Regioselective Nitration of Aromatics with Nanomagnetic Solid Superacid SO42−/ZrO2-M xO y-Fe3O4 and Its Theoretical Studies.

A series of micro- and nanosulfated zirconia loaded on Fe3O4 or other metal oxides (SO42−/ZrO2-M xO y-Fe3O4 (M=Ti4+, V5+, and Zn2+)) was prepared, characterized, and used in nitration. The nitration conditions with these solid superacids were then optimized to achieve the best regioselectivity and improve the performances of the catalysts as well. In the experimental results, SZTF (SO42−/ZrO2-TiO2-Fe3O4) showed excellent catalytic activity and it increased the surface area of SO42−/ZrO2 by up to 15 %. The increase not only facilitated the generation of NO2+, but also provided more opportunities for metal ions to interact with aromatic compounds. With chlorobenzene as substrate, theoretical research on its geometric parameters, electron clouds, and electron spin density was used to investigate the interaction between transition metals and chlorobenzene. [ABSTRACT FROM AUTHOR]