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971.
F Albert Cotton Evgeny V Dikarev Carlos A Murillo Marina A Petrukhina 《Inorganica chimica acta》2002,332(1):41-46
New dinuclear TiIV and TiIII complexes with the calix[4]arene ligand C28H20O4H4 (H4L) have been isolated from the reaction of Ti(NMe2)4, H4L, and Na (or KC8) in THF. X-ray analyses revealed a similar core structure for the two complexes Na4(THF)8[TiIV 2(μ-O)2L2] (1) and K4(THF)8[TiIII 2(μ-NMe2)2L2] (2). Two titanium atoms are bridged by two oxygen atoms in 1 and by two dimethylamido groups in 2 and are also supported by two deprotonated calix[4]arene ligands in a cone conformation. This resulted in a similar Ti?Ti separation of about 3.29 Å in 1 and 3.28 Å in 2 and in a distorted octahedral environment for each Ti center in both complexes. In contrast, in a novel complex 3, Na2(THF)6[TiIII 2L2], two TiIII atoms are supported only by two deprotonated ligands. This results in a five-coordinate environment for both titanium(III) centers with the separation between them being 3.133(1) Å. 相似文献
972.
One-pot reaction between MnCl2·4H2O, K2tcpd (tcpd2− = [C10N6]2− = (C[C(CN)2]3)2− = 2-dicyanomethylene-1,1,3,3-tetracyanopropanediide anion) and 2,2′-bipyrimidine (bpym = C8H6N4) in aqueous solution yields the new compound [Mn2(bpym)3(tcpd)2(H2O)2] (1). The molecular structure of 1 consists of a centrosymmetrical binuclear complex which includes unprecedented unidentate tcpd ligands with two bidentate and a bis-chelate bpym units. Examination of the intermolecular distances reveals that the dinuclear units are held together by hydrogen bonds involving coordinated water molecules and two nitrile groups of the tcpd ligand, giving rise to a 2D structure overall. Variable-temperature magnetic susceptibility data show the occurrence of slight antiferromagnetic coupling (J = −0.58 cm−1) between the Mn(II) ions through bridging bpym (the exchange Hamiltonian being defined as ). 相似文献
973.
Craig A. Grapperhaus Majda Kreso Gretchen A. Burkhardt Julianna V.F. Roddy Mark S. Mashuta 《Inorganica chimica acta》2005,358(1):123-130
Alkylation of bis(2-aminoethanethiolato)nickel(II) (1) with alkylating agents containing pendant donor groups has been investigated. Reaction with 2-bromoethylamine is strictly sulfur-centered yielding (2-[(2-aminoethyl)thio]ethaneamine)nickel(II)bromide, [(DAES)2Ni]Br2 (2), which was isolated as a lilac solid. Addition of chloroacetamide yields the sulfur- and nitrogen-alkylated product (2-[(2-aminoethyl)thio]acetamide)nickel(II)chloride, (AETA)NiCl2 (3a), as a green solid. Recrystallization from water/acetone yields 3a as single crystals along with single crystals of [(AETA)NiCl(OH2)]Cl (3b). The strictly S-alkylated product (2-[(2-amino-2-oxoethyl)thio]acetamide)nickel(II)iodide, [(AOTA)2Ni]I2 (4), is obtained upon reaction of 1 with iodoacetamide. A pathway is proposed consistent with the observed leaving group effect on the site of alkylation. The X-ray structures of 3a, 3b, and 4 are reported and the hydrogen-bonding network is described. 相似文献
974.
J.A. Maldonado Calvo 《Inorganica chimica acta》2005,358(13):4019-4026
The new N3O ligand 2-(pyridylmethylamino)-3-(3,5-dimethylpyrazol-1-yl)-propionic acid (L1H) was synthesized and converted to L1Zn-Cl and L1Zn-Br. These complexes are tetrameric in the solid state with bridging carboxylate functions. The reaction of deprotonated L1H with zinc nitrate or zinc perchlorate yielded the aqua complexes [L1Zn-OH2] X with and , which crystallize as carboxylate-bridged dimers. Their deprotonation produced, in situ, the hydroxide complex L1Zn-OH, which acted as a base toward p-nitrophenol and bis(p-nitrophenyl)phosphoric acid resulting in L1Zn-ONit and L1Zn-OPO(ONit)2. Tris(p-nitrophenyl)phosphate was cleaved hydrolytically by L1Zn-OH, releasing one p-nitrophenyl group. A kinetic investigation of this cleavage reaction under pseudo-first-order conditions has yielded second-order rate constants k″ of 0.9 s−1 M−1 in 50% aqueous DMSO and 4.0 s−1 M−1 in 75% aqueous DMSO. 相似文献
975.
Ludovic Chahen 《Inorganica chimica acta》2005,358(12):3417-3422
The new aryl phosphinites PPh2OR (R = 2,4,6-Me3C6H2, 1; R = 2,6-Ph2C6H3, 2) have been prepared from chlorodiphenylphosphine and the corresponding phenols. In these ligands, the ortho-positions of the aromatic phosphite function are blocked by methyl and phenyl substituents, which allows coordination to metal centres without ortho-metallation. Thus, reaction with [PdCl2(cod)] leads to the complexes trans-[PdCl2(PPh2OR)2] (R = 2,4,6-Me3C6H2, 3; R = 2,6-Ph2C6H3, 4), while the reaction with [Rh2(CO)4Cl2] gives trans-[Rh(CO)Cl(PPh2OR)2] (R = 2,4,6-Me3C6H2, 5; R = 2,6-Ph2C6H3, 6). The single-crystal X-ray structure analyses of 3 and 5 confirm the trans-coordination of the new ligands in these square-planar complexes. 相似文献
976.
