Thermochimica Acta, Vol.468, No.1-2, 21-26, 2008
Thermochemistry of adducts of some bivalent transition metal bromides with quinoline
The compounds [MBr2(quin)(n)] (where M is Mn(II), Co(II), Ni(II), Cu(II) or Zn(II); quin, quinoline; n = 1 or 2) were synthesized and characterized by melting points, elemental analysis, thermal analysis and electronic and IR spectroscopy. The enthalpies of dissolution of the adducts, metal(II) bromides and quinoline in methanol or 1.2 M aqueous HCl were measured and by using thermochemical cycles, the following parameters for the adducts have been determined: the standard enthalpies for the Lewis acid/base reactions (Delta H-r degrees), the standard enthalpies of formation (Delta H-f degrees), the standard enthalpies of decomposition (Delta H-D degrees), the lattice standard enthalpies (Delta H-M degrees) and the standard enthalpies of the Lewis acid/base reactions in the gaseous phase (Delta H-r degrees(g)). The mean bond dissociation enthalpies of the M(II)-nitrogen bonds ((D) over bar ((M-N))) have been estimated as well as the enthalpies of adduct formation in the gaseous phase. (c) 2007 Elsevier B.V. All rights reserved.
Keywords:metal(II) bromides;transition metals;thermochemistry;metal(II)-nitrogen bonds;dissolution enthalpies