title: Hydrogen Bond Symmetrization in Glycinium Oxalate under Pressure.
abstract: The study of hydrogen bonds near symmetrization limit at high pressures is of importance to understand proton dynamics in complex bio-geological processes. We report here the evidence 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 dynamic proton sharing between semioxalate units results in covalent-like 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.
authors.affiliation: High Pressure and Synchrotron Radiation Physics Division, ‡Solid State Physics Division, Bhabha Atomic Research Centre , Trombay, Mumbai 400085, India.
authors.forename: Himal
authors.initials: H
authors.lastname: Bhatt
authors.affiliation: High Pressure and Synchrotron Radiation Physics Division, ‡Solid State Physics Division, Bhabha Atomic Research Centre , Trombay, Mumbai 400085, India.
authors.forename: Chitra
authors.initials: C
authors.lastname: Murli
authors.affiliation: High Pressure and Synchrotron Radiation Physics Division, ‡Solid State Physics Division, Bhabha Atomic Research Centre , Trombay, Mumbai 400085, India.
authors.forename: A K
authors.initials: AK
authors.lastname: Mishra
authors.affiliation: High Pressure and Synchrotron Radiation Physics Division, ‡Solid State Physics Division, Bhabha Atomic Research Centre , Trombay, Mumbai 400085, India.
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Verma
authors.affiliation: High Pressure and Synchrotron Radiation Physics Division, ‡Solid State Physics Division, Bhabha Atomic Research Centre , Trombay, Mumbai 400085, India.
authors.forename: Nandini
authors.initials: N
authors.lastname: Garg
authors.affiliation: High Pressure and Synchrotron Radiation Physics Division, ‡Solid State Physics Division, Bhabha Atomic Research Centre , Trombay, Mumbai 400085, India.
authors.forename: M N
authors.initials: MN
authors.lastname: Deo
authors.affiliation: High Pressure and Synchrotron Radiation Physics Division, ‡Solid State Physics Division, Bhabha Atomic Research Centre , Trombay, Mumbai 400085, India.
authors.forename: R
authors.initials: R
authors.lastname: Chitra
authors.affiliation: High Pressure and Synchrotron Radiation Physics Division, ‡Solid State Physics Division, Bhabha Atomic Research Centre , Trombay, Mumbai 400085, India.
authors.forename: Surinder M
authors.initials: SM
authors.lastname: Sharma