TY  - JOUR
AU  - Antanasijević, Jelena
AU  - Pocajt, Viktor
AU  - Antanasijević, Davor
AU  - Trišović, Nemanja
AU  - Fodor-Csorba, Katalin
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3284
AB  - Accurate prediction of transition temperature is very helpful for the design of new liquid crystals (LCs) because even small changes in structure can dramatically alter the transition temperature, and therefore the synthesis of LCs should not be governed only by chemical intuition. A quantitative structure-property relationship (QSPR) study was performed on 243 five-ring bent-core LCs in order to predict their clearing temperatures using molecular descriptors. Decision tree and multivariate adaptive regression splines (MARS), techniques well suited for high-dimensional data analysis, were applied to select important descriptors (dimension reduction) and to generate nonlinear models. These techniques were applied both on two-dimensional (2D) descriptors only and on the pool of 2D and 3D descriptors (2& 3D). The obtained QSPR models were tested using 15% of available data, and their performance and ability to generalise were analysed using multiple statistical metrics. The best results for the external test set were obtained using the MARS model created with 2& 3D descriptors, with a high correlation coefficient of r = 0.95 and a root mean squared error of 7.41 K. All metrics suggest that the proposed QSPR model, generated by MARS, is a robust and satisfactorily accurate approach for the prediction of clearing temperatures of bent-core LCs. [GRAPHICS] .
PB  - Taylor & Francis Ltd, Abingdon
T2  - Liquid Crystals
T1  - Prediction of clearing temperatures of bent-core liquid crystals using decision trees and multivariate adaptive regression splines
EP  - 1037
IS  - 8
SP  - 1028
VL  - 43
DO  - 10.1080/02678292.2016.1155769
ER  - 

@article{
author = "Antanasijević, Jelena and Pocajt, Viktor and Antanasijević, Davor and Trišović, Nemanja and Fodor-Csorba, Katalin",
year = "2016",
abstract = "Accurate prediction of transition temperature is very helpful for the design of new liquid crystals (LCs) because even small changes in structure can dramatically alter the transition temperature, and therefore the synthesis of LCs should not be governed only by chemical intuition. A quantitative structure-property relationship (QSPR) study was performed on 243 five-ring bent-core LCs in order to predict their clearing temperatures using molecular descriptors. Decision tree and multivariate adaptive regression splines (MARS), techniques well suited for high-dimensional data analysis, were applied to select important descriptors (dimension reduction) and to generate nonlinear models. These techniques were applied both on two-dimensional (2D) descriptors only and on the pool of 2D and 3D descriptors (2& 3D). The obtained QSPR models were tested using 15% of available data, and their performance and ability to generalise were analysed using multiple statistical metrics. The best results for the external test set were obtained using the MARS model created with 2& 3D descriptors, with a high correlation coefficient of r = 0.95 and a root mean squared error of 7.41 K. All metrics suggest that the proposed QSPR model, generated by MARS, is a robust and satisfactorily accurate approach for the prediction of clearing temperatures of bent-core LCs. [GRAPHICS] .",
publisher = "Taylor & Francis Ltd, Abingdon",
journal = "Liquid Crystals",
title = "Prediction of clearing temperatures of bent-core liquid crystals using decision trees and multivariate adaptive regression splines",
pages = "1037-1028",
number = "8",
volume = "43",
doi = "10.1080/02678292.2016.1155769"
}

Antanasijević, J., Pocajt, V., Antanasijević, D., Trišović, N.,& Fodor-Csorba, K.. (2016). Prediction of clearing temperatures of bent-core liquid crystals using decision trees and multivariate adaptive regression splines. in Liquid Crystals
Taylor & Francis Ltd, Abingdon., 43(8), 1028-1037.
https://doi.org/10.1080/02678292.2016.1155769

Antanasijević J, Pocajt V, Antanasijević D, Trišović N, Fodor-Csorba K. Prediction of clearing temperatures of bent-core liquid crystals using decision trees and multivariate adaptive regression splines. in Liquid Crystals. 2016;43(8):1028-1037.
doi:10.1080/02678292.2016.1155769 .

