Deepak Patkar
@dhsgsu.ac.in
Research scholar Department of chemistry
Dr. Harisingh Gour Vishwavidhyalaya Sagar 470003
Mr. Deepak Patkar is a doctoral fellow, currently pursuing his Ph.D. degree in Theoretical and Computational Chemistry under the supervision of Dr. Milind M. Deshmukh at the Chemistry Department, Dr. Harisingh Gour Vishwavidyalaya Sagar MP 470003 India. He also received his B.Sc. and M.Sc. degrees from the same institute. He does research in Physical Chemistry, Catalysis, and Theoretical Chemistry. Their very active current project is the application of the 'Molecular Tailoring Approach based method' for the direct estimation of individual Hydrogen Bond strengths and Cooperativity in Mixed Molecular clusters.
EDUCATION
2019: Pursuing Ph.D.
2019: M.Sc. (Chemistry)
2017: B. Sc.
RESEARCH, TEACHING, or OTHER INTERESTS
Physical and Theoretical Chemistry, Analytical Chemistry, Chemistry, Spectroscopy
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Thufail M. Ismail, Deepak Patkar, Pookkottu K. Sajith, and Milind M. Deshmukh
American Chemical Society (ACS)
Nitric oxide (NO) and its redox congeners (NO+ and NO-), designated as X, play vital roles in various atmospheric and biological events. Understanding the interaction between X and water is inevitable to explain the different reactions that occur during these events. The present study is a unified attempt to explore the noncovalent interactions in microhydrated networks of X using the MP2/aug-cc-pVTZ//MP2/6-311++G(d,p) level of theory. The interactions between X and water have been probed by the molecular electrostatic potential (MESP) by exploiting the features of the most positive (Vmax) and most negative potential (Vmin) sites. The individual energy and cooperativity contributions of various types of noncovalent interactions present in X(H2O)n=1-5 complexes are estimated with the help of a molecular tailoring-based approach (MTA-based). The MTA-based analysis reveals that among various possible interactions in NO(H2O)n complexes, the water···water hydrogen bonds (HBs) are the strongest. Neutral NO can form hydrogen and pnicogen bonds (PBs) with water depending on the orientation; however, such HBs and PBs are the weakest. On the other hand, in the NO+(H2O)n complexes, the NO+···water interactions that occur through PBs are the strongest; the next one is the chalcogen bonding (CB), and the water···water HBs are the weakest. In the case of the NO-(H2O)n complexes, the HB interactions via both N and O atoms of NO- and water molecules are the strongest ones. The strength of water···water HB interactions is also seen to increase with the increase in the number of water molecules in NO-(H2O)n. The present study exemplifies the applicability of MTA-based calculations for quantifying various types of individual noncovalent interactions and their interplay in microhydrated networks of NO and its related ions.
Deepak Patkar, Mini Bharati Ahirwar, and Milind M. Deshmukh
Wiley
In the present work, the energies of various types of individual HBs observed in neutral (NH 3 ) m (H 2 O) n , (m + n = 2 to 7) clusters were estimated using the molecular tailoring approach (MTA)-based method. The calculated individual HB energies suggest that the O-H…N HBs are the strongest (1.21 to 12.49 kcal mol -1 ). The next ones are the O-H…O (3.97 to 9.30 kcal mol -1 ) HBs. The strengths of N-H…N (1.09 to 5.29 kcal mol -1 ) and N-H…O (2.85 to 5.56 kcal mol -1 ) HBs are the weakest. The HB energies in dimers also follow this rank ordering. However, the HB energies in dimers are much smaller than those obtained by the MTA-based method due to the loss in cooperativity contribution in the dimers. Thus, the calculated cooperativity contributions, for different types of HBs, falls in the range 0.64 to 5.73 kcal mol -1 . We wish to emphasize based on the energetic rank ordering obtained by the MTA-based method that the O-H of water is a better HB donor than the N-H of ammonia. The reasons for the observed energetic rank ordering are two folds: (i) intrinsically stronger O-H…N HBs than the O-H…O HBs as revealed by dimer energies and (ii) the higher cooperativity contribution in the former than the later ones. Indeed, the MTA-based method is useful in providing the missing energetic rank ordering of various type of HBs in neutral (NH 3 ) m (H 2 O) n clusters, in the literature.
