共查询到20条相似文献,搜索用时 15 毫秒
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Sellmann D Geipel F Heinemann FW 《Chemistry (Weinheim an der Bergstrasse, Germany)》2002,8(4):958-966
In the search for complexes modeling the [Fe(CN)(2)(CO)(cysteinate)(2)] cores of the active centers of [NiFe] hydrogenases, the complex (NEt(4))(2)[Fe(CN)(2)(CO)('S(3)')] (4) was found ('S(3)'(2-)=bis(2-mercaptophenyl)sulfide(2-)). Starting complex for the synthesis of 4 was [Fe(CO)(2)('S(3)')](2) (1). Complex 1 formed from [Fe(CO)(3)(PhCH=CHCOMe)] and neutral 'S(3)'-H(2). Reactions of 1 with PCy(3) or DPPE (1,2-bis(diphenylphosphino)ethane) yielded diastereoselectively [Fe(CO)(2)(PCy(3))('S(3)')] (2) and [Fe(CO)(dppe)('S(3)')] (3). The diastereoselective formation of 2 and 3 is rationalized by the trans influence of the 'S(3)'(2-) thiolate and thioether S atoms which act as pi donors and pi acceptors, respectively. The trans influence of the 'S(3)'(2-) sulfur donors also rationalizes the diastereoselective formation of the C(1) symmetrical anion of 4, when 1 is treated with four equivalents of NEt(4)CN. The molecular structures of 1, 3 x 0.5 C(7)H(8), and (AsPh(4))(2)[Fe(CN)(2)(CO)('S(3)')] x acetone (4 a x C(3)H(6)O) were determined by X-ray structure analyses. Complex 4 is the first complex that models the unusual 2:1 cyano/carbonyl and dithiolate coordination of the [NiFe] hydrogenase iron site. Complex 4 can be reversibly oxidized electrochemically; chemical oxidation of 4 by [Fe(Cp)(2)PF(6)], however, led to loss of the CO ligand and yielded only products, which could not be characterized. When dissolved in solvents of increasing proton activity (from CH(3)CN to buffered H(2)O), complex 4 exhibits drastic nu(CO) blue shifts of up to 44 cm(-1), and relatively small nu(CN) red shifts of approximately 10 cm(-1). The nu(CO) frequency of 4 in H(2)O (1973 cm(-1)) is higher than that of any hydrogenase state (1952 cm(-1)). In addition, the nu(CO) frequency shift of 4 in various solvents is larger than that of [NiFe] hydrogenase in its most reduced or oxidized state. These results demonstrate that complexes modeling properly the nu(CO) frequencies of [NiFe] hydrogenase probably need a [Ni(thiolate)(2)] unit. The results also demonstrate that the nu(CO) frequency of [Fe(CN)(2)(CO)(thiolate)(2)] complexes is more significantly shifted by changing the solvent than the nu(CO) frequency of [NiFe] hydrogenases by coupled-proton and electron-transfer reactions. The "iron-wheel" complex [Fe(6)[Fe('S(3)')(2)](6)] (6) resulting as a minor by-product from the recrystallization of 2 in boiling toluene could be characterized by X-ray structure analysis. 相似文献
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Hong‐Bin Zhao Liang Chen Bang‐Ying Wang Jun‐Xu Liao Yong‐Jun Xu 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(6):651-653
The core of the novel title centrosymmetric porphyrin derivative, C72H86N4O4, with long flexible hexyloxy substituents, is almost planar, which is anticipated to facilitate π‐electron delocalization and lead to a significant deviation between the planes of the benzene rings and the molecular plane. The two N‐bound H atoms on the pyrrole rings are disordered and the occupancy factors refined to a ratio of 0.28 (2):0.72 (2). 相似文献
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Stefan Haslinger Alexander Pthig Mirza Cokoja Fritz E. Kühn 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(12):1096-1099
Iron is of interest as a catalyst because of its established use in the Haber–Bosch process and because of its high abundance and low toxicity. Nitrogen‐heterocyclic carbenes (NHC) are important ligands in homogeneous catalysis and iron–NHC complexes have attracted increasing attention in recent years but still face problems in terms of stability under oxidative conditions. The structure of the iron(II) complex [1,1′‐bis(pyridin‐2‐yl)‐2,2‐bi(1H‐imidazole)‐κN3][3,3′‐bis(pyridin‐2‐yl‐κN)‐1,1′‐methanediylbi(1H‐imidazol‐2‐yl‐κC2)](trimethylphosphane‐κP)iron(II) bis(hexafluoridophosphate), [Fe(C17H14N6)(C16H12N6)(C3H9P)](PF6)2, features coordination by an organic decomposition product of a tetradentate NHC ligand in an axial position. The decomposition product, a C—C‐coupled biimidazole, is trapped by coordination to still‐intact iron(II) complexes. Insights into the structural features of the organic decomposition products might help to improve the stability of oxidation catalysts under harsh conditions. 相似文献
