Authors: Grace B. Panetti, Dumitru-Claudiu Sergentu, Michael R. Gau, Patrick J. Carroll, Jochen Autschbach, Patrick J. Walsh, Eric J. Schelter
Published: 2021-03-17
DOI: 10.1038/s41467-021-21766-4
Source: Full article
AbstractThe synthesis of bona fide organometallic CeIVcomplexes is a formidable challenge given the typically oxidizing properties of the CeIVcation and reducing tendencies of carbanions. Herein, we report a pair of compounds comprising a CeIV − Carylbond [Li(THF)4][CeIV(κ2-ortho-oxa)(MBP)2] (3-THF) and [Li(DME)3][CeIV(κ2-ortho-oxa)(MBP)2] (3-DME),ortho-oxa = dihydro-dimethyl-2-[4-(trifluoromethyl)phenyl]-oxazolide, MBP2– = 2,2′-methylenebis(6-tert-butyl-4-methylphenolate), which exhibit CeIV − Carylbond lengths of 2.571(7) – 2.5806(19) Å and strongly-deshielded, CeIV − Cipso13C{1H} NMR resonances at 255.6 ppm. Computational analyses reveal the Ce contribution to the CeIV − Carylbond of3-THFis ~12%, indicating appreciable metal-ligand covalency. Computations also reproduce the characteristic13C{1H} resonance, and show a strong influence from spin-orbit coupling (SOC) effects on the chemical shift. The results demonstrate that SOC-driven deshielding is present for CeIV − Cipso13C{1H} resonances and not just for diamagnetic actinide compounds.