Formation of dimeric σ-bonded argentacarboranes containing two types of closed and open Ag-H-B bridge bonds and molecular structure of [9,9′-{Ag(SbPh3)2} 2-4,9,4′,9′-(μ-H) 4-7,8,7′,8′-nido-(C2B9H 10)2]

Abstract

Anaerobic reaction of Tl2C2B9H11 with a reaction mixture of AgBr and 2-fold amount of EPh(3) in CH2-Cl2 afforded off-white sigma-bonded nido-argentacarboranes [9,9'-{Ag(EPh(3))(2)}(2)-4,9,4',9'-(mu-H)(4)-7,8,7',8'-nido-(C2B9H10)(2)] (E = As and Sb) whose dimeric nature does not remain intact in solution resulting in the wigwag fluxional motion of the Ag(EPh(3))(2) moiety around the upper C2B3 belt boron atoms of the carborane cage in the monomeric (EPh(3))(2)AgC2B9H12 unit.