title: Covalency in Ce(IV) and U(IV) halide and N-heterocyclic carbene bonds.
abstract: Oxidative halogenation with trityl chloride provides convenient access to Ce(IV) and U(IV) chloroamides [M(N{SiMe(3)}(2))(3)Cl] and their N-heterocyclic carbene derivatives, [M(L)(N{SiMe(3)}(2))(2)Cl] (L = OCMe(2)CH(2)(CNCH(2)CH(2)NDipp) Dipp = 2,6-iPr(2)C(6)H(3)). Computational analysis of the bonding in these and a fluoro analogue, [U(L)(N{SiMe(3)}(2))(2)F], provides new information on the covalency in this relative rare oxidation state for molecular cerium complexes. Computational studies reveal increased Mayer bond orders in the actinide carbene bond compared with the lanthanide carbene bond, and natural and atoms-in-molecules analyses suggest greater overall ionicity in the cerium complexes than in the uranium analogues.
authors.affiliation: School of Chemistry, Joseph Black Building, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK. Polly.arnold@ed.ac.uk
authors.forename: Polly L
authors.initials: PL
authors.lastname: Arnold
authors.forename: Zoë R
authors.initials: ZR
authors.lastname: Turner
authors.forename: Nikolas
authors.initials: N
authors.lastname: Kaltsoyannis
authors.forename: Panagiota
authors.initials: P
authors.lastname: Pelekanaki
authors.forename: Ronan M
authors.initials: RM
authors.lastname: Bellabarba
authors.forename: Robert P
authors.initials: RP
authors.lastname: Tooze