反常蓝移单电子锂键Y…Li-CH3[Y=CH3, CH2CH3, CH(CH3)2, C(CH3)3]体系的结构与性质

在密度泛函理论B3LYP/6-311++G(d,p)及MP2/6-311++G(d,p)水平上研究了单电子锂键复合物Y…Li—CH3[Y=CH3, CH2CH3, CH(CH3)2, C(CH3)3]的结构与性质. 结果表明, 三种单电子锂键复合物H3CH2C…Li—CH3(II), (H3C)2HC…Li—CH3(III)和(H3C)3C…Li—CH3(IV)单电子锂键强度依II(-26.7 kJ·mol-1)相似文献   

(CH2)2O, (CH2)2S与双卤分子间卤键的理论研究

运用量子化学密度泛函B3LYP方法, 采用6-311＋＋G(d,p)及aug-cc-pVDZ基组, 通过CP校正的几何梯度优化对(CH2)2O和(CH2)2S与双卤分子XY (XY＝Cl2, Br2, ClF, BrF, BrCl)形成的卤键复合物的几何构型、振动频率和相互作用能等进行了研究. 利用电子密度拓扑分析理论方法对卤键复合物的拓扑性质进行了分析研究, 探讨了该类分子间卤键的作用本质. 结果表明, (CH2)2O和(CH2)2S与双卤分子间的卤键介于共价键与离子键之间, 偏于静电作用成分为主. 形成卤键后, 双卤分子的键长增加, 振动频率减小, 原子积分性质发生改变. 卤键键长的变化、键能的强弱、键鞍点处的电子密度值与双卤分子的电负性有关.     

Synthesis,crystal structure,and luminescence of a new coordination polymer, {[Cd9(IDC)2(HIDC)6(Bipy)4] · 2N(CH3)(CH2CH3)2 · 2DMF} n

A new cadmium coordination polymer based on imidazole-4,5-dicarboxylic acid (H₃IDC) and 4,4′-bipyridine (Bipy), {[Cd₉(IDC)₂(HIDC)₆(Bipy)₄] · 2N(CH₃)(CH₂CH₃)₂ · 2DMF} _n , has been synthesized under solvothermal conditions and characterized by energy dispersive X-ray spectroscopy, elemental analysis, FT-IR spectroscopy, thermal analysis, and single crystal X-ray diffraction. It crystallizes in the orthorhombic system, space group Pnnm with a = 20.530(2) Å, b = 15.5957(14) Å, c = 16.3846(15) Å, α = β = γ = 90°, V = 5245.9(9) ų, and Z = 2. The complex exhibits a 3-D structure with channels along the c-axis, in which the free N,N-dimethylformamide and methyl-diethyl-amine molecules are located. The thermal behavior and luminescence of this complex have also been studied in the solid state.     

(CH2)2N和(CH3)2NH+的密度泛函理论计算

用密度泛函理论UB3LYP／6-31G（d,p）方法研究了二甲胺自由基（CH3）2N及其质子化离子（CH3）2NH 的构象和超精细结构．在由构象研究得到的两种自由基的最稳定结构上,用密度泛函的UB3LYP和UB3PW91方法及从头计算的UHF、UMP2（FULL）方法计算了α-质子、β-质子和N核上的超精细偶合常数A（Hα）、A（Hβ）和A（N）结果表明：两种自由基中甲基内旋转的位垒均很低,分别为0．46kJ·mol-1（（CH3）2NH ）和2．6kJ·mol-1（（CH3）2N）．UB3LYP／6-31G（d,p）和UB3PW91／6-31G（d,p）计算的A（Hα）、A（Hβ）和A（N）与ESR实验结果符合得很好,UMP2／6-31G（d,p）方法的计算值与实验值符合得也较好．     

The reaction of Sn[CH(SiMe3)2]2 with ethyne: formation of (HCC)Sn[CH(SiMe3)2]2(μ-trans-CHCH)Sn[CH-(SiMe3)2]2(CHCH2)

The reaction of Sn[CH(SiMe₃)₂]₂ and ethyne at ambient temperature affords a mixture of products, from which the title compound has been separated and identified by IR, ¹H, and ¹³C NMR spectroscopy.     

