SYNTHESIS, STRUCTURE, AND REACTIVITY OF THE CHIRAL RHENIUM PHENYL COMPLEX (ETA-5-C5H5)RE(NO)(PPH3)(C6H5)

Reaction of (η5-C5H6)Re(NO)(PPh3)(Cl) and C6H5Cu gives chiral, racemic phenyl complex (η5-C5H5)-Re(NO)(PPh3)(C6H5) (1, 82-92%), which undergoes a spontaneous resolution when crystallized from CH2Cl2/hexanes. The crystal structure (monoclinic, P21,a = 9.261 (2) Â, b = 14.142 (3) Â, c = 10.722 (2) À, β = 112.74 (1)°, Z = 2) exhibits an unexpected Re-Cα conformation that places one ortho carbon in the region between the nitrosyl and PPh3 ligands. Reaction of 1 and HBF4-O(C2H5)2 in CH2Cl2 at -80 °C gives, as the first species detected by NMR, ^-benzene complex [(η5-C5H6)Re(NO)(PPh3) (η2-C6H6)]+BF4-(2). Between -70 and -40 °C, 2 converts to dichloromethane complex [(η5-C5H5)Re(NO)(PPh3)-(ClCH2Cl)]+BF4- (3), even in the presence of excess benzene. Reaction of 1 and Ph3C+PF6- in CH2Cl2 at 80 °C gives bis(vinyl)alkylidene complex [(η5-C5H5)Re(NO)(PPh3) [inline formula omitted] +PF6- (7), which decomposes above -40 °C to 3 and other products that ultimately yield tetraphenylmethane. © 1990, American Chemical Society. All rights reserved.