Versatile Reactivities of ansa-Heteroborabenzene Divalent Ytterbium Amide toward Alkali-Metal Salts and the Generation of Heterometallic Ytterbium−Alkali-Metal Boratabenzene Complexes

Reactions of the ansa-heteroborabenzene divalent ytterbium amide [C5H5BCH2(CH3)2P→BC5H5]YbN(SiMe3)2 (1) with alkali-metal salts (KC5Me5, NaOiPr, NaOAr, LiNHAr, LiN(SiMe3)2, LiNEt2, and KCH2Ar) were studied. The reaction of 1 with KC5Me5 caused a ligand displacement of neutral borabenzene by KC5Me5 at the Yb ion to give a heterometallic Yb−K boratabenzene complex with a polymeric structure, while that with NaOiPr caused a ligand displacement of the anionic amido ligand at the Yb ion by an isopropoxyl ligand to give a heterometallic Yb−Na boratabenzene complex with a polymeric structure. When LiNEt2 or KCH2Ar was employed as the reagent, the [NEt2]− or [CH2Ar]− group underwent nucleophilic attack at the B atom on the neutral borabenzene to cause the disassociation of the P→B coordination bond and the generation of new boratabenzene ligands.