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The preparation and characterization of the deoxymyoglobin model (2-methylimidazole)(tetraphenylporphinato)iron(II) is described. The preparation and crystallization from chlorobenzene leads to a new crystalline phase that has been structurally characterized. The complex is the most ordered example of a deoxymyoglobin model yet characterized. The X-ray structure determination reveals a number of distortions both in the iron coordination group and in the porphyrin core that result from the steric bulk of the axial ligand. Some of these distortions have been noted previously in related species; however, the demonstration of porphyrin core distortions and an asymmetry in the Fe-N(p) bond distances are new observations. These may have functional significance for this important type of heme protein coordination group. The new structure emphasizes that high-spin iron(II) porphyrinate derivatives display substantial structural pliability with significant variations in iron atom displacements, porphyrin core hole size, and axial and equatorial Fe-N bond lengths. The new complex has also been characterized by zero-field and applied field magnetic M?ssbauer spectroscopy. M?ssbauer parameters are characteristic for high-spin iron, although they also reveal an extremely rhombic site for iron(II). Crystal data at 130 K for [Fe(TPP)(2-MeHIm)].1.5C(6)H(5)Cl: a = 12.334(3) A, b = 13.515(6) A, c = 14.241(7) A, alpha = 70.62(3) degrees, beta = 88.29(2) degrees, gamma = 88.24(3) degrees, triclinic, space group, P, V = 2238(2) A(3), Z = 2. 相似文献
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Yu‐Mei Zhang Yu‐Ping Zhang Bao‐Long Li Yong Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):m120-m122
The coordination geometry of the ZnII atom in the title complex, [Zn2(NCS)4(C6H8N6)2], is that of a distorted tetrahedron, in which the ZnII atom is coordinated by four N atoms from the triazole rings of two symmetry‐related 1,2‐bis(1,2,4‐triazol‐1‐yl)ethane ligands and two thiocyanate ligands. Two ZnII atoms are bridged by two organic ligands to form a dimer. The dimer lies about an inversion center. 相似文献
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Youngmee Kim Wonwoo Nam Mi Hee Lim Sook Won Jin Alan J. Lough Sung‐Jin Kim 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):556-557
The crystal structure of the title compound, [Fe(C44H20F8N4)(CH3O)], has been determined. The Fe atom lies 0.485 (1) Å out of the plane of the four N atoms to which it is coordinated and from the inversion centre at the origin of the unit cell. The methoxy group is axially coordinated to the Fe atom with O—Fe—N angles of 106.3 (2) and 102.4 (2)°, a C—O—Fe angle of 128.3 (5)° and an Fe—O distance of 1.788 (5) Å. Difluorophenyl rings are tilted from the porphyrin (por) plane with torsion angles of ?68.1 (6) and 77.7 (5)° across the two Cpor—C—C—Car systems. 相似文献
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Sai‐Rong Fan Guo‐Qiang Cai Long‐Guan Zhu Hong‐Ping Xiao 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(4):m177-m179
The title compound, [Cu(C7H3O6S)2(C10H9N3)2][CuI(C10H9N3)2]2·2H2O, consists of anionic CuII moieties, cationic CuI species and uncoordinated water molecules. The anionic dimeric unit consists of one crystallographically independent fully deprotonated 5‐sulfosalicylate (2‐oxido‐5‐sulfonatobenzoate) anion, a di‐2‐pyridylamine group and a CuII atom. Each CuII atom is five‐coordinate within a square‐pyramidal geometry. The anion lies on a special position of site symmetry. In the cationic monomer, the CuI atom adopts tetrahedral geometry. The cations and anions are connected by O—H·O and N—H·O hydrogen bonds. 相似文献
