
TY  - JOUR
A1  - Graddon, DP 
A1  - Siddiqi, IA 
T1  - Thermodynamics of metal-ligand bond formation. XXIX. Nickel(II) dialkylmonothiocarbamate complexes
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1977
VL  - 30
IS  - 10
SP  - 2133
EP  - 2141
KW  - 
UR  - https://doi.org/10.1071/CH9772133 
N2  - In benzene solution at concentrations below 10-2 M, measurements of molecular weights, absorption spectra and the enthalpies of reaction with bases are all consistent with Ni(SOCNR2)2 (R = Pr or Bu) existing as an equilibrium between low-spin monomeric and high-spin dimeric, probably five-coordinate, species. Enthalpies of dimerization are about -55 kJ (g-atom Ni)-1 and dimerization constants increase from 250 l. mol-1 at about 5°C to 1000 l. mol-1 at 30°C, which shows that the entropy of dimerization is not temperature-invariant. Addition of bidentate bases to the monomer is quantitative with &#916;H° about -100 kJ mol-1. Addition of pyridine, 4-methylpyridine or piperidine occurs in two steps, giving high-spin adducts, first five-coordinate NiL2B then six-coordinate NiL2B2 with K1 &#8776; K2, &#916;H1° &#8776; -100 and &#916;H2° near zero. Comparisons are made with other low-spin nickel(II) complexes which form high-spin polymers or adducts. 
ER  -

