CHARGE-TRANSFER ION-PAIRS WITH CATIONIC BIS(ARENE) IRON(II) ACCEPTORS- THERMAL ELECTRON-TRANSFER CATALYSIS OF AROMATIC DE-LIGATION

Bis(hexamethylbenzene)iron dication (HMB)2Fe2+ forms a series of charg e-transfer salts with anionic donors such as bromide, iodide, thiocyan ate, tricyanomethide, tetraphenylborate and tetracarbonylcobaltate. X- Ray crystallography of the 1:2 tricyano-methide salt identifies the st ructural origin of the charge-transfer interaction for the contact ion pair, [(HMB)2Fe2+, C(CN)3-]. The strong carbonylmetalate donors Co(CO )4- and Mn(CO)5- promote the catalytic de-ligation of bis(arene)iron(I I) by the electron-transfer chain (ETC) process previously identified in electrochemical and photochemical studies.