The teaching staff of the chair participates in the implementation of various study courses – General Chemistry, Physical Chemistry, Kinetics and Catalysis, Structure of Atoms and Molecules, X-Ray Methods in Chemistry, Data Processing Methods in Chemistry, Chromatography, etc. Several lecturers are experts of the Latvian Academy of Sciences in their respective fields of chemistry and physics.

 
Name and Surname Position

Agris Bērziņš

Chair manager, Associate professor, Senior researcher

Andris Actiņš

Professor

Liāna Orola

Associate professor

Elīna Pajuste

Associate professor

Guntars Vaivars

Associate professor

Ilva Nakurte

Assistant professor

Māra Feldmane Lecturer, Researcher, PhD student
Artis Kons

Senior researcher

Antons Podjava

Senior researcher

Toms Rēķis Researcher
Kristaps Saršūns Researcher, PhD student
Aina Semjonova

Researcher, PhD student

Aija Trimdale-Deksne Researcher, Chemist
Valda Valkovska Researcher, Lecturer, PhD student
Marta Kāne Chemist
Zane Čerpakovska

Chemist, PhD student

Juris Kostjukovs Chemist
Aldis Zekunde  Chemist
Kaspars Meijers Chemist
Anita Kalniņa

Laboratory manager

Artūrs Šilaks PhD student
   

Formation, physical properties, transformations, structure, and crystallization process of crystal phases of organic solids

Identification of factors causing different solid form landscape complexity of structurally similar compounds

Structurally similar pharmaceutically relevant compounds are studied to identify factors causing different propensity of these compounds to form solvates, hydrates and polymorphs. Detailed crystallographic analysis, computational calculations of intramolecular and intermolecular energy, specification of preparation conditions for selected crystal forms and association in solution using spectroscopic methods and molecular dynamics simulations are used.

Trimdale-Deksne, A., Kons, A., Orola, L., Mishnev, A., Stepanovs, D., Mazur, L., Skiba, M., Dudek, M.K., Fantozzi, N., Virieux, D., Colacino, E., Bērziņš, A. Crystallographic and Computational Analysis of the Solid-Form Landscape of Three Structurally Related Imidazolidine-2,4-dione Active Pharmaceutical Ingredients: Nitrofurantoin, Furazidin, and Dantrolene. Cryst. Growth Des. 2023, 23, (2), 930–945. DOI: 10.1021/acs.cgd.2c01142

Bērziņš, A., Semjonova, A., Actiņš, A., Salvalaglio, M. Speciation of Substituted Benzoic Acids in Solution: Evaluation of Spectroscopic and Computational Methods for the Identification of Associates and Their Role in Crystallization. Cryst. Growth Des. 2021, 21, (9), 4823–4836. DOI: 10.1021/acs.cgd.0c01605

Trimdale, A., Mishnev, A., Bērziņš, A. Combined Use of Structure Analysis, Studies of Molecular Association in Solution, and Molecular Modelling to Understand the Different Propensities of Dihydroxybenzoic Acids to Form Solid Phases. Pharmaceutics 2021, 13, (5), 734. DOI: 10.3390/pharmaceutics13050734

Bērziņš, A.; Zvaniņa, D.; Trimdale, A. Detailed analysis of packing efficiency allows rationalization of solvate formation propensity for selected structurally similar organic molecules. Cryst. Growth Des. 2018, DOI: 10.1021/acs.cgd.7b01457

 

Understanding the driving forces of formation, transformation mechanisms, and stability of crystal forms of pharmaceutical compounds

Pharmaceutical compounds forming numerous polymorphs, hydrates and solvates are studied to identify and rationalize the driving forces of formation of these crystal forms, the mechanisms of the observed phase transformations, and the stability of these crystal forms. For this, crystal form screening, crystal structure analysis with different crystallographic and computational chemistry tools and experimental characterization of stability and transformations of crystal forms are used.

