被指认为ILCT/LLCT跃迁.