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941.
Mathieu Auzias 《Inorganica chimica acta》2006,359(10):3412-3416
The thermal reaction of Ru3(CO)12 with the biologically active acids acetyl salicylic acid (Aspirin), α-methyl-4-(isobutyl)phenylacetic acid (Ibuprofen) and 3α,7α,12α-trihydroxy-5β-cholanic acid (cholic acid) in refluxing tetrahydrofuran, followed by addition of triphenylphosphine, gives the dinuclear complexes Ru2(CO)4(OOCR)2(PPh3)2 (1: R = C6H4-2-OCOMe, 2: R = CHMe-C6H4-4-Bui, 3: C23H39O3). The single-crystal structural analysis of 1 and 2 reveals a dinuclear Ru2(CO)4 sawhorse structure, the diruthenium backbone being bridged by the carboxylato ligands, while the two phosphine ligands occupy the axial positions at the ruthenium atoms. However, chiral carbon atoms in the carboxylic acid undergo racemisation during the thermal reaction. 相似文献
942.
The dinuclear terephthalato-bridged nickel(II) complexes [Ni2(cyclen)2(μ-tp)](ClO4)2 (1) [Ni2(trpn)2(μ-tp)(H2O)2](ClO4)2 (2) and [Ni2(3,3,3-tet)2(μ-tp)(H2O)2](ClO4)2 · 2H2O (3), where tp = terephthalate dianion, cyclen = 1,4,7,10-tetraazacyclododecane, trpn = tris(3-aminopropyl)amine and 3,3,3-tet = 1,5,9,13-tetraazatridecane, were synthesized and structurally characterized by X-ray crystallography. Their magnetic susceptibilities were also determined at variable temperatures over the range 2-300 K. The structures of these complexes consist of μ-tp bridging two Ni(II) centers in a bis(bidentate) bonding fashion in 1 and in bis(monodentate) bonding fashion in 2 and 3. The coordination geometry around the Ni(II) ions in these compounds has a distorted octahedral geometry with four nitrogen atoms from the amine ligand (cyclen, trpn or 3,3,3-tet) and two coordinated oxygen atoms supplied by the chelated carboxylate group of the bridged terephthalate ligand in 1, and by one tp-carboxylate-oxygen in 2 and 3. The sixth coordination site in the last two complexes 2 and 3 is achieved via an oxygen atom from a coordinated water molecule. The intradimer Ni…Ni distances in these complexes are 10.740, 11.428 and 11.537 Å for 1, 2 and 3, respectively. The electronic spectra of the complexes in aqueous solutions are in complete agreement with the assigned X-ray geometry around the Ni(II) centers. Also, the analysis of the infrared spectral data for the ν(COO−) stretching frequencies of the tp-carboxalato groups reveals the existence of the bis(bidentate) and bis(monodentate) coordination modes for the bridged terephthalate ligand in 1, 2 and 3, respectively. Despite the different coordination modes of the tp bridging ligand in these complexes, they all exhibit very weak antiferromagnetic coupling. The coupling constants J were found to be −2.2, −0.6 and −1.5 cm3 K mol−1 for the complexes 1, 2 and 3, respectively. The structural and magnetic results of 1-3 are discussed in relation to the other related published μ-terephthalato dinuclear Ni(II) compounds. 相似文献
943.
Qing-Jiang Pan 《Inorganica chimica acta》2006,359(10):3306-3314
Based on their MP2 optimized structures in the ground states, we obtained solution absorption spectra for trans-[PtII(CCR)2(PH3)2] (R = H (1) and Ph (2)) and trans-[PtII(CCH)2(PH2CH2PH2)]2 (3) under the time-dependent density functional theory calculations. These absorptions agree with experimental observations. The unrestricted MP2 optimization performed for 3 in the lowest-energy triplet excited state shows that upon excitation the PtPt distance shortens about 0.347 Å with respect to the 3.188 Å one in the ground state. The UMP2 calculations estimated that its 3[σ∗(dz2)σ(pz)] excited state produces the 531 nm emission, corresponding to the 580 nm one of trans-[PtII(CCPh)2(PPh2CH2PPh2)]2 in the solid state at 298 K. 相似文献
944.