Orola, L., Mishnev, A., Stepanovs, D., Bērziņš, A. Crystallographic Study of Solvates and Solvate Hydrates of an Antibacterial Furazidin. Cryst. Growth Des. 2023, 23, (2), 873–884 DOI: 10.1021/acs.cgd.2c01114

Kons, A., Mishnev, A, Mukhametzyanov, T.A., Buzyurov, A.V., Lapuk, S.E., Bērziņš, A. Hexamorphism of Dantrolene: Insight into the Crystal Structures, Stability, and Phase Transformations. Cryst. Growth Des. 2021, 21, (2), 1190–1201. DOI: 10.1021/acs.cgd.0c01508

Bērziņš, A., Kons, A., Saršūns, K., Belyakov, S., Actiņš, A. On the rationalization of formation of solvates: experimental and computational study of solid forms of several nitrobenzoic acid derivatives. Cryst. Growth Des. 2020, 20, (9), 5767–5784 DOI: 10.1021/acs.cgd.0c00331

Kons, A., Bērziņš, A., Actiņš, A., Rekis, T., van Smaalen, S., Mishnev, A. Polymorphism of R-Encenicline Hydrochloride: Access to the Highest Number of Structurally Characterized Polymorphs Using Desolvation of Various Solvates. Cryst. Growth Des. 2019, 19, (8), 4765-4773. DOI: 10.1021/acs.cgd.9b00648

 

Investigation of application of additives for controlling the polymorphic outcome of crystallization

Crystallization process in presence of additives is investigated to search for conditions under which control of the crystallization polymorphic outcome for pharmaceutical molecules and model compounds is provided. The most suitable additive, solvent, crystallization approach and conditions providing reliable control of polymorphic outcome is identified. Mechanism for the additive provided crystallization control is explored using crystallographic analysis, computational tools and exploration of properties and transformations of crystal forms.

Bērziņš, A., Trimdale-Deksne, A., Belyakov, S., ter Horst, J.H. Switching nitrofurantoin polymorphic outcome in solvent mediated phase transformation and crystallization using solvent and additives. 2022. DOI: 10.26434/chemrxiv-2022-cdl0z

Semjonova, A., Bērziņš, A. Surfactant Provided Control of Crystallization Polymorphic Outcome and Stabilization of Metastable Polymorphs of 2,6-Dimethoxyphenylboronic Acid. Crystals 2022, 12, 1738. DOI: 10.3390/cryst12121738

Semjonova, A., Bērziņš, A. Controlling the Polymorphic Outcome of 2,6-Dimethoxybenzoic Acid Crystallization Using Additives. Crystals 2022, 12, 1161. DOI: 10.3390/cryst12081161

 

Exploration of formation of solid solutions in molecular crystals

Solid solutions in molecular crystals are explored by researching the solid solution formation, structure and properties. The research is conducted in three directions: 1) factors that control the solid solution formation between structurally similar pharmaceutical molecules and model compounds are identified by constructing the phase diagrams and using structure analysis and computational calculations to rationalize the observations, 2) solid solutions allowing fine-tuning of selected properties of the studied phase, such as luminescence properties, are studied, and 3) formation of solid solutions between the enantiomers of selected pharmaceutical compounds are researched to understand the crystallization behavior of these compounds.

Saršūns, K., Bērziņš, A. Experimental and Computational Investigation of Benperidol and Droperidol Solid Solutions in Different Crystal Structures. Cryst. Growth Des. 2023, 23, (2), 1133-1144. DOI: 10.1021/acs.cgd.2c01269

Saršūns, K., Kemere, M., Karziņins, A., Klimenkovs, I., Bērziņš, A., Sarakovskis, A., Rekis, T. Fine-Tuning Solid State Luminescence Properties of Organic Crystals via Solid Solution Formation: The Example of 4-Iodothioxanthone–4-Chlorothioxanthone System. Crystal Growth & Design 2022, 22, (8), 4838-4844. DOI: 10.1021/acs.cgd.2c00313

