ÜBER DIE UMSETZUNG VON N- BZW. O-TRIMETHYLSILYLIERTEN DERIVATEN DES ETHANOLAMINS MIT PHOSPHOR(III)-HALOGEN-VERBINDUNGEN: INTRAMOLEKULARE DONATOR-AKZEPTOR-WECHSEL WIRKUNGEN IN DEN VERBINDUNGEN CH₃OCH₂CH₂N(CH₃)PCl₂, (CH₃)₂NCH₂CH₂OPCl₂, (CH₃)₂NCH₂CH₂N(CH₃)P(C₆ H₅)₂, (CH₃)₂NCH₂CH₂N(CH₃)P(C₆ H₅)Cl UND (CH₃)₂NCH₂CH₂N(CH₃)PCl₂

Abstract

The reaction of MeOCH₂CH₂N(Me)SiMe₃, Me₂NCH₂CH₂OSiMe₃, and Me₂NCH₂CH₂N(Me)SiMe₃ with PCl₃. PhPCl₂, and Ph₂PCl was found to proceed with cleavage of the N[sbnd]Si or O[sbnd]Si bond and formation of the phosphorus(III) compounds, 3 to 8. In this series of, in part, novel phosphorus(III) compounds an intramolecular donor-acceptor interaction between NMe₂ substituents and phosphorus has been observed which in the case of the product of the reaction of Me₂NCH₂CH₂N(Me)SiMe₃ with PCl₃, led to a stable intramolecular complex, , 3a. The reversible formation of an intramolecular complex, as a function of temperature, has been observed for Me₂NCH₂CH₂N(Me)P(Ph)Cl,4 while no evidence for an intramolecular interaction was noted for compounds 5, 6 and 8. For compound 7 which is obtained as a solid an intramolecular interaction between phosphorus and nitrogen seems likely in the solid state but cannot be observed by n.m.r. spectroscopy in solution in CDCl₃. A single crystal X-ray structure determination for 3a has established its identity as an intramolecular complex.

The X-ray structure determination proved the existence of a tricoordinate phosphorus atom with a rather short covalent P[sbnd]N bond with a bond-distance of 162 pm and a short coordinative P[sbnd]N bond of 184.2 pm. No interaction of the second chlorine with phosphorus was observed.