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固氮酶及合成氨Fe催化剂中N2的络合位 总被引:1,自引:0,他引:1
用乙烯为探针研究了固氮酶中N2的键合位,结果表明,乙烯不能与N2在固氮酶体系中相竞争,提出N2在固氮酶中键合位很可能是蛋白键合FeMo-co笼内6Fe位的μρ(η^2,ε4)t 3Fe+1Mo位的μ4(η^3,ε)方式,而不是笼口2Fe位的μ2(η^2)方式,在合成氨Fe催化剂中N2的络事方式可能是μ6(η^3,ε3 )。 相似文献
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It is difficult to quantify NH4+ by ion chromatography in the presence of high concentrations of Na+ due to peak overlap. The Dionex IonPac CS15 column, which contains phosphonate, carboxylate, and 18-crown-6 functional groups, was originally developed to overcome this problem. We have found that the addition of 18-crown-6 to the eluent promotes improved peak resolution between Na+ and NH4+ even at concentrations as high as 60,000 to 1 using this column. Its use also improves the separation of alkali and alkaline earth metal and amine cations. Mobile phase 18-crown-6 increased the retention times of CH3NH3+, NH4+, and K+, and decreased the retention time of Sr2+. The retention times of Li+, Na+, Mg2+, Ca2+, (CH3)2NH2+, and (CH3)3NH+ were not affected. This method makes possible the direct analysis of ammonia from nitrogenase, the enzyme responsible for biological nitrogen fixation. The resolution of the NH4+ peak from the Na+ and Mg2+ peaks improved from zero resolution to values of 6.19 and 5.65, respectively. This technique considerably reduces the analysis time of NH4+ in the presence of high concentrations of Mg2+ and Na+ over traditional indophenol measurements. 相似文献
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考察了邻苯二甲醛对固氮酶催化乙炔还原及放H2活性的影响。结果表明邻苯二甲醛是有效的固氮酶活性中心双齿螯合抑制剂。在MoS^2-4-nFeCl2-DMF自兜合成固氮酶活性中心模拟物体系中,邻苯二甲醛的加入导致线型三核络合物[Cl2FeS2MoS2FeCl2]^2-(低维结构)的特征电子吸收光谱消失。本文进一步讨论了在此双齿配体协助下上述无机盐体系自兜合成高维结构Mo-Fe-S簇化合物的可能性。 相似文献
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ZHANG Feng zhang ** XU Liang shu HUANG He qing LONG Min nan QIU Xue hui CHEN Zhong 《高等学校化学研究》1999,(3)
IntroductionNitrogenasefromavarietyofN2-fixingorganismsiscomposedoftwo-componentprotein,MoFe-proteinandFe-protein.Fe-proteincontainsasingleFe4S4-cluster,whichhasthefunctionoftransferingelectronsfromdonortoMoFe-protein.MoFe-proteincontainsP-clusterpai… 相似文献
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