Synthesis,properties, and reactions of enantiomerically pure,chiral fluorous phosphines of the formula (menthyl)P(CH2CH2(CF2)n−1CF3)2 (n=6, 8)

Reactions of (menthyl)PH₂ and H₂CCHR_f6 (menthyl=1R,3R,4S; R_fn=(CF₂)_n−1CF₃) or H₂CCHR_f8 (AIBN, refluxing THF) give (menthyl)PH(CH₂CH₂R_fn) and then (menthyl)P(CH₂CH₂R_fn)₂ (n=6, 7; n=8, 8), but with purification or other difficulties at each stage. Reactions of (menthyl)PCl₂ with IMgCH₂CH₂R_fn give, under careful conditions, analytically pure 7 or 8 in 28–32% yields after distillation. Some R_fn(CH₂)₄R_fn also form. These represent the first chiral (and non-racemic) fluorous phosphines. Reactions of 7 or 8 with [Ir(COD)Cl]₂ and CO give trans-[(menthyl)P(CH₂CH₂R_fn)₂]₂Ir(Cl)(CO) (n=6, 71%; 8, 51%) as analytically pure yellow oils. Their IR ν_CO values show the donor/acceptor properties of 7 and 8 to be intermediate between those of P((CH₂)₃R_f8)₃ and P((CH₂)₄R_f8)₃. The CF₃C₆F₁₁:toluene partition coefficients of 7 and 8 (27°C, 78.4:21.6 and 93.7:6.3) are distinctly lower than those of P((CH₂)₂R_fn)₃ (n=6, 98.8:1.2; n=8, >99.7:<0.3), reflecting the replacement of a linear C₈–C₁₀ group that is ca. 75–80% fluorinated by a cyclic C₁₀ terpenyl group. Reactions of 7 or 8 with [Rh(COD)Cl]₂ give [(menthyl)P(CH₂CH₂R_fn)₂]Rh(Cl)(COD) (n=6, 69%; 8, 70%) as orange crystallizable oils.     

Synthesis,molecular structure and reactions of the novel organometallic phosphine ligand, [WI2(CO) (η2-triphos) (η2-MeC2Me)]/0.75CH2Cl2{triphos=PhP(CH2CH2PPh2)2}

Reaction of [WI₂(CO)(NCMe)(η²-MeC₂Me)₂] with an equimolar quantity of triphos {triphos=PhP(CH₂CH₂PPh₂)₂} in CH₂Cl₂ at room temperature gave the triphos complex [WI₂(CO)(η²-MeC₂Me)] (1). The crystal structure of (1) shows that the triphos is attached to the tungsten via two adjacent phosphorus atoms, with the third phosphorus atom uncoordinated. Two crystallographically independent molecules are present, which are diastereoisomers. Preliminary studies of the reactions of (1) are described.     

Intramolecular Rearrangements of >Si(O–C·=O)(CH2–CH3) and >Si(CH2–CH·–CH3)(CH2–CH3) Radicals

Using ESR and IR spectroscopy, the structures of >Si(O–C^·=O)(CH₂–CH₃) (1) and >Si(CH₂–CH^·–CH₃)(CH₂–CH₃) (2) radicals were deciphered. The directions and kinetic parameters of reactions of intramolecular rearrangements in these radicals were determined. The reactions of hydrogen atom abstraction in radical (1) from the CH₂ and CH₃ groups were studied. It was found that the endothermic reaction of hydrogen atom abstraction from the methyl group occurs at a higher rate than the exothermic reaction with the methylene group. The differences are determined by changes in the size of a cyclic transition state. Based on the experimental data, the strengths of separate C–H bonds in surface fragments are compared. The rearrangement >Si(CH₂–CH^·–CH₃)(CH₂–CH₃) >Si(C^·(CH₃)₂)(CH₂–CH₃) was discovered and its mechanism was determined. One of its steps is the skeletal isomerization Si- (2)- _. (1)Si- (1)- _. (2). Experimental data are analyzed using the results of quantum-chemical calculations of model systems.     

