配合物[1-(4′-fluorobenzyl)pyridinium]2[Ni(dto)2](dto2-=dithiooxalate dianion)的合成及晶体结构

The complex [1-(4′-fluorobenzyl)pyridinium]₂[Ni(dto)₂] (dto^2- means dithiooxalate dianion) has been pre-pared by reaction of Na₂[Ni(S₂C₂O₂)₂] and the 1-(4′-fluorobenzyl)pyridinium chloride salt. The crystallographic data for the title complex: triclinic P1, a=8.5698(8)?, b=9.3461(9)?, c=10.5361(10)?, α=67.177(2)°, β=67.398(2)°, γ=79.611(2)°, V=717.59(12)?³, Z=1. The [Ni(dto)₂]^2- anion with the Ni atom lying on an inversion center and exhibits a quasi-planar structure. An extensive hydrogen bond network of C-H…O is clearly observed. The nature and size of cation seems to play an important factor in the type of intermolecular interactions as well as the crystal packing in this kind of complexes.     

双核钼(O)配合物[(C2H5)4N]2[Mo2(CO)8(SCH2CO2(C2H5)2]的合成, 结构, 光谱和反应性能研究

Et4NI,NaSCH2CO2C2H5和Mo(CO)6在乙腈中反应制得一种新的双核钼(0)配合物[Et4N]2-[Mo2(CO)8(SCH2CO2Et)2](1), 电化学和反应性能研究指出1在电位～-0.43V发生一有趣的双电子一步氧化, 产生[Mo2(CO)8(SCH2CO2Et)2], 若氧化反应在配位溶剂中进行, 则其部分羰基被配位溶剂分子所取代成为[Mo2(CO)6(SCH2CO2Et)2L2](L=CH3CN).在1中, Mo…Mo不存在金属键以及MoS2Mo核骨架完全不同于氧化的产物Mo(I)配合物. 这结果完全证实了双电子一步转移是由于双金属中心的金属-金属键的形成或断裂伴随桥联双金属中心结构的重排而产生的推断.     

配合物[1-(4′-bromo-2′-fluorobenzyl)pyridinium]2[Ni(mnt)2]和[1-(4′-bromo-2′-fluorobenzyl)pyrazinium]2[Ni(mnt)2](mnt2-=maleonitriledithiolate dianion)的合成及晶体结构

本文报道两个含双(马来二氰基二硫烯)镍(Ⅱ)配合物阴离子的离子对化合物。对阳离子为1-(4′-溴-2′-氟苄基)吡啶 盐时,生成配合物1。晶体数据:三斜晶系,空间P1群,a=0.7086(2)nm,b=1.0968(3)nm,c=1.1775(3)nm,α=69.914(5)°,β=89.495(5)°,γ=74.765(5)°,V=0.8259(4)nm³,Z=1。对阳离子为1-(4′-溴-2′-氟苄基)吡嗪鎓盐时,生成配合物2。晶体数据:单斜晶系,空间群P2₁/n,a=0.71554(17)nm,b=1.4262(3)nm,c=1.6725(4)nm,β=100.396(4)°,V=1.6788(7)nm³,Z=4。两个配合物中,阴离子为拟平面结构,镍原子均位于对称中心。变换对阳离子上的芳环种类对晶体的堆积结构产生影响。     

Towards Single-component Molecular Conductor [Ni（dmit）2 ] by Charge Disproportionation： 2[Ni（dmit）2]^0.5→[Ni（dmit）2 ]＋ [Ni（dmit）2]^-

A new method of synthesizing single-component molecular conductor [Ni(dmit)2] bythe reaction 2(Me4N)[Ni(dmit)2]2→ [Ni(dmit)2] (Me4N)[Ni(dmit)2] is reported. [Ni(dmit)2]exhibits a semiconductive behavior above 167 K, while from 167 K down to the measuring limit of 60 K, it exhibits metallic conductivity.     

