Axial water substitution kinetics of sulphato- and hydrogenphosphato-bridged binuclear platinum(III) complexes

Camadanli, S
Deveci, N
Gokagac, G
Isci, H
The kinetics of the axial water substitution reactions for [Pt-2(B-B)(4)(H2O)(2)](2-) (B-B = SO42-, HpO(4)(2-)) with Cl-, Br- and SCN- are reported in acidic aqueous solution. With a large excess of entering ligand and hydrogen ion, only the disubstituted product complex was formed. The reaction rates are first order with respect to the substrate complex and entering ligand and decrease with increasing H+ concentration. In the presence of 0.10 M H+, the rate constants for the replacement of the first water ligand by Cl-, Br- and SCN- are (7.84+/-0.46) x 10(-2), (6.65+/-0.41) x 10(-2) and (20.5+/-1.1) x 10(-2) M-1 s(-1) in [Pt-2(SO4)(4)(H2O)(2)](2-) (35.5+/-3.7) x 10(-2) (30.3+/-1.4) x 10(-2) and (84.9+/-13.4) x 10(-2) M-1 s(-1) in [Pt-2(HPO4)(4)(H2O)(2)](2-), respectively, at 24 degreesC and a constant ionic strength of 0.66. The entropies of activation for the reactions are negative and, in the range of -141 and -59 J K-1 mol(-1). These results support an associative-interchange, I-a, mechanism.


GOKAGAC, G; ISCI, H; MASON, WR (American Chemical Society (ACS), 1992-05-27)
Electronic absorption and 7-T magnetic circular dichroism (MCD) spectra in the UV-visible region are reported for the binuclear diplatinum(III) ions: Pt2(SO4)4X2n-, n = 2, X = H2O, NH3; n = 4, X = Cl-, Br-, OH-. Pt2(HPO4)4X2n-, n = 2, X = H2O, Me2S; n = 4, X = Cl-, Br-. Both the absorption spectra and the MCD spectra for complexes with the same axial ligand X are similar for oxo-bridging SO42- or HPO42-. However, the MCD spectra show marked differences depending upon the nature of the X ligand. The mos...
Electrochemistry of nickel(II) complexes with N,N'-bis(3,5-di-tert-butylsalicylidene)polymethylenediamines
Ozalp-Yaman, S; Kasumov, VT; Önal, Ahmet Muhtar (Elsevier BV, 2005-10-03)
The electrochemical oxidation of several N,N'-polymethylenebis(3,5-di-tert- butylsalicylaldiminato)nickel(II) complexes, Ni(L-x), has been studied by cyclic voltammetry and in situ UV-Vis spectroscopy in DMF Cyclic voltammograms of Ni(L-x) (x = 1-4) complexes displayed two-step oxidation processes under nitrogen gas atmosphere. The first oxidation peak potentials of all the Ni(II) complexes corresponds to the reversible one-electron oxidation process of the metal center, yielding Ni(III) species. EPR spectr...
Electronic absorption and MCD spectra for octacyanometallate complexes M(CN)(8)(n-), M = Mo(IV), W(IV), n=4 and Mo(V), W(V), n=3
Isci, H; Mason, WR (Elsevier BV, 2004-11-15)
Electronic absorption and 8.0 T magnetic circular dichroism (MCD) spectra are reported for M(CN)(8)(4-), M = Mo(IV) and W(IV), in aqueous solution and M(CN)(8)(3-), M = Mo(V) and W(V), in acetonitrile solutions. In addition some absorption and MCD spectra are reported for the M(CN), 3- ions embedded in thin poly methyl methacrylate (PMMA) plastic films at temperatures from 295 to 10 K. The temperature dependence of the MCD spectra confirms the presence of C terms. The solution and PMMA spectra for the both ...
Synthesis of ferrocenyl pyrazoles by the reaction of (2-formyl-1-chlorovinyl)ferrocene with hydrazines
Zora, Metin (Elsevier BV, 2007-10-15)
Synthesis of ferrocenyl-substituted pyrazoles via the reaction between (2-formyl-1-chlorovinyl)ferrocene and hydrazine derivatives is described. Depending upon the substitution pattern of hydrazine, the reaction affords 1-alkyl/aryl-5-ferrocenylpyrazoles and/or 1-alkyl/ aryl-3-ferrocenylpyrazoles. The reaction appears to be general for a variety of hydrazine derivatives.
Nonlinear effects in proline-thiourea host-guest complex catalyzed aldol reactions in nonpolar solvents
Demir, Ayhan Sıtkı; Eymur, Serkan (Elsevier BV, 2010-03-16)
An aldol reaction catalyzed by a proline-thiourea host-guest complex in a nonpolar solvent shows excellent nonlinear effects. This proline-thiourea system has the ability to form a hydrogen-bonding network. The enantiomeric excess of proline in a solution can be significantly enhanced by its incorporation with a urea molecule into its solid racemate. This suggests a general and facile route to homochirality, which may be involved in the origin of chirality on earth.
Citation Formats
S. Camadanli, N. Deveci, G. Gokagac, and H. Isci, “Axial water substitution kinetics of sulphato- and hydrogenphosphato-bridged binuclear platinum(III) complexes,” INORGANICA CHIMICA ACTA, pp. 1–6, 2003, Accessed: 00, 2020. [Online]. Available: