183720-99-2Relevant academic research and scientific papers
Thermal studies of N-propylethane-1,2-diamine and N-isopropylethane-1,2-diamine complexes of nickel(II) in the solid state
Das, Debasis,Ghosh, Ashutosh,Chaudhuri, Nirmalendu Ray
, p. 155 - 163 (1996)
[NiL3]X2 · 2H2O (X is Cl-, Br- and ClO-4; L is N-propylethane-1,2-diamine), [NiL2(H2O)2](ClO4)2, [NiL2X2] (X is Cl-, Br-, 0.5SO2-4 and 0.5SeO2-4), [NiL12(H2O)2](ClO4) 2 · 2H2O (L1 is N-isopropylethane-1,2-diamine), [NiL12X2] (X is Cl-, Br-, NCS- and O.5SeO2-4) and [NiL12SO4] · 3H2O have been synthesised from solution and their thermal studies have been carried out in the solid phase. [NiL2X2] (X is Cl- and Br-), NiLCl2 and NiL1SO4 have been prepared pyrolytically from their respective parent species in the solid state. [NiL2](ClO4)2 and [NiL12](ClO4)2 were prepared pyrolytically from their parents species, and also by storing [NiL2(H2O)2](ClO4)2 and [NiL12(H2O)2](ClO4) 2 · 2H2O in a CaCl2 desiccator, respectively; these transformations are accompanied by a pink to yellow colour change due to octahedral to square-planar configurational changes. All other bis(diamine) species have octahedral geometry. Among them, [NiL2X2] (X is Cl- and Br-) and [NiL12X2] (X is Cl-, Br- and NCS-) possess trans-octahedral configuration, whereas [NiL2X] (X is SO2-4 and SeO2-4), [NiL12SO4] · 3H2O and [NiL12SeO4] have cis-configuration. On heating, trans-[NiL12 Br2] and trans-[NiL12(NCS)2] undergo reversible endothermic phase transitions (86-99°C, ΔH = 0.52 kJ mol-1 for heating, and 92-81°C, ΔH = - 0.53 kJ mol-1 for cooling for the former, and 162-224°C, ΔH = 0.27 kJ mol- for heating and 208-150°C, ΔH = - 0.25 kJ mol-1 for cooling for the latter), most likely due to conformational changes of the diamine chelate rings.