Deepak Patkar, Milind M. Deshmukh, and Deepak Chopra
Royal Society of Chemistry (RSC)
The energetics and topological analysis based on electron density distribution have been evaluated in dimers of mono-, di- and tri-halogenated aldehdyes. This also includes various electron donating and electron withdrawing groups as well.
Deepak Patkar, Mini Bharati Ahirwar, and Milind M. Deshmukh
Wiley
In this work, we examine the strength of various types of individual hydrogen bond (HB) in mixed methanol-water MnWm, (n + m = 2 to 7) clusters, with an aim to understand the relative order of their strength, using our recently proposed molecular tailoring-based approach (MTA). Among all the types of HB, it is observed that the OM-H…OW HBs are the strongest (6.9 to 12.4 kcal mol-1). The next ones are OM-H…OM HBs (6.5 to 11.6 kcal mol-1). The OW-H…OW (0.2 to 10.9 kcal mol-1) and OW-H…OM HBs (0.3 to 10.3 kcal mol-1) are the weakest ones. This energetic ordering of HBs is seen to be different from the respective HB energies in the dimer i.e., OM-H…OM (5.0 to 6.0 kcal mol-1) > OW-H…OM (1.5 to 6.0 kcal mol-1) > OM-H…OW (3.8 to 5.6 kcal mol-1) > OW-H…OW (1.2 to 5.0 kcal mol-1). The plausible reason for the difference in the HB energy ordering may be attributed to the increase or decrease in HB strengths due to the formation of cooperative or anti-cooperative HB networks. For instance, the cooperativity contribution towards the different types of HB follows: OM-H…OW (2.4 to 8.6 kcal mol-1) > OM-H…OM (1.3 to 6.3 kcal mol-1) > OW-H…OW (-1.0 to 6.5 kcal mol-1) > OW-H…OM (-1.2 to 5.3 kcal mol-1). This ordering of cooperativity contribution is similar to the HB energy ordering obtained by MTA-based method. It is emphasized here that, the interplay between the cooperative and anti-cooperative contributions are indispensable for the correct energetic ordering of these HBs.
Deepak Patkar, Mini Bharati Ahirwar, Satya Prakash Shrivastava, and Milind M. Deshmukh
Royal Society of Chemistry (RSC)
In this work, we investigated the strengths of various self- and cross-associating hydrogen bonds (HBs) in mixed hydrogen fluoride–water cyclic (HF)m(H2O)n (m + n = 2 to 8) clusters, employing a molecular tailoring approach (MTA)-based method.
Deepak Patkar, Mini Bharati Ahirwar, Shridhar R. Gadre, and Milind M. Deshmukh
American Chemical Society (ACS)
In this work, our recently proposed molecular tailoring approach (MTA)-based method is employed for the evaluation of individual hydrogen-bond (HB) energies in linear (L) and cyclic (C) hydrogen fluoride clusters, (HF)n (n = 3 to 8). The estimated individual HB energies calculated at the MP2(full)/aug-cc-pVTZ level for the L-(HF)n are between 6.2 to 9.5 kcal/mol and those in the C-(HF)n lie between 7.9 to 11.4 kcal/mol. The zero-point energy corrections and basis set superposition corrections are found to be very small (less than 0.6 and 1.2 kcal/mol, respectively). The cooperativity contribution toward individual HBs is seen to fall between 1.0 to 4.8 kcal/mol and 3.2 to 6.9 kcal/mol for linear and cyclic clusters, respectively. Interestingly, the HB energies in dimers, cleaved from these clusters, lie in a narrow range (4.4 to 5.2 kcal/mol) suggesting that the large HB strength in (HF)n clusters is mainly due to the large cooperativity contribution, especially for n ≥ 5 (50 to 62% of the HBs energy). Furthermore, the HB energies in these clusters show a good qualitative correlation with geometrical parameters (H···F distance and F-H···F angles), stretching frequencies of F-H bonds, and electron density values at the (3, -1) bond critical points.
Mini Bharati Ahirwar, Deepak Patkar, Itee Yadav, and Milind M. Deshmukh
Royal Society of Chemistry (RSC)
In this work, we propose and test a method, based on the molecular tailoring approach (MTA), for the evaluation of individual hydrogen bond (HB) energies in ammonia (NH3)n clusters.