六聚同多酸阴离子M6On-19(M=Mo,W,n=2;M=Nb,Ta,n=8)电子结构和化学性质的密度泛函理论研究

采用B3LYP方法在Lanl2DZ水平上计算了六聚同多阴离子(M6On19^-(M=Mo和W,n=2;M=Nb和Ta,n=8)的电子结构,分析了它们的前线轨道、分子静电势(MEP)．计算结果表明,Nb6O19^8-和Ta6O19^8-是电子给体,而Nb6O19^2-和Ta6O19^2-则是电子受体,这与它们在溶液中具有不同的化学性质是一致的．     

M2TNR(M=AG, CHZ)的制备和晶体结构

通过三硝基间苯二酚(TNR,斯蒂酚酸)和氨基胍(AG)重碳酸盐、碳酰肼(CHZ)反应,制备斯蒂酚酸氨基胍和斯蒂酚酸碳酰肼。并用X-射线衍射分析、元素分析、差示扫描量热法和红外光谱对其进行了结构表征。它们的分子式分别为(NH2NHCNHNHNH2)2^+[C6H(NO3)3O2]^2.0.5H2O,(NH2NHCONHNH3)2^+[C6H(NO3)3O2]^2^-,二者都属于单斜晶系,C2/c空间群。     

线型异核三金属M—E—M（M=Mo,W;E=Hg,Zn）化合物的研究…

研究了含汞三金属化合物「η－ＲＣ５Ｈ４（ＣＯ）３Ｍ２「Ｈｇ（Ｍ＝Ｍｏ，Ｗ；Ｒ＝Ｍｅ，Ｅｔ，ＣＯ２Ｍｅ，ＣＯ２Ｅｔ）与锌粉的置换反应，发现当取代基Ｒ为给电子的Ｍｅ和Ｅｔ时底物不发生反应，而取代基Ｒ为拉电子的ＣＯ２Ｍｅ和ＣＯ２Ｅｔ时，则底物中的汞可被锌置我。     

[M(dap)3]2(Sb2Se5)·xH2O(M=Ni,x=2;M=Zn,x=0)的溶剂热合成及晶体结构

利用溶剂热法合成了2种新的有机杂化锑硒化合物[Ni(dap)3]2(Sb2Se5)].2H2O(1)和[Zn(dap)3]2(Sb2Se5)](2)(dap=1,2-丙二胺),单晶X射线衍射分析结果表明,1属于三方晶系,P3121空间群,晶胞参数为a=10.7574(14),b=10.7574(14),c=31.672(4),γ=120.00°,z=4。2属于单斜晶系,P21空间群,晶胞参数为a=10.772(2),b=16.391(3),c=11.704(2),β=100.912(4)°,z=4。在2种化合物中,Ni2 与Zn2 离子分别与3个dap配体螯合形成畸变八面体几何构型,其中dap配体的N原子是无序的,而二聚[Sb2Se5]2-阴离子是由2个SbSe3三角锥共用1个Se原子连接而成。     

M3NS3, die ersten Nitridsulfide der Lanthanide (M = La?Nd,Sm)

M₃NS₃, the First Nitride Sulfides of the Lanthanides (M = La? Nd, Sm) . The oxidation of the “light” lanthanides (M = La? Nd, Sm) with equimolar amounts of sulfur in the presence of NaN₃ as nitrogen source results in the formation of the first lanthanide nitride sulfides: M₃NS₃ (evacuated silica vessels, some NaCl as flux, 850°C, 7 d). NaCl is afterwards removed from the not moisture sensitive crude product (faint- or orange-yellow to amber-co- loured transparent needles, oftenly intergrown to feltlike bunches) upon rinsing with water. The crystal structure was determined from X-ray single crystal data for the example of Sm₃NS₃ (orthorhombic, Pnma (no. 62), a = 1 201.18(7), b = 394.32(3), c = 1 285.27(6) pm, Z = 4, R = 0.027, R_w = 0.024), and M₃NS₃ (M = La? Nd) proved to be isostructural from Guinier powder data. There are three crystallographically different M³⁺ cations in six- (1 X) and sevenfold (2 X) coordination of the N^3? and S^2? anions. [(N^3?)(M³⁺)₄] tetrahedra connected via two corners forming linear chains [N(M1)_1/1(M2)_1/1(M3)_2/2] ⁶⁺ build up the main structural feature. Arranged in the manner of a closest packing of rods, they are held together by three crystallographically different S^2? which take care for charge neutrality and three-dimensional interconnection.     

