{"title":"Heat Capacity and Bond Dissociation Energy Calculations of Some Fluorinated Ethanol’s and its Radicals: CH3-xCH2FxOH, CH3CH2-xFxOH","authors":"Hebah Abdel-Wahab, J. Bozzelli","doi":"10.4236/OJPC.2021.112002","DOIUrl":null,"url":null,"abstract":"Structures and thermochemical properties of these \nspecies were determined by the gaussian M-062x/6-31 + g (d, p) calculation \nenthalpies of formation for 19 fluorinated ethanol and some radicals were \ncalculated with a popular Ab initio and density functional theory methods: The gaussian \nM-062x/6-31 + g (d, p) via several series of isodesmic \nreactions. Entropies (S298°K in Cal·Mol-1 K-1) were estimated using the M-062x/6-31 + g (d, p) computed frequencies and geometries. \nContributions of entropy, S298°K, and heat capacities, Cp(T) due to vibration, \ntranslation, and external rotation of the molecules were calculated based on \nthe vibration frequencies and structures obtained from the M-062x/6-31 + g (d, p) Density Functional Method. Potential \nbarriers are calculated using M-062x/6-31 + g (d, p) density functional method \nand are used to calculate rotor contributions to entropy and heat capacity using \nintegration over energy levels of rotational potential. Rotational barriers \nwere determined and hindered internal rotational contributions for S298° - 1500°, and Cp (T) were calculated using the rigid rotor harmonic \noscillator approximation, with direct integration over energy levels of the \nintramolecular rotation potential energy curves. Thermochemical properties of \nfluorinated alcohols are needed for understanding their stability and reactions \nin the environment and in thermal process","PeriodicalId":59839,"journal":{"name":"物理化学期刊(英文)","volume":"11 1","pages":"13-53"},"PeriodicalIF":0.0000,"publicationDate":"2021-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"物理化学期刊(英文)","FirstCategoryId":"1089","ListUrlMain":"https://doi.org/10.4236/OJPC.2021.112002","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Structures and thermochemical properties of these
species were determined by the gaussian M-062x/6-31 + g (d, p) calculation
enthalpies of formation for 19 fluorinated ethanol and some radicals were
calculated with a popular Ab initio and density functional theory methods: The gaussian
M-062x/6-31 + g (d, p) via several series of isodesmic
reactions. Entropies (S298°K in Cal·Mol-1 K-1) were estimated using the M-062x/6-31 + g (d, p) computed frequencies and geometries.
Contributions of entropy, S298°K, and heat capacities, Cp(T) due to vibration,
translation, and external rotation of the molecules were calculated based on
the vibration frequencies and structures obtained from the M-062x/6-31 + g (d, p) Density Functional Method. Potential
barriers are calculated using M-062x/6-31 + g (d, p) density functional method
and are used to calculate rotor contributions to entropy and heat capacity using
integration over energy levels of rotational potential. Rotational barriers
were determined and hindered internal rotational contributions for S298° - 1500°, and Cp (T) were calculated using the rigid rotor harmonic
oscillator approximation, with direct integration over energy levels of the
intramolecular rotation potential energy curves. Thermochemical properties of
fluorinated alcohols are needed for understanding their stability and reactions
in the environment and in thermal process
采用高斯M-062x/6-31 + g (d, p)计算19种氟化乙醇的生成焓,确定了这些物质的结构和热化学性质,并采用流行的从头算和密度泛函理论方法计算了一些自由基:高斯M-062x/6-31 + g (d, p)通过一系列等速反应。利用M-062x/6-31 + g (d, p)计算频率和几何形状估计熵(S298°K in Cal·Mol-1 K-1)。基于M-062x/6-31 + g (d, p)密度泛函方法得到的振动频率和结构,计算了分子振动、平移和外旋对熵、S298°K和热容Cp(T)的贡献。利用M-062x/6-31 + g (d, p)密度泛函方法计算势垒,并利用旋转势的能级积分计算转子对熵和热容量的贡献。在S298°- 1500°范围内,确定了旋转势垒并阻碍了内部旋转贡献,使用刚性转子谐振子近似计算了Cp (T),并对分子内旋转势能曲线的能级进行了直接积分。为了了解氟化醇在环境和热过程中的稳定性和反应,需要研究其热化学性质