[Study on adductive reaction of Ni[(C4H9O)2PS2]2 with nitrogen base by spectrophotometric method(II)]

Reaction of Ni[(C4H9O)2PS2]2 with ethylamine, n-propylamine, n-butylamine, and n-amylamine have been studied by spectrophotometry in ethanol at 30 degrees C. For nitrogen base(B), the adduct formation of NiL2.B and NiL2.B2 is established, and their additive equilibrium constants (lg beta n) and molecular number (n) have been discussed. All the NiL2.B and NiL2.B2 complexes exhibit virtually the same electronic spectra arising from the five-coordinate NiNS4 and six-coordinate NiN2S4 chromophore respectively. The constants (lg beta n) increase with basicity (pKa) of nitrogen base and can be described by experimental formulas: lg beta 1 = -9.69 +1.15 pKa; lg beta 2 = -18.73 +2.28 pKa.