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1.
The title compound, di‐μ‐diethyl­amido‐N:N‐bis­[chloro­di­methyl­tin(IV)], consists of discrete [Sn2Cl2(CH3)4(C4H10N)2] dimer mol­ecules, with Sn atoms linked by bridging diethyl­amido groups. The coordination geometry about the metal atom is distorted trigonal bipyramidal, with the two methyl C atoms and one N atom in the equatorial plane, and the Cl and second N atom in axial positions.  相似文献   

2.
Seven new bi‐ and polyhomonuclear transition metal complexes with three polyhydroxlated bisazodianil ligands were synthesized and characterized. The ligands were derived from condensation of 6‐(5‐formyl‐2‐hydroxyphenylazo)‐2,4‐dihydroxypyrimidine with aliphatic diamines (H8L1, H8L2 and H6L3). The data of elemental and thermal analyses, molar conductance measurement, IR, electronic and ESR spectra as well as magnetic moment measurements support the formation of [L1Co7Cl6(H2O)10]·22H2O ( 1 ), [H2L2Mn6Cl6(H2O)8]·3H2O·2EtOH ( 3 ), [L2Co8Cl8(H2O)12]·24H2O ( 4 ), [H4L3Co2Cl2(H2O)2]·8H2O·2EtOH ( 6 ) with a tetrahedral geometry and [H2L1Ni5Cl4(H2O)16]·19H2O·EtOH ( 2 ), [L2Ni8Cl8(H2O)28]·8H2O·EtOH ( 5 ) with an octahedral geometry while [H6L3Cu3(H2O)7]Cl3·10H2O ( 7 ) has a distorted tetrahedral arrangement. The mode of bonding between the metal ions and the ligand molecules is determined and the metal‐metal interaction was studied. The activation thermo‐kinetic parameters for the thermal decomposition steps of the complexes E*, ΔH*, ΔS*, and ΔG* were calculated.  相似文献   

3.
Four Schiff base complexes, [Zn2L2(NCS)2] ( 1 ), [Cd2L2(NCS)2]n ( 2 ), [Zn4L2(N3)2Cl4(OH2)(CH3OH)] ( 3 ), and [Cu4L2(N3)2Cl4(OH2)(CH3OH)] ( 4 ) (where L = 2‐[(2‐dimethylaminoethylimino)methyl]phenol), were synthesized and characterized by elemental analyses, infrared spectroscopy, and single crystal X‐ray determinations. Both 1 and 2 are structurally similar polynuclear complexes. In 1 , each Zn atom has a slightly distorted square‐pyramidal coordination configuration. In the basal plane, the Zn atom is coordinated by one O and two N atoms of one L, and by one O atom of another L. The apical position is occupied by one terminal N atom of a coordinated thiocyanate anion. The Zn···Zn separation is 3.179(3) Å. While in 2 , the Cd1 atom is six‐coordinated in an octahedral coordination. In the equatorial plane, the Cd1 atom is coordinated by one O and two N atoms of one L, and by one O atom of another L. The axial positions are occupied by the terminal N and S atoms from two bridging thiocyanate anions. The coordination of Cd2 atom in 2 is similar to those of the zinc atoms in 1 . The Cd···Cd separation is 3.425(2) Å. Both 3 and 4 are novel tetra‐nuclear complexes. Each metal atom in the complexes has a slightly distorted square‐pyramidal coordination. The arrangements of the terminal metal atoms are similar, involving one O and two N atoms of one L ligand and one bridging Cl atom defining the basal plane, and one O atom of a coordinated water molecule or MeOH molecule occupying the apical position. The coordinations of the central metal atoms are also similar. The basal plane of each metal atom involves one O atom of one L ligand, one terminal Cl atom, and two terminal N atoms from two bridging azide groups. The apical position is occupied by a bridging Cl atom which also acts as a basal donor atom of the terminal metal atom. The Schiff base ligand and the four complexes showed high selectivity and antibacterial activities against most of the bacteria.  相似文献   

