Richard J. Strittmatter

The bonding in tris(η5-cyclopentadienyl) actinide complexes IV: Electronic structural effects in AnCl3 and (η5-C5H5)3An (An ≡ Th — Cf) complexes☆

Abstract The cp3An (cp ≡ η5-C5H5; An ≡ actinide element) framework is the most ubiquitous one in organoactinide chemistry. Cp3An (or modified cp) compounds have been synthesized for An  Th, U, Np, Pu, Am, Cm, Bk, and Cf, and in some cases represent the only known organometallic complex for the given element. The electronic structures of these cp3An complexes have been investigated via Xα-SW molecular orbital calculations that include quasirelativistic corrections. A comparison of the cp-metal bonding interactions as a function of the metal will be presented, with an emphasis on the relative roles of the actinide 5f and 6d atomic orbitals. The radial extension of the 5f orbitals as a function of the metal will be discussed, and the possibility of these orbitals participating in the bonding of a fourth ligand will be considered.

Relativistic DV-Sa studies of three-coordinate actinide complexes

The chemistry of the actinide elements continues to present challenges to both experimental and theoretical chemists. Actinide compounds have been found to possess a diversity of structures and reactivities that are not only extensions of but significant additions to those recognized for the transition metal elements.1 From a theoretical perspective, the number of electrons and the importance of relativistic corrections in actinide systems pose several problems: theoretical rigor is more difficult to maintain, calculations are more computationally demanding, and results are more difficult to interpret than those obtained from non-relativistic calculations. Nonetheless, significant advances have been made in the application of molecular electronic structure methods to actinide compounds. Local density functional (LDF) methods in particular have several features that make them attractive for the study of heavy element structure and bonding. We present here a brief description of a computational scheme that employs the LDF formalism to address questions in actinide electronic structure and then demonstrate its application to one system in particular: three-coordinate actinide(III) compounds.