The volume presents all chemical and physical data on mononuclear organorhenium compounds with C5H5Re(CO)2 or 3 and (C5H5)2Re fragments and, in the main part, gives all information on the large variety of mononuclear organorhenium compounds with substituted cyclopentadienyl ligands. Moreover, all compounds are described that have (5-coordinated six-membered or larger organic rings as well as ligands bonded through six carbon atoms (6L ligands such as benzene, substituted benzenes, and condensed aromatic ring systems). Volumes 1 to 4 of this series give a comprehensive overview of mononuclear organorhenium compounds.