Peculiar magnetic behavior in ion-pair complex [1-(4'-fluorobenzyl)pyridinium][Ni(mnt)2] (mnt2- = maleonitriledithiolate)

An ion-pair complex [FBzPy][Ni(mnt)2], where [FBzPy]+ = 1-(4'-fluorobenzyl)pyridinium and mnt2- = maleonitriledithiolate, forms a discrete stacking column and shows a peculiar magnetic transition from paramagnetic to diamagnetic around 90 K.     

An improved method for the synthesis of [closo-B12(OH)12]-2

The dicesium salt of the icosahedral borane anion dodecahydroxy-closo-dodecaborate(2-), closo-Cs(2)B(12)(OH)(12), Cs(2)4, was prepared using an improved synthetic pathway. Heating cesium dodecahydro-closo-dodecaborate, closo-Cs(2)B(12)H(12), Cs(2)1, with 30% hydrogen peroxide added in successive increments at 105-110 degrees C provided Cs(2)4 in 95% yield. Reaction progress was monitored using (1)H-decoupled (11)B NMR while (17)O NMR provides the most reliable way to detect the presence of peroxides in the reaction solution. The reaction may be safely increased in scale to afford Cs(2)4 in multigram quantities.     

Studies,on the synthesis,structure, IR spectra and reactivity of a new dinuclear Mo(0) complex, [Et4N]2[Mo2(CO)8(SCH2CO2Et)2]

Reaction of Et₄NI, NaSCH₂CO₂Et and Mo(CO)₆ in CH₃CN affords a new dinuclear molybdenum (0) complex, [Et₄N]₂[Mo₂(CO)₈(SCH₂CO₂Et)₂] (1). Electrochemistry and reactivity investigation indicate that 1 undergoes an interesting two-electron oxidation in a single step (-0.43 V) and a substitution of its carbonyls by coordinating solvents resulting in two kinds of Mo(I)-complexes, Mo₂(CO)₈(SCH₂CO₂Et)₂ and (Mo₂(CO)₆SCH₂CO₂Et)₂(CH₃CN)₂. vC=O and vMo-CO have been assigned. The crystal and molecular structure has been determined from three-dimensional X-ray data. 1 crystallized in the triclinic, space group with a=10.362(1), b=10.391(1), c= 10.815(2)Å; α=91.64(2)°, β=100.07(2)°, γ=114.46(1)°; Z=1; R=4.8% for 2975 reflections with I>3σ(I). Nonbonding of Mo … Mo [3.939(1)Å] and the configuration of MoS₂Mo unit in 1 are very different from those in related Mo(I)-product. These results confirm our previous speculation that the two-electron character derives from creation or cleavage of a metal-metal single bond coupled with structural rearrangement in a bridged bimetallic center.     

Synthesis, crystal structure and properties of the semiconducting salts (TTF)2[Ni(dtcr)2] and (ET)2[Ni(dtcr)2] based on [Ni(dtcr)2] dianions (dtcr = dithiocroconate)

The first examples of CT salts based on [Ni(dtcr)2] dianions (1) (dtcr = dithiocroconate = 4,5-disulfanylcyclopent-4-ene-1,2,3-trionate), (TTF)2[Ni(dtcr)2] (TTF = tetrathiafulvalene) (2) and (ET)2[Ni(dtcr)2] [ET = bis(ethylenedithio)tetrathiafulvalene] (3) are reported. The redox-active dianion 1, containing oxo-groups in the periphery of the molecule, has been selected to investigate the role of the oxo-groups in promoting intermolecular interactions and hopefully their conducting properties. The salts 2 and 3 have been prepared by electrocrystallisation methods and 3 shows a semi-metallic behaviour: sigma = 1 x 10(-3) omega(-1) cm(-1) at room temperature, with a low activation energy 60 meV, while crystals of 2 were unsuitable for conductivity measurements. The X-ray structural characterisation shows an alternate dianion-(cation)2 stacking and the capability of the oxo-groups to promote interstack contacts. In 2, the TTF donors are present as face-to-face dimers of monocations (D2)2+. The stacking arrangement is different in 3, where ET monocations stack along two directions ([110] and [110]) in the same manner, with the repeating sequence (ET)-(ET)-[Ni(dtcr)2]-(ET)-(ET) and are almost parallel to each other, with interplanar distances of 3.575 angstroms. Both structures are built on a dianion and two donor molecules, each one with a charge of +1. Diffuse reflectance combined with vibrational spectra complement structural results well. Crystal data: both 2 and 3 crystallise in the monoclinic space group P2(1)/c with a = 8.6340(8) angstroms, b = 21.586(2) angstroms, c = 7.5960(8) angstroms, beta = 95.625(11) degrees and V = 1408.9(2) angstroms3 for 2 and with a = 9.3700(7), b = 7.4410(6), c = 28.278(2) angstroms, beta = 99.039(6) degrees, V = 1947.1(3) angstroms3 for 3.     

