Bis(imido) rhenium complexes bearing C- or N-capped ‘tripodal’ ligands: Bi- versus tri-dentate ligation

The differing geometrical constraints of the tripodal ligands tris(hydroxyphenyl)amine (N-cappedH3) and tris(3,5-di-t-Bu-2-hydroxyphenyl)methane (C-cappedH3) led, on reaction with [Re(t-BuN)3(OSiMe3)], to the isolation of the complexes [Re(t-BuN)2(N-capped)] (1) and [Re(OSiMe3)(t-BuN)2(C-cappedH)] (2), respectively. Both 1 · 1/2MeCN and 2 have been structurally characterized using X-ray synchrotron radiation.