Browsing by Author "Skinner, H. A."

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    Microcalorimetric Studies: Thermal Decomposition and Iodination of Metal Carbonyls
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (9), 1972) Connor, J. A.; Skinner, H. A.; Virmani, Y.
    The Calvet high temperature microcalorimeter was used to measure the enthalpies of thermal decomposition and the enthalpies of reaction with iodine vapour, of carbonyls of Mo, Mn, and Cr. ΔH°f(c) values for Mo(CO)6, Mn2(CO)10, Cr(CO)6, Mn(CO)5Cl and Mn(CO)5Br were obtained. These studies have confirmed the literature value for ΔH°f(Mn2(CO)10, c), but disagree with the currently accepted value for ΔH°f(Cr(CO)6, c). The bond dissociation energies D[(CO)5Mn—Cl] and D[(CO)5Mn—Br] were evaluated at 73 and 61 kcal mol–1 respectively: these values are ca. 20 kcal mol–1 less than the mean bond dissociation energies, D(Mn—Cl) and D(Mn—Br), in MnCl2(g) and MnBr2(g), and ca. 15 kcal mol–1 less than the dissociation energies in the diatomic molecules MnCl, MnBr.
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    Microcalorimetric Studies: Enthalpies of Formation of Amino-acid and Peptide Complexes of Coppcr(ll) and Nickel(II)
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (9), 1972) Tipping, E. W.; Skinner, H. A.
    Measurements of the enthalpies of decomposition by acid at 24–25°C of a number of amino-acid and peptide complexes of CuII and NiII in solution (µ= 0.100 M) have been made using a Beckman microcalorimeter. The enthalpies of formation (from ions in solution) are derived for glycyl-glycinato(2-)copper(II), (glycylglycinato)(glycylglycinato(2-))copper(II) anion, leucylglycinato(2-)-copper(II), glycylglycinatonickel(II) cation, di(glycylglycinato)nickel(II), tri(glycylglycinato)nickel(II) anion, (glycylglycinato)(glycylglycinato(2-))nickel(II) anion, di(glycylglycinato(2-))nickel(II) dianion, glycinamidocopper(II) dication, di(glycinamido)copper(II) dication and di(glycinamido(1-))-copper(II). Equilibrium formation constants for certain of these complexes were measured from pH titration measurements. The bond strength of N→CuII in solution is greater than N→NiII whether the N atom belongs to amino or to peptide groupings.