Thermochemistry and bond energies of acetohydrazide, amides and cyclic alkyl ethers

Structure, thermochemical properties, bond energies and internal rotation potentials of Acetic Acid Hydrazide (CH_3CONHNH_2), Acetamide (CH_3CONH_2) and N-methyl Acetamide (CH3CONHCH3) and their radicals corresponding to loss of hydrogen atom have been studied. Gas phase standard enthalpies of formation and bond energies were calculated using the DFT methods B3LYP/6-31G(d,p), B3LYP/6-31G(2d,2p) and the composite CBS-QB3 methods employing a series of work reactions to further improve accuracy of the [Delta]H_f (298K). Molecular structures, vibration frequencies and internal rotor potentials were calculated at DFT level. The enthalpies of the parent molecules CH_3-C=ONHNH_2, CH_3-C=ONH_2 and CH_3-C=ONHCH_3 are evaluated as -28.6, -58.1 and -56.5 kcalmol^{-1} respectively at B3LYP/6-31G(D,P), B3LYP/6-31G(2d,2p) and CBS-QB_3 levels. Bond dissociation energies for H--CH_2C=ONHNH_2, CH_3-C=ON(--H)NH_2, CH_3- C=ONHNH--H, H--CH_2C=ONH_2, CH_3-C=ONH--H, H--CH_2-C=ONHCH_3, CH_3-C=ON(- -H)CH_3 and CH_3-C=ONHCH_2 - H are 99.9, 78.2, 81.9, 100.1, 111.5, 99.9, 104.2 and 93.7 kcal mol-1 respectively. The computed DFT and the Complete Basis Set enthalpy values are in close agreement with each other; and this accord is attributed to use of isodesmic work reactions for the analysis. The agreement also suggests this combination of B3LYP / work reaction approach is acceptable for larger molecules. Cyclic ethers are a major initial product from the reactions or hydrocarbon radicals with triplet dioxygen (^3O_2) in low to moderate temperature oxidation and combustion reaction systems and atmospheric chemistry of small hydrocarbons. Thermochemical properties, [Delta]H _{f(298)}, S _{298} and Cp (T) (10K

Name thesis:degree_name

Master of Science in Pharmaceutical Chemistry - (M.S.)

Discipline thesis:degree_discipline

Chemistry and Environmental Science

Year

2011

Author dc:creator

• Charaya, Sumit

Contributors dc:contributor

• Joseph W. Bozzelli
• Tamara M. Gund
• Rubik Asatryan

• Acetic acid hydrazide
• Acetamide
• Acetohydrazide
• Cyclic ethers
• Medicinal-Pharmaceutical Chemistry

Repository record dc:identifier

https://digitalcommons.njit.edu/theses/88

OAI identifier oai:identifier

oai:digitalcommons.njit.edu:theses-1087