Syntheses and(Crystal Structures of Two New One-dimensional Double Hydrogen-bonding-chain Complexes [Ni(bipy)2Cl]·ClO4 and [Zn(bipy)2Cl]·BF4

Two new transition metal complexes, [Ni(bipy)2Cl]·ClO4 (bipy = 2,2'-bipyridine) 1 and [Zn(bipy)2Cl]·BF4 2, have been synthesized and characterized by single-crystal X-ray diffraction analysis. Both 1 and 2 crystallize in monoclinic space group P21/n with Z = 4. For 1, a = 10.776(1), b = 12.067(1), c = 16.146(2)(A), β= 93.021(2)o, V = 2031.9(4)(A)3, Mr = 505.98, Dc = 1.654 g/cm3, μ = 1.255 mm-1, F(000) = 1032, the final R = 0.0406 and wR = 0.1002 for 3983 observed reflections with Ⅰ ＞ 2σ(I). For 2, a = 10.758(4), b = 12.058(4), c = 16.135(5) (A), β = 104.57(1)o, V = 2025.7(12) (A)3, Mr = 500.00, Dc = 1.639 g/cm3, μ = 1.396 mm-1, F(000) = 1008, the final R = 0.0470 and wR = 0.1237 for 3759 observed reflections with Ⅰ ＞ 2σ(I). The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. A one-dimen- sional zigzag double hydrogen-bonding-chain is generated by the intermolecular M-bipy …anion…bipy--M hydrogen bonding interactions between the chelating ligands of bipy and anion.     

Thermal decomposition reaction kinetics of complexes of [Sm(o-MOBA)3bipy]2·H2O and [Sm(m-MOBA)3bipy]2·H2O

The complexes of [Sm(o-MOBA)₃bipy]₂·H₂O and [Sm(m-MOBA)₃bipy]₂·H₂O (o(m)-MOBA = o(m)-methoxybenzoic acid, bipy-2,2′-bipyridine) have been synthesized and characterized by elemental analysis, IR, UV, XRD and molar conductance, respectively. The thermal decomposition processes of the two complexes were studied by means of TG–DTG and IR techniques. The thermal decomposition kinetics of them were investigated from analysis of the TG and DTG curves by jointly using advanced double equal-double steps method and Starink method. The kinetic parameters (activation energy E and pre-exponential factor A) and thermodynamic parameters (ΔH ^≠ , ΔG ^≠ and ΔS ^≠) of the second-step decomposition process for the two complexes were obtained, respectively.     

Binary group 15 polyazides. structural characterization of [Bi(N3)4]-, [Bi(N3)5]2-, [bipy·Bi(N3)5]2-, [Bi(N3)6]3-, bipy·As(N3)3, bipy·Sb(N3)3, and [(bipy)2·Bi(N3)3]2 and on the lone pair activation of valence electrons

The binary group 15 polyazides As(N(3))(3), Sb(N(3))(3), and Bi(N(3))(3) were stabilized by either anion or donor-acceptor adduct formation. Crystal structures are reported for [Bi(N(3))(4)](-), [Bi(N(3))(5)](2-), [bipy·Bi(N(3))(5)](2-), [Bi(N(3))(6)](3-), bipy·As(N(3))(3), bipy·Sb(N(3))(3), and [(bipy)(2)·Bi(N(3))(3)](2). The lone valence electron pair on the central atom of these pnictogen(+III) compounds can be either sterically active or inactive. The [Bi(N(3))(5)](2-) anion possesses a sterically active lone pair and a monomeric pseudo-octahedral structure with a coordination number of 6, whereas its 2,2'-bipyridine adduct exhibits a pseudo-monocapped trigonal prismatic structure with CN 7 and a sterically inactive lone pair. Because of the high oxidizing power of Bi(+V), reactions aimed at Bi(N(3))(5) and [Bi(N(3))(6)](-) resulted in the reduction to bismuth(+III) compounds by [N(3)](-). The powder X-ray diffraction pattern of Bi(N(3))(3) was recorded at 298 K and is distinct from that calculated for Sb(N(3))(3) from its single-crystal data at 223 K. The [(bipy)(2)·Bi(N(3))(3)](2) adduct is dimeric and derived from two BiN(8) square antiprisms sharing an edge consisting of two μ(1,1)-bridging N(3) ligands and with bismuth having CN 8 and a sterically inactive lone pair. The novel bipy·As(N(3))(3) and bipy·Sb(N(3))(3) adducts are monomeric and isostructural and contain a sterically active lone pair on their central atom and a CN of 6. A systematic quantum chemical analysis of the structures of these polyazides suggests that the M06-2X density functional is well suited for the prediction of the steric activity of lone pairs in main-group chemistry. Furthermore, it was found that the solid-state structures can strongly differ from those of the free gas-phase species or those in solutions and that lone pairs that are sterically inactive in a chemical surrounding can become activated in the free isolated species.     

