Pressure-Induced Reversible Amorphization in Hydrogen-Bonded Crystalline Phenyl Carbamate Form-I

Abstract

We characterized the high-pressure response of hydrogen-bonded crystalline phenyl carbamate (C7H7NO2, PC) form-I through in situ synchrotron X-ray diffraction (XRD) and Raman spectroscopy in a diamond anvil cell (DAC) under pressures of up to ∼13 GPa at room temperature. No evidence for the polymorphic transformation of crystalline PC form-I crystal to form-II was observed under high pressure. The evolution of the XRD patterns and Raman spectra indicated that crystalline PC form-I underwent reversible pressure-induced amorphization (PIA) at 12.7 GPa. Ab initio calculations were performed to account for the changes in molecular arrangements and hydrogen-bonded networks in PC form-I under pressure. Hirshfeld surfaces and fingerprint plots were utilized to directly compare the variations in packing patterns and intermolecular interactions. On the basis of the experimental and calculated results, we proposed that PIA in crystalline PC form-I is driven by the competition between close packing and long-range order. This competition is accompanied by hydrogen-bond collapse.

High‐pressure‐induced phase transition in 1,3‐diphenylurea: The approaching of N–H⋯O hydrogen‐bonded chains

“…The changes of Hirshfeld surface also confirm the sharp compression between the hydrogen‐bonded chains. Respectively, the blue and red regions on the Hirshfeld surface regions represent long and short interactions . As shown in Figure a–d, the energy on the surface of carbon atoms on both the phenyl rings and C═O groups noted by the red arrows increases significantly under high pressure; also, all the red areas are significantly deepened from 1 atm to 10.0 GPa.…”

“…Respectively, the blue and red regions on the Hirshfeld surface regions represent long and short interactions. [46,47] As shown in Figure 6a-d, the energy on the surface of carbon atoms on both the phenyl rings and C═O groups noted by the red arrows increases significantly under high pressure; also, all the red areas are significantly deepened from 1 atm to 10.0 GPa. This phenomenon indicates that the increase in the intermolecular interactions between the hydrogen-bonded chains is faster than the enhancement of the N-H⋯O hydrogen bonds.…”

Exploring the Polymorphism of Cinchomeronic Acid at High Pressure

“…The crystal structures of organic molecules can be efficiently stabilized by hydrogen bonds because of the structures, directionality, specificity, and cooperativity. , Given the geometry of hydrogen bonds and the cooperativity of multiple interactions that can be markedly altered by external forces, high-pressure techniques can be used in analyzing molecular crystals that are efficiently formed by hydrogen bonds and in exploring novel polymorphs. − A novel polymorph, δ-glycine, was obtained from β-glycine at 0.8 GPa. The transition resulted in an equal number of N–H···O hydrogen bonds but also increased the number and strength of C–H···O hydrogen bonds. − Individual molecules in the polymorphs I and II of paracetamol formed two-dimensional layers linked by N–H···O–H and O–H···OC hydrogen bonds.…”

“…The crystal structures of organic molecules can be efficiently stabilized by hydrogen bonds because of the structures, directionality, specificity, and cooperativity. 17,18 Given the geometry of hydrogen bonds and the cooperativity of multiple interactions that can be markedly altered by external forces, high-pressure techniques can be used in analyzing molecular crystals that are efficiently formed by hydrogen bonds and in exploring novel polymorphs. 19 This variation is likely due to the distortion of the N−H•••O hydrogen bonds between the molecular chains.…”

High pressure structural behaviour of 5,5′-bitetrazole-1,1′-diolate based energetic materials: a comparative study from first principles calculations

“…The effect of pressure may also induce variations in electrostatic interactions, vdW forces, hydrogen bonding networks, p-p stacking and other effects, leading to new molecular rearrangements and reorientations, thereby tuning the crystal structure symmetry. [7][8][9] However, as a pervasive intermolecular interaction, the precise knowledge of hydrogen bonding is very essential because of its importance in understanding the dynamics of chemical systems, function and structural stability. 11 These hydrogen bonding networks among the molecules of crystalline materials are signicant as they can provide fundamental insight into the behavior and properties of elements and chemicals, and help in applications such as tunable sensitivity of energetic materials, hydrogen storage, pharmaceuticals, etc.…”