Publications with shared reference: Synthesis and single-crystal structure determination of bis(triphenylphosphine) (diisopropyldithiocarbamato)nickel(II) perchlorate chloroform solvate and [1,2-bis(diphenylphosphino-k.P,P′)ethane] (diisopropyldithiocarbamato)nickel(II) perchlorate chloroform solvate: Steric effect of bulky alkyl substituents on the dithiocarbamate, free and chelating phosphines on the NiS2P2 chromophore