Syntheses and Crystal Structures of Two New One-dimensional Double Hydrogen-bonding-chain Complexes [Ni(bipy)_2Cl]·ClO_4 and [Zn(bipy)_2Cl]·BF_4

Two new transition metal complexes, [Ni(bipy)2Cl]·ClO4 (bipy = 2,2'-bipyridine) 1 and [Zn(bipy)2Cl]·BF4 2, have been synthesized and characterized by single-crystal X-ray diffraction analysis. Both 1 and 2 crystallize in monoclinic space group P21/n with Z = 4. For 1, a = 10.776(1), b = 12.067(1), c = 16.146(2) , β = 93.021(2)o, V = 2031.9(4) 3, Mr = 505.98, Dc = 1.654 g/cm3, μ = 1.255 mm–1, F(000) = 1032, the final R = 0.0406 and wR = 0.1002 for 3983 observed reflections with I > 2σ(I). For 2, a = 10.758(4), b = 12.058(4), c = 16.135(5) , β = 104.57(1)o, V = 2025.7(12) 3, Mr = 500.00, Dc = 1.639 g/cm3, μ = 1.396 mm–1, F(000) = 1008, the final R = 0.0470 and wR = 0.1237 for 3759 observed reflections with I > 2σ(I). The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. A one-dimen-sional zigzag double hydrogen-bonding-chain is generated by the intermolecular M-bipy ···anion···bipy- M hydrogen bonding interactions between the chelating ligands of bipy and anion.     

THE INTERACTION OF BIS[2-MERCAPTOETHANESULFONATO (2−)-Sl,BIS[L-CYSTEINATO(1−)-S], AND BIS[L-PENICILLAMINATO(1−)-Sl- DIMETHYLTIN (IV), WITH RAT HEMOGLOBIN: A119Sn MöSSBAUER SPECTROSCOPIC STUDY

Abstract

The title compounds, representative of classes of diorganotin (IV) derivatives active against murine leukemia P-388. interact with rat hemoglobin (selected as a model protein) by: i) co-crystallization. with formation of microcrystalline pellets, and: ii) diffusion into hemoglobin crystals from the supernatant solution (as determined for the 2-mercaptoethanesulfonato derivative). The nature of the Me₂Sn^IV species in hemoglobin has been investigated by ¹¹⁹Sn Mössbauer spectroscopy, and a C₂SnS₂ tetrahedral geometry has been assigned by the point-charge model rationalization of the nuclear quadrupole splitting parameter.

Binding into crystalline hemoglobin has been ascribed to Coulomb interactions and to hydrogen bonding between the sulfonate and the aminoacid tails of the organotin (IV) derivatives and functional groups of the globin.     

Polymorphic Study of 2-(2-benzofuryl) Δ-2 Imidazoline

The compound 2-(2-benzofuryl) Δ-2 imidazoline, has been studied by DSC, TG, X-ray diffraction and thermomicroscopy. We shall see that in the case of a study by DSC this compound presents a strange behaviour, which apparently is in contradiction with the thermodynamic rules. In a case of monotropy, if we have the α-phase (stable) and the γ-phase (metastable), after melting and cooling only theα-phase could crystallise. But this compound can give, according to the rate of cooling, theγ-phase metastable. The rate of cooling is of fundamental importance and the monotropic behaviour of this compound will be explained using the Gibbs function G=f(T) for P=1 atm. This revised version was published online in August 2006 with corrections to the Cover Date.     

