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301.
Understanding the charge transfer process between bioactive molecules and inorganic or organic molecules is significant as this interaction can be used to interpret bioactive molecule–receptor interactions. A comprehensive spectrophotometric study has been performed to explore the complexation chemistry of the amino acids, tyrosine, lysine and arginine, with iodine as σ acceptor. The molecular structure, spectroscopic characteristics and the interactive modes have been deduced from UV–Vis and IR spectra. The binding ratio of complexation has been determined to be 1:1 for iodine with the amino acids. The association constant (K), extinction coefficient (ε max), ionization potential (IP), energy of the charge transfer complex (E CT), resonance energy (R N ), dissociation energy (W) and standard Gibbs energy (ΔG°) have been computed. An in silico study has been carried out using GAMESS computations to understand the structural features. Highest occupied molecular orbital and lowest unoccupied molecular orbital calculations helped us in characterizing the chemical reactivity and kinetic stability of the molecules. A good consistency between experimental and computational results has been found. 相似文献
302.
Arunapriya Lakkadi Naveen Baindla Parthasarathy Tigulla 《Journal of solution chemistry》2017,46(12):2171-2190
A charge-transfer (CT) complex that forms from the reaction of the donor 4-amino aniline (4AA) and the π-acceptor 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) have been studied and characterized experimentally and as well as theoretically at room temperature. The experimental work includes the application of UV–visible spectroscopy to identify the CT band of the CT-complex. The composition of the complex has been investigated using spectrophotometric titration and Job’s method of continuous variation and found to be 1:1. Furthermore, to calculate the formation constant and molar extinction coefficient, we have used the Benesi–Hildebrand equation. Infrared, 1H NMR, 13C NMR and mass spectral studies were used to characterize and confirm the formation of the CT-complex. The experimental studies were supported by quantum chemical simulations using density functional theory. The computational analysis of molecular geometry, Mulliken charges, and molecular electrostatic potential surfaces of reactants and complexes are helpful in assigning the CT route. The C=O bond length of DDQ increased upon complexation with 4AA. We have also observed that a substantial amount of charge has been transferred from 4AA to DDQ in the process of complexation. An excellent consistency has been achieved between experimental and theoretical results. 相似文献
303.
T. C. Easwaran Nambudiri K. Parthasarathy 《Complex Analysis and Operator Theory》2016,10(7):1565-1575
We present approximations of a large class of Weyl–Heisenberg frame operators on \(L^{2}({\mathbb {R}})\) by Gabor Bessel sequence operators generated by compactly supported smooth functions. 相似文献
304.
Tangirala Ramesh Borra Anoosha Satyavathi Bankupalli Thella Prathap Kumar Padmaja K. V. Srinivasan Madapusi P. Parthasarathy Rajarathinam Bhargava Suresh 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6807-6815
Journal of Thermal Analysis and Calorimetry - Crystallization is an experimental phenomenon that does not always depend on predicted data for efficient processing. It, therefore, becomes important... 相似文献
305.
Ramalingam Parthasarathy 《Natural product research》2015,29(24):2282-2286
Lovastatin is a potent drug for lowering blood cholesterol. An endophytic fungus Phomopsis vexans was isolated from the healthy leaf tissues of Solanum xanthocarpum, a medicinal plant, and screened for lovastatin production. The fungus was identified by their characteristic cultural morphology and molecular analysis. The strain had a component with the same TLC Rf value and HPLC retention time as authentic lovastatin. The presence of lovastatin was further confirmed by FT-IR, UV, 1H, 13C NMR and LC–MS analyses. The amount of lovastatin produced by this endophytic fungus was quantified to be 550 mg/L, and thus the fungus can serve as a potential material to improve the production of lovastatin. 相似文献
306.
K. R. Parthasarathy 《印度理论与应用数学杂志》2015,46(6):781-807
In this lecture we present a brief outline of boson Fock space stochastic calculus based on the creation, conservation and annihilation operators of free field theory, as given in the 1984 paper of Hudson and Parthasarathy [9]. We show how a part of this architecture yields Gaussian fields stationary under a group action. Then we introduce the notion of semigroups of quasifree completely positive maps on the algebra of all bounded operators in the boson Fock space Γ(? n ) over ? n . These semigroups are not strongly continuous but their preduals map Gaussian states to Gaussian states. They were first introduced and their generators were shown to be of the Lindblad type by Vanheuverzwijn [19]. They were recently investigated in the context of quantum information theory by Heinosaari et al. [7]. Here we present the exact noisy Schrödinger equation which dilates such a semigroup to a quantum Gaussian Markov process. 相似文献
307.
Sandip A. Pujari Dr. Parthasarathy Gowrisankar Prof. Dr. Krishna P. Kaliappan 《化学:亚洲杂志》2011,6(11):3137-3151
A formal total synthesis of palmerolide A has been accomplished by assembling three fragments by means of successive Julia–Kocienski olefination, Yamaguchi esterification, and ring‐closing metathesis (RCM). Our initial efforts to combine the first two fragments through a Julia–Kocienski reaction between a secondary sulfone and a ketone were not successful; nevertheless, it was feasible between a primary sulfone and aldehyde. Yamaguchi esterification with the third fragment then set the stage for a RCM reaction. Initial failure of the RCM with a PMB‐ether adjacent to the olefins and the difficulty in cleaving the PMB‐ether prompted us to change the choice of protecting groups, which then paved the way to the macrocyclic core of palmerolide A. 相似文献
308.
This paper discusses birth and death processes that are related to the celebrated Ramanujan’s theta functions. The pertinent transient system size probabilities are calculated numerically via a truncation of continued fractions. 相似文献
309.
A. Abdul Ajees M. N. Ponnuswamy S. Parthasarathy C. A. M. A. Huq 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):824-826
In the structures of the title compounds, 6,7‐dihydrodibenzo[e,g]azulen‐8(5H)‐one, C18H14O, (I), and 12,13‐dihydrobenzo[e]napth[2,1‐g]azulen‐14(11H)‐one, C22H16O, (II), the azulene group is in a boat‐envelope conformation. The structures are stabilized by weak C—H?O interactions. 相似文献
310.
We show how to color the tiles in a heirarchical tiling system so that the resulting system is not only repetitive (i.e.,
has the local isomorphism property) but has prescribed color symmetries as well.
Received March 9, 1998, and in revised form August 3, 1998. 相似文献