Salicylamide cocrystals: screening, crystal structure, sublimation thermodynamics, dissolution, and solid-state DFT calculations

J Phys Chem B. 2014 Jun 19;118(24):6803-14. doi: 10.1021/jp5032898. Epub 2014 Jun 5.

Abstract

A new cocrystal of 2-hydroxybenzamide (A) with 4-acetamidobenzoic acid (B) has been obtained by the DSC screening method. Thermophysical analysis of the aggregate [A:B] has been conducted and a fusion diagram has been plotted. Cocrystal formation from melts was studied by using thermomicroscopy. A cocrystal single-crystal was grown and its crystal structure was determined. The pattern of noncovalent interactions has been quantified using the solid-state DFT computations coupled with the Bader analysis of the periodic electron density. The sublimation processes of A-B cocrystal have been studied and its thermodynamic functions have been calculated. The classical method of substance transfer by inert gas-carrier was chosen to investigate sublimation processes experimentally. The lattice energy is found to be 143 ± 4 kJ/mol. It is lower than the sum of the corresponding values of the cocrystal pure components. The theoretical value of the lattice energy, 156 kJ/mol, is in reasonable agreement with the experimental one. A ternary phase diagram of solubility (A-B-ethanol) has been plotted and the areas with solutions for growing thermodynamically stable cocrystals have been determined.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzamides / chemistry
  • Calorimetry, Differential Scanning
  • Crystallography, X-Ray
  • Gases / chemistry
  • Molecular Conformation
  • Salicylamides / chemistry*
  • Solubility
  • Temperature
  • Thermodynamics
  • para-Aminobenzoates / chemistry

Substances

  • 2-hydroxybenzamide
  • Benzamides
  • Gases
  • Salicylamides
  • para-Aminobenzoates
  • Acedoben
  • salicylamide