THE INTERCONVERSION OF OXO AND IMIDO LIGANDS AT A DIMOLYBDENUM CENTER - X-RAY CRYSTAL-STRUCTURE OF [MO(ETA-C5H4ME)(NPH)(MU-NPH)]2 - Green, M; Hogarth, G; Konidaris, P; Mountford, P (JOURNAL OF ORGANOMETALLIC CHEMISTRY, 1990)