The synthesis and reactivity of the heptanuclear dianion [Os7(CO)20]2− including the synthesis and structural characterizations of the compounds [Os7(CO)20(AuPEt)3 2] and [Os8(CO)20(η6-C6H6]

Reduction of the heptaosmium cluster [Os₇(CO)₂₁] With [Et₄N][NH₄) gives the cluster dianion [Os₇(CO)₂₀]^2–,1, in high yield. The reaction of the dianion with [AuPR ₃Cl] (R=Et or Ph) in the presence of TlPF₆ forms [Os₇((CO)₂₀(AuPR ₃)₂] [R=Et (2a);R = Ph(2b)] in 80% yield, while the corresponding reaction with (Os(C₆H₆)(CH₃CN)₃]²⁺ gives [Os₈(CO)₂₀ ( ⁶-C₆H₆)] (3) in reasonable yield (ca. 30%). The dianion,1, and the clusters2 and3 have been fully characterized by bout spectroscopic and crystallographic methods. The crystal structure of the [Ph₄P]⁺ salt of1 shows that the metals in the anion adopt a capped octahedral geometry, with all twenty carbonyl ligands in terminal sites. The metal core geometry in2a is best described as a tricapped octahedron, and is based on the structure of the dianion1 with two adjacent octahedral faces capped by the Au atoms of the two AuPEt₃ groups. In a similar fashion, the geometry of3 is related to that of1 with the addition of an Os(C₆H₆) unit capped to a triangular face, to give a bicapped octahedral framework.     

Surface Mediated Organometallic Synthesis: Formation of [H5Os10(CO)24]− by Hydrogenation of Silica-Supported [Os(CO)3(OH)2]n as a Springboard for a High-Yield Synthesis of [H4Os10(CO)24]2− Starting from α-[Os(CO)3Cl2]2 and Working in Ethylene Glycol Solution

New high yield routes to the high nuclearity hydrido carbonyl clusters [H₅Os₁₀(CO)₂₄]^- and [H₄Os₁₀(CO)₂₄]^2-, model systems for the chemisorption of CO and H₂ on metal surfaces, are reported. [H₅Os₁₀(CO)₂₄]^- is obtained in good yields by hydrogenation (1 atm) at 200°C of physisorbed [Os(CO)₃(OH)₂]_n whereas in refluxing ethylene glycol solution, that is less acidic than the silica surface, [H₄Os₁₀(CO)₂₄]^2- is obtained in high yield starting from [Os(CO)₃(OH)₂]_n or, more conveniently, from -[Os(CO)₃Cl₂]₂ in the presence of the stoichiometric amount of sodium carbonate. The quantitative equilibrium

三维超分子化合物[Ag2(tdpc)(bipy)2][ Ag2(bipy)2(H2O)]·12H2O的合成和晶体结构

以银离子、3,3 ',4,4'-二苯硫酮四羧酸阴离子(tdpc)和4,4'-联吡啶(bipy),合成了一种新型化合物[十二水合(3,3',4,4'-二苯硫酮四羧酸)(4,4'-联吡啶)水合银][ Ag2 (tdpc)(bipy)2][ Ag2 (bipy)2 (H2O)]·12H2O,该化合物为链状结构,Ag…Ag相互...     

Dissociation kinetics of [Fe(phen)3]2+, [Fe(bipy)3]2+ and [Fe-(4,4′-Me2bipy)3]2+ in the presence of cyanide ion in aqueous solution at pressures up to 1 kilobar

Summary Rate constants for dissociation, in aqueous solution at 25° C, of [Fe(phen)₃]²⁺, [Fe(bipy)₃]²⁺, and [Fe(4,4-Me₂bipy)₃]²⁺ in the presence of cyanide, and of the last-named complex also in the presence of hydroxide, are significantly decreased by the application of pressure (up to 1 kbar). Kinetic measurements were carried out using a high pressure cell of improved design to that used in our earlier investigations. Volumes of activation, V ^*, are scarcely sensitive to ligand or to attacking nucleophile, being in the range of 10–12 cm³ mol^–1. An explanation of these results resides in an associative mechanism, a scheme invoked for similar reactions reported previously.     

多钼酸盐[4,4-′H_2bipy]_2 [β-Mo_8O_(26)]的水热合成和晶体结构

利用水热合成方法制备了化合物[4,4′-H2b ipy]2[-βMo8O26],用元素分析、X射线单晶衍射和电子顺磁共振对其结构进行了表征.结构解析表明标题化合物是由β型[Mo8O26]4-多阴离子与质子化的4,4′-联吡啶通过氢键作用形成的三维结构超分子化合物.     