The synthesis, the spectroscopic and structural characterization of different thiophenolate-capped zinc clusters are reported and described. In particular, different reactions of 4-chlorobenzenethiol with zinc salts yield the clusters [Me4N][Et3NH][Zn4(μ-S-C6H4-Cl)6(S-C6H4-Cl)4] (2a), [Et3NH]2[Zn4(μ-S-C6H4-Cl)6(S-C6H4-Cl)4] (2b), and [Me4N]2[Zn4(μ-S-C6H4-Cl)6(S-C6H4-Cl)4] (2c), and also the thiophenolate derivative [Et3NH]2[Zn4(μ-S-C6H5)6(S-C6H5)4] (1b) was obtained.The nanosized thiophenolate-capped clusters were investigated by 1H and 13C NMR, elemental analysis, and electrospray ionization (ESI) mass spectrometry. NMR experiments provided insights into the dynamic behaviour of the clusters. The thermal decomposition patterns of 2c were analyzed in air as well as in nitrogen, indicating the formation of zinc oxide and metallic zinc, respectively. The X-ray structure of 2a revealed that the cluster core consists of an adamantane-like framework analogous to those realized in many other M4(SR)10 metal complexes. 相似文献
977.
The reactions of O2CH3 radicals with CuII(glycine)2 and CuII(GGG), GGG = glycylglycylglycine, in aqueous solutions were studied.The results demonstrate that the peroxyl radicals oxidize the copper complexes forming relatively stable intermediates of the type LmCuIII-OOCH3. These intermediates decompose via oxidation of the ligands glycine and GGG, respectively. Substituents on the alkyl of the peroxyl radical affect somewhat the kinetics of reaction but not the mechanism of oxidation. It is suggested that analogous reactions are probably contributing to the radical-induced deleterious biological processes. 相似文献
978.
Thomas Riis-Johannessen John C. Jeffery Craig R. Rice 《Inorganica chimica acta》2005,358(9):2781-2798
Reaction of the potentially tetradentate N-donor ligand 6,6′-bis(4-methylthiazol-2-yl)-2,2′-bipyridine (L1) with the transition metal dications CoII, NiII, CuII, CdII and HgII results in the formation of mononuclear [M(L1)]2+ complexes, in which a planar ligand coordinates to the metals via all four N-donors. In contrast, reaction of L1 with CuI and AgI monocations, affords dinuclear double stranded helicate species [M2(L1)2]2+ (where M = CuI or AgI), in which partitioning of the ligand into two bis-bidentate pyridyl-thiazole chelating units allows each ligand to bridge both metal centres. X-Ray crystallography, electrospray mass spectroscopy and NMR spectroscopy reveal that the complexes [Mn(L1)m]z+ (where n = 1, m = 1 and z = 2, when M = CoII, NiII, CuII, CdII and HgII; n = 2, m = 2 and z = 2, when M = CuI), retain their solid-state structures in solution. Conversely, whilst 1H NMR studies suggest that combination of equimolar amounts of Ag(X)(where ) and L1 (in either nitromethane or acetonitrile) results in the formation of a helicate in solution, in the solid-state, an anion-templating effect gives rise to either mononuclear or dinuclear helicate structures [Agn(L1)n][X]n (where n = 2 when X = OTf−; n = 1 when ). 相似文献
979.
The reaction of quadruply bonded dimolybdenum complex, [Mo2(μ-OAc)4] (1), with lithiated amidinato, Li[(NiPr)2CR] (R = tBu; 2a, Me; 2b, Ph; 2c), was investigated. The reaction of 1 with 2a afforded the dark-red solid, whereas the product was so highly unstable that the product was not able to be characterized. In the case of acetamidinato 2b, lantern-type mixed-ligand quadruply bonded dimolybdenum complex, [Mo2(μ-OAc){μ-(NiPr)2CMe}3] (3), was obtained as a yellow solid. In the reaction with benzamidinato 2c, symmetrical lantern-type dimolybdenum complex, [Mo2(μ-OAc)2 {μ-(NiPr)2CPh}2] (4), was isolated as a yellow solid. In the latter reaction, intermediary red compound (5), which is considered to be stereoisomer of 4 possessing non-lantern-type skeleton, was formed. However, isolation of 5 as a single component was not successful due to isomerization to 4. Complex 5 readily reacted with dry oxygen to give dimolybdenum(V) complex, [{Mo(η-(NiPr)2CPh)oxo}2 (μ-OAc)2(μ-oxo)] (6), as a red solid. These complexes were characterized spectroscopically as well as, in some cases, by X-ray analyses. 相似文献
980.
The preparation and characterization of organolithium O,C,O-pincer compound [2,6-(tBuOCH2)2C6H3]-Li (1) is described. The X-ray diffraction techniques revealed the dimeric structure of 1 consisting of two lithium atoms Li(1) and Li(2) and two monoanionic chelating aryl ligands in the solid state, where each lithium atom is coordinated by two oxygen atoms of two different ligands. The NMR spectroscopy and cryoscopy measurements established monomer-dimer equilibrium of 1 in concentrated solutions of non-coordinated solvents, while the diluted solutions of 1 consist of monomer only. 相似文献