Towards clustered carbonyl cations [M3(CO)14]2+ (M = Ru, Os): the need for innocent deelectronation. Issue 32 (10th August 2022)

• Record Type: Journal Article
• Authors: Sellin, Malte; Friedmann, Christian; Mayländer, Maximilian; Richert, Sabine; Krossing, Ingo
• Is Part Of: Chemical science. Volume 13:Issue 32(2022)
• Page Start: 9147
• Page End: 9158
• Publication Date: 2022-08-10
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2sc02358j
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Trimeric M3 (CO)12 (M = Ru, Os) reacts with typical inorganic oxidants to unwanted side products. Yet, the 9, 10-dichlorooctafluoroanthracene radical cation deelectronates these under CO pressure to give the first homotrimetallic [M3 (CO)14 ] 2+ salts. Abstract : To access the hitherto almost unknown class of clustered transition metal carbonyl cations, the trimetal dodecacarbonyls M3 (CO)12 (M = Ru, Os) were reacted with the oxidant Ag + [WCA] −, but yielded the silver complexes [Ag{M3 (CO)12 }2 ] + [WCA] − (WCA = [Al(OR F )4 ] −, [F{Al(OR F )3 }2 ] − ; R F = –OC(CF3 )3 ). Addition of further diiodine I2 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 [Ru4 N(CO)13 ] + in low yield. Obviously, ionization of M3 (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 M3 (CO)12 under a CO atmosphere and leads to the structurally characterized cluster salts [M3 (CO)14 ] 2+ ([WCA] − )2 including a linear M3 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.