Synthesis, crystal structures, and laser flash photolysis of 3-nitro-7a,15-methanonaphtho[1′,2′:6,7][1,3]oxazepino[3,2-a]indole derivatives

Abstract

The condensation of 1-substituted 9,9a-dihydro-1H-imidazo[1,2-a]indol-2(3H) -ones with 2-hydroxy-6-nitro-1-naphthaldehyde afforded 1′-carbamoylmethyl- 8-nitrospiro[benzo[f]chromene-3,2′-indole] derivatives, which underwent intramolecular cyclisation to derivatives of 3-nitro-7a,15- methanonaphtho[1′,2′:6,7][1,3]oxazepino[3,2-a]indole upon treatment with a strong base. Laser excitation of the obtained uncoloured molecules of trans-and cis-3-nitro-7a,15-methanonaphtho[ 1′,2′:6,7][1,3] oxazepino[3,2-a]indole induced the formation of short-lived photogenerated species, which absorb in the visible spectrum and thermally revert to the ground state on a nanosecond time scale. © ARKAT-USA, Inc.