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81.
Shyam Sundar Mondal Namita Jaiswal Partha Sarathi Bera Ranjay K. Tiwari Jogendra Nath Behera Nripen Chanda Subhas Ghosal Tanmoy Kumar Saha 《应用有机金属化学》2021,35(1)
A series of copper (II) ( 1 and 3 ) and cobalt (II/III) ( 2 , 4 and 5 ) complexes comprising different imino‐phenolate ligands DCH , DTH and DBH 2 (where DCH = 2,4‐dichloro‐6‐((mesitylimino)methyl)phenol, DTH = 2,4‐di‐tert‐butyl‐6‐((mesitylimino)methyl) phenol and DBH 2 = 2,4‐dibromo‐6‐((mesitylimino)methyl)phenol) have been prepared with excellent yield and high purity. By utilizing different spectroscopic tools such as UV–visible, electrospray ionization (ESI)‐mass, Fourier‐transform infrared (FTIR) spectrometry and elemental analysis, the prepared complexes ( 1 – 5 ) were thoroughly characterized. The molecular structure of the synthesized complexes was ascertained by using single‐crystal X‐ray diffraction studies (SCXRDs). The experiment reveals that Complexes 1 – 5 bind to calf thymus DNA (CT‐DNA) through non‐intercalative way with good interacting abilities. However, 1 – 5 are excellent quenchers of the fluorescence intensity of bovine serum albumin (BSA) following the static pathway. Additionally, they had shown remarkable cytotoxic potential against MCF‐7 (mammary gland adenocarcinoma) and A549 (lung adenocarcinoma) cell lines. The IC50 values associated with these complexes were much lower than the conventional drug cisplatin. Apoptosis‐induced cell death was confirmed from the DNA fragmentation studies and Hoechst 33342 staining. The 2′,7′‐dichlorofluorescein diacetate (DCFDA) assay indicates that the complex mediated reactive oxygen species (ROS) generation is accountable for governing the apoptosis mechanism via oxidative cell distress. Apart from these studies, by carrying out density functional theory (DFT) method, highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) energy gap calculations and optimized structures of the synthesized complexes were accomplished. 相似文献
82.
Kapil Shyam Lokare Nicolas Frank Beatrice Braun‐Cula Itziar Goikoetxea Joachim Sauer Christian Limberg 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(40):12513-12517
To gain molecular level insights into the properties of certain functions and units of extended oxides/hydroxides, suitable molecular model compounds are needed. As an attractive route to access such compounds the trapping of early intermediates during the hydrolysis of suitable precursor compounds with the aid of stabilizing ligands is conceivable, which was tested for the aluminum(III)/water system. Indeed, trisilanols proved suitable trapping reagents: their presence during the hydrolysis of AliBu2H in dependence on the amount of water used allowed for the isolation of tri‐ and octanuclear aluminum hydroxide cluster complexes [Al3(μ2‐OH)3(THF)3(PhSi(OSiPh2O)3)2] ( 1 ) and [Al8(μ3‐OH)2(μ2‐OH)10(THF)3(p‐anisylSi(OSiPh2O)3)4] ( 2 ). 1 can be regarded as the Al(OH)3 cyclic trimer, where six protons have been replaced by silyl residues. While 2 features a unique [Al8(μ3‐OH)2(μ2‐OH)10]12+ core. In contrast to most other known aggregates of this type, 1 and 2 can be readily prepared at reasonable scales, dissolve in common solvents, and retain an intact framework even in the presence of excessive amounts of water. This finding paves the way to future research addressing the reactivity of the individual functional groups. 相似文献
83.
84.
85.
Anurag K. Singh 《代数通讯》2020,48(6):2681-2682
AbstractWe comment on a conjecture of Lynch on annihilators of local cohomology.Communicated by Lawrence Ein 相似文献
86.
dc conductivity as a function of temperature has been measured for as-evaporated and annealed films of amorphous Si, grown by the vacuum evaporation technique. The experimental data suggest that conduction in the higher temperature range (~175–300 K) is by the thermally activated holes in the localized states near the valence band edge while conduction in the lower temperature range (~77–175 K) is found to be thermally assisted tunnelling in the localized states near the Fermi level. The activation energy for both the processes is found to increase with an increase in the annealing temperature. The average hopping distance, calculated for conduction near the Fermi level, is also found to increase with an increase in the annealing temperature. 相似文献
87.
Mariappan Periasamy Mallesh Beesu D. Shyam Raj 《Journal of organometallic chemistry》2008,693(17):2843-2846
Iron carbonyl complexes prepared in situ using the Fe(CO)5/NaH/MeI reagent combination and alkynes at 25 °C give the corresponding cyclobutenediones in 50-65% yields after CuCl2 · 2H2O oxidation. 相似文献
88.
