Reduction of bis(2-bromocyclohexenyl)diselenide, prepared from cyclohexeno-1,2,3-selenadiazole by the procedure of Meier et al., followed by reaction with cadmium chloride, yielded the novel single source Cd/Se precursor [Cd(SeC6H8Br)2], which upon thermolysis in a high boiling reaction medium formed CdSe quantum dots (Q.dots). Powder X-ray diffraction analysis showed them to contain cubic CdSe and TEM indicated the particle size to be <5 nm. The absorption spectrum of the asprepared Q.dots had a blue shift of >200 nm with respect to bulk CdSe and photoluminescence measurements at an excitation energy of 350 nm showed shallow trap band-edge emission.