Syntheses and X-ray Characterization of Novel [M4(H2O)2(XW9O34)2] n− (M=CuII, X=CuII; and M=FeIII, X=FeIII) Polyoxotungstates

Two novel examples of sandwich type heteropolyanions were synthesized and characterized by X-ray crystal structure and elemental analysis as well as infrared spectroscopy. Na₁₃[H₃Cu₄(H₂O)₂(CuW₉O₃₄)₂]39H₂O (1) and Na₉K[Fe₄(H₂O)₂(FeW₉O₃₄)₂]32H₂O (2) were prepared in aqueous solution by reaction of sodium tungstate with Fe^III and Cu^II cations, respectively. 1 crystallizes in the monoclinic space group P2₁/n (a=13.054(3) Å, b=17.729(4) Å, c=20.998(4) Å, =93.50(3)°), while 2 is triclinic, space group P¯1 (a=12.316(2) Å, b=13.716(3) Å, c=14.925(3) Å, =99.36(3)°, =104.21(3)°, =101.55(3)°). Each anion consists of two [XW₉O₃₄] ^n– moieties (X=Fe^III, n=11 (1) and Cu^II, n=12 (2)) which can be described as -B-isomers of the defect Keggin anion. These units are linked via a belt of four Fe^IIIO₆ or Cu^IIO₆ groups. Two transition metal atoms fill their octahedral coordination sphere with one additional water ligand.     

Nitridsulfidchloride der Lanthanide: I. Der Formeltyp M4NS3Cl3 (M = La?Nd)

Nitride Sulfide Chlorides of the Lanthanides. I. The Composition M₄NS₃Cl₃ (M = La Nd) The oxidation of the „light”︁ lanthanides (M = La Nd) with sulfur and NaN₃ the presence of the chlorides MCl₃ results in the formation of the first lanthanide nitride sulfide chlorides M₄NS₃Cl₃ when appropriate molar ratios of the reactants are used. The addition of some NaCl (or an excess of MCl₃) as a flux secures complete and fast reaction (7 d) at 850°C in evacuated silica vessels as well as single-crystalline products. Since these nitride sulfide chlorides (fine transparent needles) are not sensitive against hydrolysis, the surplus chloride can be removed easily with water. The crystal structure was determined from X-ray single crystal data for the example of La₄NS₃Cl₃ (hexagonal, P6₃mc (no. 186), Z = 2, a = 941.40(3), c = 700.36(3) pm, R = 0.026, R_w = 0.021) and the nitride sulfide chlorides M₄NS₃Cl₃ with M = Ce Nd proved to be isostructural from Guinier powder data. According to their Ba₃OCl₆-analogue structure, two crystallographically different M³⁺ cations are present (CN(M1) = 10, CN(M2) = 8). „Isolated”︁ tetrahedra [(N³⁻)(M³⁺)₄] build up the Mayn structural feature according to [NM₄]S₃Cl₃. They are hexagonally closest packed and interconnected via the crystallographically different but by X-ray diffraction indistinguishable anions S²⁻ and Cl⁻, which take care for charge neutrality.     

