Synthesis and photochemical properties of azidohemicyanine

Photochemical activity of azidohemicyanine (1-methyl-4-(4-azidostyryl)quinolinium iodide) was predicted by quantum chemical calculations and confirmed experimentally. The azidohemicyanine, which was synthesized, is characterized by a long-wavelength absorption band (LWAB) in the spectral region 350–500 nm with a maximum at 417 nm; it decomposes with a quantum yield of 0.84±0.17 upon irradiation within the LWAB, the quantum yield being independent of the presence of oxygen. The reaction products identified by ESI mass spectrometry include the corresponding primary amine as well as azo, hydrazo, nitroso, and nitro compounds, some of them are unidentified. The azidohemicyanine possesses the longest-wavelength visible light sensitivity among aromatic azides known so far. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1402–1408, July, 2008.