Acta Crystallographica Section C

Crystal Structure Communications

Volume 58, Part 3 (March 2002)

Acta Cryst. (2002). C58, o174-o177 [doi:10.1107/S0108270102000173]

4-Amino derivatives of 7-nitro-2,1,3-benzoxadiazole: the effect of the amino moiety on the structure of fluorophores

S. Saha

Abstract: The crystal structures of three 4-amino derivatives of 7-nitro-2,1,3-benzoxadiazole with increasing substituent ring size, viz. 7-nitro-4-(pyrrolidin-1-yl)-2,1,3-benzoxadiazole, C₁₀H₁₀N₄O₃, 7-nitro-4-(piperidin-1-yl)-2,1,3-benzoxadiazole, C₁₁H₁₂N₄O₃, and 4-(azepan-1-yl)-7-nitro-2,1,3-benzoxadiazole, C₁₂H₁₄N₄O₃, have been determined in order to understand their photophysical behaviour. All three were found to crystallize in centrosymmetric space groups. There is considerable electron delocalization compared with the parent compound, although the five-membered oxadiazole ring apparently does not participate in this. The length of the C-N bond between the amino N atom and the 7-nitrobenzoxadiazole system is found to be shorter than in similar compounds, as is the C-N_nitro bond. In each structure, the nitro group lies in the plane of the benzoxadiazole unit.

Formula: C₁₀H₁₀N₄O₃, C₁₁H₁₂N₄O₃ and C₁₂H₁₄N₄O₃

Online 20 February 2002


	Structure factor file (CIF format) (88.2 kbytes) Contains datablock I

	Structure factor file (CIF format) (96.2 kbytes) Contains datablock II

	Structure factor file (CIF format) (104.0 kbytes) Contains datablock III

Notes:

To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.

The download button will force most browsers to prompt for a file name to store the data on your hard disk.

Where possible, images are represented by thumbnails.