3-(4-nitrophenyl)-6-((1e)-prop-1-enyl)-5,6-dihydro[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole (en)1,2,4-triazolo[3,4-b][1,3,4]thiadiazole, 5,6-dihydro-3-(4-nitrophenyl)-6-(1-propenyl)- (en)