Antanasijević, Jelena, Pocajt, Viktor, Antanasijević, Davor, Trišović, Nemanja, Fodor-Csorba, Katalin, "Prediction of clearing temperatures of bent-core liquid crystals using decision trees and multivariate adaptive regression splines" in Liquid Crystals, 43, no. 8 (2016):1028-1037,
https://doi.org/10.1080/02678292.2016.1155769 . .

TY  - JOUR
AU  - Antanasijević, Jelena
AU  - Antanasijević, Davor
AU  - Pocajt, Viktor
AU  - Trišović, Nemanja
AU  - Fodor-Csorba, Katalin
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3392
AB  - Accelerating progress in the discovery of new bent-core liquid crystal (LC) materials with enhanced features relies on the understanding of structure-property relationships that underline the formation of LC phases. The aim of this study was to develop a model for the prediction of LC behaviour of five-ring bent-core systems using a QSPR approach that combines dimension reduction techniques (e.g. genetic algorithms etc.) for the selection of molecular descriptors and decision trees, multivariate adaptive regression splines (MARS) and artificial neural networks (ANN) as classification methods. A total of 27 models based on separate pools of calculated molecular descriptors (2D; 2D and 3D) and published experimental outcomes were evaluated. Overall, the results suggest that the acquired ANN LC classifiers are usable for the prediction of LC behaviour. The best of these models showed high accuracy and precision (91% and 97%). Since the best classifier is able to successfully capture trends in a homologous series, it can be used not only to screen new bent-core structures for potential LCs, but also for the estimation of influence of structural modifications on LC phase formation, as well as for the evaluation of LC phase stability.
PB  - Royal Society of Chemistry
T2  - RSC Advances
T1  - A QSPR study on the liquid crystallinity of five-ring bent-core molecules using decision trees, MARS and artificial neural networks
EP  - 18464
IS  - 22
SP  - 18452
VL  - 6
DO  - 10.1039/c5ra20775d
ER  - 

@article{
author = "Antanasijević, Jelena and Antanasijević, Davor and Pocajt, Viktor and Trišović, Nemanja and Fodor-Csorba, Katalin",
year = "2016",
abstract = "Accelerating progress in the discovery of new bent-core liquid crystal (LC) materials with enhanced features relies on the understanding of structure-property relationships that underline the formation of LC phases. The aim of this study was to develop a model for the prediction of LC behaviour of five-ring bent-core systems using a QSPR approach that combines dimension reduction techniques (e.g. genetic algorithms etc.) for the selection of molecular descriptors and decision trees, multivariate adaptive regression splines (MARS) and artificial neural networks (ANN) as classification methods. A total of 27 models based on separate pools of calculated molecular descriptors (2D; 2D and 3D) and published experimental outcomes were evaluated. Overall, the results suggest that the acquired ANN LC classifiers are usable for the prediction of LC behaviour. The best of these models showed high accuracy and precision (91% and 97%). Since the best classifier is able to successfully capture trends in a homologous series, it can be used not only to screen new bent-core structures for potential LCs, but also for the estimation of influence of structural modifications on LC phase formation, as well as for the evaluation of LC phase stability.",
publisher = "Royal Society of Chemistry",
journal = "RSC Advances",
title = "A QSPR study on the liquid crystallinity of five-ring bent-core molecules using decision trees, MARS and artificial neural networks",
pages = "18464-18452",
number = "22",
volume = "6",
doi = "10.1039/c5ra20775d"
}

Antanasijević, J., Antanasijević, D., Pocajt, V., Trišović, N.,& Fodor-Csorba, K.. (2016). A QSPR study on the liquid crystallinity of five-ring bent-core molecules using decision trees, MARS and artificial neural networks. in RSC Advances
Royal Society of Chemistry., 6(22), 18452-18464.
https://doi.org/10.1039/c5ra20775d

Antanasijević J, Antanasijević D, Pocajt V, Trišović N, Fodor-Csorba K. A QSPR study on the liquid crystallinity of five-ring bent-core molecules using decision trees, MARS and artificial neural networks. in RSC Advances. 2016;6(22):18452-18464.
doi:10.1039/c5ra20775d .

