BEITRAEGE ZUR CHEMIE DES BORS. CLXXV. UEBER DEN EINFLUSS STERISCHER FAKTOREN AUF DIE KONFORMATION VON DIBORYLAMINEN

Article abstract of DOI:10.1016/S0022-328X(00)99655-4

The aminoborane Ph2BN(CMe3)SiMe3 possesses a relatively long BN bond (1.433 Angstroem) and a nonplanar C2BNCSi (τ(C2B/NCSi) 45 deg) skeleton as shown by X-ray structure analysis.In addition, the structure of five diborylamines have been determined by X-ray methods.The compounds (mes2B)2NH and (mes2BNH)3B belong to diborylamines with a coplanar conformation for the C2BNHBC2 (or C2BNHBN2) units, while the diborylamines (Ph2B)2NH and (Ph2B)2NMe adopt a twist conformation.Finally, an orthogonal conformation was detected for t-Bu2BNMe-9-borafluorene.The t-Bu2B group stands almost perpendicular on the BNC-9-borafluorene plane.Consequently two distincly different BN bond lengths (1.482 and 1.392 Angstroem) are observed.The influence of steric effects on the conformation and bonding parameters is discussed.