排序方式: 共有52条查询结果,搜索用时 15 毫秒
1.
Ghandi K Addison-Jones B Brodovitch JC McCollum BM McKenzie I Percival PW 《Journal of the American Chemical Society》2003,125(32):9594-9595
Muoniated free radicals have been detected in muon-irradiated aqueous solutions of acetone at high temperatures and pressures. At temperatures below 250 degrees C, the radical product is consistent with muonium addition to the keto form of acetone. However, at higher temperatures, a different radical was detected, which is attributed to muonium addition to the enol form. Muon hyperfine coupling constants have been determined for both radicals over a wide range of temperatures, significantly extending the range of conditions under which these radicals and the keto-enol equilibrium have been studied. 相似文献
2.
3.
Four‐component reaction of aminodiazines (2‐aminopyrimidine and 2‐aminopyrazine), glyoxal, formaldehyde, and methanol yields trans‐4,5‐dimetoxy‐1,3‐bis(2‐pyrimidinyl)imidazolidine (5a) and trans‐4,5‐dimetoxy‐1,3‐bis(2‐pyrazinyl)imidazolidine (5b), respectively. Changing methanol to acetonitrile leads to the formation of the corresponding 1,3‐bis(2‐pyrimidinyl) and‐1,3‐bis(2‐pyrazinyl)‐ derivatives of trans‐4,5‐dihydroxyimidazolidine (6). Details of the proposed mechanism are discussed. 相似文献
4.
Mehdi Janbazi Yavar T. Azar Farhood Ziaie Khashayar Ghandi Chérif F. Matta Muhammad Shadman Lakmehsari 《International journal of quantum chemistry》2020,120(12):e26211
Alanine is used as a transfer standard dosimeter for gamma ray and electron beam calibration. An important factor affecting its dosimetric response is humidity which can lead to errors in absorbed dose calculations. Ab initio molecular dynamics calculations were performed to determine the environmental effects on the electron paramagnetic resonance (EPR) parameters of L-α-alanine radicals in acidic and alkaline solutions. A new result, not dissimilar to the closed-shell amino acid molecule alanine, is that the non-zwitterionic form of the alanine radical is the stable form in the gas phase while the zwitterionic neutral alanine radical is not a stable structure in the gas phase. Geometric and EPR parameters of radicals in both gas and solution phases are found to be dependent on hydrogen bonding of water molecules with the polar groups and on dynamic solvation. Calculations on the optimized free radicals in the gas phase revealed that for the neutral radical, hydrogen bonding to water molecules drives a decrease in the magnitudes of g-tensor components g xx and g yy without affecting neither g zz component nor the hyperfine coupling constants (HFCCs). The transfer from the gas to solution phase of the alanine radical anion is accompanied with an increase in the spin density on the carboxylic group's oxygen atoms. However, for the neutral radical, this transfer from gas to solution phase is accompanied with the decrease in the spin density on oxygen atoms. Calculated isotropic HFCCs and g-tensor of all radicals are in good agreement with experiment in both acidic and alkaline solutions. 相似文献
5.
Mehdi Ghandi Meysam Khodadadi Alireza Abbasi 《Journal of the Iranian Chemical Society》2016,13(9):1691-1698
Synthesis of novel hybrid derivatives of two known scaffolds, pyrrolidine-2-one and piperazine, is described. Initially, the Ugi reaction of phenylglyoxal, aromatic amines, coumarin-3-carboxylic acid and isocyanides in methanol resulted in the formation of dihydrochromeno[3,4-c]pyrrole-3,4-diones. The obtained products were then treated with N-alkylpiperazines in dichloromethane to afford the novel N-substituted pyrrolidine-2-one containing piperazine derivatives in satisfactory yields. The proof of the structures was carried out by means of spectroscopic information and X-ray crystallography. 相似文献
6.
7.
K. Buchholt P. Eklund J. Jensen J. Lu R. Ghandi M. Domeij C.M. Zetterling G. Behan H. Zhang A. Lloyd Spetz L. Hultman 《Journal of Crystal Growth》2012,343(1):133-137
Epitaxial Ti3GeC2 thin films were deposited on 4° off-cut 4H-SiC(0001) using magnetron sputtering from high purity Ti, C, and Ge targets. Scanning electron microscopy and helium ion microscopy show that the Ti3GeC2 films grow by lateral step-flow with {112?0} faceting on the SiC surface. Using elastic recoil detection analysis, atomic force microscopy, and X-Ray diffraction the films were found to be substoichiometric in Ge with the presence of small Ge particles at the surface of the film. 相似文献
8.
Faezeh Farzaneh Leila Tayebi Mehdi Ghandi 《Reaction Kinetics and Catalysis Letters》2007,91(2):333-340
Vit-B12/ Al-MCM-41 catalyzed successfully the epoxidation either of cis or trans — stilbene with O2 as oxidant and isobutyraldehyde as co-reductant with 86–98% reactivity and 97–100% selectivity. Other olefins such as norbornene
and styrene undergo epoxidation reaction under similar conditions with good to fair selectivity. Details of the reactions
will be presented in this article. 相似文献
9.
We have developed a facile and efficient method for the synthesis of functionalized novel furylquinolines. A variety of quinoline–furan conjugates were obtained via the condensation of 2-chloroquinoline-3-carbaldehyde with acetylenecarboxylates and isocyanides in good to excellent yields. 相似文献
10.
Firouzeh Zarkesh Faezeh Farzaneh and Mehdi Ghandi 《Reaction Kinetics and Catalysis Letters》2006,89(2):247-252
Summary About 8.5% of benzene was alkylated with 1-dodecene in the presence of Na+-montmorillonite. When the reaction was carried out with montmorillonite exchanged with Mn2+, Cu2+, Ni2+, Zn2+ and Fe2+ ions as catalyst (M2+/mont.), 91 to 95% of 1-dodecene was remarkably converted to a mixture of linear monoalkylbenzenes. 相似文献