Lanthanum-induced 13C-n.m.r. shifts: a novel probe of π-electron delocalisation
Abstract
La(fod)3(fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyloctane-3,5-dionato) diamagnetic complexation shifts can be used as a sensitive probe of the extent and pattern of π-electron delocalisation in aromatic and olefinic aldehydes and ketones and hence as a tool for the assignment of 13C-n.m.r. signals in complex, unsaturated molecules.