CONTRIBUTIONS TO THE CHEMISTRY OF BORON .231. SYNTHESIS AND STRUCTURES OF BORYLATED HYDRAZINES

The diboration of the diazene PhN=NSiMe(3) (15) by diborane(4) derivat ives provides a new synthetic route to N,N'-diborylated hydrazines. Th e product formed depends on the type of the diborane(4) compound. Thus , addition of dimesityldiboron dichloride to 15 in a 1:1 ratio afforde d (mesClB)PhN-N(SiMe(3))(BClmes) (16) while bis(dimethylamino)diboron dichloride was found to react in a 1:2 ratio to give a triazadiborolid ine derivative 17. In addition, it was demonstrated that in the solid state Me(2)N-N(BPh(2))(2) (8) is a derivative of a three-membered dihy droazadiboriridine C while its isomer, (Ph(2)B)MeN-NMe(BPh(2)) (7), fo rms no BN coordinative bond. The new 3,6-difluoro-1,2,4,5-tetraza-3,6- diborine 13 shows a twist conformation. The molecular structures of al l these compounds were determined by X-ray crystal structure analysis, and the influence of the B substituent on the conformation is discuss ed.