Formation of M(4)Se(4) cuboids (M = As, Sb, Bi) via secondary pnictogen-chalcogen interactions in the co-crystals MX(3)·Se[double bond, length as m-dash]P(p-FC(6)H(4))(3) (M = As, X = Br; M = Sb, X = Cl; M = Bi, X = Cl, Br)

The reactions of the group 15 trihalides, MX(3) (M = As, Sb, Bi; X = Cl, Br), with the phosphine selenide SeP(p-FC(6)H(4))(3) result in the formation of co-crystals of formula MX(3)·SeP(p-FC(6)H(4))(3). No reaction was observed with MI(3) (M = As, Sb, Bi). The structures of MX(3)·SeP(p-FC(6)H(4))(3) (M = As, X = Br 2; M = Sb, X = Cl 3; M = Bi, X = Cl 5; M = Bi, X = Br 6) have been established, and are isomorphous, crystallising in the cubic I23 space group. All the structures feature a primary MX(3) unit, which has three weak secondary MSe interactions to SeP(p-FC(6)H(4))(3) molecules. However, each of these SeP(p-FC(6)H(4))(3) molecules bridges three MX(3) molecules, resulting in the generation of an M(4)Se(4) (M = As, Sb, Bi) distorted cuboid linked by the pnictogen-chalcogen interactions. Four opposing corners of the cuboid are occupied by the M atom (M = As, Sb, Bi) of an MX(3) pyramid, and the other four by the selenium atom of the phosphine selenide.     

M≡E and M=E Complexes of Iron and Cobalt that Emphasize Three-fold Symmetry (E = O, N, NR)

Mid-to-late transition metal complexes that feature terminal, multiply bonded ligands such as oxos, imides, and nitrides have been invoked as intermediates in several catalytic transformations of synthetic and biological significance. Until about ten years ago, isolable examples of such species were virtually unknown. Over the past decade or so, numerous chemically well-defined examples of such species have been discovered. In this context, the presentreview summarizes the development of 4- and 5-coordinate Fe(E) and Co(E) species under local three-fold symmetry.     

氧心羧桥异三核过渡金属簇合物[Fe2MO(CH3COO)6Py3].Py(1,M=Mn;2,M=Co;3,M=Ni)和[Fe2MO(CCl3COO)6(THF)3](4,M=Mn;5,M=Co;6,M=Ni)电子光谱的研究

The UV/VIS spectra for pyridine solution of complexes [Fe_2MO(CH_3COO)_6Py_2]·Py and THF solution of complexes Fe_2MO(CCl_3COO)_6(THF)_3 were studied. The d-d transitions were assigned and the ligand field parameters(B,D_q,β) were calculated for the related metal ions according to ligand field theory (Tanabe-Sugano diagram) in terms of O_h symmetry and reasonably good fits were obtained for the calculated and observed frequencies. The calculated results show that (1) the larger the ionic potential for M~(2+) ion, the larger the values of B, D_q for Fe~(3+) ion (2) the ligand field parameters of metal ions vary in parallel with the electronagativity of R in RCOO~-.     

噻吩在M(111)(M=Pd,Pt, Au)表面的吸附

采用密度泛函理论(DFT), 选取DMol³程序模块, 对噻吩在M(111) (M=Pd, Pt, Au)表面上的吸附行为进行了探讨. 通过对噻吩在不同底物金属上的吸附能、吸附构型、Mulliken 电荷布居、差分电荷密度以及态密度的分析发现, 噻吩在Pd(111)面上的吸附能最大, Pt(111)面次之, Au(111)面最小. 吸附后, 噻吩在Au(111)面上的构型几乎保持不变, 最终通过S端倾斜吸附于top 位; 噻吩在Pd(111)及Pt(111)面上发生了折叠与变形, 环中氢原子向上翘起, 最终通过环平面平行吸附于hollow 位. 此外, 噻吩环吸附后芳香性遭到了破坏, 环中碳原子发生sp³杂化, 同时电子逐渐由噻吩向M(111)面发生转移, M(111)面上的部分电子也反馈给了噻吩环中的空轨道, 这种协同作用最终导致了噻吩分子稳定吸附于M(111)面.     

