Iridium(I) and Rhodium(I) Carbonyl Complexes with the Bis(3-tert-butylimidazol-2-ylidene)borate Ligand and Unusual B−H Fluorination

Iridium(I) and rhodium(I) carbonyl complexes [H2B(ImtBu)2]M(CO)2 (M = Ir, 1a; M = Rh, 1b) with the bis(3-tert-butylimidazol-2-ylidene)borate ligand have been prepared. Reactions of 1a,b with [FeCp2][PF6] or AgPF6 unexpectedly yielded the B−F products [F2B(ImtBu)2]M(CO)2 (M = Ir, 2a; M = Rh, 2b), respectively. IR peaks of the CO ligands have been used to evaluate the electronic effects of bis(3-tert-butylimidazol-2-ylidene)borate and its fluorinated derivative.采用双(3-叔丁基咪唑-2-亚基)硼酸盐配体(bis(3-tert-butylimidazol-2-ylidene)borate)，成功合成了铱(I)与铑(I)羰基配合物[H₂B(ImtBu)₂]M(CO)₂（M=Ir时记为1a，M=Rh时记为1b）。将1a、1b分别与六氟磷酸二茂铁([FeCp₂][PF₆])或六氟磷酸银(AgPF₆)进行反应，意外得到了含硼-氟键的产物[F₂B(ImtBu)₂]M(CO)₂（M=Ir时记为2a，M=Rh时记为2b）。借助一氧化碳配体的红外吸收峰，评估了双(3-叔丁基咪唑-2-亚基)硼酸盐及其氟化衍生物的电子效应。