1,4,7,10-Tetraazacyclotridecane-1,4,7,10-tetraacetic acid, 12-((4-nitrophenyl)methyl)- 12-((4-Nitrophenyl)methyl)-1,4,7,10-tetraazacyclotridecane-1,4,7,10-tetraacetic acid 12-(4-Nitrobenzyl)-1,4,7,10-tetraazacyclotridecane-1,4,7,10-tetraacetic acid 12-Nbtcta 128924-91-4