Missing link in the ligand-field photolysis of [Mo(CN)8]4-: synthesis, X-ray crystal structure, and physicochemical properties of [Mo(CN)6]2-

Photoinduced dissociation of two Mo-CN bonds in [Mo(CN)8]4- affords the octahedral complex anion [Mo(CN)6]2-. This hexacyanomolybdate(IV) ion is also obtainable from tetracyanooxomolybdate via a thermal substitutional synthetic route. The anion represents the missing link in the ligand-field photolysis of octacyanomolybdate(IV); it is characterized by means of single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic susceptibility measurements as well as IR, Raman, 1H and 13C NMR, and electronic spectroscopy.     

[Mo12S12O12(OH)12(H2O)6]: A Cyclic Molecular Cluster Based on the [Mo2S2O2]2+ Building Block

The pH-dependent self-condensation of the [Mo ₂ S ₂ O ₂ ] ²⁺ complex fragment gives the wheellike Mo₁₂ cluster depicted on the right (ball-and-stick model; large balls: S, medium balls: O, small balls: Mo). Applying this synthetic strategy to other starting materials could provide access to other polyoxothiometalates with well-defined cavities.     

Reactivity of [Mo(NHNRPh)(NNRPh)(acac)X2] (R=Ph,Me; X=Br,I) toward tertiary phosphines

The reactivity of mixed [organohydrazido(1-)][organohydrazido(2-)]molybdenum(VI) complexes [Mo(NHNRPh)(NNRPh)(acac)X₂] {R?=?Ph, X?=?Br (1); R?=?Ph, X?=?I (2) and R?=?Me; X?=?I (3)} with tertiary phosphines as PPh₃, PMePh₂ and PMe₂Ph are examined. The syntheses of [Mo(NNPh₂)₂Br₂(PPh₃)] (4), [Mo(NNPh₂)₂Br₂(PMePh₂)₂] (5), [Mo(NNPh₂)₂Br₂(PMe₂Ph)₂] (6), [Mo(NNPh₂)₂(acac)I(PPh₃)] (7), [Mo(NNPh₂)₂(acac)(PMePh₂)₂]⁺I^? (8) and [Mo(NNMePh)₂(acac)(PMePh₂)₂]⁺I^? (9) are reported. All complexes were characterized by elemental analysis, UV-visible, IR, ¹H and ³¹P{H} NMR spectroscopy.     

Synthesis,crystal structure,and magnetism of the binuclear radical complex [N-hydrogenpyridinium]2[Ni(tdas)2]2

The binuclear radical complex [N-hydrogenpyridinium]₂[Ni(tdas)₂]₂ (tdas = 1,2,5-thiazole-3,4-dithiolate) has been prepared and its crystal structure determined by X-ray crystallography. In the binuclear radical complex, the two nickel ions assume a distorted pyramidal geometry and are bridged by two sulfurs of different tdas anionic ligands. ESR spectra and the theoretical calculations reveal a very strong antiferromagnetic interaction in the binuclear radical complex, leading to diamagnetic crystals. The theoretical calculations also reveal a very weak antiferromagnetic interaction between adjacent radical complexes. This study is the first to report the magnetism of a binuclear radical nickel complex with tdas as ligand.     