Mishra A Fousková P Angelovski G Balogh E Mishra AK Logothetis NK Tóth E 《Inorganic chemistry》2008,47(4):1370-1381
Three novel GdDO3A-type bismacrocyclic complexes, conjugated to Ca (2+) chelating moieties like ethylenediaminetetraacetic acid and diethylenetriamine pentaacetic acid bisamides, were synthesized as potential "smart" magnetic resonance imaging contrast agents. Their sensitivity toward Ca (2+) was studied by relaxometric titrations. A maximum relaxivity increase of 15, 6, and 32% was observed upon Ca (2+) binding for Gd 2L (1), Gd 2L (2), and Gd 2L (3), respectively (L (1) = N, N-bis{1-[{[({1-[1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecane-10-yl]eth-2-yl}amino)carbonyl]methyl}-(carboxymethyl)amino]eth-2-yl}aminoacetic acid; L (2) = N, N-bis[1-({[({alpha-[1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecane-10-yl]- p-tolylamino}carbonyl)methyl]-(carboxymethyl)}amino)eth-2-yl]aminoacetic acid; L (3) = 1,2-bis[{[({1-[1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecane-10-yl]eth-2-yl}amino)carbonyl]methyl}(carboxymethyl)amino]ethane). The apparent association constants are log K A = 3.6 +/- 0.1 for Gd 2L (1) and log K A = 3.4 +/- 0.1 for Gd 2L (3). For the interaction between Mg (2+) and Gd 2L (1), log K A = 2.7 +/- 0.1 has been determined, while no relaxivity change was detected with Gd 2L (3). Luminescence lifetime measurements on the Eu (3+) complexes in the absence of Ca (2+) gave hydration numbers of q = 0.9 (Eu 2L (1)), 0.7 (Eu 2L (2)), and 1.3 (Eu 2L (3)). The parameters influencing proton relaxivity of the Gd (3+) complexes were assessed by a combined nuclear magnetic relaxation dispersion (NMRD) and (17)O NMR study. Water exchange is relatively slow on Gd 2L (1) and Gd 2L (2) ( k ex (298) = 0.5 and 0.8 x 10 (6) s (-1)), while it is faster on Gd 2L (3) (k ex (298) = 80 x 10 (6) s (-1)); in any case, it is not sensitive to the presence of Ca (2+). The rotational correlation time, tau R (298), differs for the three complexes and reflects their rigidity. Due to the benzene linker, the Gd 2L (2) complex is remarkably rigid, with a correspondingly high relaxivity despite the low hydration number ( r 1 = 10.2 mM (-1)s (-1) at 60 MHz, 298 K). On the basis of all available experimental data from luminescence, (17)O NMR, and NMRD studies on the Eu (3+) and Gd (3+) complexes of L (1) and L (3) in the absence and in the presence of Ca (2+), we conclude that the relaxivity increase observed upon Ca (2+) addition can be mainly ascribed to the increase in the hydration number, and, to a smaller extent, to the Ca (2+)-induced rigidification of the complex. 相似文献
89.
CO2 Hydrogenation over Oxide‐Supported PtCo Catalysts: The Role of the Oxide Support in Determining the Product Selectivity 下载免费PDF全文
Dr. Shyam Kattel Dr. Weiting Yu Dr. Xiaofang Yang Dr. Binhang Yan Yanqiang Huang Weiming Wan Dr. Ping Liu Prof. Dr. Jingguang G. Chen 《Angewandte Chemie (International ed. in English)》2016,55(28):7968-7973
By simply changing the oxide support, the selectivity of a metal–oxide catalysts can be tuned. For the CO2 hydrogenation over PtCo bimetallic catalysts supported on different reducible oxides (CeO2, ZrO2, and TiO2), replacing a TiO2 support by CeO2 or ZrO2 selectively strengthens the binding of C,O‐bound and O‐bound species at the PtCo–oxide interface, leading to a different product selectivity. These results reveal mechanistic insights into how the catalytic performance of metal–oxide catalysts can be fine‐tuned. 相似文献
90.
Trapping Aluminum Hydroxide Clusters with Trisilanols during Speciation in Aluminum(III)–Water Systems: Reproducible,Large Scale Access to Molecular Aluminate Models 下载免费PDF全文
Dr. Kapil Shyam Lokare Nicolas Frank Dr. Beatrice Braun‐Cula Dr. Itziar Goikoetxea Prof. Dr. Joachim Sauer Prof. Dr. Christian Limberg 《Angewandte Chemie (International ed. in English)》2016,55(40):12325-12329
To gain molecular level insights into the properties of certain functions and units of extended oxides/hydroxides, suitable molecular model compounds are needed. As an attractive route to access such compounds the trapping of early intermediates during the hydrolysis of suitable precursor compounds with the aid of stabilizing ligands is conceivable, which was tested for the aluminum(III)/water system. Indeed, trisilanols proved suitable trapping reagents: their presence during the hydrolysis of AliBu2H in dependence on the amount of water used allowed for the isolation of tri‐ and octanuclear aluminum hydroxide cluster complexes [Al3(μ2‐OH)3(THF)3(PhSi(OSiPh2O)3)2] ( 1 ) and [Al8(μ3‐OH)2(μ2‐OH)10(THF)3(p‐anisylSi(OSiPh2O)3)4] ( 2 ). 1 can be regarded as the Al(OH)3 cyclic trimer, where six protons have been replaced by silyl residues. While 2 features a unique [Al8(μ3‐OH)2(μ2‐OH)10]12+ core. In contrast to most other known aggregates of this type, 1 and 2 can be readily prepared at reasonable scales, dissolve in common solvents, and retain an intact framework even in the presence of excessive amounts of water. This finding paves the way to future research addressing the reactivity of the individual functional groups. 相似文献