SYNTHESIS, STRUCTURE AND PROPERTIES OF NE W TRANSITION-METAL COMPLEXES OF 9,10-DIHYDRO-9,10-DIMETHYL-9,10-DIBORAANTHRACENE

Reactions of 9,10-Dihydro-9,10-dimethyl-9,10-diboraanthracene (1) with the isolobal 14 VE metal complex fragments Ru(CO)(3), Co(C5H5), Fe(C7 H8) and Ni(C8H12) yield the 18 VE compounds 2, 3, 4, and 5. With (CO)( 3)Cr(CH3CN)(3) complexation takes place at the carbacyclic moiety of 1 to give 6. Neither reduction nor carbonylation of 6 at 40 bar CO pres sure result in a slippage of the chromium carbonyl group towards the h eterocyclic part of 1. The reaction of 3 with (CO)(3)Cr(CH3CN)(3) lead s to the 34 VE ''slipped'' triple-decker 7. The complexes 2, 3, and 4 are reversibly reduced to give the paramagnetic 19 VE monoanions. The electrochemistry of 2, 3, and 4 as well as ESR data of 3(-) and 4(-) a re reported. The constitutions of 2, 3, 4, and 5 have been confirmed b y X-ray structure analyses.