Tetraphenylbismuth aroxides: Synthesis and structure

Tetraphenylbismuth aroxides Ph4BiOAr (Ar = C₆H₃Cl₂-2,6, C₆H₂(Br₂-2,6)(t-Bu)-4, C₆H₂(Br₂-2,6)(NO₂)-4 · 1/2C₆H₆, C₆H₃(NO₂)₂-2,4, C₆H₂(NO₂)₃-2,4,6) were synthesized in the yield up to 90% by the reaction of pentaphenylbismuth with phenols and triphenylbismuth diaroxides and studied by X-ray diffraction. The Bi atoms of tetraphenylbismuth aroxides have a distorted trigonal-bipyramidal coordination with the axial O atom of the aroxide group. The axial angles CBiO vary from 171.7(2)° to 179.3(3)°. The distances Bi-O change in the interval 2.453(2)–2.925(7) Å depending on the nature of substituents in the aromatic ring of the phenol residue. The increasing distance Bi-O in the series of compounds under study correlates with the tendency of the BiC₄ fragment to form the tetrahedral configuration.