Thermochimica Acta, Vol.404, No.1-2, 117-123, 2003
Thermochemistry of adducts of tin(IV) bromide with heterocyclic bases
The compounds [SnBr4(L)(n)] (where L is pyridine (py), 3-methylpyridine (beta-pico), 4-methylpyridine (gamma-pico), piperidine (pipd), morpholine (morph), piperazine (pipz), 3-cyanopyridine (3-cyanopy), 4-cyanopyridine (4-cyanopy), quinoline (quin) or 2.2'-bipyridine (bipy) and n = 1 or 2) were synthesized and characterized by elemental analysis, melting points, thermal studies and IR spectroscopy. The enthalpies of dissolution of adducts, tin(IV) bromide and ligands in 25% (v/v) aqueous 1.2 M HCl in methanol were measured and, by thermochemical cycles, the standard enthalpies for the Lewis acid/base reaction (Delta(r)H(theta)), the standard enthalpies of formation (Delta(f)H(theta)), the standard enthalpies of decomposition (Delta(D)H(theta)), the lattice standard enthalpies (Delta(M)H(theta)) and the standard enthalpies for the Lewis acid/base reaction in the gaseous phase (Delta(r)H(theta)(g)) are determined. The mean standard enthalpies of the tin-nitrogen coordinated bonds D(Sn-N) are estimated. (C) 2003 Elsevier Science B.V. All rights reserved.