Stepwise synthesis of [Os3(CO)8(R2C2)(R′2C2)] from [Os3(CO)10(R2C2)] under mild conditions,x-ray crystal structure of [Os3(CO)8(Ph2C2)2]; a bis(alkyne) without an osmacyclopentaidiene ring

Treatment of a solution of [Os₃(CO)₁₀(R₂C₂)] (R = Me (1, R = Ph (2)) in CH₂Cl₂ with Me₃No/MeCN in the presence of R′₂C₂ affords the new organometallic cluster [Os₃(CO)₈(R₂C₂)(R′₂C₂)] (R = R′ = Me (3), R = R′ = Ph (4) and R = Ph, R′ = Me (5)). A single crystal X-ray analysis of compound 4 has established a triangular metal framework with both the alkyne units coordinated in a μ₃-η²-6-mode. In toluene, at 80°C, compound 4 undergoes rearrangement to the known compound, [Os₃H(CO)₈(Ph)C₂(C₆H₄))] (6) in which CC bond formation has occurred to produce an osmacyclopentadiene ring.     

手性配合物[M(bipy)_3]~(2+)(M=Fe,Ru,Os)圆二色谱的理论解析

应用密度泛函理论,在DFT/B3LYP/LanL2DZ水平上优化了铁族配合物[M(bipy)3]2+(M=Fe,Ru,Os;bipy=2,2′-联吡啶)在溶液中的基态几何结构,并用TDDFT/B3LYP方法和相同的基组计算了该类配合物的激发能、旋转强度和振子强度,绘制了相应的圆二色谱.计算的谱带位置虽有一定的红移或蓝移,但各谱带的带形和符号均与实验谱吻合.对跃迁性质的分析表明,三个配合物在长波区,除[Fe(bipy)3]2+的第一个谱带是以d-d跃迁为主外,其他谱带均是荷移跃迁为主.短波区的两个强带则是以π-π*跃迁为主的激子耦合带:对于铁配合物,TDDFT可以正确预言其正负带的强度比,但对钌和锇配合物而言,由于对激子跃迁中荷移成份的贡献估计不足,计算的比值偏小.这一结论为进一步改进有关的计算模型指明了方向.     

Synthesis,Structure and Fluorescence of a Copper(II) Complex [Cu_2(bipy)_2(Hpht)_2Cl](Hpht)(bipy=2,2'-Bipyridine,H_2pht=o-Phthalic Acid)

1 INTRODUCTION o-Phthalic acid (H2pht) is a versatile ligand for co-ordinating to metal ions in various modes, such asmonodentate bonding through a carboxylic O atom[1],bidentate fashion via two carboxylic O atoms[2] andtriple coordination through its three carboxylic Oatoms[3], and bridging mode with two or four Oatoms of its carboxylate groups[4]. The coordinationproperties thus allow for the preparation of complex-es with a large variety of architectures, forming iso-lated mono-, di…     

系列二亚胺Os(II)配合物[Os(L)2(CN)2(phen)] (L＝PH3, DMSO; phen＝1,10-邻二氮杂菲)及[Os(PH3)2(phen)Br2]电子结构和 光谱性质的理论研究

采用自旋限制和非限制B3LYP/UB3LYP方法分别优化了系列Os(II)二亚胺配合物[Os(L)2(CN)2(phen)] [phen＝1,10-邻二氮杂菲; L＝Ph3 (1), 二甲基亚砜(DMSO) (2)]及[Os(PH3)2(phen)Br2] (3)的基态和激发态几何构型. 通过TD-DFT方法结合PCM溶剂化模型计算了配合物1～3在二氯甲烷溶液中的吸收和发射光谱并指认了相应的跃迁性质. 通过理论化学计算, 揭示了π酸配体及π碱配体对配合物磷光发射性质的影响及原因. 并进一步解释了配合物3易于在Os—Br键处断裂而发生反应的量子化学机理. 对配合物在不同溶剂中的磷光发射性质的计算表明, 溶剂对配合物的量子产率存在着影响并且配合物具有溶剂化显色效应.     

