钌(Ⅱ)联吡啶配合物cis-[Ru~Ⅱ(bpy)_2(L)_2]的配体取代效应(CNDO/2)

用ＣＮＤＯ／２方法经ＳＣＦ计算获得了钌（Ⅱ）联吡啶配合物ｃｉｓ－［ＲｕⅡ（ｂｐｙ）２（Ｌ）２］的电子结构（其中ｂｐｙ＝２，２′－二联吡啶；Ｌ＝Ｃｌ－，ＮＣＳ－，ＣＮ－，ＮＨ３，ＮＣＣＨ３）．计算结果表明，这些钌（Ⅱ）联吡啶配合物的ＬＵＭＯ均定域于配体ｂｐｙ的最低能π轨道，而其ＨＯＭＯ均定域于中心钌（Ⅱ）原子的ｄπ轨道．随着配体Ｌ的σ电子给予能力的增强，对应配合物的ＨＯＭＯ能级相应增大，ＬＵＭＯ能级亦有所增大，两者之差值则降低．这些钌（Ⅱ）联吡啶配合物的ＨＯＭＯ和ＬＵＭＯ能级变化趋势分别与相应的第一氧化和第一还原电势变化趋势相同，并且ＨＯＭＯ和ＬＵＭＯ能级与其光谱最低吸收能和第一氧化还原电势呈现出很好的线性相关性．计算结果与实验数据相吻合．     

Pd_2X_2（dpm）_2（X＝NCO~－，CH_3CO_2~－，SCN~－，

采用ＮＭＲ方法考察了室温和低温（－７８～－６０℃）下Ｐｄ２Ｘ２（ｄｐｍ）２（Ｘ＝ＮＣＯ－，ＣＨ３ＣＯ，ＳＣＮ－和ＮＯ，ｄｐｍ＝Ｐｈ２ＰＣＨ２ＰＰｈ２）与Ｈ２Ｓ在ＣＤ２Ｃｌ２或ＣＤＣｌ３中的反应。结果表明，在Ｘ＝ＮＣＯ－和ＣＨ３ＣＯ的情况下，Ｈ２Ｓ优先与这些Ｐｄ配合物的阴离子作用生成相应的共轭酸ＨＸ和Ｐｄ２（ＳＨ）２（ｄｐｍ）２，后者在Ｈ２Ｓ存在下又进一步转化为Ｐｄ２（ＳＨ）２（ｄｐｍ）２（μ－Ｓ）；当Ｘ＝ＳＣＮ－和ＮＯ时，反应则生成结构可能为［Ｐｄ２（Ｈ）（ＳＨ）（μ－ＳＨ）（ｄｐｍ）２］＋的双核Ｐｄ配合物。     

Pd2X2（dpm）2（X=NCO^—,CH3CO2^—,SCN^—,NO^—3;dpm=Ph2PCH2PPh2）配合…

采用ＮＭＲ方法考察了室温和低温（－７８～－６０℃）下Ｐｄ２Ｘ２（ｄｐｍ）２（Ｘ＝ＮＣＯ＾－，ＣＨ３ＣＯ＾－２，ＳＣＮ＾－和ＮＯ＾－３，ｄｐｍ＝Ｐｈ２ＰＣＨ２ＰＰｈ２）与Ｈ２Ｓ在ＣＤ２Ｃｌ２或ＣＤＣｌ３中的反应。结果表明，在Ｘ＝ＮＣＯ＾－和ＣＨ３ＣＯ＾－２的情况下，Ｈ２Ｓ优先与这些Ｐｄ配合物的阴离子作用生成相应的共轭酸ＨＸ和Ｐｄ２（ＳＨ）２（ｄｐｍ）２，后者在Ｈ２Ｓ存在下又进一步转化为Ｐｄ２（ＳＨ）     