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Yue Zhang You‐Tao Si Ming‐Qiang Hu Chang‐Neng Chen Qiu‐Tian Liu 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(11):m499-m500
The novel title double‐butterfly Fe/S cluster complex, [Fe4(C4H8S2)2(CO)12], which is structurally similar to the active site of the Fe‐only hydrogenases, contains two inversion‐related Fe2S2(CO)6 subcluster cores connected by two equivalent butyl chains to afford a 16‐membered macrocycle. The formation of the 16‐membered macrocycle has an influence on the C—S—Fe angles, while the Fe—Fe and Fe—S bond lengths remain similar to those in related complexes. 相似文献
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Coordinatively Unsaturated Diiron Complexes: Synthesis and Crystal Structures of [Fe2(CO)4(μ‐H)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] and [Fe2(CO)4(μ‐CH2)(μ‐H)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] [Fe2(μ‐CO)(CO)6(μ‐H)(μ‐PtBu2)] ( 1 ) reacts spontaneously with dppm (dppm = Ph2PCH2PPh2) to give [Fe2(μ‐CO)(CO)4(μ‐H)(μ‐PtBu2)(μ‐dppm)] ( 2 c ). By thermolysis or photolysis, 2 c loses very easily one carbonyl ligand and yields the corresponding electronically and coordinatively unsaturated complex [Fe2(CO)4(μ‐H)(μ‐PtBu2)(μ‐dppm)] ( 3 ). 3 exhibits a Fe–Fe double bond which could be confirmed by the addition of methylene to the corresponding dimetallacyclopropane [Fe2(CO)4(μ‐CH2)(μ‐H)(μ‐PtBu2)(μ‐dppm)] ( 4 ). The reaction of 1 with dppe (Ph2PC2H4PPh2) affords [Fe2(μ‐CO)(CO)4(μ‐H)(μ‐PtBu2)(μ‐dppe)] ( 5 ). In contrast to the thermolysis of 2 c , yielding 3 , the heating of 5 in toluene leads rapidly to complete decomposition. The reaction of 1 with PPh3 yields [Fe2(CO)6(H)(μ‐PtBu2)(PPh3)] ( 6 a ), while with tBu2PH the compound [Fe2(μ‐CO)(CO)5(μ‐H)(μ‐PtBu2)(tBu2PH)] ( 6 b ) is formed. The thermolysis of 6 b affords [Fe2(CO)5(μ‐PtBu2)2] and the degradation products [Fe(CO)3(tBu2PH)2] and [Fe(CO)4(tBu2PH)]. The molecular structures of 3 , 4 and 6 b were determined by X‐ray crystal structure analyses. 相似文献
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David G. Billing A. Lemmerer 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):m264-m266
The title compound, {(C4H12N)2[PbI3]I·2H2O}n, crystallizes as an organic–inorganic hybrid. The six‐coordinate Pb atom lies on a centre of inversion and all the I atoms lie on mirror planes; the two independent cations both lie across mirror planes. The structure contains anionic chains along [100] of fused [PbI3]− units forming face‐sharing octahedra. Four cations enclose channels occupied by isolated iodide ions and water molecules of hydration. 相似文献
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Angela Mller 《无机化学与普通化学杂志》2001,627(11):2537-2541
The Mixed‐Valent Oxoferrate(II,III) K3[Fe2O4] – A Stuffed Variant of the K2[Fe2O4] Type of Structure K3[Fe2O4] has been obtained by tempering “Cs3K3CdO4” in sealed Fe containers (36 d at 450–480 °C) as dark red transparent single crystals of rectangular shape. The structure determination (IPDS diffractometer data, MoKα, 1891 collected reflections, 234 symmetry independent, R1 = 0.033, wR2 = 0.088) confirms the space group Fddd; a = 596.11(9), b = 1140.3(1), c = 1717.9(3) pm; Z = 8. K3[Fe2O4] exhibits a structure with [FeO4] tetrahedra connected via corners leading to a three‐dimensional network closely related to the KFeO2 type of structure. From the oxidation at 520 °C of iron metal with KO2 in the presence of Na2O black single crystal of K2[Fe2O4] have been obtained. K2[Fe2O4] crystallizes in the space group Pbca with Z = 8 and a = 559.18(7), b = 1122.1(1), c = 1592.8(2) pm (IPDS diffractometer data, MoKα, collected refelctions: 9543, 1213 symmetry independent, R1 = 0.043, wR2 = 0.102). 相似文献
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Huub Kooijman Stefania Tanase Elisabeth Bouwman Jan Reedijk Anthony L. Spek 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(11):m510-m512
