Mixed-Ligand Complexes. Part VII. Some Mixed Chelates of Cobalt (III)

Inorganic Chemistry Laboratory, University of Burdwan, Burdwan Manuscript received 31 July 1972; revised 28 February 1973; accepted 23 April 1973 The following mixed chelates of cobalt(III) have been prepared and characterised : [Co(en) (BigH)2]3+(en = ethylenediamine, BigH = biguanide), [Co (gly) (BigH)2]2+ (glyH = glycine), [Co (Pic) (BigH)2]2+ (PicH = picolinic acid), Co (Lut) (BigH) +(LutH = pyridine 2,6 dicarboxylic acid), [Co(IDA)(BigH)2]3+(IDAH2 = iminodiacetic acid) and [Co(DMG)(BigH)2]3+(DMGH 2 = dimethyl­glyoxime). A number of salts of each cation have been prepared and their ionic natures have been verified from conductance and equivalent weights. Electronic spectra reveal expected trends. Lutidinate anion and iniinodiacetate anion behave as bidentates in the mixed chelates. Separation of diastereoisomers has been achieved for [Co(en)(BigH)2]3+ and [Co(Pic)(BigH)2]2+. The dias­tereoisomers of [Co(en) (BigH)2]2+ racemised in presence of iodide ion. The enantiomers of [Co (Pic) (BigH)2]I2 have been characterised