Thermal studies of bis(2-aminoethyl)methylamine complexes of nickel(II) in the solid state

摘要: Abstract [NiL 2 ]X · n H O (where L is bis(2-aminoethyl)methylamine, and  = 0 when X Cl − , Br SCN CF 3 COO  = 3 0.5SO 4 2− 0.5SeO ) NiLX ( NO  = 1 have been synthesized investigated thermally in the solid state. All bis, as well monotriamine complexes possess octahedral geometry. [Nil ](SCN) upon heating undergoes irreversible phase transition (155–180°C; Δ  = 5.6 kJ mol −1 yielding an isomeric species which on further shows reversible (182–205°C for heating,  = 2.8 kJ mol ; 170–200°C cooling,  = −2.8 kJ mol ]SO ·3H endothermic after deaquation 172–200°C;  = 6.8 kJ mol ). Nil(NO also a (195–220°C;  = 8.9 kJ mol The transitions are proposed to be due conformational change chelate rings of triamine. NiLAO (A = S or Se) exhibit thermochromism, blue-to-greenish-blue elimination two molecules water greenish-blue-to-light-green residual molecule. effect methyl substitution N – position bis(2-aminoethyl)amine not noticeable with respect thermal stability complexes, but pronounced case induced solid-state isomerization.