Saršūns, K., Bērziņš, A., Rekis, T. Solid Solutions in the Xanthone–Thioxanthone Binary System: How Well Are Similar Molecules Discriminated in the Solid State? Cryst. Growth Des. 2020, 20, (12), 7997–8004. DOI: 10.1021/acs.cgd.0c01241

Rekis, T. Crystallization of chiral molecular compounds: what can be learned from the Cambridge Structural Database?, Acta Cryst. B 2020, 76, 307-315. DOI: 10.1107/S2052520620003601

Rekis, T., Bērziņš, A. On the structural aspects of solid solutions of enantiomers: an intriguing case study of enantiomer recognition in the solid state. CrystEngComm 2018, 20, 6909-6918. DOI: 10.1039/C8CE01245H

Rekis, T.; Bērziņš, A.; Sarceviča, I.; Kons, A.; Balodis, M.; Orola, L.; Lorenz, H.; Actiņš, A. A Maze of Solid Solutions of Pimobendan Enantiomers: An Extraordinary Case of Polymorph and Solvate Diversity. Cryst. Growth Des. 2018, 18, (1), 264–273. DOI: 10.1021/acs.cgd.7b01203

 

Chromatographic studies of natural substances and bioanalytical samples and development of methods for the analysis of such samples

Development and use of chromatographic methods for determining the composition of natural substances and bioanalytical samples

Mažylytė, R.; Kaziūnienė, J.; Orola, L.; Valkovska, V.; Lastauskienė, E.; Gegeckas, A.  Phosphate Solubilizing Microorganism Bacillus sp. MVY-004 and its Significance for Biomineral Fertilizers’ Development in Agrobiotechnology. Biology 2022, 11, 2, 254. DOI: 10.3390/biology11020254

Ramata-Stunda, A.; Petriņa, Z.; Valkovska, V.; Borodušķis, M.; Gibnere, L.; Gurkovska, E. Nikolajeva, V.  Synergistic Effect of Polyphenol-Rich Complex of Plant and Green Propolis Extracts with Antibiotics against Respiratory Infections Causing Bacteria. Antibiotics 2022, 11, 2, 160. DOI: 10.3390/antibiotics11020160

Ramata-Stunda, A.; Valkovska, V.; Borodušķis, M.; Livkiša, D.; Kaktiņa, E.; Silamiķele, B.; Borodušķe, A.; Pentjušs, A.; Rostoks, N. Development of metabolic engineering approaches to regulate the content of total phenolics, antiradical activity and organic acids in callus cultures of the highbush blueberry (Vaccinium corymbosum), Agron. Res. 2020, 18, 1860-1872. DOI: 10.15159/ar.20.054

 

Phytochemical composition of dye species and their use in wool dyeing

Valkovska, V.; Orola L. Characterization of Pigments from "Malus domestica" Leaves for Wool Dyeing. Key Eng. Mater., 2021, 850, 63-68. 10.4028/www.scientific.net/KEM.903.63

Batarāga, A.; Valkovska, V. Phytochemical Profile of Chokeberry (Aronia melanocarpa). Key Eng. Mater. 2020, 850, 184-189. 10.4028/www.scientific.net/KEM.850.184

 

 


Development of chromatography and solid phase extraction sorbents for analysis of specific bioanalytical samples

Podjava, A., Šilaks, A. Synthesis and sorptive properties of molecularly imprinted polymer for simultaneous isolation of catecholamines and their metabolites from biological fluids. J. Liq. Chromatogr. Relat. Technol. 2021, 44, (3-4), 181-188. DOI: 10.1080/10826076.2021.1874980

Podjava, A., Šilaks, A. Study of chromatographic properties of catecholamines and their acidic metabolites using novel molecularly imprinted polymers as stationary phases. Key Eng. Mater. 2021, 903, 15-21. DOI: 10.4028/www.scientific.net/KEM.903.15


Ion-conducting polymer composite membranes with ionic liquids and inorganic nanoparticles

