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Updated: Jun 20, 2026

Synthesis of Zeolites Using the ADOR (Assembly-Disassembly-Organization-Reassembly) Route
Published on: April 3, 2016
Glycine canonical and zwitterionic isomers within zeolites
Gang Yang1, Lijun Zhou, Chengbu Liu
1Institute of Theoretical Chemistry, Shandong University, Jinan 250100, PR China. theobiochem@gmail.com
Abstract:
The glycine zwitterion (GlyA) in the gas phase is not a local energy minimum and transforms to the canonical isomer (GlyB) via a barrierless process. Within ZSM-5 zeolite, it is rendered geometrically stable and even has a lower energy of 7.57 kcal mol(-1) than GlyC, the most stable isomer of glycine in the gas phase; GlyB represents the lowest energy minimum, which is facile to transform into the zwitterion with low-energy barrier (4.46 kcal mol(-1)). In addition, the zwitterion can be efficiently obtained by adsorption of glycine in the deprotonated form at the acidic site of HZSM-5 zeolite. The relative stability of glycine isomers in silicalite-1 increases in the order GlyA
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