Synthese, struktur und eigenschaften neuer Übergangsmetallkomplexe des 9,10-dihydro-9,10-dimethyl-9,10-diboraanthracens

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(C7H8) and Ni(C8H12) yield the 18 VE compounds 2, 3, 4 and 5. With (CO)3Cr(CH3CN)3 complexation takes place at the carbacyclic moiety of 1 to give 6. Neither reduction nor carbonylation of 6 at 40 bar CO pressure result in a slippage of the chromium carbonyl group towards the heterocyclic part of 1. The reaction of 3 with (CO)3Cr(CH3CN)3 leads 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− are reported. The constitutions of 2, 3, 4 and 5 have been confirmed by X-ray structure analyses.