A crystal chemical analysis based on the stereoatomic model of crystal structures and Voronoi–Dirichlet polyhedra is performed to study non-covalent interactions in imidazole crystal structures determined for a wide range of pressures. It is established that the formation of various non-covalent contacts in imidazole crystal structures is determined by external pressure. It is shown that the area of Voronoi–Dirichlet molecular polyhedra depends on the external pressure. The topology of H-bonding between imidazole molecules and the influence of external pressure on the characteristics of N–H⋯N hydrogen bonds in the structures of imidazole crystals are analyzed.

С использованием стереоатомной модели строения кристаллов и полиэдров Вороного-Дирихле осуществлен кристаллохимический анализ невалентных взаимодействий в структурах кристаллов имидазола, расшифрованных в широком диапазоне давлений. Показано, что в зависимости от величины внешнего давления в кристаллических структурах имидазола реализуются различные невалентные контакты. Установлена линейная зависимость значений площади молекулярных полиэдров Вороного-Дирихле от величины внешнего давления. Проанализирована топология связывания молекул имидазола друг с другом посредством водородных связей, а также влияние величины внешнего давления на характеристики водородных связей N–H···N в структурах кристаллов имидазола.

The authors analyze temperature dependences of the retention of derivatives of quinoline, 1,2,3,4-tetrahydroquinoline, and pyridazino[4,5-c]quinoline under conditions of reversed-phase high-performance liquid chromatography on octadecyl silica gel. The thermodynamic characteristics of sorption of these compounds are calculated. The change in the enthalpies of sorption are found to depend on the content of acetonitrile in the water–acetonitrile eluent.

В статье рассмотрены вопросы, связанные с исследованием производных азотистых гетероциклов в условиях обращенно-фазового варианта высокоэффективной жидкостной хроматографии. Определены сорбционные и физико-химические характеристики некоторых производных азолов. Предложено использование спектрального подхода для групповой идентификации компонентов сложных смесей азотистых гетероциклов и корреляций между удерживанием и физико-химическими параметрами для индивидуальной идентификации. The article deals with issues related to the study of nitrogenous heterocycles derivatives under conditions of a reversed-phase high-performance liquid chromatography. The sorption and physicochemical characteristics of some azole derivatives have been determined. The use of a spectral approach for group identification of nitrogenous heterocycles complex mixtures components and correlations between retention and physicochemical parameters for individual identification is proposed.

The authors study the laws governing the sorption of some derivatives of 1,2,3,4-tetrahydroquinoline and pyridazino[4,5-c]quinoline from water–acetonitrile solutions on an octadecyl-functionalized silica gel under reverse-phase high-performance liquid chromatography. The physicochemical characteristics and retention factors of sorbates at different acetonitrile concentrations in the eluent are determined. Dependences of the change in the retention factor as a function of sorbate structure and eluent composition are analyzed.

Laws governing the sorption of quinoline derivatives on hypercrosslinked polystyrene are studied under conditions of reverse-phase high-performance liquid chromatography. Factors of sorbate retention at different concentrations of acetonitrile in the eluent are determined. An analysis is performed of the dependences of variation in the enthalpy of sorption and the entropy term of the temperature dependence of the retention factor on the content of the organic component in the eluent for the studied compounds.

A crystal chemical analysis is performed of the structures of some imidazole derivatives capable of polymorphic transformations. Characteristics of molecular Voronoi–Dirichlet polyhedra are used to analyze nonvalent intra- and intermolecular interactions in the crystal structures of imidazole conformational polymorphs.

The chromatographic retention of 1,2,4-triazine and 1,2,4-triazole derivatives on octadecyl silica gel, super–cross linked polystyrene, and porous graphitized carbon is studied using water-acetonitrile mobile phase. The effect the structure of sorbate molecules and the nature of the sorbent have on the retention characteristics under conditions of RP HPLC is analyzed. The influence of the acetonitrile concentration in the eluent on the retention of the investigated compounds by sorbents of various nature is illustrated.

The structure of water–acetonitrile solutions of derivatives of quinoline and tetrahydroquinoline is investigated by means of аb initio molecular dynamics. It is shown that the propensity of molecules to form different types of hydrogen bonds depends largely on both the nature of the functional groups and on steric factors. When porous graphitic carbon is used as a sorbent, a linear correlation is observed between the fraction of configurations with hydrogen bonds and the logarithm of the retention factor under conditions of reverse-phase liquid chromatography.

Исследована зависимость хроматографического удерживания производных 1,2,4-триазина и 1,2,4-триазола из водно-ацетонитрильных растворов на октадецилсиликагеле от строения молекул сорбатов. Проанализировано влияние физико-химических параметров молекул гетероциклов и их топологии на характеристики удерживания в условиях ОФ ВЭЖХ.

The retention of 16 quinoline and tetrahydroquinoline derivatives was investigated under liquid chromatography conditions using porous graphitized carbon (PGC), octadecyl silica (ODS) and hypercrosslinked polystyrene (HCLP) stationary phases. For most of the analytes, retention on PGC was greater than on ODS, while retention on HCLP was even greater than on both ODS and PGC. The non-linearity of retention dependencies on acetonitrile content in the eluent was observed for compounds containing carboxy, hydrazo and methoxy groups. The relationships between quinolines structure and their retention factors were investigated. It was found that sorption on different sorbents correlated with different descriptors. Retention on ODS was found to be highly correlated with lipophilicity only while on HCLP it depended on both lipophilicity and polarizability of the sorbates. The feature of PGC was a good correlation of retention factors with topological and geometrical parameters. Additionally, ability of PGC to form OH…π bonds with hydroxymethylquinolines was found. The observed regularities allow one to rationally optimize the chromatographic analysis of structurally similar compounds, which is very important for bioactive substances.

The dependence of the chromatographic retention of 1,2,4-triazine and 1,2,4-triazole derivatives from water–acetonitrile solutions over octadecyl silica on the structure of sorbate molecules is studied. The effect the physicochemical parameters and topology of heterocycle molecules have on the retention characteristics under RP HPLC conditions is analyzed.

Sixth order connectivity indices are calculated for 29 benzotriazole derivatives. Correlations between the connectivity indices, physicochemical characteristics, and retention factors of the mentioned compounds are obtained for reversed-phase high-performance liquid chromatography conditions. Based on the correlations obtained, a predictive calculation of the retention factors of some benzotriazole derivatives is performed.

The aim of our study was to investigate relationships between quinoline derivatives structure and their retention under reversed-phase liquid chromatography conditions. Retention factors of quinolines were experimentally measured and various geometrical and physicochemical parameters representing analytes molecular structure were calculated. Equations connecting chromatographic data with computed characteristics for the set of 17 investigated compounds were constructed. It was shown that the most precise dependencies include combination of physico-chemical and geometrical parameters.

A number of physicochemical characteristics of ten 1,2,3,4-tetrahydroquinoline derivatives synthesized for the first time, along with their third order Wiener and Randič indices are calculated by quantum chemical methods. Correlations between the topological indices, physicochemical parameters, and retention factors of the mentioned compounds are obtained for conditions of reversed-phase high performance liquid chromatography on porous graphitized carbon.

Regularities of the sorption of 1,2,3,4-tetrahydroquinoline derivatives on octadecylsilyl silica gel and porous graphitic carbon from aqueous acetonitrile solutions were investigated. The effect the molecular structure and physicochemical parameters of the sorbates have on their retention characteristics under conditions of reversed phase HPLC are analyzed.