Photolytic or Oxidative Fragmentation of Trityl Diazeniumdiolate (O 2 N 2 CPh 3 - ): Evidence for Both C-N and N-N Bond Cleavage.

Exposure of [K(18-crown-6)(THF) 2 ][CPh 3 ] (THF = tetrahydrofuran; Ph = phenyl) to an atmosphere of nitric oxide (NO) cleanly generates [K(18-crown-6)][O 2 N 2 CPh 3 ] ( 1 ) in excellent yields. A subsequent reaction of [ZnCl 2 (THF) 2 ] with 3 equiv of 1 affords the C -diazeniumdiolate complex [K(18-crown-6)][Zn(O 2 N 2 CPh 3 ) 3 ] ( 2 ). Both 1 and 2 were characterized by 1 H and 13 C{ 1 H} NMR spectroscopy, and their structures were confirmed by X-ray crystallography. Photolysis of 2 using 371 nm light resulted in the formation of three trityl-containing products, namely, Ph 3 CH, 9-phenylfluorene, and Ph 3 CN(H)OCPh 3 ( 3 ). In addition, we detected nitrous oxide (N 2 O), as well as small amounts of NO in the reaction mixture. In contrast, oxidation of 2 with 1.2 equiv of [Ag(MeCN) 4 ][PF 6 ] resulted in the formation of O(CPh 3 ) 2 as the major trityl-containing product; N 2 O was also detected in the reaction mixture, but NO was not apparently formed in this case. The observation of these fragmentation products indicates that the [O 2 N 2 CPh 3 ] - ligand is susceptible to both C-N bond and N-N bond cleavage. Moreover, the different product distributions suggest that [O 2 N 2 CPh 3 ] - is susceptible to different modes of fragmentation.