Sintese e termoquimica de adutos de trihaletos de arsenio com aminas heterociclicas

AUTOR(ES)
DATA DE PUBLICAÇÃO

1985

RESUMO

The adducts AsX3.nL (L = piridina (py), b-picolina (b-pyco) or g-picolina (g-pyco); X = Cl, Br or I; n = 1, 1.5 or 2), were isolated and characterized by elemental analysis, melting point determination, infrared spectroscopyr and thermogravimetric analyses. All adducts are crystalline solids sensitive to moisture. The infrared data indicated the coordination of the ligands by the splitting and dislocation of the bands of the coordinated ligand a compared with the free ligand. The enthalpies of dissolution in ethanol or diethanolamina of all the adducts, arsenic(III) trihalides and ligands, were determined by means of appropriated thermochemical cycles. The standard enthalpies for the reactions: AsX3(s,l)+ nL(l) = AsX3.nL(s), DH°R AsX3nL(s) = AsX3(s,l)+ nL(g),DH°D AsX3(g)+ nL(g) = AsX3nL(s), DH°M were calculated. The values of standard enthalpies of formation of adducts and metal-nitrogen bonds were also calculated.The thermochemical parameters allow the conclusion of the order of acidity AsCI3 >AsI3 and the basicity order g-pyco>>b-pyco >py.

ASSUNTO(S)

termoquimica entalpia termodinamica

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