Antanasijević, Jelena, Antanasijević, Davor, Pocajt, Viktor, Trišović, Nemanja, Fodor-Csorba, Katalin, "A QSPR study on the liquid crystallinity of five-ring bent-core molecules using decision trees, MARS and artificial neural networks" in RSC Advances, 6, no. 22 (2016):18452-18464,
https://doi.org/10.1039/c5ra20775d . .

TY  - JOUR
AU  - Trišović, Nemanja
AU  - Antanasijević, Jelena
AU  - Toth-Katona, Tibor
AU  - Kohout, Michal
AU  - Salamonczyk, Miroslaw
AU  - Sprunt, Samuel
AU  - Jakli, Antal
AU  - Fodor-Csorba, Katalin
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3111
AB  - A new series of azo-containing bent-core liquid crystals derived from 3-hydroxybenzoic acid has been synthesized. Their mesomorphic properties have been characterized by polarizing optical microscopy, differential scanning calorimetry, small-angle X-ray diffraction and electro-optic studies. Almost all the compounds form an enantiotropic modulated smectic (B-7 type) phase over relatively broad temperature ranges. Structural modifications, such as the type and length of the terminal chains, the rigidity of wings, and the presence of a Cl-substituent in different positions of the bent core, affect the appearance and temperature range, but not the type of the mesophase of the investigated compounds. Light-induced changes in the texture and phase transition of the mesophase, attributed to the decrease of the order parameter due to trans-cis isomerization, have also been observed.
PB  - Royal Society of Chemistry
T2  - RSC Advances
T1  - Azo-containing asymmetric bent-core liquid crystals with modulated smectic phases
EP  - 64891
IS  - 80
SP  - 64886
VL  - 5
DO  - 10.1039/c5ra09764a
ER  - 

@article{
author = "Trišović, Nemanja and Antanasijević, Jelena and Toth-Katona, Tibor and Kohout, Michal and Salamonczyk, Miroslaw and Sprunt, Samuel and Jakli, Antal and Fodor-Csorba, Katalin",
year = "2015",
abstract = "A new series of azo-containing bent-core liquid crystals derived from 3-hydroxybenzoic acid has been synthesized. Their mesomorphic properties have been characterized by polarizing optical microscopy, differential scanning calorimetry, small-angle X-ray diffraction and electro-optic studies. Almost all the compounds form an enantiotropic modulated smectic (B-7 type) phase over relatively broad temperature ranges. Structural modifications, such as the type and length of the terminal chains, the rigidity of wings, and the presence of a Cl-substituent in different positions of the bent core, affect the appearance and temperature range, but not the type of the mesophase of the investigated compounds. Light-induced changes in the texture and phase transition of the mesophase, attributed to the decrease of the order parameter due to trans-cis isomerization, have also been observed.",
publisher = "Royal Society of Chemistry",
journal = "RSC Advances",
title = "Azo-containing asymmetric bent-core liquid crystals with modulated smectic phases",
pages = "64891-64886",
number = "80",
volume = "5",
doi = "10.1039/c5ra09764a"
}

Trišović, N., Antanasijević, J., Toth-Katona, T., Kohout, M., Salamonczyk, M., Sprunt, S., Jakli, A.,& Fodor-Csorba, K.. (2015). Azo-containing asymmetric bent-core liquid crystals with modulated smectic phases. in RSC Advances
Royal Society of Chemistry., 5(80), 64886-64891.
https://doi.org/10.1039/c5ra09764a

Trišović N, Antanasijević J, Toth-Katona T, Kohout M, Salamonczyk M, Sprunt S, Jakli A, Fodor-Csorba K. Azo-containing asymmetric bent-core liquid crystals with modulated smectic phases. in RSC Advances. 2015;5(80):64886-64891.
doi:10.1039/c5ra09764a .

Trišović, Nemanja, Antanasijević, Jelena, Toth-Katona, Tibor, Kohout, Michal, Salamonczyk, Miroslaw, Sprunt, Samuel, Jakli, Antal, Fodor-Csorba, Katalin, "Azo-containing asymmetric bent-core liquid crystals with modulated smectic phases" in RSC Advances, 5, no. 80 (2015):64886-64891,
https://doi.org/10.1039/c5ra09764a . .