Synthesis of sulfonated polyether ether ketone membranes with different degree of sulfonation and evaluation of the influence of the degree of sulfonation on the physical properties of these membranes. Preparation and characterization of polymer composite membranes with ionic liquids, zirconium oxide nanoparticles and carbon dispersions. Testing of the obtained membranes in alternative energy and solid-state ionic devices (fuel cells, batteries, chemical reactors, such as CO2 reduction reactors). Supervisor of the research direction assoc. prof. Guntars Vaivars, the research is carried out in collaboration with Laboratory of Chemical Technologies, Institute of Solid State Physics, University of Latvia.

Pajuste, E., Reinholds, I., Vaivars, G., Antuzevičs, A., Avotiņa, L., Sprūģis, E., Mikko, R., Heikki, K., Meri, R.M., Kaparkalējs, R. Evaluation of radiation stability of electron beam irradiated Nafion® and sulfonated poly (ether ether ketone) membranes. Polym. Degrad. Stab. 2022, 200, 109970. DOI: 10.1016/j.polymdegradstab.2022.109970

Vaivars, G., Krūkle-Bērziņa, K., Markus, M. Modelling IR spectra of sulfonated polyether ether ketone (SPEEK) membranes for fuel cells. Key Eng. Mater. 2020, 850, 138-143.DOI: 10.4028/www.scientific.net/KEM.850.138


Innovative materials for energy

Studies of radionuclides, their behavior, separation methods and application in various sectors of the economy are being conducted. Supervisor of the research direction assoc. prof. Elīna Pajuste, he research is carried out in collaboration with Department of Radiation Processes, Institute of Chemical Physics, University of Latvia.

E. Pajuste, A.S. Teimane, G. Kizane, L. Avotina, M. Halitovs, A. Lescinskis, A. Vitins, P. Kalnina, E. Lagzdina, R.J.J. Zabolockis. Tritium in plasma-facing components of JET with the ITER-Like-Wall, Phys. Scr. 2021, 96, 124050. DOI: 10.1088/1402-4896/ac29db

E. Pajuste, G. Kizane, L. Avotina, A.S. Teimane, K. Vonda, A. Lescinskis. Novel method for determination of tritium depth profiles in metallic samples, Nucl. Fusion 2019, 59, 106006. DOI: 10.1088/1741-4326/ab3056

E. Pajuste, G. Kizane, A. Vitins, I. Igaune, L. Avotina, R. Zarins. Structure, tritium depth profile and desorption from 'plasma-facing' beryllium materials of ITER-Like-Wall at JET, Nucl. Mater. Energy 2017, 12, 642 - 647. DOI: 10.1016/j.nme.2017.03.017


Studies of new application possibilities of Latvian clay minerals in the national economy

In the laboratory of clay research, Faculty of Chemistry, research on the sustainable and diverse use of underground resources, including the development of new products (materials) and technologies, is conducted. The most active research directions are:

  • Characterization, enrichment and modification of clays and clay minerals;
  • Scaling and optimization of technological processes (e.g., organophilization);
  • Development, testing and application of new products (materials) in real-life conditions – clay-based additive for "in-can" paints for protection, reducing the use of biocides, as well as for the sustainability of the paint; https://www.paintsforlife.eu/;
  • Search for effective sorbents for the collection/recovery of the critical element phosphorus – a potential alternative to agricultural fertilizers;
  • Material synthesized from the Latvian underground resources for the treatment of domestic and industrial wastewater.

J. Kostjukovs, J. Karasa, S. Kostjukova. A metal free antimicrobial and UV protection additive. EU patent application WO2018130880.

J. Kostjukovs, A. Actinš, J. Karasa. Mechanochemical method for obtaining organoclays from smectites. EU patent Nr. EP2690067 B1.

J. Kostjukovs, Actiņš A., I. Sarceviča, J. Karasa. Method for obtaining smectites from clay having low levels of smectites. EU patent Nr. EP2465820 B1.

