Beiträge zur Chemie des Bors, 137 [1]. Über eine einfache Synthese eines Amino-imino-borans und seiner Addukte mit Bortrichlorid und Bortribromid / Contribution to the Chemistry of Boron, 137 [1]. A Convenient Synthesis of an Amino-Imino-Borane and its Adducts with Boron Trichloride and Boron Tribromide

Abstract

The amino-imino-borane (1) has been synthesized in high yield by a three step reaction. Pure 1 dimerizes fairly rapidly but can be stored as a monomer in solution for several weeks. It adds BCl3 and BBr3 with haloboration. The resulting diborylamines, 6 and 7, form a four membered cyclic internal coordination compound. The structure of the corresponding bromo derivative has been determined by X-ray crystallography. Its B2N2- ring is planar and contains four significantly different BN bonds. One of these is the shortest BN bond length yet observed for tricoordinated boron and nitrogen atoms (134 pm). Considering bond lengths the adduct can be looked upon as a coordination compound of an aminoborane with an iminoborane.