Azomethine derivatives. Part VII. Diphenylketiminoboron dihalides

Abstract

The preparation of the crystalline diphenylketiminoboron dihalides (Ph₂C:NBX₂)_n(X = Cl, Br, or I) from ethereal Ph₂C:NLi and BX₃ is described. The difluoride (Ph₂C:NBF₂)_n, difficult to separate from LiF when similarly prepared, is better obtained from (n/3)(Ph₂C:N)₃B +(2n/3)BF₃,OEt₂. Cryoscopic, i.r., and mass spectroscopic evidence is presented indicating dimeric structures (n= 2) for X = I, Br, and probably also Cl. The extent of association of the difluoride is less certain.

An attempt to prepare the aldiminoboron dichloride (MeCH:NBCl₂)_n from ethereal HBCl₂ and MeCN failed. This reaction, and that between ethereal H₂BCl and MeCN, afforded some MeCN,BCl₃ and materials apparently containing borazine rings.