Discovery of Unconventional Phase of L‐Tartaric Acid by Acoustic Shocked Conditions—X‐Ray Diffraction and Raman Spectroscopic Approach

ABSTRACT Syntheses of new organic molecules and the discovery of high‐pressure phases of known organic molecules under extreme conditions have always been a special interest in the fields of chemical science, geological sciences, and astrochemistry, owing to their profound significance for both the fundamental and advanced understanding of the origins of life on Earth. Laboratory‐based dynamic shock‐wave‐recovery experiments on organic species have made a tremendous contribution to the identification of the synthetic role of natural shockwaves on the pre‐biological processes of space‐related organic molecules. In the present study, we consider L‐tartaric acid (LTA‐ P 2 1 ) as a test sample, which is a potential molecule that may be present in the interstellar medium (ISM). It is subjected to acoustic shock waves with 0, 50, and 100 shocks, respectively, to understand its high‐pressure structural science. Significant differences are observed in the X‐ray diffraction lines, Raman spectral lines, morphology, and optical transmittance spectra of the LTA under shocked conditions. To identify the formation of new phases, Le Bail refinements were performed, revealing P 2 1 ‐ P 1 and P1‐P1 transitions under 50‐ and 100‐shocked conditions and further validated by the analyses of the lattice Raman modes, surface morphology, and optical bandgap energies. A possible mechanism is proposed based on the thermal conductivity‐dependent shock waves‐driven superheating approach. By presenting unequivocal explanations for the present work, it is believed that the acoustic shock waves have enough driving force to discover new crystallographic structures in organic species, such that tabletop shock tubes can be effectively considered powerful tools for discovering new organic species and phases.