ABSTRACT:The main interaction between thiophene and zeolites leads to the formation of a hydrogen bond between the S atom of thiophene and the OH group of zeolites, giving 1:1 stable molecular complexes. The present work reports a theoretical study about the structural, vibrational, and topologic properties of the charge distribution of the molecular complexes between thiophene and a series of Brönsted acid sites of zeolites, modeled as the H 3 SiOHAlH 3 (B 1 ), (OH) 3 Si(OH)Al(OH) 3 (B 1 OH), and H 3 Si(OH)Al(OH) 2 OSiH 3 (B 2 ) clusters. The studied properties were calculated at a Hartree-Fock level with the standard 6-31+G(d,p) basis set. Additionally, electron correlation effects for geometric and vibrational properties were evaluated at second-order Møller-Plesset (MP2) and BLYP for B 1 -thiophene complex, whereas the BLYP technique was employed for the complexes of thiophene with B 1 OH and B2 clusters. Symmetry restriction was considered for structure calculations, being C 2v for thiophene, C s for zeolite clusters, and C s linear conformation for the complexes. It was found that these linear thiophene-zeolite complexes reproduce the tendencies in the experimental frequency shifts of the OH vibration mode from the adsorption of thiophene in ZSM5 zeolites. The topologic properties of the complexes give a pattern for the interaction of