A Triplet Iron Carbyne Complex
Jiahao Rao, Shicheng Dong, Chengbo Yang, Qing Liu, Xuebing Leng, Dongyang Wang, Jun Zhu, Liang Deng
Abstract
Tuning the spin state of metal carbynes, which have broad applications in organic synthesis and material science, presents a formidable challenge for modern chemists as the strong field nature of carbyne ligands dictates low-spin ground spin states ( S = 0 or 1/2) for known metal carbynes. Through the oxidative addition reaction of a low-coordinate iron(0) N -heterocyclic carbene complex with the C−S bond of a thioazole-2-ylidene, we synthesized the first triplet ( S = 1) metal terminal carbyne, an iron cyclic carbyne complex. Different from the classical metal carbynes, the triplet complex features an LXZ -type carbyne ligand and a weak Fe≡C triple bond, which endow it with the unique reactivity pattern of facile carbyne coupling, weak affinity toward nucleophiles, and facial addition reactions with electrophiles.