J. Karasa, S. Kostjukova, J. Kostjukovs, D. Štēbelis, I. Putna-Nīmane. Clay-based additive as a restorer’s tool to tackle the algae growth. European Coatings Journal 2022, 4, 30-33. ISSN 0930-3847

S. Kostjukova, J. Karasa, J. Kostjukovs, D. Štēbelis, Ieva Putna-Nīmane. Additive auf Tonbasis – Hilfsmittel für Restauratoren zur Bekämpfung von Algenbewuchs (Für ein algenfreies Kulturerbe). Farbe und Lack, 2022, 2, 48-55. ISSN 0014-7699.

Formation, physical properties, transformations, structure, and crystallization process of crystal phases of organic solids

Crystal engineering of pharmaceutical multicomponent phases for more efficient crystalline phase design

Supervisor: Dr.chem. Agris Bērziņš

Latvian Council of Science Fundamental and applied research project lzp-2018/1−0312. 01.09.2018 – 31.08.2021

Funding 300 000 EUR

Crystal engineering can be used as a tool for optimization of properties of pharmaceuticals. Nevertheless, the available knowledge still limits the use of this tool, as there are many aspects of formation of intermolecular interactions in the solid state which are far from being rationalized. The aim of this research project is to develop general models and approaches for rationalization of formation of multicomponent phases of pharmaceuticals. The multicomponent phases selected for this study are solvates and solid solutions of pharmaceutical substances. The findings of this study would allow simpler and more efficient design of pharmaceutical multi-component phases, therefore improving production efficiency and reducing costs associated with the design of the final commercial form of new pharmaceutical solids for Latvian pharmaceutical companies.


AI driven IP intelligence engine for early stage drug discovery

UL supervisor: assoc. prof. Agris Bērziņš

IT Health InnoStars RIS innovation project. 06.2020 – 12.2020.

Funding 74 000 EUR, UL share 24 000 EUR.

Collaboration partner: Semantic Intelligence, Ltd.

The aim of the project is to develop an artificial intelligence tool for targeted search of information in patents and other scientific literature, which would allow the search to be performed both using field-specific keywords and using in a traditional way drawn structural formulas of organic compounds.


Development of method to control the crystallization of selected pharmaceutical molecules using templates and study of the control mechanism

Supervisor: Dr.chem. Agris Bērziņš

ERDF funded individual postdoctoral project 1.1.1.2/VIAA/1/16/195. 01.11.2017 – 31.10.2020

Funding 133 806 EUR

Collaboration partners: University College London, Department of Chemistry, Prof. Sally L. Price; University College London, Department of Chemical Engineering, Dr. Matteo Salvalaglio; University of Strathclyde, EPSRC Centre for Innovative Manufacturing in Continuous Manufacturing and Crystallisation, Prof. Joop ter Horst.

The aim is to develop a method for controlling the crystallization of solvates and/or polymorphs of selected model pharmaceuticals using templates using innovative approach for template design and selection, as well as use multidisciplinary contemporary analytical and computational tools to rationalize the crystallization mechanism.


Development of integrated experimental and computational methods to aid prediction of properties and crystal form diversity of active pharmaceutical ingredients.

Supervisor: Dr.chem. Toms Rēķis

Project funded by Mikrotikls Ltd., administrated by University of Latvia Foundation. 01.01.2018 – 31.12.2019.

Funding 51 863 EUR

In this project general rules will be identified to understand the relationship between the molecular structure of organic substances and crystal structures and crystal form diversity of these compounds, which are valid for a wide range of active pharmaceutical ingredients (API). The formation of solid phases of selected API model substances will be studied using experimentally observed phase formations and computational modeling tools. The obtained results are expected to be practically useful and used for the development of new pharmaceutical substances.