TY  - JOUR
AU  - Marković, J. M.
AU  - Trišović, Nemanja
AU  - Toth-Katona, Tibor
AU  - Milčić, Miloš
AU  - Marinković, Aleksandar
AU  - Zhang, C.
AU  - Jakli, Antal
AU  - Fodor-Csorba, Katalin
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2809
AB  - Three series of bent-core mesogens having pyridine as the central unit have been synthesized and characterized. A series of 2,6-diaminopyridine derivatives capable of forming inter- and intramolecular hydrogen bonds exhibit very high melting points. A decrease in the polarity of the central part of the bent-core obtained by replacing the amide with ester linkages results in derivatives with lower melting points and formation of B2- and B7-like mesophases. The introduction of the olefinic groups, which connect the pyridine ring with the inner aromatic rings, helps to further lower the polarity of the central part in the five ring system and led to the formation of B1 and B7 phases. The phases have been determined by optical microscopy observations and differential scanning calorimetry (DSC) and confirmed by X-ray studies. The bending angles and polarity of the investigated five-ring systems have been calculated by the density functional theory (DFT) method.
PB  - Royal Soc Chemistry, Cambridge
T2  - New Journal of Chemistry
T1  - A structure-property relationship study of bent-core mesogens with pyridine as the central unit
EP  - 1760
IS  - 4
SP  - 1751
VL  - 38
DO  - 10.1039/c3nj01430d
ER  - 

@article{
author = "Marković, J. M. and Trišović, Nemanja and Toth-Katona, Tibor and Milčić, Miloš and Marinković, Aleksandar and Zhang, C. and Jakli, Antal and Fodor-Csorba, Katalin",
year = "2014",
abstract = "Three series of bent-core mesogens having pyridine as the central unit have been synthesized and characterized. A series of 2,6-diaminopyridine derivatives capable of forming inter- and intramolecular hydrogen bonds exhibit very high melting points. A decrease in the polarity of the central part of the bent-core obtained by replacing the amide with ester linkages results in derivatives with lower melting points and formation of B2- and B7-like mesophases. The introduction of the olefinic groups, which connect the pyridine ring with the inner aromatic rings, helps to further lower the polarity of the central part in the five ring system and led to the formation of B1 and B7 phases. The phases have been determined by optical microscopy observations and differential scanning calorimetry (DSC) and confirmed by X-ray studies. The bending angles and polarity of the investigated five-ring systems have been calculated by the density functional theory (DFT) method.",
publisher = "Royal Soc Chemistry, Cambridge",
journal = "New Journal of Chemistry",
title = "A structure-property relationship study of bent-core mesogens with pyridine as the central unit",
pages = "1760-1751",
number = "4",
volume = "38",
doi = "10.1039/c3nj01430d"
}

Marković, J. M., Trišović, N., Toth-Katona, T., Milčić, M., Marinković, A., Zhang, C., Jakli, A.,& Fodor-Csorba, K.. (2014). A structure-property relationship study of bent-core mesogens with pyridine as the central unit. in New Journal of Chemistry
Royal Soc Chemistry, Cambridge., 38(4), 1751-1760.
https://doi.org/10.1039/c3nj01430d

Marković JM, Trišović N, Toth-Katona T, Milčić M, Marinković A, Zhang C, Jakli A, Fodor-Csorba K. A structure-property relationship study of bent-core mesogens with pyridine as the central unit. in New Journal of Chemistry. 2014;38(4):1751-1760.
doi:10.1039/c3nj01430d .

Marković, J. M., Trišović, Nemanja, Toth-Katona, Tibor, Milčić, Miloš, Marinković, Aleksandar, Zhang, C., Jakli, Antal, Fodor-Csorba, Katalin, "A structure-property relationship study of bent-core mesogens with pyridine as the central unit" in New Journal of Chemistry, 38, no. 4 (2014):1751-1760,
https://doi.org/10.1039/c3nj01430d . .