SYNTHESIS AND METAL COMPLEXATION REACTIONS OF BIS-DIOXOCYCLAMS FROM PHOTOCHEMICAL-REACTION OF BIS-CHROMIUM ALKOXYCARBENE COMPLEXES WITH IMIDAZOLINES

Bis-chromium alkoxycarbene complexes, bridged via the alkoxy groups, u nderwent photochemical cycloaddition to protected imidazolines to give protected bis-azapenams. Deprotection followed by treatment with acid produced bis-dioxocyclams bridged top and bottom with four-, five-, s ix-, and twelve-atom alpha,omega-diol linkages. These bis-dioxocyclam ligands formed mono- and bis-nickel(II) complexes. The five-atom bridg ed system (-O(CH2)(3)O-) was characterized by X-ray crystallography an d had a number of unusual features.