杂多阴离子的有机金属化学(Ⅲ)──缺位Keggin阴离子PW_9O_(34)~(9-)的酯基锡杂多配合物的合成及性质

利用酯基锡与缺位Ｋｅｇｇｉｎ结构杂多阴离子ＰＷ９Ｏ９－３４反应，合成了６种新的杂多阴离子有机金属配合物Ｍ９［（Ｒ′ＯＯＣＣＨＲ″ＣＨ２ＳｎＯＨ２）３（ＰＷ９Ｏ３４）２］·ｘＨ２Ｏ（Ｍ＝（ＣＨ３）４Ｎ＋，Ｋ＋；Ｒ′＝ＣＨ３＿，ＣＨ３ＣＨ２＿；Ｒ″＝Ｈ，ＣＨ３＿），通过元素分析、ＩＲ光谱、紫外电子光谱、１ＨＮＭＲ、３１ＰＮＭＰ、１８３ＷＮＭＲ和ＴＧＡ－ＤＳＣ热分析等测试手段对标题配合物进行了表征和性质研究，确定该系列配合物为Ａ－β－ＰＷ９型夹心配合物结构．     

2,2′-(1,2-亚乙基双氮次甲基)二喹啉及其Cu2+、Zn2+、Ni2+、Mn2+配合物的合成与表征

本文报道２,２′－（１,２－亚乙基双氮次甲基）二喹啉及其与Ｃｕ２＋、Ｚｎ２＋、Ｎｉ２＋、Ｍｎ２＋配合物的合成,并通过元素分析、红外光谱、紫外光谱、Ｘ－射线粉末衍射、热分析及核磁共振等手段对配体和配合物进行了表征。配合物的化学组成为Ｍ．Ｌ．（ＣｌＯ４）２·Ｈ２Ｏ（Ｍ＝Ｃｕ２＋、Ｚｎ２＋、Ｎｉ２＋、Ｍｎ２＋离子;Ｌ＝Ｃ２２Ｈ１８Ｎ４）。     

三羰基环戊二烯基钼负离子与1,3—二卤丙烷的反应

三羰基环戊二烯基钼负离子与１，３－二卤丙烷在一缩二乙二醇二甲醚介质中反应，生成环卡宾配合物ＣｐＭｏＸ（ＣＯ２）ＣＯ（ＣＨ２）２ＣＨ２（Ｘ＝Ｂｒ．Ｉ）硅桥连双环戊二烯基三羰基钼负离子与１，３－二卤丙烷顺利地进行类似反应，生成相应的硅桥连双（环卡宾钼配合物）－Ｅ（Ｃ５Ｈ１ＭｏＸ（ＣＯ）２ＣＯ（ＣＨ２）２ＣＨ２）２（Ｅ＝Ｍｅ２Ｓｉ，Ｍｅ２ＳｉＳｉＭｅ２，Ｍｅ２ＳｉＯＳｉＭｅ２），化合物硅氧硅桥联二茂二钼     

[Cu2（Gly—GlyO）2（4,4‘—bpy）（OH）2].9H2O配合物的合成,晶…

将Ｇｌｙ－ＧｌｙＯ，４，４＇－联吡啶与Ｃｕ（ＮＯ３）２．Ｈ２Ｏ在二次水溶液中反应，合成出以４，４＇－ｂｐｙ为中继基，Ｃｌｙ－ＧｌｙＯ为螯环的新型双核铜配合物，经Ｘ射线单晶结构分析确定该配合物晶体的化学结构式为［（Ｈ２ＮＣＨ２ＣＯＮＨＣＨ２ＣＯＯ）Ｃｕ（ＯＨ）（Ｃ１０Ｈ８Ｎ２）Ｃｕ（ＯＨ）（Ｈ２ＮＣＨ２ＣＯＮＨＣＨ２ＣＯＯ）］．９Ｈ２Ｏ。晶体属Ｐ１空间群，晶胞参数α＝１．１４１２ｎｍ，ｂ＝１．２２９     

水溶性铑膦配合物HRh(CO)(TPPTS)_3及其相关体系的~1H-NMR研究

在液体高分辨ＮＭＲ谱仪上, 测定并比较了具有高效烯烃氢甲酰化活性的水溶性铑膦配合物ＨＲｈ（ＣＯ）（ＴＰＰＴＳ）３ 及与此有关的配体ＴＰＰＴＳ和ＯＴＰＰＴＳ分别在Ｄ２Ｏ、混合溶剂Ｄ２Ｏ－ＴＨＦ（ｄ８）－ＣＤ３ＯＤ中的１Ｈ－ＮＭＲ谱图, 并借助１Ｈ－１Ｈ ＣＯＳＹ谱对上述３ 种化合物的１Ｈ－ＮＭＲ谱峰进行了指认; 讨论了影响化学位移和偶合常数的因素, 为水溶性铑膦配合物催化剂的结构与催化性能的关联及新催化剂设计研究提供了基础数据．     