新树型配体 TBOAA 与钴配合物的研究

研究了新配体N，N’，N”－（三苯甲酰）－三乙氨基胺（TOBAA）与二价钴离子生成配合物的光度特征和电化学特征。在较宽的pH范围内，新试剂和钴离子形成2：1的配合物，并且在一定范围内其吸光度与浓度具有良好的线性关系。     

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.     

Heterometallic cluster [CpMn(CO)2]2S2Ni(Dppe) containing the binuclear manganese disulfide complex as a ligand

A reaction of the disulfide complex [CpMn(CO)₂]₂S₂ with the Ni(0) diphosphine acetylene complex, (Dppe)Ni(C₂Ph₂) (I), yielded the heterometallic complex [CpMn(CO)₂]₂S₂Ni(Dppe) (II). An X-ray diffraction study revealed lateral coordination of the disulfide group to the Ni atom in complex II, which results in lengthening of both the S-S and Mn-S bonds against those in the starting complex. However, the Mn-S and Ni-S bonds are still much shorter than the sums of the covalent radii of the corresponding atoms.     

Syntheses and characterization of the metal maleonitrilediselenolates [K([2.2.2]-cryptand)]2[M(Se2C2(CN)2)2] (M = Ni, Pd, Pt) and [Ni(dmf)(5)Cl]2[Ni(Se2C2(CN)2)2

Reaction of KNH(2), K(2)Se, Se, [2.2.2]-cryptand, and a metal source yields the metal bis(maleonitrilediselenolates) [K([2.2.2]-cryptand)](2)[M(Se(2)C(2)(CN)(2))(2)] (M = Ni, 1; Pd, 2, Pt, 3). These compounds are isostructural and crystallize with four formula units in the monoclinic space group P2(1)/c in cells at T = 153 K with parameters (a (A), b (A), c (A), beta (deg), V (A(3))) of 12.220(1), 15.860(2), 15.306(1), 107.64(2), 2827(1) for 1; 12.291(1), 15.669(1), 15.548(1), 108.55(1), 2839(1) for 2; and 12.292(3), 15.671(3), 15.569(3), 108.59(3), 2842(1) for 3. The cation of 1 has been substituted to yield [Ni(dmf)(5)Cl](2)[Ni(Se(2)C(2)(CN)(2))(2)] (4). [Ni(dmf)(5)Cl](2)[Ni(Se(2)C(2)(CN)(2))(2)] (4) crystallizes with one molecule in the triclinic space group P1 in a cell with parameters (T = 153 K) of a = 8.842(2) A, b =13.161(3) A, c = 13.831(3) A, alpha = 110.08(3) degrees, beta = 95.23(3) degrees, gamma = 93.72(3) degrees, V = 1484(1) A(3). The electronic absorption and infrared spectra are characteristic of metal maleonitrilediselenolates. Cyclic voltammetry shows that the maleonitrilediselenolate (mns) complexes are more easily oxidized than their maleonitriledithiolate (mnt) analogues.     

Triple ring contraction of a [2+2] macrocyclic ligand

Schiff base condensation of 2,6‐diformylpyridine and 1,3‐diaminopropan‐2‐ol in the presence of a Ba^II template ion yields a complex containing a [2+2] macrocycle, [Ba₂(μ_1,2‐ClO₄)₂(H₂L1)₂], where H₂L1 is 3,7,15,19,25,26‐hexaazatricyclo[19.3.1.1^9,13]hexacosa‐1(25),2,7,9(26),10,12,14,19,21,23‐decaene‐5,17‐diol. On transmetallation with Cu^II cations, the macrocycle undergoes three successive ring contractions, yielding crystals of (acetato‐κO)[26,28‐dioxa‐3,7,15,19,25,27‐hexaazahexacyclo[19.3.1.1^2,5.1^9,13.1^17,10.0^3,8]octacosa‐1(25),9(27),10,12,14,21,23‐heptaene‐κ⁵N]copper(II) perchlorate, [Cu(CH₃COO)(C₂₀H₂₂N₆O₂)]ClO₄ or [Cu(CH₃COO)(L2)]ClO₄, in which the macrocycle ring size has been reduced from 20 members in H₂L1 to 16 in L2.