All-metal aromaticity of cyclo -Bi 3 3 - in diuranium and dithorium inverse-sandwich-type complexes

作者：Junru Ding, John A. Seed, Katrin Beuthert, Benjamin Peerless, Julia Rienmüller, Andreas Schmidt, Ashley J. Wooles, Louise S.; id_orcid 0000-0002-9451-3557 Natrajan, Chuan-Ling Chen, Zhong-Ming Sun, Florian Weigend, Jingzhen Du, Stephen T. Liddle, Stefanie Dehnen · 发表于：Open MIND · 年份：2026 · DOI：10.48420/31378627.v1 · 研究领域：Chemistry、Computational chemistry、Chemical physics、Crystallography

Delocalised [4n+2]p-aromaticity in cyclic planar unsaturated organic molecules conceptually underpins organic chemistry. Recently, the study of all-metal aromaticity has burgeoned, but whilst there has been interest in cyclo -{E 3 } (E = P, As, Sb, Bi) species as cyclopropenium analogues, the formation of cyclo -{Bi 3 } remains rare. Thus, the potential aromaticity of 2/6p- cyclo -Bi 3 +/3 - as the heaviest 6p-analogue of cyclopropylium has remained open to different interpretations. Here, we report formation of diuranium and dithorium 6p- cyclo -Bi 3 3 - inverse sandwich complexes, complementing the small number of acyclic- and cyclic-Bi n (n = 3-5) compounds. The 6p- cyclo -Bi 3 3 - ring exhibits significant ring currents similar to 6p-benzene, 2p-(C 3 H 3 ) + , or 6p-(C 3 H 3 ) 3 - . Calculations reveal similar ring currents for 6p cyclo -Bi 3 3 - , 2p cyclo -Bi 3 + , and 0p cyclo -Bi 3 3 + , demonstrating dominant s- over p-aromaticity in cyclo -Bi 3 3 - despite the favourability of describing cyclo -Bi 3 3 - with localised rather than delocalised bond descriptions. Confirmation of 6p- cyclo -Bi 3 3 - s-aromaticity provides the heaviest all-metal 6p analogue to p-aromatic (C 3 H 3 ) +/3 - , developing organic-inorganic aromaticity benchmarking.