Synthesis,Molecular Structure,and Thermal Properties of the Supramolecular Complex [Zn{NH(CH2)4O}{S2CN(C2H5)2}2]2 · CH2N(CH2)4O}2

The supramolecular complex [Zn{NH(CH₂)₄O}{S₂CN(C₂H₅)₂}₂]₂ · CH₂N(CH₂)₄O}₂ (I) has been synthesized and studied by X-ray crystallography and thermal analysis. The noncentrosymmetric complex is composed of two structurally nonequivalent molecules of the adduct of bis(diethyldithiocarbamato)zinc with morpholine, which are linked with the outer-sphere N,N’-dimorpholinomethane molecule through two hydrogen bonds N-H?O. The major differences between the adduct molecules are related to the strength of Zn-N bonds, spatial orientation of the coordinated morpholine heterocyclic rings, and the proportion between the contributions of the trigonal bipyramidal (TBP) and tetragonal pyramidal (TP) components to the geometry of zinc polyhedra. Calculations show that the geometry of the zinc polyhedra is almost halfway between TBP and TP. The thermal destruction of supramolecular compound I is accompanied by desorption of the outer-sphere and coordinated organic molecules. At the final stage, defragmentation of the “dithiocarbamate part” of the complex leads to the formation of ZnS.     

Ab initio study of Eu3+–L (L=H2O,H2S,NH2CH3, S(CH3)2, imidazole) complexes

The ground states and binding energies of Eu³⁺–L (L=H₂O,H₂S,NH₂CH₃,S(CH₃)₂, imidazole) complexes has been determined using ab initio techniques. The binding is mostly electrostatic as expected. The empty f orbital is different for the S compounds, being a π-like orbital, while for the O and N containing ligands it is a σ-like orbital. However, the range in the binding energies for the different f holes is small.     

Synthesis and Structure of Acetonitrile Solvates of Copper(II) Monofluoroacetate and Silver(I) Trifluoroacetate, [Cu2(CH2FCOO)4· 2CH3CN](CH3CN) and Ag3(CF3COO)3(CH3CN)2

Compounds [Cu₂(CH₂FCOO)₄· 2CH₃CN](CH₃CN) (I) and Ag₃(CF₃COO)₃(CH₃CN)₂(II) were synthesized and studied by X-ray structural analysis. Crystals Iare monoclinic, space group C2/c, a= 27.854(6), b= 8.286(2), c= 19.428(4) Å, = 106.82(3)°, V= 4292(2) ų, Z= 8, R ₁= 0.0426; crystals IIare triclinic, space group , a= 8.676(2), b= 9.819(2), c= 11.961(2) Å, = 95.27(3), = 109.59(3)°, = 104.60(3)°, V= 911.4(3) ų, Z= 2, R ₁= 0.0252. Structure Iis composed of the structural units (lanterns) typical of copper(II) carboxylates. The presence of an additional acetonitrile molecule noncoordinated by the copper atoms makes it possible to consider compound Ias a lattice clathrate. Structure IIhas no analogs among the silver carboxylates. It simultaneously contains silver atoms with coordination numbers varying from 2 to 4.     

[ZnN(CH2CH2NH2)2(CH2CH2N=CHC6H4O)]·Pic的合成与晶体结构

在不加任何碱的条件下,三[2-(亚水杨基胺)乙基]胺与苦味酸锌[Zn(Pic)26H2O]在乙醇中反应,得到了较为少见的多胺单缩合西夫碱配体的配合物[ZnN(CH2CH2NH2)2(CH2CH2N=CH-C6H4O)]Pic。化学式为C19H23N7O8Zn,Mr=542.81,晶体属三斜晶系,空间群为P,晶胞参数为a=0.7494(3),b=1.1917(5),c=1.3142(6)nm,a=78.111(7),b=79.093(7),g=78.577(7),V=1.1121(8)nm3,Dc=1.621g/cm3,m(MoKa)=1.167mm-1,Z=2,F(000)=560,在1.602s(I)的可观测点为2433个,最终偏离因子R=0.0555,wR=0.1139。配合物中Zn(II)与配体的4个N原子和1个O原子配位形成变形的三角双锥结构,桥头N和O为锥顶,4个配位N中桥头N与金属离子的配位作用最弱。晶体通过p-p堆积和分子内、分子间的氢键作用形成二维层状超分子结构。     

