Triplet bismuthinidenes featuring unprecedented giant and positive zero field splittings

Mengyuan Wu; Wang Chen; Dongmin Wang; Yizhen Chen; Shengfa Ye; Gengwen Tan

doi:10.1093/nsr/nwad169

Triplet bismuthinidenes featuring unprecedented giant and positive zero field splittings

Natl Sci Rev. 2023 Jun 12;10(10):nwad169. doi: 10.1093/nsr/nwad169. eCollection 2023 Oct.

Authors

Mengyuan Wu¹, Wang Chen^{2

3}, Dongmin Wang^{4

1}, Yizhen Chen^{4

1}, Shengfa Ye², Gengwen Tan^{4

1

5}

Affiliations

¹ Innovation Center for Chemical Sciences, Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
² State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
³ University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, Sun Yat-sen University, Guangzhou 510275, China.
⁵ State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China.

Abstract

Isolation of triplet pnictinidenes, which bear two unpaired electrons at the pnictogen centers, has long been a great challenge due to their intrinsic high reactivity. Herein, we report the syntheses and characterizations of two bismuthinidenes M^sFluind^t^Bu-Bi (3) and M^sFluind*-Bi (4) stabilized by sterically encumbered hydrindacene ligands. They were facilely prepared through reductions of the corresponding dichloride precursors with 2 molar equivalents of potassium graphite. The structural analyses revealed that 3 and 4 contain a one-coordinate bismuth atom supported by a Bi-C single σ bond. As a consequence, the remaining two Bi 6p orbitals are nearly degenerate, and 3 and 4 possess triplet ground states. Experimental characterizations with multinuclear magnetic resonance, magnetometry and near infrared spectroscopy coupled to wavefunction based ab initio calculations concurred to evidence that there exist giant and positive zero field splittings (>4300 cm^-1) in their S = 1 ground states. Hence even at room temperature the systems almost exclusively populate the lowest-energy nonmagnetic Ms = 0 level, which renders them seemingly diamagnetic.

Keywords: bismuth; bismuthinidene; theoretical calculation; triplet state; zero field splitting.