Cobalt(II) complexes of sulfadiazine formulated as [Co(C10H9N4O2S)2(CH3OH)2] and [Co(C10H9N4S)2(H2O)2] have been synthesized and characterized by elemental analysis, infrared and UV-Vis spectroscopy and magnetic susceptibility measurements. The crystal structures of the complex [Co(C10H9N4O2S)2(CH3OH)2] and of free sulfadiazine are also reported. The cobalt complex and the sulfadiazine ligand both crystallize in the monoclinic space group, P21/c, with sulfadiazine acting as a bidentate ligand. Cobalt is coordinated to two-sulfonamide nitrogen and the pyrimidine nitrogen of the sulfadiazine. Two molecules of methanol complete the octahedral geometry around the cobalt, with interligand hydrogen bonding between methanol and sulfadiazine. Infrared spectroscopy confirmed the presence of water molecule in the coordination sphere of [Co(C10H9N4S)2(H2O)2]. The electronic spectra and magnetic moments of both complexes were similar, indicating that both complexes have similar structure. 相似文献
945.
The heterotrimetallic complex, [{LCuMn(H2O)}{Cr(phen)(C2O4)2}](ClO4) · H2O (1), has been obtained by assembling heterobinuclear cations, [LCuMn]2+, with [Cr(phen)(C2O4)2]− ions (H2L is the compartmental Schiff-base resulting from the stepwise condensation of 2,6-diformyl-p-cresol with ethylenediamine and diethylenetriamine). The copper(II) and manganese(II) ions are hosted into the compartments of the macrocyclic ligand. [Cr(phen)(C2O4)2]− acts as a ligand, being coordinated through one oxalato oxygen atom to the apical position of the square pyramidal copper(II) ion. The cryomagnetic investigation of 1 reveals an antiferromagnetic interaction between CuII and MnII within the compartmental ligand (J = −39 cm−1). The interaction between CuII and CrIII across the oxalato bridge is negligible. The crystal structure of [LCuPb](ClO4)2 · H2O, a useful precursor in obtaining 3d-3d′ complexes, is also reported. 相似文献
946.
Luigi Busetto 《Inorganica chimica acta》2006,359(10):3345-3352
Different protic nucleophiles (i.e.Ph2CNH, PhSH, MeCO2H, PhOH) can be added to the CC bond of [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){C(OMe)CCTol}(Cp)2][SO3CF3] (1), affording new diiron alkenyl methoxy carbene complexes.The additions of Ph2CNH and MeCO2H are regio and stereoselective, resulting in the formation of the 5-aza-1-metalla-1,3,5-hexatriene [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){Cα(OMe)CβHCγ(Tol)(NCPh2)}(Cp)2][SO3CF3] (2), and the 2-(acyloxy)alkenyl methoxy carbene complex [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){Cα(OMe)CβHCγ(Tol)OC(O)Me)}(Cp)2][CF3SO3] (5); the E isomer of the former and the Z of the latter are formed exclusively.Conversely, the addition of PhSH is regio but not stereoselective; thus, both the E and Z isomers of [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){Cα(OMe)CβHCγ(Tol)(SPh)}(Cp)2][SO3CF3] (3) are formed in comparable amounts.Compounds 3 and 5 are demethylated upon chromatography through Al2O3, resulting in the formation of the acyl complexes [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){Cα(O)CβHCγ(Tol)(SPh)}(Cp)2] (4) and [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){Cα(O)CβHCγ(Tol)OC(O)Me}(Cp)2] (6), respectively, both with a Z configured CβCγ bond.Finally, the reaction of 1 with PhOH proceeds only in the presence of an excess of Et3N affording the 2-(alkoxy)alkenyl acyl complex [Fe2{μ-CN(Me)(Xyl)}(μ- CO)(CO){Cα(O)CβHCγ(Tol)(OPh)}(Cp)2] (7). The crystal structures of 4 · CH2Cl2 and 7 · 0.5CH2Cl2 have been determined by X-ray diffraction experiments. 相似文献
947.