4.
Model Pb(II) thiocomplexes with mono- and bidentate ligands of the composition [Pb(L1,2) n ]2−n (L1 is (SC6H5) (thiophenolate ion), L2 is (S2CN(CH3)2) (dithiocarbamate ion), n is the number of ligands of 2–6), which simulate fragments of the crystal structures of Pb(II) complex compounds with organic ligands, are studied within density functional theory. Geometric and energy parameters of model complexes with different coordination geometries of the Pb atom are determined and the stereochemical activity of the lone electron pair (LEP, E) of the Pb2+ ion is estimated in them. In the studied complexes, the highest Pb-S binding energy is found for the Pb atom surrounded by 2–4 ligands. The geometry of the Pb atom coordinated by S donor atoms can be described in terms of the valence shell electron pair repulsion (VSEPR) model with stereochemically active LEP. The coordination number (cn) of the Pb atom in the most energetically favorable complexes [Pb(SC6H5) n ]2−n is (3+E) − (4+E), and in [Pb(S2CN(CH3)2) n ]2−n complexes, it is (4+E) and (6+E). Configurations with the mentioned cns are most often observed in the crystal structures of Pb(II) thiocomplex compounds.  相似文献   

5.
Metal complexes of the antimalarials trimethoprim (TMP), chloroquine (CQ), and pyrimethamine (pyrm) formulated as [Mn(TMP)Cl2(CH3OH)], [Co(TMP)2Cl2(CH3OH)], [Pt(CQ)2Cl2] and [Cu(pyrm)2(CH3COO)2] have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, IR and UV-Vis spectroscopy. The IR and electronic spectra are consistent with the proposed geometry for the complexes. The Mn(II) and Pt(II) complexes are four coordinate while the Cu(II) and Co(II) have octahedral geometry. The complexes were tested for in vitro activity against cultures of Trypanosoma cruzi, L. donovani, T. b. rhodesiense and the resistant strains of Plasmodium falciparum to determine their antiprotozoal activities and for their cytotoxicity with L-6 cells. The Pt(II) complex of chloroquine showed enhanced activity against the resistant strain of Plasmodium falciparum.  相似文献   

6.
The Cl atom-initiated oxidation of CH2Cl2 and CH3Cl was studied using the FTIR method in the photolysis of mixtures typically containing Cl2 and the chlorinated methanes at 1 torr each in 700 torr air. The results obtained from product analysis were in general agreement with those reported by Sanhueza and Heicklen. The relative rate constant for the Cl atom reactions of CH2Cl2 and CH3Cl was determined to be k(Cl +CH3Cl)/k(Cl + CH2Cl2) = 1.31 ± 0.14 (2σ) at 298 ± 2 K.  相似文献   

7.
Two new uranyl complexes [UO2(DPDPU)2(NO3)2](C6H5CH3) (1) and [UO2(PMBP)2 (DPDPU)](CH3C6H4CH3)0.5 (2), (DPDPU?=?N,N′-dipropyl-N,N′-diphenylurea, HPMBP?= 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5) were synthesized and characterized. The coordination geometry of the uranyl atom in 1 is distorted hexagonal bipyramidal, coordinated by two oxygen atoms of two DPDPU molecules and four oxygen atoms of two bidentate nitrate groups. The coordination geometry of the uranyl atom in 2 is distorted pentagonal bipyramidal, coordinated by one oxygen atom of one DPDPU molecule and four oxygen atoms of two chelating PMBP molecules.  相似文献   

8.
Reaction of 1‐phenyl‐4‐phenylacetyl‐2‐thiosemicarbazide (H2L) with diphenyllead(IV) dichloride and acetate afforded the complexes [PbPh2Cl2(H2L)2] and [PbPh2L]. The ligand and the complexes were characterized by elemental analyses, 1H and 13C NMR spectroscopy and X‐ray crystallography. In the asymmetric unit of crystals of the ligand there are four independent molecules of H2L and four molecules of water, which associate in the lattice as two independent sheets. The complex [PbPh2Cl2(H2L)2]·4MeOH has slightly distorted all‐trans octahedral geometry around the lead atom, and the fact that the ligand is S‐bound rather than O‐bound suggests that PbPh2Cl2 behaves as a “soft” Lewis acid. Hydrogen bonds involving NH groups, Cl atoms and MeOH molecules form a three‐dimensional supramolecular structure. In [PbPh2L]·Me2CO, the L2? anion bridges between two metal centres, binding to one strongly via the N and S atoms and weakly via the O atom, and to the other via the O atom, thus creating polymeric chains along the b axis. The double deprotonation and metallation of H2L induce significant changes in its configuration and lengthen the C‐S and C‐O bonds, suggesting an evolution of the dianion towards a thiol‐enol form.  相似文献   

