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Indore, India

Devi Ahilya University also called Indore University, is a university operated by the state of Madhya Pradesh at Indore, India, named after Devi Ahilya Bai Holkar belonging to the Holkar dynasty of the Marathas. Wikipedia.

Density Functional Theory calculations have been performed for the σ-hydroboryl complexes of iron, ruthenium and osmium [(H) 2Cl(PMe 3) 2M(σ-H-BR)] (M = Fe, Ru, Os; R = OMe, NMe 2, Ph) at the BP86/TZ2P/ZORA level of theory in order to understand the interactions between metal and HBR ligands. The calculated geometries of the complexes [(H) 2Cl(PMe 3) 2Ru(HBNMe 2)], [(H) 2Cl(PMe 3) 2Os(HBR)] (R = OMe, NMe 2) are in excellent agreement with structurally characterized complexes [(H) 2Cl(P iPr 3) 2Os(σ-H-BNMe 2)], [(H) 2Cl(P iPr 3) 2Os{σ-H-BOCH 2CH 2OB(O 2CH 2CH 2)}] and [(H) 2Cl(P iPr 3) 2Os(σ-H- BNMe 2)]. The longer calculated M-B bond distance in complex [(H) 2Cl(PMe 3) 2M(σ-H-BNMe 2)] are due to greater B-N π bonding and as a result, a weaker M-B π-back-bonding. The B-H2 bond distances reveal that (i) iron complexes contain bis(σ-borane) ligand, (ii) ruthenium complexes contain (σ-H-BR) ligands with a stretched B-H2 bond, and (iii) osmium complexes contain hydride (H2) and (σ-H-BR) ligands. The H-BR ligands in osmium complexes are a better trans-directing ligand than the Cl ligand. Values of interaction energy, electrostatic interaction, orbital interaction, and bond dissociation energy for interactions between ionic fragments are very large and may not be consistent with M-(σ-H-BR) bonding. The EDA as well as NBO and AIM analysis suggest that the best bonding model for the M-σ-H-BR interactions in the complexes [(H) 2Cl(PMe 3) 2M(σ-H-BR)] is the interaction between neutral fragments [(H) 2Cl(PMe 3) 2M] and [σ-H-BR]. This becomes evident from the calculated values for the orbital interactions. The electron configuration of the fragments which is shown for C in Fig. 1 experiences the smallest change upon the M-σ-H-BR bond formation. Since model C also requires the least amount of electronic excitation and geometry changes of all models given by the ΔE prep values, it is clearly the most appropriate choice of interacting fragments. The π-bonding contribution is 14-22% of the total orbital contribution. © The Royal Society of Chemistry 2012. Source

Geometry, electronic structure, and bonding analysis of the terminal neutral bis(borylene) complexes of cobalt, rhodium, and iridium [(η 5-C 5H 5)M(BNX 2) 2] (M = Co, Rh, Ir; X = Me, SiH 3, SiMe 3) were investigated at the DFT/BP86/TZ2P/ ZORA level of theory. The calculated geometry of iridium complex [(η 5-C 5H 5)Ir{BN- (SiMe 3) 2} 2] is in excellent agreement with structurally characterized iridium complex [(η 5-C 5Me 5)Ir{BN(SiMe 3) 2} 2]. Pauling, Mayer, and Nalewajski-Mrozek bond multiplicities of the optimized structures of bis(borylene) complexes show that the M?B bonds in these complexes are nearly M=B double bonds. On substitution of the BNX 2 ligand by the more π-acidic CO ligand, the calculated M?B bond distances increase, while substitution of the BNX 2 ligand by the less π- acidic PMe 3 ligand results in a decrease of the calculated M?B bond distances. The acute B?M?B bond angle and short B?B bond distance, in particular in cobalt bis(borylene) complexes, reveal the presence of a MB 2 interaction consistent with some degree of weak B?B bonding. The π-bonding contribution is, in all complexes, smaller (28.4?32.6% of total orbital contributions) than the σ-bonding contribution. The BNX 2 ligands are relatively poor π acceptors compared with the CO ligand, but better π acceptors than the PMe3 ligand. The contribution of M ? BNX 2 δEσ is clearly the dominant term of the orbital interaction. The σ-donor ability of borylene ligands BNX 2 is greater in bis(borylene) complexes [(η 5-C 5H 5)M(BNX 2) 2] than in carbonyl borylene complexes [(η 5-C 5H 5)(CO)M(BNX 2)] and phosphine borylene complexes [(η 5-C 5H 5)(PM 3)M(BNX 2) 2]. The absolute value of various energy terms for the M=B bond decreases upon going from X = Me to SiH 3 and SiMe 3. © 2011 American Chemical Society. Source

