Syntheses and characterization of N,N′-dipropyl/diisopropylethane-1,2-diamine complexes of nickel(II) nitrate: Thermal studies and X-ray single crystal structure analysis of cis-nitratobis (N,N′-dipropylethane-1,2-diamine)nickel(II) nitrate

Abstract

The blue complex cis-[Ni(dipren)2(NO3)](NO3) 1 and the greenish blue cis-[Ni(dipren)2(H2O2](NO3)2 · 2H2O2 (dpren/dpren = dipropyl/diisopropylethane-1,2-diamine) have been synthesized. Complex 2 upon heating loses four water molecules in a single step and undergoes melting accompanied with colour change, greenish blue to deep green, 2a. Configuration of the complexes 1,2 and 2a have been proposed to be cis-octahedral on the basis of magnetic, IR and electronic spectroscopic studies and confirmed in case of complex 1 by X-ray single crystal structure analysis. The role of steric factor of the alkyl groups on the selectivity of coordinating mode of nitrate ion is studied.