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971.
Sailaja S Reddy KR Rajasekharan MV Hureau C Rivière E Cano J Girerd JJ 《Inorganic chemistry》2003,42(1):180-186
Dimeric [Mn(salpn)NCS](2)(1) and polymeric [Mn(salpn)NCS](n)(2) are formed by the reaction of Mn(CH(3)CO(2))(2).4H(2)O, the schiff base, and thiocyanate. The formation of the two polymorphic forms is solvent and temperature dependent. 1: orthorhombic, space group Pbca, with a = 12.573(2) A, b = 13.970(7) A, c = 18.891(9) A, and Z = 8. 2: orthorhombic, space group Pna2(1), with a = 12.5277(14) A, b = 11.576(2) A, c = 11.513(2) A, and Z = 4. The dimers in 1 are held together by weak noncovalent S...pi (phenyl) interactions leading to a chain along the a-axis. Each monomeric unit of the polymer in 2 is related to its adjacent ones by a 2-fold screw axis leading to a helix along the c-axis. The exchange coupling is nondetectable in the dimer. The magnetic susceptibility of the helical chain fits a classical chain law with J = -3.2 cm(-1) and shows a weak ferromagnetic ordering below 7 K due to spin canting effects. 相似文献
972.
The reaction of α-tosyloxy ketones, sodium azide, and terminal alkynes in presence of copper(I) in aqueous polyethylene glycol afforded regioselectively 1,4-disubstituted 1,2,3-triazoles in good yield at ambient temperature. The one-pot exclusive formation of 1,4-disubstituted 1,2,3-triazoles involves in situ formation of α-azido ketones, followed by cycloaddition reaction with terminal alkyne. The generality of this one-pot method was demonstrated by synthesizing an array of diverse 1,4-disubstituted 1,2,3-triazoles. 相似文献
973.
Substituent effects on 199Hg1H and 199Hg13C spinspin coupling constants have been studied for neopentylmercury derivatives, (CH3)3CCH2HgR(or X), where R is covalently bonded Me, Et, t-Bu, neopentyl, and vinyl, and X is easily ionizable CN, Br, Cl, OCOCH3, and ONO2. Linear relationships exist between the methylene J(13CH) and 2J(HgH), 4J(HgC) and 2J(HgC) and 3J(HgC); but deviations from linearity occur for the chloride, bromide, acetate, and nitrate in the relationships between 2J(HgH) and 4J(HgH), 2J(HGH) and 2J(HGC). These deviations are discussed in terms of hyperconjugative pπdπ bonding between the methylene CH bonds and mercury. 相似文献
974.
The reaction of 2-aminobenzoxazoles (1a-b) with aroyl isothiocyanates in acetone gave 4-arylbenzoxazolo [3,2-a]-s-triazine-2-thiones (3a-g), aroylthioureas (5a-e) and 2-benzoxazolones (6a-b). A reasonable pathway for the formation of 3, 5 and 6 from 1 has been suggested. 相似文献
975.
Rajendra Prasad Reddy Bhoomireddy L.G. Bhavani Narla Vasu Govardhana Reddy Peddiahgari 《应用有机金属化学》2019,33(3)
Cu2O nanoparticles supported on hydrogen trititanate nanotubes (Cu2O/HTNT) catalysts have been efficiently catalyzed the multicomponent synthesis of 1,2,3‐triazoles in water at room temperature from different azide precursors, for example organic halides, sulfonates and anilines. The catalysts were synthesized by hydrothermal & wet‐impregnation methods and was characterized by HR‐TEM, EDS, XRD, XPS, N2‐adsorption desorption and ICP‐MS analysis. The catalyst could be recycled by centrifugation and reused up to seven cycles. The 1‐benzyl‐4‐(4‐chlorophenyl)‐1H‐1,2,3‐triazole ( 25 ) structure was proven by single crystal X‐ray diffraction studies. 相似文献
976.
Nemallapudi Bakthavatchala Reddy Grigory V. Zyryanov Guda Mallikarjuna Reddy Avula Balakrishna Adivireddy Padmaja Venkatapuram Padmavathi Cirandur Suresh Reddy Jarem Raul Garcia Gundala Sravya 《Journal of heterocyclic chemistry》2019,56(2):589-596
A new class of bis heterocycles‐benzimidazolyl pyrazoles were prepared from the Michael acceptor (E)‐3‐(1H‐benzimidazol‐2‐yl)‐1‐aryl‐prop‐2‐en‐1‐one. The thiamide group was exploited to develop thiazole ring on treatment with p‐fluorophenacyl bromide to get tris heterocycles. All the lead compounds were tested for antimicrobial activity. The compound 7d having nitro substituent on the aromatic ring showed greater antimicrobial activity particularly against Pseudomonas aeruginosa and Penicillium chrysogenum. 相似文献
977.
Subramanya Gopal Hegde Lokesh Koodlur Suman Y. Reddy Manjunatha Narayanarao 《中国化学会会志》2019,66(12):1708-1712
Employment of metal nanoparticles has been one of the most promising synthetic strategies for a number of chemical transformations. New spiroindane‐1,3‐diones were synthesized through [3 + 2] cycloaddition in moderate to high yields by a three‐component reaction of heterocyclic chalcone derivatives, ninhydrin, and sarcosine/L‐proline. The presence of heterogenous MgSiO3 nanoparticles (NPs) under microwave irradiation showed a robust effect in improving the yield of the desired products. Furthermore, the catalyst may be recovered and reused without significant loss of activity. 相似文献
978.
Raghupathi Mutyala Venkatram R. Reddy Ravikiran Donthi V.S. Ramakrishna Kallaganti Rajesh Chandra 《Tetrahedron letters》2019,60(10):703-706
The enantioselective synthesis of the tetrahydropyranopyrazole scaffold has been achieved. The quinidine catalyzed reaction of allenoates with arylidenepyrazolones proceeded with high enantio- and diastereoselectivity while the reactions of alkylidenepyrazolones were less efficient. Allene ketones also afforded tetrahydropyranopyrazole derivatives in high yields, however, with only moderate enantioselectivity. The primary adduct undergoes further functional group transformations without effecting the initially formed chiral centre. 相似文献
979.
Nagamani Nuvula Gowrisankar M. Krishna T. Srinivasa Reddy K. Chandra Sekhara 《Journal of Thermal Analysis and Calorimetry》2019,138(4):2481-2489
Journal of Thermal Analysis and Calorimetry - Using recently constructed experimental phase diagram isotactic polypropylene–1,2,4,5-tetrachlorobenzene (TeCB), we formulate a physically... 相似文献
980.
Srikanth Annareddygari Venkateshwer Reddy Kasireddy Jayachandra Reddy 《Journal of heterocyclic chemistry》2019,56(12):3267-3276
A new and efficient method for the synthesis of various aza‐fused poly‐hetero aromatics has been described. This protocol includes an intermolecular condensation followed by metal‐free base‐promoted intramolecular C―N coupling reaction. The advantage of this one‐pot transformation lies in the use of simple cyclic amidines‐like compounds without prefunctionalization of the starting heterocycles. 相似文献