
TY  - JOUR
A1  - Graddon, DP 
A1  - Watton, EC 
T1  - Complexes of cobalt(II) halides with 4-methylpyridine and 2-methylpyridine
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1965
VL  - 18
IS  - 4
SP  - 507
EP  - 520
KW  - 
UR  - https://doi.org/10.1071/CH9650507 
N2  - Complexes of CoCl2, CoBr2, CoI2, and Co(NCS)2 with two and four molecules of 4-methylpyridine and two molecules of 2-methylpyridine have been prepared. Their magnetic properties, conductivities, and reflectance and absorption spectra in the visible region show that all the compounds of the type CoX2B2 are tetrahedral except Co(NCS)2(4-mepy)2, which is an octahedral polymer like its pyridine analogue. Infrared spectra in the 3-15 &#956; region lend no support to the suggestion that there may be differences in the extent of &#960;-bonding between the metal and the base or the metal and NCS- in tetrahedral and octahedral complexes.   It is suggested that the position of the ligands in the spectrochemical series and the relative stabilities of the compounds CoX2B2 with respect to dissociation into CoX2B4 and free base can be explained in terms of repulsion effects between the non-bonding electron pairs on the ligands and metal d&#1108;-orbitals on the one hand and the non-bonding electron pairs of neighbouring ligands on the other. 
ER  -

