SYNTHESIS AND PROPERTIES OF COORDINATION-COMPLEXES OF ACRYLONITRILE, METHACRYLONITRILE AND CIS TRANS-CROTONONITRILE WITH THE CHLORIDES BCL3, TICL4, SNCL4 AND SBCL5

The coordination complexes of acrylonitrile, CH2 = CHCN, methacrylonitrile, CH2 = CMeCN, and cis/trans crotononitrile, MeCH = CHCN, with a series of metal and metalloid chlorides, MCln, where M = Ti(IV), Sn(IV), B(III) and Sb(V), have been prepared and the coordination is shown to be sigma-bonded through the nitrogen "lone pair" to the metal centre. The olefinic protons of the 1:1 complexes of TiCl4 and SnCl4, on coordination, show an upfield shift in the H-1 NMR spectra. Electrical conductivity measurements in nitrobenzene solution show all the addition compounds of SnCl4 and TiCl4 to be non-electrolytes and therefore non-ionic. Consistent with this observation, all of the compounds except for the SbCl5 complex are volatile at room temperature while the 2:1 complexes of TiCl4 with acrylonitrile and methacrylonitrile tend to dissociate in the vapour phase into the 1:1 complex and free ligand. The IR spectra of the complexes have also been studied and in all cases the cyanide stretching frequency increases, showing coordination occurs through the nitrile group.