Formation of Unusual Molecular Complexes by Some Organotin(Aryl azo)benzoates

Department of Chemistry, North Bengal Universlty, Darjeeling-784 480, West Bengal

Triorganotin-o-(4-N,N-dimetbyl amino benzene azo)benzoates are characterised by an unusual ability to form molecular complexes with a wide variety of molecules including saturated hydrocarbons. Formation constants vary from ~10^-2 lftre mole^-1 for the saturated hydrocarbon complexes to ~10^-2 litre mote^-1 for chloranll complexes. The bathochromic shift of the π-π* transition as well ·as the presence of CT band In nitrobenzene complex suggest these to be of donor-acceptor type, the organotin molecule behaving as the donor. Protonated species are formed by the action of protle solvents on the complexes. Possible reasons for the unusual donor ability is discussed.