Pressure‐Induced Intersite Bi?M (M=Ru, Ir) Valence Transitions in Hexagonal Perovskites

Pressure‐induced charge transfer from Bi to Ir/Ru is observed in the hexagonal perovskites Ba_3+nBiM_2+nO_9+3n (n=0,1; M=Ir,Ru). These compounds show first‐order, circa 1 % volume contractions at room temperature above 5 GPa, which are due to the large reduction in the effective ionic radius of Bi when the 6s shell is emptied on oxidation, compared to the relatively negligible effect of reduction on the radii of Ir or Ru. They are the first such transitions involving 4d and 5d compounds, and they double the total number of cases known. Ab initio calculations suggest that magnetic interactions through very short (ca. 2.6 Å) M M bonds contribute to the finely balanced nature of their electronic states.     

氧心羧桥异三核过渡金属簇合物[Fe_2MO(CH_3COO)_6Py_3]·Py(1,M=Mn;2,M=Co;3,M=Ni)和[Fe_2MO(CCl_3COO)_6(THF)_3](4,M=Mn;5,M=Co;6,M=Ni)电子光谱的研究

氧心羧桥三核物通式为[M_3O(RCOO)_6L_3]~(n+)(n=1,0)虽然它在三十年代就已合成出来,但是引起人们广泛兴趣的还是近年来发现的它所具有的特殊稳定性和不寻常的物理化学性质。我们测定了不同M~(2+)离子,两种羧桥的铁系列异三核标题簇合物的晶体结构和有关物理性质。该类型化合物的结构可以看成由共享μ_3-O顶点的三个金属离子的配位八面体组     

All-Metallic Zn=Zn Double-π Bonded Octahedral Zn2M4 (M=Li,Na) Clusters with Negative Oxidation State of Zinc

Zn=Zn double bonded-especially double-π bonded-systems are scarce due to strong Coulomb repulsion caused by the Zn atom's internally crowded d electrons and very high energy of the virtual π orbitals in Zn₂ fragments. It is also rare for Zn atoms to exhibit negative oxidation states within reported Zn−Zn bonded complexes. Herein, we report Zn=Zn double-π bonded octahedral clusters Zn₂M₄ (M=Li, Na) bridged by four alkali metal ligands, in which the central Zn atom is in a negative oxidation state. Especially in D_4h−Zn₂Na₄, the natural population analysis shows that the charge of the Zn atom reaches up to −0.89 |e| (−1.11 |e| for AIM charge). Although this cooperation inevitably increases the repulsion between two Zn atoms, the introduction of the s¹-type ligands results in occupation of degenerated π orbitals and the electrons being delocalized over the whole octahedral framework as well, in turn stabilizing the octahedral molecular structure. This study demonstrates that maintaining the degeneracy of the π orbitals and introducing electrons from equatorial plane are effective means to construct double-π bonds between transitional metals.     

Interactions of M(z)-X complexes (M = Cu, Ag, and Au; X = He, Ne, and Ar; and z = ±1)

The coupled cluster singles and doubles method with perturbative treatment of triple excitations is applied to calculate the potentials of M(z)-X complexes (M = Cu, Ag, and Au; X = He, Ne, and Ar; and z = ±1). The bond functions and the basis set superposition errors are considered to obtain accurate interaction energies. The potential energy curves of all complexes are obtained. The vibrational energy levels and the spectroscopic parameters for these complexes are determined. The analytical potential energy functions are also fitted based on the potential energies.     

双帽Keggin型杂多阴离子[PM12O40(VO)2]n-(M=Mo,n=5; M=V,n=9)的离散变分方法研究

使用密度泛函理论的离散变分方法(DFT-DVM)研究了双帽Keggin型杂多阴离子[PM₁₂O₄₀(VO)₂]^n--(M=Mo,n=5; M=V,n=9),即[PMo₁₂O₄₀(VO)₂]^5- (a)和[PV₁₂O₄₀(VO)₂]^9- (b)的电子结构,讨论了双帽的形成对Keggin型杂多阴离子的电子结构和催化性质的影响,并与其Keggin型杂多阴离子(PM₁₂O₄₀)_n-(M=Mo,n=3; M=V,n=15)的计算结果进行了对比分析,计算结果表明,双帽的形成对Keggin型杂多阴离子的电子结构产生了很大的影响,因而它们在催化活性上可能会表现出较大的差异.