 

Chromatographic studies of natural substances and bioanalytical samples and development of methods for the analysis of such samples

Synthesis and application of a novel molecularly imprinted polymer for selective solid-phase extraction of catecholamines and their metabolites

Supervisor: Dr.chem. Antons Podjava

Latvian Council of Science Fundamental and applied research project lzp-2022/1-0141. 2023 –2025

Funding 300 000 EUR


Development and characterization of genome-edited blueberry (Vaccinium corymbosum L.) cultures for production of high-value secondary metabolites

Supervisor: assoc. prof., Dr.biol. Nils Rostoks

Latvian Council of Science Fundamental and applied research project lzp-2018/1-0101. 01.09.2018 – 31.08.2021

Funding 300 000 EUR


Development of new selective solid-phase extraction sorbents for the simultaneous separation of catechylamines and their acid-type metabolites from samples of biological origin

Supervisor: Dr.chem. Antons Podjava

ERDF funded individual postdoctoral project 1.1.1.2/VIAA/1/16/224. 01.11.2017 – 31.10.2020

Funding 133 806 EUR

 

Ion-conducting polymer composite membranes with ionic liquids and inorganic nanoparticles

All projects of this research direction are primarily implemented by Institute of Solid State Physics, University of Latvia.

Advanced polymer – ionic liquid composite sodium-ion electrolytes.

Supervisor: assoc. prof. Guntars Vaivars

Latvian Council of Science Fundamental and applied research project lzp- 2020/1-0391. 2021 –2023

Funding 300 000 EUR

Collaboration partner: Institute of Solid State Physics, University of Latvia


CO2-based Electrosynthesis of ethylene oXIDE – CO2EXIDE.

Coordinator: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.

Corresponding UL representative: assoc. prof. Guntars Vaivars

Horizon 2020 project. 2018 - 2021.

Collaboration partner: Institute of Solid State Physics, University of Latvia

http://www.co2exide.eu/

 

 

Innovative materials for energy

All projects of this research direction are primarily implemented by Institute of Chemical Physics, University of Latvia.

Graphene-based electrochemical pumping for radioactive hydrogen isotope separation

Supervisor: assoc. prof. Elīna Pajuste

ERDF co-financed project. 04.2020. – 03.2023.

UL funding 407 337.68 EUR.

Collaboration partner: SIA Baltic Scientific Instruments.


Novel and efficient approach of medical 43Sc, 44Sc and 47Sc radionuclide separation and purification from irradiated metallic targets towards radiopharmaceutical development for theranostics

Supervisor: assoc. prof. Elīna Pajuste

Latvian Council of Science Fundamental and applied research project lzp-2021/1-0539. 03.01.2022. – 30.12.2024.

Funding: 299 999.70 EUR


Top quark and Higgs physics at the CMS experiment, development of crystal scintillator detectors and sub-detectors of the CMS detector, and the development of particle accelerator technology for societal applications in collaboration with CERN

UL supervisor: assoc. prof. Elīna Pajuste

National Research Program project. VPP-IZM-CERN-2020/1-0002. 10.2020. – 10.2022.

UL funding 125 000 EUR.

Collaboration partners: Riga Technical University, Institute of Solid State Physics, University of Latvia.


Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium

UL supervisor: assoc. prof. Elīna Pajuste

Horizon 2020 project. 01.2014. – 12.2022.

UL funding 150 000 EUR.

Collaboration partners: project coordinated by Max-Planck-Gesellschaft zur Forderung der Wissenschaften EV, Germany, other institutions of the consortium


PRISMAP: The European medical isotope programme: Production of high purity isotopes by mass separation

UL supervisor: assoc. prof. Elīna Pajuste

Horizon 2020 project. 05. 2021. – 04.2025.

UL funding 110 750 EUR.

Collaboration partners: project coordinated by European Organization for Nuclear Research (CERN), Switzerland, other institutions of the consortium

 

Studies of new application possibilities of Latvian clay minerals in the national economy

The research is carried out in collaboration with the Faculty of Geography and Earth Sciences, University of Latvia.

