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A DFT Study of the Acidity of Ultrastable Y Zeolite: Where Is the Brønsted/Lewis Acid Synergism?
Author(s) -
Mota Claudio J. A.,
Bhering Daniel L.,
Rosenbach Nilton
Publication year - 2004
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.200353049
Subject(s) - lewis acids and bases , brønsted–lowry acid–base theory , chemistry , acid strength , zeolite , hydrogen bond , catalysis , density functional theory , conjugated system , inorganic chemistry , base (topology) , cluster (spacecraft) , acid–base reaction , medicinal chemistry , organic chemistry , computational chemistry , polymer , molecule , mathematical analysis , mathematics , computer science , programming language
The effect of extra‐framework aluminum (EFAL) species on the acidity of a HT 6 cluster (T=Si, Al) was studied by density functional calculations. A higher acid strength, compared to an isolated site, was only found with Al(OH) 2 + . The increase in acid strength was not due to Brønsted/Lewis acid synergism, as previously reported, but to the stabilization of the conjugated base through hydrogen bonding with the EFAL hydroxy groups (see picture).