@article { ISI:000290127500055, title = {Halogen bonding in 2,5-dichloro-1,4-benzoquinone: insights from experimental and theoretical charge density analysis}, journal = {Crystal Growth \& Design}, volume = {11}, number = {5}, year = {2011}, month = {MAY}, pages = {1855-1862}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Experimental charge density distribution in 2, 5-dichloro-1, 4-benzoquinone has been carried out using high resolution X-ray diffraction data at 90 K to quantitatively evaluate the nature of C-Cl center dot center dot center dot O=C halogen bond in molecular crystals. Additionally, the halogen bond is studied from geometrical point of view and the same has been visualized using Hirshfeld surface analysis. The obtained results from experimental charge density analysis are compared with periodic quantum calculations using B3LYP 6-31G(d,p) level of theory. The topological values at bond critical point, three-dimensional static deformation density features and electrostatic potential isosurfaces unequivocally establish the attractive nature of C-Cl center dot center dot center dot O=C halogen bond in crystalline lattice.

}, issn = {1528-7483}, doi = {10.1021/cg2000415}, author = {Hathwar, Venkatesha R. and Gonnade, Rajesh G. and Munshi, Parthapratim and Bhadbhade, Mohan M. and Row, Tayur N. Guru} } @article {47159, title = {Experimental and theoretical charge density, intermolecular interactions and electrostatic properties of metronidazole}, journal = {Acta Crystallographica Section B-Structural Science Crystal Engineering and Materials}, volume = {75}, year = {2019}, month = {DEC}, pages = {942-953}, type = {Article}, abstract = {

Metronidazole is a radiosensitizer; it crystallizes in the monoclinic system with space group P2(1)/c. The crystal structure of metronidazole has been determined from high-resolution X-ray diffraction measurements at 90 K with a resolution of (sin 0/lambda) max = 1.12 angstrom(-1). To understand the charge-density distribution and the electrostatic properties of metronidazole, a multipole model refinement was carried out using the Hansen-Coppens multipole formalism. The topological analysis of the electron density of metronidazole was performed using Bader{\textquoteright}s quantum theory of atoms in molecules to determine the electron density and the Laplacian of the electron density at the bond critical point of the molecule. The experimental results have been compared with the corresponding periodic theoretical calculation performed at the B3LYP/6-31G** level using CRYSTAL09. The topological analysis reveals that the N-O and C-NO2 exhibit less electron density as well as negative Laplacian of electron density. The molecular packing of crystal is stabilized by weak and strong inter- and intramolecular hydrogen bonding and H center dot center dot center dot H interactions. The topological analysis of O-H center dot center dot center dot N, C-H center dot center dot center dot O and H center dot center dot center dot H intra- and intermolecular interactions was also carried out. The electrostatic potential of metronidazole, calculated from the experiment, predicts the possible electrophilic and nucleophilic sites of the molecule; notably, the hydroxyl and the nitro groups exhibit large electronegative regions. The results have been compared with the corresponding theoretical results.

}, keywords = {atomic valence index, Electron density, Electrostatic potential, intermolecular interactions, metronidazole, radiosensitizer}, doi = {10.1107/S2052520619011272}, author = {Kalaiarasi, Chinnasamy and George, Christy and Gonnade, Rajesh G. and Hathwar, Venkatesha R. and Poomani, Kumaradhas} } @article {46640, title = {Investigation of bond topological and electrostatic properties of plumbagin molecule: an experimental and theoretical charge density study}, journal = {Journal of Molecular Structure}, volume = {1220}, year = {2020}, month = {NOV}, pages = {128714}, type = {Article}, abstract = {

Plumbagin is a naturally occurring derivative with several medicinal properties including antioxidants, antifungal, antimalarial, leprosy and antitumor properties; their structural and electrostatic properties are yet to be determined. The crystal structure of plumbagin has been solved; it shows that the compound crystallizes in P2(1)/c space group with two molecules in the asymmetric unit. The electron density distribution of both molecules have determined from multipole model refinement. Among all the C-O bonds of both molecules (I \& II), the OH group connected C-O bond and the methyl group connected C-C bond exhibits less electron density and the negative Laplacian of electron density as well. Further, the electrostatic potential (ESP) surface of two plumbagin molecules show some difference in their electronegative regions. The carbonyl O-atoms exhibit high electronegative ESP regions which are the key reactive locations of plumbagin when bind with the active site of target protein and in the ESP map, an aromatic pi-cloud also observed in one of the molecule. The electron density distribution of O-H center dot center dot center dot O intermolecular interactions between the molecules I and II, reveals that these interactions are found very stronger than the other interactions in the crystal. (C) 2020 Elsevier B.V. All rights reserved.