[C5H4C(CH3)2CH2CH=CH2]Sm(OH)Cl·2MgCl2·4THF的晶体结构分析

用Ｘ－射线晶体结构衍射法测定了［Ｃ５Ｈ４Ｃ（ＣＨ３）２ＣＨ２ＣＨ＝ＣＨ２］Ｓｍ（ＯＨ）Ｃｌ·２ＭｇＣｌ２·４ＴＨＦ的晶体结构。它属三斜晶系,空间群为Ｐ＾－１,ａ＝１０．７７３（２）,ｂ＝１２．８３６（３）,ｃ＝１５．４７８（３）Ａ,ａ＝１１１．４６（３）,β＝１０７．７１（３）,γ＝９２．５４（３）°,Ｖ＝１８６８（１）Ａ＾３,Ｍｒ＝８２７．９１,Ｄｘ＝１．４７２ｇ／ｃｍ＾３,μ＝２．０００６ｍｍ     

Hydrothermal Synthesis,Crystal Structure and Thermal Stability Properties of the Complex [Cd2(phen)2(C14HuO3)4(CH3CH2OH)]·(CH3OH)·(H2O)

T A dinuclear cadmium complex[Cd2(phen)2(C14H11O3)4(CH3CH2OH)]·(CH3OH)·(H2O)has been synthesized with benzilic acid and 1,10-phenanthroline by hydrothermal method.The crystal structure was determined bv X-ray diffraction with crystal parameters as follows:triclinic system with space group P-1,α=1.21298(10),b=1.32586(1 1),c=2.4815(2)nm,α=76.2630(10),β=81.4500(10),γ=69.1700(10)°V=3.6143(5)nm3,Dc=1.438g/cm3,Z=1,F(000)=1600,the final GOOF=0.937,R=0.0521 and wR=0.1328.In the title complex,the dinuclear structure is defined by carboxyl oxygen atoms adopting a monodentate bridged coordination mode.The coordination environment of Cd(Ⅱ)ion is CdO4N2,giving a distorted octahedral coordination geometry.TG analysis shows that the title complex is stable under 140℃.     

Complexes [Ni2(μ-OH2)(μ-O2CCH(CH3)2)2L2–4((CH3)2CHCO2)2]: Synthesis,Structure, and Mass Spectrometric Studies

Russian Journal of Coordination Chemistry - Three new binuclear aqua-bridged nickel(II) 2-methylpropionate complexes [Ni2(μ-OH2)(μ-O2CCH(CH3)2)2L2–4((CH3)2CHCO2)2] (L is...     

Cluster Complexes of Polythioether Macrocycles: The Synthesis and Molecular Structures of Ru6(CO)13(cis-SCH2 CHMe(CH2SCH2CHMe)2CH2)(μ6-C) and Ru6(CO)13(trans-SCH2 CHMe(CH2SCH2CHMe)2CH2)(μ6-C)

The reaction of a mixture of cis-3,7,11-trimethyl-1,5,9-trithiacyclododecane, cis-Me₃12S3, 1 and trans-3,7,11-trimethyl-l,5,9-trithiacyclododecane, trans-Me₃12S3, 2, with Ru₆(CO)₁₇(μ ₆-C), 3, yielded three new cluster compounds Ru₆(CO)₁₃(μ-η³-cis-SCH₂CHMe(CH₂SCH₂CHMe)₂CH₂)(μ ₆-C) 4, and two isomers of Ru₆(CO)₁₃(μ-η³-cis-SCH₂CHMe(CH₂SCH₂CHMe)₂CH₂)(μ ₆-C) 5a and 5b. The molecular structures of 4 and 5b were established by single crystal X-ray diffraction analyses. In both complexes, the macrocycles have adopted tridentate coordination with one of the sulfur atoms in a bridging position. Two carbonyl ligands occupy bridging positions in each compound. Crystal Data for 4·Me₂CO: space group=P2₁/n, a=11.295(1) Å, b=17.547(3) Å, c=20.318(3) Å, β=93.71(1)°, Z=4, 2900 reflections, R=0.025. Crystal Data for 5b·1.5 C₆H₆: space group=Pbca, a=31.8900(8) Å, b=23.4330(6) Å, c=21.6240(4) Å, Z=16, 12163 reflections, R=0.040.     