9.
Two cobalt complexes, [Co(LSe)(phen)] · CH2Cl2 (1) and [Co(LSe)(N,N-Me2en)(CH3COO)] (2) have been synthesized and characterized by elemental analyses, magnetic measurements, i.r. studies etc. Single crystal X- ray studies reveal that in complex (1) cobalt atom is in +2 oxidation state with trigonal bipyramidal geometry, while in complex (2) it is in +3 oxidation state and surrounded octahedrally. The asymmetric unit of complex (2) contains two crystallographically independent discrete molecules. Complex (1) was found to be paramagnetic with μeff = 2.19 BM indicating a low spin cobalt(II) d7 system, whereas complex (2) is found to be diamagnetic with cobalt(III) in low spin d6 state. The kinetic studies on the reduction of (2) by ascorbic acid in 80% MeCN–20% H2O (v/v) at 25 °C reveal that the reaction proceeds through the rapid formation of inner-sphere adduct, probably by replacing the loosely coordinated AcO group, followed by electron transfer in a slow step and is supported by a large Q (formation constant) value.  相似文献   

10.
Three mercury(II) complexes containing double-betaine and halide ligands, [(HgCl2)2(L1)] n (1), [(HgBr2)2(L1)(H2O)2] n (2), and [2HgCl2(HL1)·Hg2Cl6] n (3) [L1=O2CCH2N+(CH2CH2)3-N+H2CO2 ], have been prepared and shown to have polymeric structures by single-crystal X-ray analysis. Complex (1) exhibits an infinite zigzag chain in which each mercury(II) atom is coordinated by pairs of carboxylate oxygen atoms and chloride ligands in a distorted tetrahedral geometry. In complex (2), the mercury(II) atom is in an unusual square-planar coordination geometry, and weak mercury-ligand and hydrogen bonding extend the structural skeletons into a three-dimensional network. Complex (3) consists primarily of an assembly of HgCl2(HL1) moieties and [Hg2Cl6] anions, and the mercury(II) atoms are in planar T-shaped and distorted tetrahedral coordination environments, respectively. The resulting three-dimensional network is based on the cross-linkage of nearly planar, wide ribbons running in thea direction.  相似文献   

11.
Abstract

The synthesis of Ti(iso)Cl2 (iso = the dianion of 2, 2′-ethylidenebis(4, 6-di-rert-butylphenol)) is described. Metathesis reactions of this complex with Grignard reagents, as well as alkali metal salts, yielded Ti(iso)X2 (X = CH3, CH, Ph, CH2SiMe3, OCMe3, or NMe2). Reactions of the Ti-C bond in Ti(iso)(CH3)2 toward halogens, active hydrogen compounds, and acetone were studied. In addition. Ti(iso)(X)(Y) (X = CI or CH3; Y = OC6H2-2, 6-tBu2-4-Me) could be prepared with the formation of only one coordination isomer. The new complexes have been thoroughly characterized by 1H and 13C NMR spectroscopies. The solid state structure of Ti(iso)Cl2 was determined via single crystal X-ray diffraction methods. The complex is monomeric, with approximately tetrahedral geometry about the titanium ion. The structure of Ti(iso)Cl2 is compared to that of Ti(ultra)Cl2 (ultra = the dianion of 2, 2′-mefhylenebis(6-tert-butyl-4-mefhylphenol)), which was redetermined to greater precision.  相似文献   

12.
Two new Ni(II) complexes of 2,6-bis[1-(2,6-diethylphenylimino)ethyl]pyridine (L1), 2,6-bis[1-(4-methylphenylimino)ethyl]pyridine (L2 ) have been synthesized and structurally characterized. Complex Ni(L1)Cl2?·?CH3CN (1), exhibits a distorted trigonal bipyramidal geometry, whereas complex Ni(L1)(CH3CN)Cl2 (2), is six-coordinate with a geometry that can best be described as distorted octahedral. The catalytic activities of complexes 1, 2, Ni{2,6-bis[1-(2,6-diisopropyl-phenylimino)ethyl]pyridine} Cl2?·?CH3CN (3), and Ni{2,6-bis[1-(2,6-dimethylphenylimino) ethyl]pyridine}Cl2?·?CH3CN (4), for ethylene polymerization were studied under activation with MAO.  相似文献   

