Nopol synthesis over Sn-MCM-41. The effect of solvent and Sn precursor

Introduction Nopol is an unsaturated alcohol useful for the synthesis of fragrances, pesticides and household products [1]. It has been traditionally obtained by condensation of β-pinene and paraformaldehyde at high temperatures or using homogeneous Lewis acid catalysts [2]. Recently, heterogeneous catalysts: FePO4, Sn-MCM-41 and Zn-Al-MCM-41, have been reported for nopol synthesis under mild conditions [33-45 ]. FePO4 (4 h, CH3CN) and Sn-MCM41 (1 h, toluene) showed the highest nopol yield (>98 %). Solvent effect on nopol yield was previously reported over FePO4 [3]. However, to the best of our knowledge the effect of solvent type on nopol yield over Sn-MCM-41 has not been published yet. In this regard, here we report on catalytic activities of Sn-MCM-41 to obtain nopol using solvents of different polarities. Sn-MCM-41 materials were prepared by chemical vapor deposition (CVD) using two Sn precursors, SnCl4 and SnCl2. Figure 1. UV-VIS spectra of synthesized materials (A) SnCl2-M113, (B) SnCl4-M16