Chlorine reaction with platinum triamine [Pt(N,N-DimeTm)PyCl3]Cl (N,N-DimeTm = (CH3)2N(CH2)3NH2). Crystal structure of [Pt(N,N-DimeTm)Cl2], [Pt(N,N-DimeTm(Py)Cl3]Cl · H2O and [Pt{(CH3)2N(CH2)2C(O)NH}(Py)Cl3]

Treatment of platinum(II) diamine [Pt(N,N-DimeTm)Cl₂] (I) with pyridine gave tetramine [Pt(N,N-DimeTm)Py₂]Cl₂ (II); by oxidation with chlorine this was converted to Pt(IV) triamine, [Pt“(N,N-DimeTm(Py)Cl₃]Cl (III) with a six-membered chelate ring. According to X-ray diffraction data, the reaction of complex II with chlorine is accompanied by removal of the pyridine molecule from the trans-position to the NH₂ group of N,N-dimethyltrimethylenediamine. The reaction of complex III with chlorine at 20°C afforded a mixture of compounds (IV) and the complex [Pt“(CH₃)₂N(CH₂)₂C(O)NH”(Py)Cl₃] (V) with an amidate six-membered metal ring, dimethylpropioamide, which was also isolated upon refluxing a mixture of IV in an aqueous solution. The UV/Vis and IR spectra of the obtained complexes were studied, and X-ray diffraction analysis of I, III, and V was performed. The crystals of I are triclinic, space group P $ \bar 1 $ ; a = 7.6526(4) Å, b = 11.5571(6) Å, c = 12.4432(7) Å, α = 113.85(1)°, β = 96.54(2)°, γ = 106.78(2)°; Z = 4; R _hkl = 0.051. The crystals of III are monoclinic, space group C2/c; a = 36.715(2) Å, b = 7.8179(4) Å, c = 29.721(16) Å, β = 127.80(1)°; Z = 16; R _hkl = 0.036. The crystals of V are monoclinic, space group P2₁/n; a = 7.0398(6) Å, b = 27.458(2) Å, c = 7.687(6) Å, β = 106.270(1)°; Z = 4; R _hkl = 0.052.     

Effects of excitation energy on the autodetachment lifetimes of small iodide-doped ROH clusters (R═H-, CH3-, CH3CH(2)-)

The effect of excitation energy on the lifetimes of the charge-transfer-to-solvent (CTTS) states of small (4 ≤ n ≤ 10) iodide-doped water and alcohol clusters was explored using femtosecond time-resolved photoelectron imaging. Excitation of the CTTS state at wavelengths ranging from 272 to 238 nm leads to the formation of the I···(ROH)(n)(-) (R═H-, CH(3)-, and CH(3)CH(2)-) species, which can be thought of as a vibrationally excited bare solvent cluster anion perturbed by an iodine atom. Autodetachment lifetimes for alcohol-containing clusters range from 1 to 71 ps, while water clusters survive for hundreds of ps in this size range. Autodetachment lifetimes were observed to decrease significantly with increasing excitation energy for a particular number and type of solvent molecules. The application of Klots' model for thermionic emission from clusters to I(-)(H(2)O)(5) and I(-)(CH(3)OH)(7) qualitatively reproduces experimental trends and reveals a high sensitivity to energy parametrization while remaining relatively insensitive to the number of vibrational modes. Experimental and computational results therefore suggest that the rate of electron emission is primarily determined by the energetics of the cluster system rather than by details of molecular structure.