[Cu2（Gly—GlyO）2（4,4‘—bpy）（OH）2].10H2O配合物的合成,晶 …

合成了以４，４－ｂｐｙ为中继基，Ｇｌｙ，ＧｌｙＯ为螯环的新型双核铜配合物。经Ｘ射线单昌结构分析确定该配合化合物的化学式为「（Ｈ２ＣＣＨ２ＣＯＮＨＣＨ２ＣＯＯ）Ｃｕ（ＯＨ）Ｃｕ（ＯＨ）（Ｃ１０Ｈ８Ｎ２０Ｃｕ（ＯＨ）－（Ｈ２ＮＣＨ２ＣＯＮＨＨＣＨ２ＯＯ）．」１０Ｈ２Ｏ。     

UNUSUAL FORMATION OF ORGANO－NEODYMIUM AND －SAMARIUM CATIOHS AND X－RAY STRUCTURE OF［（MeOCH_2CH_2C_5H_4）_2Sm（thf）］［Co（CO）_4］

ＵＮＵＳＵＡＬ　ＦＯＲＭＡＴＩＯＮ　ＯＦ　ＯＲＧＡＮＯ－ＮＥＯＤＹＭＩＵＭ　ＡＮＤ　－ＳＡＭＡＲＩＵＭ　ＣＡＴＩＯＨＳ　ＡＮＤ　Ｘ－ＲＡＹ　ＳＴＲＵＣＴＵＲＥ　ＯＦ［（ＭｅＯＣＨ_２ＣＨ_２Ｃ_５Ｈ_４）_２Ｓｍ（ｔｈｆ）］［Ｃｏ（ＣＯ）_４］ＵＮＵＳＵＡ...     

Hückel and Möbius Aromaticity in Charged Sigma Complexes

In sigma complexes, intermediates in nucleophilic and electrophilic aromatic substitution and other reactions, delocalization in the aromatic ring is formally disrupted. Unexpectedly, computational evidence is presented that favorable processes contain aromatic sigma complexes. Tetracoordinated carbon therein surprisingly employs orbitals that are more similar to sp² than to sp³ hybrids in sigma bonds with adjacent ring atoms. Both leaving groups and nucleo- or electrophiles may donate electrons to the π-system depending on the availability of p-type orbitals to fulfill Hückel (4N+ 2) or Möbius (4N) rules of aromaticity in analogy to conjugated transition-metal metallacycles.     

The Relationship Between Relative Hydration Free Energies of 99mTcON2S2 Complexes and Their Brain Uptakes

A thermodynamic integration dual-transform method was firstly applied to calculating the relative hydration free energies of ^99mTcON2S2 complexes. The relationship between the brain uptakes(B, U. ) of ^99mTcON2S2 complexes with different substituted functional groups and their relative hydration free energies was investigated. The simulation results show that the experiment brain uptake(B. U. ) data are strongly influenced by the relative hydration free energies of ^99mTcON2S2 complexes, thus the simulations can provide the useful information for the medicine design of ^99mTc brain imaging agents.     

An overlap expansion method for improving ab initio model potentials: anisotropic intermolecular potentials of N2, CO, and C2H2 with He*(2(3)S)

An overlap expansion method is proposed for improving ab initio model potentials. Correction terms are expanded in terms of overlap integrals between orbitals of the interacting system. The method is used to improve ab initio model potentials for N2+He*(2(3)S), CO+He*(2(3)S), and C2H2+He*(2(3)S). Physical meanings of the optimization are elucidated in terms of target orbitals. Correction terms are found to be dominated by the components of HOMO, LUMO, next-HOMO, and next-LUMO on the target molecule. The present overlap expansion method using a limited number of correction terms related to frontier orbitals provides an efficient and intuitive approach for construction of highly anisotropic intermolecular interaction potentials.     

