Substituted hydrocarbon: a CCSD(T) and local vibrational mode investigation

Autor(es)

Ann Delgado, Alexis Antoinette ^[1] ; Sethio, Daniel ^[2] ; Matthews, Devin ^[1] ; Oliveira, Vytor ^[3] ; Kraka, Elfi ^[1]

Afiliação do(s) autor(es)

^[1] Southern Methodist Univ, Dept Chem, Dallas, TX 75275 - USA

^[2] Uppsala Univ, Dept Chem BMC, Uppsala - Sweden

^[3] Inst Tecnol Aeronaut ITA, Dept Quim, Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Molecular Physics; v. 119, n. 21-22, SI AUG 2021.
• Citações Web of Science: 0

Resumo

Substituent effects on the carbon-carbon bonds of hydrocarbons have been a topic of interest within the past seven decades as resultant information would enable one to tune the activity of CC bonds. However, current assessments of the C equivalent to C, C=C, and C-C bond strength of acetylene, ethylene, and ethane as well as their derivatives rely on indirect measures such as bond length and bond dissociation enthalpy. In this work, we introduce a quantitative measure of the intrinsic strength of C equivalent to C, C=C, and C-C bonds for a set of 40 hydrocarbon systems consisting of 3 parent structures, 36 hydrocarbon derivatives involving CF3, CH3, CHO, F, NH2, or OH groups, and a conjugated system, based on vibrational spectroscopy. Local mode force constants k(a)(CC) were computed at the CCSD(T)/cc-pVTZ level of theory for systems 1-32 and 34-40 and CCSD(T)/cc-pVDZ for 33. From k(a)(CC), we derived related bond strength orders BSO n(CC) in order to provide quantitative measures of intrinsic bond strength. Topological electron density and natural population analyses were carried out as to analyze the nature of these bonds and complement bond strength measures. For substituted hydrocarbon systems, we found the strengthening/weakening of the CC bonds occurs as the covalent nature of the bond increases/decreases by means of varying charge delocalizations. Our findings provide new guidelines for desirably modulating C equivalent to C, C=C, and C-C bond strength and for the design of prospective pathways for bond cleavage reactions. {[}GRAPHICS] . (AU)

• Processo FAPESP: 18/13673-7 - Desenho de novos reagentes de iodo hipervalente com base em estudos teóricos de elevada acurácia
• Beneficiário: Vytor Pinheiro Oliveira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado