Abstract
Synthesis of multicomponent solid forms is an important method of modifying and fine-tuning the most critical physicochemical properties of drug compounds. The design of new multicomponent pharmaceutical materials requires reliable information about the supramolecular arrangement of molecules and detailed description of the intermolecular interactions in the crystal structure. It implies the use of a combination of different experimental and theoretical investigation methods. Organic salts present new challenges for those who develop theoretical approaches describing the structure, spectral properties, and lattice energy Elatt. These crystals consist of closed-shell organic ions interacting through relatively strong hydrogen bonds, which leads to Elatt > 200 kJ/mol. Some technical problems that a user of periodic (solid-state) density functional theory (DFT) programs encounters when calculating the properties of these crystals still remain unsolved, for example, the influence of cell parameter optimization on the Elatt value, wave numbers, relative intensity of Raman-active vibrations in the low-frequency region, etc. In this work, various properties of a new two-component carbendazim maleate crystal were experimentally investigated, and the applicability of different DFT functionals and empirical Grimme corrections to the description of the obtained structural and spectroscopic properties was tested. Based on this, practical recommendations were developed for further theoretical studies of multicomponent organic pharmaceutical crystals.
Highlights
Organic salts are crystalline ionic compounds that contain one or more organic ions in their structure
The abbreviations used for relative intensities are vs, very strong; s, strong; Atomic numbering is given in Figure 2; the IR intensities are given in parenthesis; plane waves (PW) stands for the plane-wave basis set with a cut-off energy of 100 Ry and PAW pseudopotentials; (e) in the calculations, this is a doublet of bands with almost identical wave numbers and IR intensities
We investigated the influence of cell parameter optimization on the Elatt value, as well as the structural and spectroscopic properties of the new two-component carbendazim maleate crystal
Summary
Organic salts are crystalline ionic compounds that contain one or more organic ions in their structure. Non-directed dispersion interactions cause problems for DFT computations in both the GTO and PW versions, making it necessary to use the dispersion corrections of different nature It is not yet investigated how the dispersion corrections [42,43,44], as well as other parameters such as optimization of cell parameters [7,9,30,34], type of the functional, and basis set, affect the observable properties (e.g., sublimation enthalpy [28,45], IR/Raman spectra [46,47,48], metric [18,22] and electron density features [42] at bond critical points of conventional and non-conventional hydrogen bonds) of molecular crystals with short (strong) or ionic H-bonds.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
