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71.
E. D. Jemmis K. T. Giju K. Sundararajan K. Sankaran V. Vidya K. S. Viswanathan J. Leszczynski 《Journal of Molecular Structure》1999,510(1-3):59-68
The details of weak C–Hπ interactions that control several inter and intramolecular structures have been studied experimentally and theoretically for the 1:1 C2H2–CHCl3 adduct. The adduct was generated by depositing acetylene and chloroform in an argon matrix and a 1:1 complex of these species was identified using infrared spectroscopy. Formation of the adduct was evidenced by shifts in the vibrational frequencies compared to C2H2 and CHCl3 species. The molecular structure, vibrational frequencies and stabilization energies of the complex were predicted at the MP2/6-311+G(d,p) and B3LYP/6-311+G(d,p) levels. Both the computational and experimental data indicate that the C2H2–CHCl3 complex has a weak hydrogen bond involving a C–Hπ interaction, where the C2H2 acts as a proton acceptor and the CHCl3 as the proton donor. In addition, there also appears to be a secondary interaction between one of the chlorine atoms of CHCl3 and a hydrogen in C2H2. The combination of the C–Hπ interaction and the secondary ClH interaction determines the structure and the energetics of the C2H2–CHCl3 complex. In addition to the vibrational assignments for the C2H2–CHCl3 complex we have also observed and assigned features owing to the proton accepting C2H2 submolecule in the acetylene dimer. 相似文献
72.
Vidya Niranjan Sanjana Jayaprasad Akshay Uttarkar Raviraj Kusanur Jitendra Kumar 《Molecules (Basel, Switzerland)》2023,28(1)
Breast cancer, a heterogeneous disease, is among the most frequently diagnosed diseases and is the second leading cause of death due to cancer among women after lung cancer. Phytoactives (plant-based derivatives) and their derivatives are safer than synthetic compounds in combating chemoresistance. In the current work, a template-based design of the coumarin derivative was designed to target the ADP-sugar pyrophosphatase protein. The novel coumarin derivative (2R)-2-((S)-sec-butyl)-5-oxo-4-(2-oxochroman-4-yl)-2,5-dihydro-1H-pyrrol-3-olate was designed. Molecular docking studies provided a docking score of −6.574 kcal/mol and an MM-GBSA value of −29.15 kcal/mol. Molecular dynamics simulation studies were carried out for 500 ns, providing better insights into the interaction. An RMSD change of 2.4 Å proved that there was a stable interaction and that there was no conformational change induced to the receptor. Metadynamics studies were performed to calculate the unbinding energy of the principal compound with NUDT5, which was found to be −75.171 kcal/mol. In vitro validation via a cytotoxicity assay (MTT assay) of the principal compound was carried out with quercetin as a positive control in the MCF7 cell line and with an IC50 value of 55.57 (+/−) 0.7 μg/mL. This work promoted the research of novel natural derivatives to discover their anticancer activity. 相似文献
73.
74.
This Letter reports on structural and photoluminescence properties of Zn1 − xMnxO nanocrystalline powders, which were synthesized by using oxalate precursor decomposition method. From the XRD features, we have noticed that all samples exhibit wurtzite crystal structure. The origin of photoluminescence properties of Mn doped and undoped ZnO have been discussed. 相似文献
75.
In this paper, we provide a new proof for the Dedekind \(\eta \)-function identities discovered by Somos. During this process, we found two new Dedekind \(\eta \)-function identities. Furthermore, we extract interesting partition identities from some of the \(\eta \)-function identities. 相似文献
76.
Mowery BP Prasad V Kenesky CS Angeles AR Taylor LL Feng JJ Chen WL Lin A Cheng FC Smith AB Hirschmann R 《Organic letters》2006,8(20):4397-4400
The design, synthesis, and evaluation of a series of catechol-based non-peptide peptidomimetics of the peptide hormone somatostatin have been achieved. These ligands comprise the simplest known non-peptide mimetics of the i + 1 and i + 2 positions of the somatostatin beta-turn. Incorporation of an additional side chain to include the i position of the beta-turn induces a selective 9-fold affinity enhancement at the sst2 receptor. 相似文献
77.
A convenient and efficient one pot sequence has been developed for the transformation of alcohols to amines using Sodium azide, triphenylphosphine in CC14-DMF. 相似文献
78.
Abstract A new and a simple approach toward synthesis of 1,3,5-trisubstituted pyrazoles from chalcone arylhydrazones via oxidative cyclization has been achieved. 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone was successfully used as an oxidizing agent to give excellent yields of pyrazoles. 相似文献
79.
H. J. Pant V. K. Sharma M. Vidya Kamudu S. G. Prakash S. Krishna Moorthy G. Anandam N. V. S. Ramani Gursharan Singh 《Journal of Radioanalytical and Nuclear Chemistry》2009,280(1):47-56
Radiotracer technique was applied to measure the circulation rates of fine coal particles in standpipe of a pilot-scale bubbling
circulating fluidized bed system (CFBS). 198Au adsorbed on coal particles was used as a radiotracer. The radiotracer was injected into the standpipe and monitored at
four different downstream locations. The circulation times and circulation rates were determined from the measured tracer
concentration curves at different operating conditions. The measured parameters were intended to be used for optimizing the
performance of existing CFBSs operating in industry and design of a new CFBS to be used as coal gasifier. 相似文献
80.
We have conceptualized [n]-oxa-[n]-peristylanes as a new family of "oxa bowls" having a crownlike shape and potential C(nv)() symmetry. Recognizing their equivalence to the corresponding [n]-formyl-[n]-cycloalkanes, we have conceived of a general synthetic strategy in which "intramolecular cascade acetalizations" constitute the pivotal step. As our first synthetic effort, we describe the synthesis of pentaoxa-[5]-peristylane 3b from the readily available Diels-Alder adduct 10 of 5,5-dimethoxy-tetrachlorocyclopentadiene and maleic anhydride. The norbornyl framework of 10 serves as the rigid structural matrix to build the stereochemical features and latent aldehyde functionalities as in 9 through a series of functional group adjustments. Ozonation of 9 furnished 3b in a one-step transformation in which five tetrahydrofuran rings were generated. While 3b exhibited C(5v) symmetry in solution, its symmetry in the solid state was observed to be C(s) by X-ray crystallography. In the solid state, 3b is endowed with a multicolumnar architecture, whose distinctive features include C-H...O interactions involving the less acidic cyclopentane hydrogens. Indeed, all the 10 CH moieties and 5 oxygen atoms (through both the lone pairs) of 3b (C(10)H(10)O(5)) are involved in short C-H...O contacts (strong and soft) and its crystal structure indicates marked proclivity toward maximal hydrogen bonding. 相似文献