Towards clustered carbonyl cations [M 3 (CO) 14 ] 2+ (M = Ru, Os): the need for innocent deelectronation.

To access the hitherto almost unknown class of clustered transition metal carbonyl cations, the trimetal dodecacarbonyls M 3 (CO) 12 (M = Ru, Os) were reacted with the oxidant Ag + [WCA] - , but yielded the silver complexes [Ag{M 3 (CO) 12 } 2 ] + [WCA] - (WCA = [Al(OR F ) 4 ] - , [F{Al(OR F ) 3 } 2 ] - ; R F = -OC(CF 3 ) 3 ). Addition of further diiodine I 2 to increase the redox potential led for M = Ru non-specifically to divalent mixed iodo-Ru II -carbonyl cations. With [NO] + , even the N-O bond was cleaved and led to the butterfly carbonyl complex cation [Ru 4 N(CO) 13 ] + in low yield. Obviously, ionization of M 3 (CO) 12 with retention of its pseudo-binary composition including only M and CO is difficult and the inorganic reagents did react non-innocently. Yet, the radical cation of the commercially available perhalogenated anthracene derivative 9,10-dichlorooctafluoroanthracene (anthracene Hal ) is a straightforward accessible innocent deelectronator with a half-wave potential E 1/2 of 1.42 V vs. Fc 0/+ . It deelectronates M 3 (CO) 12 under a CO atmosphere and leads to the structurally characterized cluster salts [M 3 (CO) 14 ] 2+ ([WCA] - ) 2 including a linear M 3 chain. The structural characterization as well as vibrational and NMR spectroscopies indicate the presence of three electronically independent sets of carbonyl ligands, which almost mimic M(CO) 5 , free CO and even [M(CO) 6 ] 2+ in one and the same cation.