Metal salts with highly electronegative cations as efficient catalysts for the liquid-phase nitration of benzene by NO2 to nitrobenzene

Metal salts with highly electronegative cations have been used to effectively catalyze the liquid-phase nitration of benzene by NO2 to nitrobenzene under solventfree conditions. Several salts including FeCl3, ZrCl4, AlCl3, CuCl2, NiCl2, ZnCl2, MnCl2, Fe(NO3)(3) center dot 9H(2)O, Bi (NO3)(3) center dot 5H(2)O, Zr(NO3)(4) center dot 5H(2)O, Cu(NO3)(2) center dot 6H(2)O, Ni (NO3)(2) center dot 6H(2)O, Zn(NO3)(2) center dot 6H(2)O, Fe-2(SO4)(3), and CuSO4 were examined and anhydrous FeCl3 exhibited the best catalytic performance under the optimal reaction conditions. The benzene conversion and selectivity to nitrobenzene were both over 99%. In addition, it was determined that the metal counterion and the presence of water hydrates in the salt affects the catalytic activity. This method is simple and efficient and may have potential industrial application prospects.