A fifty-four compound series of 5-lipoxygenase and cyclooxygenase inhibitory activity of substituted 3,4-dihydroxychalcones was subjected to the development of a robust quantitative structure-activity relationship (QSAR) and pharmacophore model and the investigation of structure-activity relationship analysis using Molecular Design Suite software version 3.5.The requirements for the 5-lipoxygenase and cyclooxygenase activity are explored with 2D, group based and k-Nearest Neighbor studies. Simulated annealing is applied as variable selection methods for an effective comparison and model development. Several statistical expressionswere developed using partial least square (PLS) analysis. The best QSAR models were further validated by leave-one-out method of cross-validation. The statistically significant best 2D-QSAR model was selected, having correlation coefficient r2 = 0.9338, and cross-validated squared correlation coefficient q2 = 0.7832 with external predictive ability of pred-r2 = 0.8169 was developed by simulated annealing PLS with the descriptors like Average -ve potential, SsCH3E-index, SsClE-index, SsOH count, and HUMO Energy. Group based QSAR model indicates that molar refractivity and methoxy, ethoxy, carboxylic groups in R1 positions can enhance activity. The obtained 3D-QSAR (k-Nearest Neighbor) model using simulated annealing as a variable selection method has an excellent correlation coefficient value (r2 = 0.8537) along with good statistical significance as shown by high Fisher's ratio (F = 73.86). The model also exhibits good predictive power confirmed by the high value of cross-validated correlation coefficient (q2 = 0.7841). The k-Nearest Neighbor contour maps suggest some important structural features like electronegative substituents which are essential for the activity exhibited by these compounds, and inclusion of electron-donating substituents will enhance the 5-lipoxygenase and cyclooxygenase inhibition activity. The pharmacophore analysis of the molecules demonstrated that the aromatic/aliphatic and hydrogen bond donor features are important pharmacophore contours favorable for these activities. The information rendered by 2D-QSAR, group based and 3D-QSAR models may lead to a better understanding of structural requirements of chalcone derivatives and also aid in designing novel potent 5-lipoxygenase and cyclooxygenase molecules. © Springer Science+Business Media 2013. Source

Geometry and bonding energy analysis of Fe-E bonds in the ferrio-ylenes [(η5-C5H5)(L)2Fe(ER)] (L = CO, PMe3; E = Si, Ge, Sn, Pb; R = Ph, Me) were investigated at the DFT, DFT-D3 and DFT-D3(BJ) methods using density functionals (BP86, PW91, PBE, revPBE and TPSS). The TPSS functional yields better geometry and calculated geometrical parameters for the model ferrio-ylenes are in agreement with the experimental values for ferrio-ylenes. The Fe-E bonds in these complexes are essentially Fe-E single bonds. In all studied complexes, the π-bonding contribution to the total Fe-ER bond is significantly smaller than that of the σ-bonding. The electrostatic interactions ΔEelstat are larger than the covalent bonding ΔEorb terms in all ferrio-ylene complexes. The DFT-D3 method provide quite accurate estimate of the dispersion energy for the studied complexes. The contribution of dispersion interactions is large in computing accurate bond dissociation energies between the interacting metal fragments. The Fe-E bond dissociation energies (BDEs) with shared electron bonding follow the order revPBE < BP86 < TPSS < PBE < PW91. Significant finding of the present study is that the dispersion interactions are almost same for both the bonding models (shared electron and donor-acceptor models). The dispersion interactions are largest for complexes [(η5-C5H5)(PMe3) 2Fe(EPh)] and smallest for [(η5-C5H 5)(CO)2Fe(EMe)]. The strengths of dispersion interactions are sensitive to the (i) separation between the interacting fragments, (ii) size of ancillary ligands and (iii) substituent of the ligand fragment. The DFT-D3 dispersion corrections to the BDEs are smaller than the corresponding DFT-D3(BJ) dispersion corrections. © 2014 Elsevier B.V. All rights reserved. Source

New, simple and cost-effective UV-spectrophotometric, RP-HPLC and densitometric methods were developed for the estimation of pseudoephidrine sulphate and desloratidine in bulk and pharmaceutical formulations. In this study, a first-derivative spectroscopic method was used for simultaneous determination of pseudoephidrine sulphate and desloratidine using the zero-crossing technique. The measurements were carried out at wavelengths of 265.1 and 279.5 nm for pseudoephidrine sulphate and desloratidine, respectively. The second method based on reverse phase-high performance liquid chromatography separation was performed by using C18 column Phenomenex Luna C18 (5 μm×25 cm×4.6 mm i.d.) coupled with a guard column of same material, in mobile phase acetonitrile:methanol:triethylamine (20:5:75). The pH of mobile phase was adjusted to 4.8 ± 0.1 with 50% orthophosphoric acid. The flow rate was 1.0 ml min-1 and the separated drugs were detected using an UV detector at the wavelength of 280 nm. The method employed RP-TLC aluminium plates pre-coated with silica gel 60 RP-18 F254 S as the stationary phase. The mobile phase consisted of glacial acetic acid: methanol (90:10 v/v). The system was found to give compact spot for pseudoephidrine sulphate (Rf value of 0.26 ± 0.08) and Rf value of 0.48 ± 0.16 for desloratidine. Densitometric detection was carried out at λ = 296 nm. For preparation of a calibration plot, 200-600 and 100-600 ng/spot standard solutions of pseudoephidrine sulphate and desloratidine were applied, respectively. This method is simple, precise, and sensitive and applicable for the simultaneous determination of pseudoephidrine sulphate and desloratidine in formulation. Source

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