 

LIFE ALFIO – Alina Life Formulations in Open-Source Platform (ALOSP).

Project Manager: Solvita Kostjukova

EU LIFE+ Programme, and the Administration of Latvian Environment Protection Fund. LIFE17EVN/LV000318. 01.07.2018. – 31.12.2022.

Collaboration partners: ALINA, Ltd. and Riga Technical University

Funding: 2 398 160 EUR


Unused Latvia's natural mineral resources for the development of innovative composite materials for phosphorus recovery from small municipal and industrial wastewater treatment plants to implement the principles of circular economy (CircleP)

Supervisor: Andrejs Krauklis

Latvian Council of Science Fundamental and applied research project lzp-2021/1-0090. 03.01.2022. – 30.12.2024

Collaboration partners: Riga Technical University

Funding: 300 000 EUR


Clay mineral – anthocyanin composite material sensors for food quality control

Supervisor: Rūta Ozola-Davidāne

ERDF co-financed projects. KC-PI-2020/11. 01.04.2020. – 30.06.2022.

Funding: 288 038,98 EUR

Trimdale-Deksne, A., Kons, A., Orola, L., Mishnev, A., Stepanovs, D., Mazur, L., Skiba, M., Dudek, M.K., Fantozzi, N., Virieux, D., Colacino, E., Bērziņš, A. Crystallographic and Computational Analysis of the Solid-Form Landscape of Three Structurally Related Imidazolidine-2,4-dione Active Pharmaceutical Ingredients: Nitrofurantoin, Furazidin, and Dantrolene. Cryst. Growth Des. 2023, 23, (2), 930–945. DOI: 10.1021/acs.cgd.2c01142

Factors determining why three chemically similar active pharmaceutical ingredients, antibacterial drugs nitrofurantoin and furazidin and the muscle relaxant dantrolene, have a different propensity to form crystalline phases such as solvates, hydrates and polymorphs have been identified. Detailed studies of the crystalline structures and computational calculations were carried out by analyzing the ability of these compounds to adopt different conformation, their tendency to form various intermolecular interactions and the possibility to adopt different energetically efficient molecular packing.

 

Kons, A., Bērziņš, A., Actiņš, A., Rekis, T., van Smaalen, S., Mishnev, A. Polymorphism of R-Encenicline Hydrochloride: Access to the Highest Number of Structurally Characterized Polymorphs Using Desolvation of Various Solvates. Cryst. Growth Des. 2019, 19, (8), 4765-4773. DOI: 10.1021/acs.cgd.9b00648

It has been discovered that the pharmaceutical compound R-encenecline hydrochloride forms 12 polymorphs, 10 of which have been structurally characterized in this study, by making this substance the compound with the largest number of crystallographically characterized polymorphs at the time of the publication. It was found that the large variety of polymorphs is observed because during the desolvation of R-encenecline hydrochloride solvates only small structural changes often occur. Moreover, in contrast to other compounds forming large number of polymorphs, R-encenecline hydrochloride in all structures adopt the same molecular conformation.

Text, whiteboard Description automatically generated

 

Saršūns, K., Kemere, M., Karziņins, A., Klimenkovs, I., Bērziņš, A., Sarakovskis, A., Rekis, T. Fine-Tuning Solid State Luminescence Properties of Organic Crystals via Solid Solution Formation: The Example of 4-Iodothioxanthone–4-Chlorothioxanthone System. Crystal Growth & Design 2022, 22, (8), 4838-4844. DOI: 10.1021/acs.cgd.2c00313

The possibility to fine-tune the solid-state luminescence properties of a solid solution formed by two organic luminophores by changing the ratio of the components has been investigated. It was found that in the studied system it is possible to obtain a solid solution in two different structures. In one of the structures change of the component ratio in a wide interval did not provide a possibility to significantly influence the photoluminescence spectrum, whereas in the other structure, despite the component ratio could be changed in smaller range, a significant influence of the component ratio on the photoluminescence spectrum was observed.

