Pressure-imposed changes of benzoic acid crystals

Abstract

Structural and energetic properties of benzoic acid crystals at pressure elevated from ambient condition up to 2.21 GPa were characterized. The directly observed variations of cell parameters and consequently cell volume are associated with many other changes including energetic, geometric, and electronic characteristics. First of all the non-monotonous change of lattice energy are noticed with the rise of pressure since the increase of stabilization up to 1GPa is followed by systematic decrease of lattice energies after extending the hydrostatic compression. There is also an observed increase of C22(8) synthon stabilization interaction with increase of pressure. The lattice response rather than interaction within synthons are source of observed pressure-related trend of lattice energy changes. The energy decomposition analysis revealed that the total steric interactions determine the overall trend of lattice energy change with the rise of pressure. Besides geometric aromaticity index was used as a measure of geometric changes. Serious discrepancies were noticed between HOMA values computed with the use of experimental and optimized geometries of the ring. Even inclusion of uncertainties of experimental geometries related to limited precision of X-ray diffraction measurements does not cancel mentioned discrepancies. Although HOMA exhibit similar trends at modest pressures the diversity became surprisingly high at more extreme conditions. This might suggest limitations of periodic DFT computations at elevated pressures and the experimentally observed breaking of molecules at very high pressures will probably not be accounted properly in this approach. Also limitation of direct use of experimental geometries were highlighted.Electronic supplementary materialThe online version of this article (doi:10.1007/s00894-015-2635-z) contains supplementary material, which is available to authorized users.

Accurate lattice energies of organic molecular crystals from periodic turbomole calculations

“…Experimental vibrational lattice frequencies were used to calculate . This ZPE is in excellent agreement with calculated ZPEs for naphthalene and benzoic acid . When using the 2 RT ‐approximation from eq.…”

“…This ZPE is in excellent agreement with calculated ZPEs for naphthalene [62] and benzoic acid. [63,64] When using the 2RT-approximation from eq. (3), E latt,exp is underestimated by 0.4-1.4 kJ mol 21 for benzoic acid and naphthalene, respectively.…”

In silico screening of dicarboxylic acids for cocrystallization with phenylpiperazine derivatives based on both cocrystallization propensity and solubility advantage

“…This structure is classified in graph theory as R 2 2 (8), and is stabilized by two very strong hydrogen bonds. The contributions of these hydrogen bonds to the total stabilization energy of the crystal lattice can significantly exceed 50%; e.g., in crystals of aromatic carboxylic acids, the synthon stabilization energy exceeds the sum of the other kinds of intermolecular interactions that occur in the crystal lattice [60–62]. It is true that increasing the pressure can affect all types of interactions in a nonmonotonic manner [62], but the synthon stabilization energy still provides the dominant share of the total energy of the crystal.…”

“…The contributions of these hydrogen bonds to the total stabilization energy of the crystal lattice can significantly exceed 50%; e.g., in crystals of aromatic carboxylic acids, the synthon stabilization energy exceeds the sum of the other kinds of intermolecular interactions that occur in the crystal lattice [60–62]. It is true that increasing the pressure can affect all types of interactions in a nonmonotonic manner [62], but the synthon stabilization energy still provides the dominant share of the total energy of the crystal. It is worth mentioning that linear trends [41, 63] between the stabilization energies of homo- and heterosynthons and the values of the Hammett constants σ describing the electrophilic and nucleophilic character of the substituents have been observed.…”

“…This is clearly demonstrated by the statistical analysis of existing cocrystals, which show that the formation of heterosynthon patterns is much preferred to the formation of homosynthon patterns [64, 65]. For example, a homosynthon formed from two carboxyl groups is far less common than a heterosynthon generated from amide and carboxyl groups, despite the fact that the energy of a pair of carboxyl groups is generally a few to several kcal/mol higher than the energy of the amide and carboxyl pair [39, 62, 63]. In this context, while the linear trends observed in Fig.…”