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Abstract The study of actinide electronic structure and bonding within rigorously controlled environments is fundamental to advancing nuclear applications. Here, we report a new set of isostructural actinide organometallics; An(COT^big)₂, (An = Th, U, Np, and Pu), where COT^bigis 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 to exploref-orbital contributions in bonding. Combined experimental and computational studies reveal that An(COT^big)₂complexes strongly differ from the previously published coplanar An(COT)₂sandwiches due to the bent geometry and electron-withdrawing nature of the substituents. While COT^bigdisplays comparatively weaker electron donation, the low-energyf-ftransitions in An(COT^big)₂have increased molar absorptivity consistent with the removal of the parity selection rule and better energetic matching between ligand and actinide 5forbitals as the series is traversed. For Pu(COT^big)₂, covalent mixing of donor 5fmetal orbitals and the ligand-π orbitals is especially strong. 

Organometallic cerium(iv) and thorium(iv) alkynyl complexes were synthesized, and compared experimentally and theoretically. A cerium(iv)trans-influence ligand series was observed and analyzed. 

Abstract This computational study explores the copper (I) chloride catalyzed synthesis of (E)‐1‐(2,2‐dichloro‐1‐phenylvinyl)‐2‐phenyldiazene (2Cl‐VD) from readily available hydrazone derivative and carbon tetrachloride (CCl₄).2Cl‐VDhas been extensively utilized to synthesize variety of heterocyclic organic compounds in mild conditions. The present computational investigations primarily focus on understanding the role of copper (I) andN¹,N¹,N²,N²‐tetramethylethane‐1,2‐diamine (TMEDA) in this reaction, TMEDA often being considered a proton scavenger by experimentalists. Considering TMEDA as a ligand significantly alters the energy barrier. In fact, it is only 8.3 kcal/mol higher compared to the ligand‐free (LF) route for the removal of a chlorine atom to form the radical·CCl₃but the following steps are almost barrierless. This intermediate then participates in attacking the electrophilic carbon in the hydrazone. Crucially, the study reveals that the overall potential energy surface is thermodynamically favorable, and the theoretical turnover frequency (TOF) value is higher in the case of Cu(I)‐TMEDA complex catalyzed pathway. 

Abstract Reaction of Tl(OTf) with 2 equiv of bis(diisopropylamino)cyclopropenylidene (BAC) in THF results in formation of [Tl(BAC)₂(OTf)] (1) in moderate yields. Subsequent reaction of1with [K][H₂‐9‐BBN] ([H₂‐9‐BBN]⁻ = dihydrido 9‐boratabicyclo[3.3.1]nonane) in THF results in formation of [Tl(BAC)(μ‐H₂‐9‐BBN)]₂(3), also in moderate yield. Complex3is the first reported thallium borohydride. We attribute its thermal stability to the strong donor ability of the BAC co‐ligand. Both1and3exhibit trigonal pyramidal geometries about Tl⁺in the solid‐state, indicative of the presence of stereochemically active lone pairs. The hydride environment in3is calculated to exhibit a 3.9 ppm downfield shift attributed to spin‐orbit effects from the adjacent Tl center.