}, keywords = {Dipole moment, Electron density, Electrostatic potential, intermolecular interactions, Plumbagin}, issn = {0022-2860}, doi = {10.1016/j.molstruc.2020.128714}, author = {Kalaiarasi, Chinnasamy and Sivanandam, Magudeeswaran and Suganya, Suresh and Christy, George and Gonnade, Rajesh G. and Hathwar, Venkatesha R. and Kumaradhas, Poomani} } @article {49329, title = {Rational design of zero-dimensional manganese(II) halide hybrids with suppressed melting temperatures}, journal = {JOURNAL OF PHYSICAL CHEMISTRY C}, volume = {128}, year = {2024}, month = {AUG }, pages = {14849-14859}, type = {Journal Article}, keywords = {ORGANIC-INORGANIC PEROVSKITES, TRANSITION}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.4c04444}, author = {Singh, Shivangi and Marayathungal, Jumana Hasin and Das, Deep Kumar and Khan, Akram Aadil and Bakthavatsalam, Rangarajan and Hathwar, Venkatesha R. and Kundu, Janardan} } @article {49933, title = {Supercooled liquid phases of luminescent zero dimensional metal halide hybrids}, journal = {Journal of Physical Chemistry Letters}, volume = {16}, year = {2025}, month = {SEP}, pages = {9391-9400}, type = {Article}, abstract = {

Chemical design of metal halide hybrids (MHHs) with suppressed melting point (T-m) allows access to glassy phases from their liquid-melts. Thermal phase change (crystal-melt-glass) properties of glassy MHHs (with glass transition temperature T-g \> room temperature) have been exploited for device applications. However, room temperature stable supercooled liquid (SCL) MHHs (with T-g \< room temperature), originating from glass-SCL phase change, remain inaccessible. Here, a molecular design strategy is reported to access ambient stable, melt-processable, SCL multimetallic bromide hybrids (Mn2+,Cd2+; Mn2+,Zn2+; Benzyltributylammonium) with low T-g (15-16 degrees C), low T-m (90-100 degrees C), green luminescence, and high optical transparency. Structural, optical, thermal, and computational analyses highlight chemical design principles and support dopant (Mn2+) based luminescence. Rheological measurements confirm the SCL phase that shows thermal hysteresis and estimate relaxation time scales. This work provides a new material platform showcasing enhanced melt-processability for fabrication of moldable devices, unravelling chemical makeup-property correlation and expanding the material phase types of MHHs.

}, issn = {1948-7185}, doi = {10.1021/acs.jpclett.5c01979}, author = {Kumar Das, Deep and Marayathungal, Jumana Hasin and Palakkolil, Athira and Sarma, Dhritismita and Khan, Akram Aadil and Kumar, M. Praveen and Kudlu, Ashwath and Choudhary, Mahendra and Hathwar, Venkatesha R. and Pujala, Ravi Kumar and Mahata, Arup and Kundu, Janardan} } @article {50080, title = {Exploring the interplay of electron density distribution and electrostatic potential in the interaction of nilutamide and flutamide with androgen receptors using quantum crystallography}, journal = {RSC Advances }, volume = {16}, year = {2026}, month = {JAN}, pages = {3830-3849}, type = {Article}, abstract = {

Prostate cancer is a malignant disease commonly found in men. Androgens support the growth and survival of prostate cancer cells. To control this growth and the spread of cancer cells, anti-androgen drugs are necessary to block androgen activity. Effective blocking of androgens depends mainly on the structure, intermolecular interactions and charge density distribution, electrostatic potential (ESP) and binding affinity of drug molecules. Nilutamide (NIL) and flutamide (FLU) are two structurally related non-steroidal anti-androgen drugs (NSAAs) which exhibit serious side effects. The present study explores the charge density distribution, electrostatic potential and intermolecular interactions of NIL and FLU determined from a high-resolution X-ray diffraction experiment and a solid-state quantum chemical theoretical study. Topological analysis of charge density reveals the electron density at the bond critical points of chemical bonds and intermolecular interactions. The electrostatic potential derived from the charge density distribution of both molecules in the crystal has been mapped, which allows a prediction of how the electrostatic interactions, hydrogen bonds, and van der Waals forces govern the binding of these two drug molecules with the androgen receptor at the electronic level. The ESP of interacting groups of both molecules in the androgen active site is approximated to the ESP of those groups in the crystals. The charge density distribution and the electrostatic potential of both molecules were compared. The difference in charge density is reflected in the ESP of NO2, CF3 and NH groups and the aromatic ring of both molecules, which is important for drug binding, metabolic stability and toxicity. A molecular docking simulation of both molecules with androgen receptors shows the difference in interactions and binding affinity in the binding pocket of the androgen receptor. The results of the high-resolution X-ray experiment and the advanced computational charge density study of NIL and FLU allows us to understand drug binding and is useful to relate their differing biological effects and toxicities at the electronic level. This information pertains to the design of a new potential androgen inhibitor with improved binding affinity and fewer side effects.

}, doi = {10.1039/d5ra07636f}, author = {Balasubramanian, Hemalatha and Poomani, Kumaradhas and Kandasamy, Saravanan and Hathwar, Venkatesha R. and Gonnade, Rajesh G.} }