13.
Hu  Chuanjiang  Zhang  Wenwei  Xu  Yan  Zhu  Huizhen  Ren  Xiaoming  Lu  Changsheng  Meng  Qingjin  Wang  Huaqin 《Transition Metal Chemistry》2001,26(6):700-703
New racemic complexes of titanium with Schiff bases derived from condensation of salicylaldehyde with dl-alanine (H2Sal-dl-Ala) and dl-valine (H2Sal-dl-Val) have been prepared. The crystal structure of [(Sal-dl-Val)2Ti·CH2Cl2 bis(N-salicylidenevalinato)titanate(IV) CH2Cl2] has been solved by single-crystal X-ray diffraction methods; the crystal is a racemate consisting of a pair of enantiomers (Sal-d-Val)2Ti and (Sal-l-Val)2Ti. The Schiff-base ligand acts as a double negatively-charged tridentate ONO chelate, coordinated to the titanium atom. The geometry around titanium is a distorted octahedron. The i.r. and u.v.–vis. spectra of the complexes have been evaluated.  相似文献   

14.
Abstract

Preparation and isolation of a pentanuclear mixed metal complex having the formula [Cu3Y2(Cl?CH2COO)12(H2O)8] · 2H2O was accomplished by the reaction of a mixture of copper(II) nitrate and yttrium nitrate with sodium chloroacetate in aqueous solution. The structure of the complex was determined by X-ray crystallography. It consists of linear centrosymmetric pentanuclear molecules with a four-coordinate copper atom at the inversion site and the other two copper atoms having a 4 + 1 coordination geometry at both ends. Two yttrium atoms separate the three copper atoms. Each yttrium atom is bridged to the neighbouring terminal copper atom by four carboxylato ligands in a syn-syn fashion forming a dimer with the Y…Cu distance being 3.5311(8) Å. Each dimer is then linked to the central copper atom via a carboxylato bridging ligand in a syn-anti fashion. Two other carboxylato ligands coordinate to the central copper to complete its planar coordination. The apical site of each terminal copper atom is occupied by a water molecule. The eight-coordinate geometry of each yttrium atom is completed by three water molecules. Bridging and the monodentate carboxylato ligands were characterized by IR analysis. TG studies confirmed the numbers of coordinated and lattice water molecules.  相似文献   

15.
The [M(HL)2(H2O)2]X2 complexes were synthesized (M = Mn(II), Co(II), Ni(II), Cu(II), Zn; X = CH3COO, Cl, BF4 ) that incorporate bidentately coordinated molecules of N,N-dimethylhydrazide of 4-nitrobenzoic acid (HL). The latter molecules chelate the metal atom through the carbonyl O atom and the N atom of dimethylamino group. The square-planar complexes of Cu and Ni with deprotonated form of a ligand with composition ML2 were also isolated. The synthesized complexes were studied by IR, electronic and EPR spectroscopies, and by cyclic voltammetry.  相似文献   

16.
The reaction of Schiff base 1,7-bis-(pyridin-2-yl)-2,6-diaza-1,6-heptadiene (L) with either NiCl2·6H2O or [PdIICl2(CH3CN)2]/Na[BF4] in 1?:?1 stoichiometry yielded mononuclear ionic complexes, trans-[NiII(L)(H2O)2]Cl2·3H2O (1·3H2O) and [PdII(L)][BF4]2 (2), respectively; the reaction of L with [PdIICl2(CH3CN)2] in 1?:?2 ratio yielded dinuclear cis-[PdII 2(μ-L)Cl4] (3). Complexes 1–3 were characterized by vibrational spectroscopy and X-ray diffraction; diamagnetic 2 and 3 were also characterized by NMR in solution. The molecular structures of 1 and 2 displayed tetradentate coordination of L with formation of two five-membered and one six-membered chelate rings for both complexes. In 3, L showed bidentate coordination mode for each pyridylimine toward PdII. Complex 1 has distorted octahedral geometry around NiII and an extended hydrogen-bond network; distorted square planar geometry around PdII in 2 and 3 was observed.  相似文献   

17.
Two new potentially octadentate N2O6 Schiff-base ligands 2-((E)-(2-(2-(2-((E)-2-hydroxy-3-methoxybenzylideneamino)phenoxy)phenoxy)phenylimino)methyl)-6-methoxyphenol H2L1 and 2-((E)-(2-(2-(2-((E)-2-hydroxy-3-methoxybenzylideneamino)phenoxy)-4-tert-butylphenoxy)phenylimino)methyl)-6-methoxyphenol H2L2 were prepared from the reaction of O-Vaniline with 1,2-bis(2′-aminophenoxy)benzene or 1,2-bis(2′-aminophenoxy)-4-t-butylbenzene, respectively. Reactions of H2L1 and H2L2 with copper(II) and zinc(II) salts in methanol in the presence of N(Et)3 gave neutral [CuL1]?·?0.5CH2Cl2, [CuL2], [ZnL1]?·?0.5CH2Cl2, and [ZnL2] complexes. The complexes were characterized by IR spectra, elemental analysis, magnetic susceptibility, ESI–MS spectra, molar conductance (Λm), UV-Vis spectra and, in the case of [ZnL1]?·?0.5CH2Cl2 and [ZnL2], with 1H- and 13C-NMR. The crystal structure of [ZnL1]?·?0.5CH2Cl2 has also been determined showing the metal ion in a highly distorted trigonal bipyramidal geometry. The electrochemical behavior of H2L2 and its Cu(II) complex, [CuL2], was studied and the formation constant of [CuL2] was evaluated using cyclic voltammetry. The logarithm value of formation constant of [CuL2] is 21.9.  相似文献   