Synthesis and Crystal Structure of Bis[2-[2-(diethylamino)ethyliminomethyl]-4-nitrophenolato]dimethanolcobalt(II) Dinitrate

1 INTRODUCTION The significance of cobalt coordination com- pounds in biological systems is recognized[1～3]. In many instances the cobalt coordination compounds of Schiff bases have been suggested as models to describe energy transfer in naturally occurring systems. In such cases the coordination sphere about the metal ion is believed to play an important role in determining the nature of the model system[4, 5]. In order to investigate the structures of such complexes, we report herein t…     

Synthesis and Crystal Structur of （4,4＇-H2bipy）[CdBr4]-H2O

The title compound (4,4'-H2bipy)[CdBr4]·H2O 1 has been synthesized via hydrothermal reaction and characterized by X-ray diffraction. The crystal belongs to monoelinic,space group P21/c with a=8.260(3), b=23.926(7), c=9.774(2) (A), β=106.777(9)°,C10H12Br4CdN2O, Mr=608.26, V=1849.4(9)(A)3, Z=4, Dc=2.185 g/cm3, S=1.005, μ(MoKα)=9.814 mm-1, F(000)=1128, R=0.0646 and wR=0.0989. The crystal structure analysis of 1reveals that the title compound features an isolated structure, based on discrete 4,4'-H2bipy moieties and lattice water molecules which are linked by hydrogen bonds together with tetrahedral cadmium atoms terminally coordinated by four bromine atoms.     

系列二亚胺Os(Ⅱ)配合物[Os(L)2(CN)2(phen)](L=PH3,DMSO;phen=1,10-邻二氮杂菲)及[Os(PH3)2(phen)Br2]电子结构和光谱性质的理论研究

采用自旋限制和非限制B3LYP/UB3LYP方法分别优化了系列Os(Ⅱ)二亚胺配合物[Os(L)2(CN)2(phen)][phen=1,10-邻二氮杂菲;L=PH3(1),二甲基亚砜(DMSO)(2)]及[Os(PH3)2(phen)Br2](3)的基态和激发态几何构型.通过TD-DFT方法结合PCM溶剂化模型计算了配合物1～3在二氯甲烷溶液中的吸收和发射光谱并指认了相应的跃迁性质.通过理论化学计算,揭示了π酸配体及π碱配体对配合物磷光发射性质的影响及原因.并进一步解释了配合物3易于在Os-Br键处断裂而发生反应的量子化学机理.对配合物在不同溶剂中的磷光发射性质的计算表明,溶剂对配合物的量子产率存在着影响并且配合物具有溶剂化显色效应.     

Reactivity of triosmium clusters with 3,4-dimethyl-1-phenylphosphole and cyanoethyldi-tert-butylphosphine ligands: X-ray crystal structures of [Os3(CO)9(μ-OH)(μ-H)(η1-PhPC4H2Me2)] and [Os3(CO)11(η1- t Bu2PC2H4CN)]

Reaction of [Os₃(μ-H)₂(CO)₁₀] with 3,4-dimethyl-1-phenylphosphole in refluxing cyclohexane affords two substituted triosmium clusters: [Os₃(CO)₉(μ-H)(μ³:η¹:η¹:η²-PhPC₄H₃Me₂)] (1) and [Os₃(CO)₉(H)(μ²-η¹:η²-PhPC₄H₄Me₂)] (2), of which cluster 2 exhibits two chromatographically non-separable isomeric forms attributed to terminal and bridging coordination of the hydride ligand, respectively. When this reaction is performed in refluxing THF, the only product is the cluster [Os₃(CO)₉(μ-OH)(μ-H)(η¹-PhPC₄H₂Me₂)] (3). Crystallographic information obtained for cluster 3 shows the phosphole ligand occupying an equatorial position, as expected, while the OH group is asymmetrically bridging unlike previously reported similar compounds. Additionally, interaction of the labile cluster [Os₃(CO)₁₁(CH₃CN)] with cyanoethyldi-tert-butylphosphine in dichloromethane at room temperature was found to give [Os₃(CO)₁₁(η¹- ^t Bu₂PC₂H₄CN)] (4) as the only product; its crystallographic characterization shows that the phosphine ligand coordinates by means of the phosphorus atom in an equatorial fashion, analogous to compound 3.