金属串配合物[Ni3(L)4(NCS)2](L = dpa-, mpta-, mdpa-, mppa-)结构和磁性的理论研究

应用密度泛函理论BP86方法结合自然键轨道分析方法对具有分子导线潜在应用前景的金属串配合物[Ni₃(L)₄(NCS)₂](L = dpa^- (1), mpta^- (2), mdpa^- (3), mppa^- (4))进行研究,分析了桥联配体L对Ni―Ni相互作用和磁耦合性质的影响.结果得到: (1)配合物的基态均是对应于五重态(HS)的反铁磁(AF)单重态, HS的能量和结构与AF态相近, Ni₃⁶⁺链形成了三中心四电子σ键(σ₂σ_nb¹σ^*1). (2) dpa^-引入甲基成为mdpa^-,对Ni―Ni、Ni―N距离影响不大; 3H-吡咯环和噻唑环取代吡啶环后, N1―N2、Ni―Ni距离增大, Ni2―N2键长缩短,但噻唑环的影响较小;故Ni―Ni相互作用强度为1 ≈ 3 > 2 > 4. (3)预测了3和4的J_ab值为-103和-88 cm^-1,随Ni―Ni相互作用增强磁耦合效应增大. Ni―Ni相互作用越大,通过Ni₃⁶⁺链σ型轨道的直接磁耦合越强; Ni2―N2键越强,通过涉及桥联配体的间接磁耦合越强,直接磁耦合比间接磁耦合更强.     

Hinge Distortion in Platinum(II) Dimers with a Pt(2)S(2) Ring. An ab Initio Molecular Orbital Study

Ab initio calculations have been carried out for Pt(II) dimers with S(2)(-) and/or RS(-) bridging ligands in order to elucidate the factors governing the structural preference, planar or hinged, of these complexes. Calculations have been performed for systems which model all structurally characterized Pt(II) binuclear complexes. All possible determinants of the hinge angle have been taken into account in the ab initio calculations. These show that electronic rather than steric effects govern the geometry of the central Pt(2)S(2) ring. Only one minimum of energy has been found for each complex, but the energetic cost of the hinge motion is low. Complexes with two S(2)(-), or with one S(2)(-) and one RS(-), bridging ligands are hinged; the decrease of the through-ring antibonding interaction between the in-plane sulfur p orbitals with folding appears to be the determinant for hinging. Complexes with two RS(-) bridging ligands can be planar or hinged depending on the relative orientation, syn or anti, of the R groups, on the nature, L(4) or L(2)L(2)', of the terminal ligands, and in the latter case on their disposition, cis or trans. However, the aromatic or aliphatic nature of bridging thiolates does not influence the geometry of the Pt(2)S(2) ring significantly. Conclusions drawn from platinum dimers can be extended to the palladium analogs.     

几种过渡金属混配配合物的构型和量子化学研究

对几种五配位的过渡金属配合物晶体结构构型进行了详细讨论,通过扭曲角的计算证明它们均为正三角双锥(TBP)和正向四方锥(TP)的过渡构型。运用AM1量子化学计算方法,对混配体的一些物理化学参数,特别是配位N原子轨道对前线轨道的贡献进行了研究。结果表明,配位N原子轨道对前线轨道的贡献不大,而且也不影响配位构型的变化。计算还表明大多数以三(2-苯并咪唑亚甲基)胺为配体的过渡金属配合物均具有扭曲的三角双锥构型,而铜配合物的构型随协同配体的不同,在正三角双锥和正向四方锥之间的变化范围很大,这是由于铜离子较强的John-Teller效应造成的。     

Fe2S2(SH)4[2-,3-]的从头计算

正确的能级次序应与分子的活性位置一致.实验证实,铁硫蛋白或模型化合物Fe_2S_2(SR)~(2-)及Fe_4S_4(SR)_4~(2-)的活性位置在端基,易于发生多种取代反应,而Fe_2S_2和Fe_4S_4实一般是稳定的.但是,经过电化学还原生成的Fe_2S_2(SR)_4~(3-),却不可逆地二聚化,生成Fe_4S_4(SR)_4~(2-)     

Sulfur bridging interactions of cis-planar NiII-S2N2 coordination units with nickel(II), copper(I,II), zinc(II), and mercury(II): a library of bridging modes, including NiII(micro2-SR)2MI,II rhombs

