La制备和研究反应性炔基-,环丙基-,et acylcetenes,de meme que les calculs sur lesorbitalesmoleculaires suggerent que les substituants conjugues n'ont pas en general, d'effets stabilisants importants surle
Reactions of CO2 +, CO2CO2 + and H2O+ ions with various neutral molecules
作者:Asit B. Rakshit、Peter Warneck
DOI:10.1039/f29807601084
日期:——
A drift chamber mass spectrometer apparatus was used to determine products and rate coefficients at 300 K for reactions of CO2+, CO2CO2+ and H2O+ with H2, CH4, SO2, O2, C2H2, C2H4, COS, CS2, NH3, NO2 and NO. Charge transfer is the predominant reaction channel in most cases. Reaction efficiencies are discussed by comparison with rate coefficients calculated from the capture mechanism according to averaged
使用漂移室质谱仪设备确定在300 K下CO 2 +,CO 2 CO 2 +和H 2 O +与H 2,CH 4,SO 2,O 2,C 2 H反应的产物和速率系数2,C 2 H 4,COS,CS 2,NH 3,NO 2和不。在大多数情况下,电荷转移是主要的反应通道。通过与根据平均偶极子定向理论从捕获机制计算出的速率系数进行比较,讨论了反应效率。
Gas phase basicities and relative proton affinities of compounds between water and ammonia from pulsed ion cyclotron resonance thermal equilibriums measurements
作者:J. F. Wolf、R. H. Staley、I. Koppel、M. Taagepera、R. T. McIver、J. L. Beauchamp、R. W. Taft
DOI:10.1021/ja00458a032
日期:1977.8
indicate that protonation is thermodynamically favored in the gas phase at the carbonyl oxygen of the latter. Large effects of polar electronegative substituents have been observed for various oxygen and nitrogen bases. An evaluation of entropy effects in gas phase protontransferequilibria shows such effects to bemore » generally small for simple bases and approximately equal to entropy effects expected
用于精确测定质子转移平衡常数的脉冲离子回旋共振方法已应用于 46 种碳、氮、氧、磷、硫、砷和硒碱,重复重叠序列,获得水和氨的相对质子亲和力. 在可能进行比较的情况下,结果通常与高压质谱法获得的结果一致。结果为分子结构对基础强度的内在影响提供了重要的新见解。说明了这些结果在导出其他气态离子热化学数据中的应用。特别是,甲基取代基对质子亲和力的影响已被广泛评估,并解释了与 n 碱共轭酸的均裂键解离能的相应影响和取代甲基阳离子的氢化物亲和力的比较。正烷基取代基对水和醇与羧酸及其酯的质子亲和力影响的比较表明,质子化在气相中在后者的羰基氧处是热力学有利的。对于各种氧和氮碱,已经观察到极性电负性取代基的巨大影响。对气相质子转移平衡中的熵效应的评估表明,这种效应对于简单的碱基通常较小,大约等于分子旋转对称数变化时预期的熵效应。最后,目前的结果为评估绝对质子亲和力和相对离子溶剂化能提供了基础。« 更少
Thermodynamics and kinetics of carbon dioxide binding to two stereoisomers of a cobalt(I) macrocycle in aqueous solution
作者:Carol Creutz、Harold A. Schwarz、James F. Wishart、Etsuko Fujita、Norman Sutin
DOI:10.1021/ja00009a022
日期:1991.4
The thermodynamics and kinetics of binding of CO 2 , CO, and H + to N-racemic and N-meso stereoisomers of the cobalt (I) macrocycle CoL + (L=5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) have been determined in aqueous media with use of the pulseradiolysis technique and transient ultraviolet-visible spectroscopy. N-rac- or N-meso-CoL + was produced by the hydrated electron
CO 2 、CO 和 H + 与钴 (I) 大环 CoL + 的 N-外消旋和 N-内消旋立体异构体结合的热力学和动力学(L=5,7,7,12,14,14-六甲基- 1,4,8,11-四氮杂环十四-4,11-二烯)已在水性介质中使用脉冲辐射分解技术和瞬态紫外-可见光谱法测定。N-rac- 或 N-meso-CoL + 是通过 N-rac- 或 N-meso-CoL 2+ 的水合电子还原产生的,通常添加叔丁醇以清除羟基自由基
trans-Influence of anionic, neutral, and bridging ligands on the nuclear magnetic resonance spectra of methyl- and fiuorobenzyl-bis(dimethylglyoximato)rhodium(III) complexes. Some observations on bridge formation
作者:Claude Bied-Charreton、Alain Gaudemer、Carey A. Chapman、David Dodd、B. Dass Gupta、Michael D. Johnson、Bill L. Lockman、Bernard Septe
DOI:10.1039/dt9780001807
日期:——
the methyl groups in the latter complexes. The 13C chemical shifts show no correlation with any of the usual trans-effect parameters for a wide range of neutral and anionic vans ligands. Similar considerations have been applied to a number of bridgedcomplexes in which fluoro-benzyl- and/or other alkyl-bis(dimethylglyoximato)-rhodium(III) and -cobalt(III) complexes are bonded to the two ends of cyanide
Kinetics of the reaction of O2+ with CH4 from 500 to 1400 K: A case for state specific chemistry
作者:Itzhak Dotan、A. A. Viggiano
DOI:10.1063/1.1352033
日期:2001.4.8
Rateconstants and branching ratios have been measured for the reaction of O2+ with CH4 over the temperature range from 500 to 1400K. The rateconstants increase dramatically over this temperature range, in good agreement with a previous study from our laboratory. A complex chemistry was found. The main product at low temperature, CH2O2H+, disappears almost completely at high temperature, in part
在 500 至 1400 K 的温度范围内测量了 O2+ 与 CH4 反应的速率常数和支化率。速率常数在此温度范围内显着增加,与我们实验室先前的研究非常一致。发现了一种复杂的化学反应。低温下的主要产物 C 2H+ 在高温下几乎完全消失,部分原因是热解离。高温下的主要产物是 +和HCO+;后一种离子以前没有被观察到。在高温下同样突出的是 H3O+ 和 CH3+。在所有温度下都观察到少量 C +。在高温下观察到少量 H2O+。还报告了 O2+ 与 CD4 反应的支化比,证实了离子分配。与漂移管和光束结果的比较表明, 的振动激发比其他形式的能量更能促进这些通道中的几个。通过 t-C OH+ 2A″ 中间通道的通道...