Syntheses and Structures of Mono- and Dinuclear Cationic Base-Stabilized Platinum Borylene Complexes

A series of fully characterized cationic, base-stabilized borylene complexes of the type trans[(CY3P)(2)Pt(Br)[B(Nc(5)H(4)-4-R)X}][BAr4f] (R = Me, X = NMe2, Pip, Br; R = tBu, X = Pip) were synthesized by addition of Na[BAr4f] and a pyridine Lewis base to boryl complexes trans-[(CY3P)(2)-Pt(Br){B(Br)X}], inducing a formal 1,2-bromide shift from the boron atom to the platinum center. Furthermore, the reactions of [Pt(PCY3)(2)] With 1,4-(Br2B)(2)-C6H4 allowed for the isolation of the dinuclear boryl complex 1,4-trans-[[(CY3P)(2)(Br)Pt(BBr)}(2)-C6H4] and trans-[(CY3P)(2)Pt(Br)-1-{B(Br)-C6H4-4-{BBr2(PCY3)}}]. The former was treated with K[B(C6F5)(4)], which afforded the abstraction of both platinum-bound bromides and formation of the dicationic boryl complex 1,4-trans-[((CY3P)(2)Pt(BBr)}(2)C6H4][B(C6F5)(4)](2). This compound was converted into the base-stabilized borylene species 1,4-trans[{(CY3P)(2)(Br)Pt{B(NC5H4-4-Me)}}(2)-C6H4][B(C6F5)(4)](2) by reaction with 4-methylpyridine.