AnCOTbig

open data for the actinocene manuscript:
Trends in actinide electronic structure revealed from asymmetric, isostructural transuranic metallocenes
Keywords: Actinocene, transuranic, organometallics, cyclooctatetraene, COT, C-ligand, thorium, uranium, neptunium, plutonium.
Abstract
A new set of isostructural actinide organometallics is reported; An(COTbig)2 for An = Th, U, Np, and Pu, where COTbig is the bulky 1,4-bis(triphenylsilyl)-substituted cyclooctatetraenyl dianion (1,4-(Ph3Si)2C8H6)2-. The actinide(IV) metallocene sandwiches have a clam-shell structure, offering a new molecular symmetry by which to explore f-orbital contributions in actinide bonding. A mixture of experimental and computational investigation reveals that the An(COTbig)2 complexes strongly differ from the previously published coplanar An(COT)2 sandwiches as a result of both the bent geometry and electron withdrawing nature of the ligand substituents. While COTbig displays comparatively weaker electron donation, the low-energy f-f transitions in An(COTbig)2 have increased molar absorptivity due to the removal of the parity selection rule and the better energetic match between ligand and actinide 5f orbitals as the series is traversed. For Pu(COTbig)2, covalent mixing of donor 5f metal orbitals and the ligand-π orbitals is especially strong.