Four cobalt(III) complexes containing the polypyridine pentadentate ligands N,N-bis(2-pyridylmethyl)amine-N′-ethyl-2-pyridine-2-carboxamide (PaPy3H), N,N-bis(2-pyridylmethyl)amine-N′-[1-(2-pyridylethyl)acetamide (MePcPy3H), and N,N-bis(2-pyridylmethyl)amine-N′-(2-pyridylmethyl)acetamide (PcPy3H), have been synthesized. All three ligands bind the Co(III) center in the same fashion with the exception of loss of conjugation between the carboxamide moiety and the pyridine ring in the latter two. The structures of [(PaPy3)Co(OH)][(PaPy3)Co(H2O)](ClO4)3 · 3H2O (1), [(PaPy3)Co(NO2)](ClO4) · 2MeCN (2), [(MePcPy3)Co(MeCN)](ClO4)2 · 0.5MeCN (3), and [(PcPy3)Co(Cl)](ClO4) · 2MeCN (4) have been determined. These ligands with strong-field carboxamido N donor stabilize the +3 oxidation state of the Co center as demonstrated by the facile oxidation of the corresponding Co(II) complexes (prepared in situ) by H2O2, [Fe(Cp)2](BF4), or nitric oxide (NO). The Co-Namido bond distances of 1-4 lie in the narrow range of 1.853-1.898 Å. 1H NMR spectra of these complexes confirm the low-spin d6 ground states of the metal centers. 相似文献
948.
Alexander V. Ivanov Andrey V. Gerasimenko Oleg N. Antzutkin 《Inorganica chimica acta》2006,359(12):3855-3864
Crystalline N,N-cyclo-pentamethylenedithiocarbamate (PmDtc) cadmium(II) complex was prepared and studied by means of 15N, 113Cd CP/MAS NMR spectroscopy and single-crystal X-ray diffraction. The unit cell of the cadmium(II) compound comprises two centrosymmetric isomeric binuclear molecules [Cd2{S2CN(CH2)5}4], which display structural inequivalence in both 15N and 113Cd NMR and XRD data. There are pairs of the dithiocarbamate ligands exhibiting different structural functions in both isomeric molecules. Each of the terminal ligands is bidentately coordinated to the cadmium atom and forms a planar four-membered chelate ring [CdS2C]; whereas pairs of the tridentate bridging ligands combine two neighbouring cadmium atoms forming an extended eight-membered tricyclic moieties [Cd2S4C2], whose geometry can be approximated by a ‘chair’ conformation. The structural states of cadmium atoms were characterised by almost axially symmetric 113Cd chemical shift tensors. All experimental 15N resonance lines were assigned to the nitrogen structural sites in both isomeric binuclear molecules. 相似文献
949.
The dinuclear complex [Cu2(dpbp)2(NCMe)4][BF4]2 (1) has been prepared by treating [Cu(NCMe)4][BF4] with 4,4′-bis(diphenylphosphino)biphenylene (abbreviated as dpbp). Reactions of 1 with 2,2′-bipyridine and 1,1′-bis(diphenylphosphino)ferrocene (abbreviated as dppf) afford [Cu2(dpbp)2(2,2′-bipy)2][BF4]2 (2) and [Cu2(dpbp)(dppf)2][BF4]2 (3), respectively. In contrast, compound 1 reacts with tetra(2-pyridyl)ethyl-1,4-diaminobutane (abbreviated as tpyda) to produce the polymeric complex {[Cu2(dpbp)(tpyda)][BF4]2}n (4). Compounds 1-4 are photoluminescent with the emission band (λmax) in the range 510-554 nm. The crystal structures of 1 and 4 have been determined by an X-ray diffraction study. 相似文献
950.