实验和计算热化学:在-2-基酸盐 (酸盐) 中,分子内键的强度有多大
Sergey P Verevkin1,2, Svetlana V Portnova3, Vladimir N Emel'yanenko1
1Competence Centre CALOR, Department Life, Light &Matter of Faculty of Interdisciplinary Research at University of Rostock, 18059, Rostock, Germany. sergey.verevkin@uni-rostock.de.
在基2-基酸盐中量化分子内键强度具有挑战性. 这项研究确定了这些化合物的稳定强度为-43kJ/mol,独立于基链长度.
科学领域:
- 物理化学 物理化学
- 有机化学 有机化学
- 计算化学计算化学
背景情况:
- 结合 (HB) 在分子相互作用中至关重要.
- 量化分子内HB强度,特别是在有机分子中,仍然很困难.
- 已知基二基酸盐具有强大的分子内键.
研究的目的:
- 准确量化基2-基酸盐中分子内键的强度.
- 为了研究基链长度对分子内HB强度的影响.
- 用量子化学计算验证实验热化学数据.
主要方法:
- 使用蒸汽压力测量和燃烧热量计来实验性地确定形成的气相度.
- 使用G3MP2和G4量子化学方法验证实验数据.
- 计算分子内HB强度通过比较cis-和trans-conformers,平衡反应,"护骨"方法和"HB和Out"方法.
主要成果:
- 甲基,乙基,n-propyl和n-butyl 2-hydroxybenzoates形成的实验气相度在298.15K时确定.
- 通过多种热化学方法,甲基2-基酸盐的分子内键强度始终为-43kJ/mol.
- 确定的分子内键强度独立于研究化合物的链长度.
结论:
- 该研究成功量化了基2-基酸盐中的分子内键强度.
- 对于这种类型的化合物,已经确定了 -43 kJ / mol 的稳定的分子内键强度.
- 在基2-基酸中,分子内键强度不受基链的长度的影响.
更多相关视频
06:35Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
06:31Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators
Published on: November 27, 2015
相关概念视频
Relative Stabilities of Alkenes
Hydrogen Bonds
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Structure and Bonding of Alkenes
Doubly bonded carbons are sp2 hybridized and have a trigonal planar geometry. The double bond is composed of a σ bond formed by the overlap of hybrid orbitals and a π bond produced by the lateral overlap of unhybridized 2p orbitals on both the carbons. Each carbon atom is...
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