Sulfur bridging interactions between three cis-planar NiII-S2N2 complexes and NiII, CuI,II, ZnII, and HgII reactants were investigated by synthesis and X-ray crystal structures of some 24 complexes. This work was stimulated by recent crystallographic structures of the A-cluster of carbon monoxide dehydrogenase/acetylcoenzyme A synthase. This bridged biological assembly has the minimal formulation [Fe4S4]-(micro2-SCys)-[M((micro2-SCys)2Gly)Ni] with M = NiII, CuI, and ZnII at sites distal and proximal, respectively, to the iron-sulfur cluster. Bridges supported by representations of the distal nickel site were sought by reactions of the complexes [NiII(LH-S2N2)]2- and [NiII(LR-S2N2)], with 5-5-5 chelate ring patterns. Reaction products implicate the bridges Ni-(micro2-S)1,2-M in a variety of molecular structures, some with previously unknown connectivities of bridge atoms. The most frequently encountered bridge units are the nonplanar rhombs Ni(2-S)2M involving both sulfur atoms of a given complex. Those with M = NiII are biologically relevant inasmuch as the catalytic metal at the proximal site is nickel. The complex [Ni(L-655)]2-, containing the 6-5-5 ring pattern and coordination sphere of the distal nickel site, was prepared and structurally characterized. It was shown to sustain Ni2(micro2-S)2 rhombic interactions in the form of trinuclear [[Ni(L-655)]2Ni]2- and [[Ni(L-655)]Ni(R2PCH2CH2PR2)] (R = Et, Ph) in which the second NiII simulates the proximal site. Bridging interactions of NiII-S2N2 complexes are summarized, and geometrical features of Ni2(2-S)2 rhombs in these complexes, as dependent on ring patterns, are considered (LH-S2N2 = N,N'-ethylenebis(2-mercaptoisobutyramide)(4-); LR-S2N2 = trans-rac-N,N'-bis(2-mercapto-2-methylprop-1-yl)-1,2-cyclohexanediamine(2-); L-655 = N-(2-mercaptopropyl)-N'-(2'-mercaptoethyl)glycinamide(4-)).     

Electronic structure,chemical bonding,and oxidation numbers of first‐row transition metals in [MePIm2] complexes and their cations

The qualitative structures of the upper one‐electron energy levels of imidazole‐coordinated first‐row transition metal porphyrin [MePIm₂] complexes established in the present study have shown that the second oxidation number of the first‐row transition metals in the neutral complexes do not change in their cations and double cations. It was found that occupied orbitals of the density functional theory method obtained with B3LYP functional are not correctly ordered. Therefore, they cannot be used in investigations of the orbital structure of the upper molecular orbitals. A qualitative analysis of density functional theory method wave functions in terms of Mulliken and natural charges of atoms, together with an analysis of electrostatic potentials of the neutral [MePIm₂] complex, its single and double cations, demonstrates that the highest occupied orbitals of these complexes are mainly formed by atomic orbitals of the porphyrin ring atoms. Therefore, transition metal atoms are not active in chemical reactions with these complexes unless the 3d electrons of transition metal atoms are excited, for example by light. A mechanism of an electron transfer reaction that occurs between a heme cytochrome and Fe‐oxide mineral surface is discussed in the light of the obtained results. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Low-temperature complexes of europium atoms and dimers with cyanophenylpyridines and alkylcyanophenylpyridines

It is shown by IR-Fourier and UV-visible spectroscopy that two biligand complexes of different stoichiometric composition Ln·2L and 2Ln·2L (Ln = Eu; L = 4-pentyl-4′-cyanophenylpyridine) are formed in the course of low-temperature co-condensation of metal and ligand vapors on the surfaces cooled with liquid nitrogen. Quantum-chemical modeling of the equilibrium structures of the mono-and binuclear complexes of europium with unsubstituted cyanophenylpyridyl and para-ethylcyanophenylpyridyl ligands was carried out. The main geometrical parameters of these compounds were determined. For mononuclear complexes, there is a competition between two mechanisms of coordination of the metal atom: formation of sandwich π complexes by interactions with the π orbitals of the aromatic ligand system and σ coordination at the nitrogen atoms of the pyridine ring. The sandwich structures of the binuclear complexes with 4-ethylcyanophenylpyridine are stabilized by N…H intermolecular contacts between the N atom of the cyano group and the terminal H atom of the ethyl group. The spectral shifts and the relative thermal stability of complexes with varying nuclearity are discussed.