We report here the evidences of hydrogen bond symmetrization in the simplest amino acid- carboxylic acid complex, glycinium oxalate, at moderate pressures of 8 GPa using in-situ infrared and Raman spectroscopic investigations combined with first-principles simulations. The protonation of the semioxalate units through dynamic proton movement results in infinite oxalate chains. At pressures above 12 GPa, the glycine units systematically reorient with pressure to form hydrogen bonded supramolecular assemblies held together by these chains.
@article{arxiv.1508.01073,
title = {Hydrogen Bond Symmetrization in Glycinium Oxalate under Pressure},
author = {Himal Bhatt and Chitra Murli and A. K. Mishra and Ashok K. Verma and Nandini Garg and M. N. Deo and R. Chitra and Surinder M. Sharma},
journal= {arXiv preprint arXiv:1508.01073},
year = {2016}
}