 

Sarceviča, I.; Orola, L.; Nartowski, K.P; Khimyak, Y.Z.; Round, A.N.; Fábián, L. Mechanistic and Kinetic Insight into Spontaneous Cocrystallization of Isoniazid and Benzoic Acid. Mol. Pharmaceutics 2015, 12, (8), 2981-2992. DOI: 10.1021/acs.molpharmaceut.5b00250

The isoniazid - benzoic solid-phase co-crystallization reaction was studied by attempting to obtain the information on the mechanism and rate of this reaction. Although the reaction is spontaneous, it was determined that the rate is significantly affected by temperature and relative humidity, as well as sample pretreatment. Particular attention was paid to investigating the role of the moisture.

 

Mažylytė, R.; Kaziūnienė, J.; Orola, L.; Valkovska, V.; Lastauskienė, E.; Gegeckas, A.  Phosphate Solubilizing Microorganism Bacillus sp. MVY-004 and its Significance for Biomineral Fertilizers’ Development in Agrobiotechnology. Biology 2022, 11, 2, 254. DOI: 10.3390/biology11020254

Podjava, A., Šilaks, A. Synthesis and sorptive properties of molecularly imprinted polymer for simultaneous isolation of catecholamines and their metabolites from biological fluids. J. Liq. Chromatogr. Relat. Technol. 2021, 44, (3-4), 181-188. DOI: 10.1080/10826076.2021.1874980

Pajuste, E., Reinholds, I., Vaivars, G., Antuzevičs, A., Avotiņa, L., Sprūģis, E., Mikko, R., Heikki, K., Meri, R.M., Kaparkalējs, R. Evaluation of radiation stability of electron beam irradiated Nafion® and sulfonated poly (ether ether ketone) membranes. Polym. Degrad. Stab. 2022, 200, 109970. DOI: 10.1016/j.polymdegradstab.2022.109970

Luo, H., Vaivars, G., Agboola, B., Mu, S., Mathe, M. Anion exchange membrane based on alkali doped poly(2,5-benzimidazole) for fuel cell. Solid State Ion. 2012, 208, 52-55. DOI: 10.1016/j.ssi.2011.11.029

E. Pajuste, A.S. Teimane, G. Kizane, L. Avotina, M. Halitovs, A. Lescinskis, A. Vitins, P. Kalnina, E. Lagzdina, R.J.J. Zabolockis. Tritium in plasma-facing components of JET with the ITER-Like-Wall, Phys. Scr. 2021, 96, 124050. DOI: 10.1088/1402-4896/ac29db

E. Pajuste, G. Kizane, L. Avotina, A.S. Teimane, K. Vonda, A. Lescinskis. Novel method for determination of tritium depth profiles in metallic samples, Nucl. Fusion 2019, 59, 106006. DOI: 10.1088/1741-4326/ab3056

J. Kostjukovs, A. Actinš, J. Karasa. Mechanochemical method for obtaining organoclays from smectites. EU patent Nr. EP2690067 B1.

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PXRD diffractometer D8 Advance (Bruker)

Diffractometer is equipped with a Cu X-ray tube and a 1D position sensitive detector. PXRD can be used for identification and quantification of crystalline phases. Database ICDD PDF-2 allows identification of inorganic phases and common organic phases.


PXRD diffractometer D8 Discover (Bruker)

Diffractometer is equipped with a Cu X-ray tube and a 1D position sensitive detector. Diffraction patterns can be measured at a very wide temperature range (from –190 to 450°C) or different relative humidity (0−90% in temperature range of 25 − 90°C).


Differential scanning calorimeter DSC25 (TA Instruments)

Analysis of phase transitions and heat capacity can be performed in a temperature range from −90 to 725°C in open or closed pans.


Thermogravimeter / Differential scanning calorimeter TG/DSC 2 (Mettler Toledo)

Analysis of phase transitions and weight change can be performed in a temperature range from 20 to 1600°C.