title: The interaction strengths and spectroscopy parameters of the C2H2∙∙∙HX and HCN∙∙∙HX complexes (X = F, Cl, CN, and CCH) and related ternary systems valued by fluxes of charge densities: QTAIM, CCFO, and NBO calculations.
abstract: This theoretical work exhibits a new systematic study of structural parameters, electronic properties, infrared vibration modes, and molecular topography of hydrogen complexes, namely linear-type HCN⋯HX and T-type C2H2⋯HX (X = F, Cl, CN, and CCH). Ideally, the knowledge of the ternary systems of C2H2⋯HCN⋯HF and HCN⋯HCN⋯HF whose subparts integrate the linear and T-shaped complexes were used to give support in this current research. By means of computational calculations carried out in both levels B3LYP and MP2, the variations of the HX bond lengths are clearly overestimated in the HCN⋯HX linear complexes. In agreement with the analyses of the electrostatic potentials, the higher intermolecular energies of these complexes agree with the larger red-shifts in the stretch frequencies in HX. Also, the QTAIM descriptors and NBO calculations were used to inspect the interaction strength as well as to confirm the π cloud as a proton accepting center. By taking into account the absorption intensity ratio as a standard parameter to predict the interaction strength and intermolecular characterization, the formalism of the charge-charge flux-overlap modified (CCFO) was applied.
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte, 59215-000, Nova Cruz, RN, Brazil.
authors.forename: Marco A A
authors.initials: MA
authors.lastname: Viana
authors.affiliation: Departamento de Química - Centro das Ciências Exatas e da Natureza, Universidade Federal da Paraíba, 58051-900, João Pessoa, PB, Brazil.
authors.forename: Regiane C M U
authors.initials: RC
authors.lastname: Araújo
authors.affiliation: Departamento de Química - Centro das Ciências Exatas e da Natureza, Universidade Federal da Paraíba, 58051-900, João Pessoa, PB, Brazil.
authors.forename: José A Maia
authors.initials: JA
authors.lastname: Neto
authors.affiliation: Departamento de Química - Centro das Ciências Exatas e da Natureza, Universidade Federal da Paraíba, 58051-900, João Pessoa, PB, Brazil.
authors.forename: Henrique C
authors.initials: HC
authors.lastname: Chame
authors.affiliation: Ciência e Tecnologia da Paraíba, Instituto Federal de Educação, Campus Guarabira, 58200-000, Guarabira, PB, Brazil.
authors.forename: Arquimedes M
authors.initials: AM
authors.lastname: Pereira
authors.affiliation: Centro das Ciências Exatas e das Tecnologias, Universidade Federal do Oeste da Bahia, Campus Reitor Edgard Santos, 47805-000, Barreiras, BA, Brazil. boazgaldino@gmail.com.
authors.forename: Boaz G
authors.initials: BG
authors.lastname: Oliveira
keywords: CCFO; Hydrogen bond; Infrared absorption; NBO; QTAIM