The title compound, [Fe(C12H8N3O2)2]ClO4·2C2H3N, contains FeIII in a distorted octahedral coordination environment, with the Fe—N(pyridine) bonds significantly longer than the Fe—N(amine) bonds. The crystal packing involves a bifurcated C—H⋯(O,O) contact that is also found in all other [M(C12H8N3O2)2] complexes reported previously. 相似文献
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Srinivasan Natarajan Yurii Prots Bastian Ewald Rainer Niewa Rüdiger Kniep 《无机化学与普通化学杂志》2006,632(1):37-41
Two polymorphs of a zero‐dimensional (molecular) zinc phosphate with the formula [Zn(2,2′‐bipy)(H2PO4)2]2 have been synthesized by a mild hydrothermal route and their crystal structures were determined by single crystal X‐ray diffraction (triclinic, space group (No. 2), Z = 2, α‐form: a = 8.664(1), b = 8.849(2), c = 10.113(2) Å, α = 97.37(2)°, β = 100.54(2)°, γ = 100.98(2)°, V = 737.5(3) Å3; β‐form: a = 7.5446(15), b = 10.450(2), c = 10.750(2) Å, α = 67.32(3)°, β = 81.67(3)°, γ = 69.29(3)°, V = 731.4(3) Å3). Both structures consist of distorted trigonal‐bipyramidal ZnO3N2 units condensed with PO2(OH)2 tetrahedra through common vertices giving rise to dimers [Zn(2,2′‐bipy)(H2PO4)2]2. The structures are stabilized by extensive inter‐ and intramolecular hydrogen bond interactions. Both modifications display subtle differences in their packing originating from the hydrogen bond interactions as well as π…π interactions between the organic ligands. 相似文献
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Xiu‐Hong Yang Ming‐Xing Yang Li‐Juan Chen Jing Guo Shen Lin 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(5):369-373
The title compound, [Cd3(C8H10O4)3(C12H9N3)2(H2O)2]n or [Cd3(chdc)3(4‐PyBIm)2(H2O)2]n, was synthesized hydrothermally from the reaction of Cd(CH3COO)2·2H2O with 2‐(pyridin‐4‐yl)‐1H‐benzimidazole (4‐PyBIm) and cyclohexane‐1,4‐dicarboxylic acid (1,4‐chdcH2). The asymmetric unit consists of one and a half CdII cations, one 4‐PyBIm ligand, one and a half 1,4‐chdc2− ligands and one coordinated water molecule. The central CdII cation, located on an inversion centre, is coordinated by six carboxylate O atoms from six 1,4‐chdc2− ligands to complete an elongated octahedral coordination geometry. The two terminal rotationally symmetric CdII cations each exhibits a distorted pentagonal–bipyramidal geometry, coordinated by one N atom from 4‐PyBIm, five O atoms from three 1,4‐chdc2− ligands and one O atom from an aqua ligand. The 1,4‐chdc2− ligands possess two conformations, i.e.e,e‐trans‐chdc2− and e,a‐cis‐chdc2−. The cis‐1,4‐chdc2− ligands bridge the CdII cations to form a trinuclear {Cd3}‐based chain along the b axis, while the trans‐1,4‐chdc2− ligands further link adjacent one‐dimensional chains to construct an interesting two‐dimensional network. 相似文献
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Marciela Scarpellini Ademir Neves Adailton J. Bortoluzzi Antnio C. Joussef 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):356-358
In the title mononuclear complex, [Cu(C5H9N3)(C10H15N5)](ClO4)2, the CuII centre is surrounded by two N‐donor ligands, which impose a square‐pyramidal environment on the metal. The new tridentate ligand [2‐(imidazol‐4‐yl)ethyl][(1‐methylimidazol‐2‐yl)methyl]amine (HISMIMA) lies in the basal plane, while the histamine ligand occupies the apical and one of the basal positions around the CuII ion. 相似文献
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Synthesis and Crystal Structure of [C(NMe2)3]2[(CO)4Fe(μ‐InCl2)2Fe(CO)4] Treatment of [C(NMe2)3]2[(CO)4FeInCl3] ( 1 ) with hot water produces the dinuclear complex [C(NMe2)3]2[(CO)4Fe(μ‐InCl2)2Fe(CO)4] ( 2 ) which could be crystallized from dichloromethane/pentane. 2 crystallizes in the monoclinic space group P21/n with a = 835.7(1), b = 1187.8(1), c = 1902.7(1) pm, β = 91.877(5)° and Z = 2. The anion contains a four‐membered Fe—In—Fe—In ring with octahedral environment at the iron atom and tetrahedral coordination at the In atom. 相似文献