Metallaboratranes:  Tris(methimazolyl)borane Complexes of Rhodium(I)

Abstract

The syntheses and reactivity of the first rhodaboratranes, [RhX(PPh 3 ){B(mt) 3 }] (X = Cl, H) and [Rh(η 4 -C 8 H 12 ){B(mt) 3 }]Cl, are described in detail together with preliminary investigations of the mechanistic processes involved. The subsequent exploitation and circumvention of the lability of [RhCl(PPh 3 ){B(mt) 3 }] in the synthesis of a range of isonitrile, [Rh(CNR)(PPh 3 ){B(mt) 3 }]Cl (R = t Bu, C 6 H 3 Me 2 -2,6, C 6 H 2 Me 3 -2,4,6), phosphine, [Rh(PMe 3 ) n (PPh 3 ) 2 - n {B(mt) 3 }]Cl ( n = 0, 1, 2), and dialkyldithiocarbamate, [Rh(S 2 NEt 2 ){B(mt) 3 }]Cl, complexes is described, along with the attempted synthesis of [Rh(CN t Bu) 2 {B(mt) 3 }]Cl from [Rh(η 4 -C 8 H 12 ){B(mt) 3 }]Cl. Single-crystal X-ray structure determinations of [Rh(L)(L‘){B(mt) 3 }]Cl (L = CN t Bu, CN(C 6 H 3 Me 2 -2,6), L‘ = PPh 3; L = L‘ = PMe 3 ) are reported.