Trioxorhenium(VII) complexes with imidazolin-2-iminato ligands

摘要

The Staudinger reaction of the N-heterocyclic carbenes 1,3-di-tert-butylimidazolin-2-ylidene (1a), 1,3-dimesitylimidazolin-2-ylidene (1b) and 1,3-diisopropyl-4,5-dimethytimidazolin-2-ylidene (1c) with trimethylsilyl azide in boiling toluene furnishes the corresponding 2(trimethylsilylimino)imidazolines 2a-c. Treatment of Re2O7 with a twofold excess of these N-silylated imines results in the formation of the imidazolin-2-iminato trioxorhenium(VII) complexes 3a-c and hexamethyldisiloxanc, Me3SiOSiMe3. The molecular structures of 2a, 3a and 3b are reported. In addition, the X-ray crystal structure determination of complex 3c . H2O is presented, which has formed by hydrolysis and cleavage of the metal-nitrogen bond in 3c. 3c H2O consists of 2-aminoimidazolium cations and tetraoxorhenate(VII) anions, which are linked by N-H-O hydrogen bonds.