18.
The valence shell electron pair repulsion (VSEPR) model—also known as the Gillespie–Nyholm rules—has for many years provided a useful basis for understanding and rationalizing molecular geometry, and because of its simplicity it has gained widespread acceptance as a pedagogical tool. In its original formulation the model was based on the concept that the valence shell electron pairs behave as if they repel each other and thus keep as far apart as possible. But in recent years more emphasis has been placed on the space occupied by a valence shell electron pair, called the domain of the electron pair, and on the relative sizes and shapes of these domains. This reformulated version of the model is simpler to apply, and it shows more clearly that the Pauli principle provides the physical basis of the model. Moreover, Bader and his co-workers' analysis of the electron density distribution of many covalent molecules have shown that the local concentrations of electron density (charge concentrations) in the valence shells of the atoms in a molecule have the same relative locations and sizes as have been assumed for the electron pair domains in the VSEPR model, thus providing further support for the model. This increased understanding of the model has inspired efforts to examine the electron density distribution in molecules that have long been regarded as exceptions to the VSEPR model to try to understand these exceptions better. This work has shown that it is often important to consider not only the relative locations and sizes, but also the shapes, of both bonding and lone pair domains in accounting for the details of molecular geometry. It has also been shown that a basic assumption of the VSEPR model, namely that the core of an atom underlying its valence shell is spherical and has no influence on the geometry of a molecule, is normally valid for the nonmetals but often not valid for the metals, including the transition metals. The cores of polarizable metal atoms may be nonspherical because they include nonbonding electrons or because they are distorted by the ligands, and these nonspherical cores may have an important influence on the geometry of a molecule.  相似文献   

19.
A series of titanium(IV) complexes Ti(O‐i‐Pr)Cl3(THF)(PhCOR) (R = H ( 1 ), CH3 ( 2 ), or Ph ( 3 )) is prepared quantitatively from reactions of [Ti(O‐i‐Pr)Cl2(THF)(μ‐Cl)]2 with 2 molar equiv. PhCOR. Treatment of Ti(O‐i‐Pr)Cl3 with 2 molar equiv. of PhCOR affords the disubstituted complexes Ti(O‐i‐Pr)Cl3(PhCOR)2 (R = CH3 ( 4 ) or Ph ( 5 )). The 13C NMR study of these complexes shows that the relative bonding abilities are in the order of PhCOCH3 > PhCHO > PhCOPh. The molecular structure of 5 reveals that one of the benzophenone ligands is trans to the strongest 2‐propoxide ligand with a long Ti‐O(carbonyl) distance of 2.193(5) Å which is much longer than the other Ti‐O(carbonyl) distance of 2.097(4) Å by ?0.1 Å. All ligands cis to the alkoxide ligand are bending away from the alkoxide ligand with the RO‐Ti‐L angles ranging from 93.6(2) to 99.0(2)°.  相似文献   

20.
The title compound, [Ti2(CF3O3S)4(C14H15NO2S)2]·2CH2Cl2, consists of unique centrosymmetric dimers, with an eight‐membered ring derived from the monomer subunits by formation of two Ti—(N,O)—S—O head‐to‐tail sequences around a crystallographic inversion centre, and two ordered di­chloro­methane solvate mol­ecules. The Ti ion has distorted octahedral coordination, through the N atom and one O atom of one p‐toluene­sulfon­amido group linked by an ethyl group to the bound cyclo­penta­diene moiety, one O atom from the other p‐toluene­sulfon­amido group and two singly bound tri­fluoro­methanesulfonates moieties which are coordinated in pseudo‐cis positions. Both Ti—O(sulfonamido) bond lengths [2.149 (3) and 2.388 (3) Å] are considered bonding interactions.  相似文献   

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