title: Homodimers of cytosine and 1-methylcytosine. A DFT study of geometry, relative stability and H-NMR shifts in gas-phase and selected solvents.
abstract: Dimers of cytosine and its N¹-methylated counterpart were investigated in gas-phase and in various solvents including chloroform, dimethylsulfoxide, and water. The studies were performed at DFT/M06-2X/6-31+G(d,p) level of theory. Relative stabilities of tautomers of cytosine solvated explicitly by a small number of solvent molecules were evaluated. Further solvation effect calculations for homodimers were carried out with conductor-like polarizable continuum model (CPCM). H-NMR shifts and IR frequencies for optimized structures were calculated and compared with available experimental data.
authors.affiliation: Interdisciplinary Center for Nanotoxicity, Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS, 39217, USA.
authors.forename: Guvanchmyrat
authors.initials: G
authors.lastname: Paytakov
authors.forename: Leonid
authors.initials: L
authors.lastname: Gorb
authors.forename: Andriy
authors.initials: A
authors.lastname: Stepanyugin
authors.forename: Svitlana
authors.initials: S
authors.lastname: Samiylenko
authors.forename: Dmytro
authors.initials: D
authors.lastname: Hovorun
authors.forename: Jerzy
authors.initials: J
authors.lastname: Leszczynski
mesh_terms: D002725:Chloroform / Q000737:chemistry; D003596:Cytosine / Q000031:analogs & derivatives* / Q000737:chemistry*; D019281:Dimerization; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D005740:Gases / Q000737:chemistry; D006860:Hydrogen Bonding; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D005740:Gases; D012997:Solvents; D014867:Water; C031532:1-methylcytosine; D002725:Chloroform; D003596:Cytosine; D004121:Dimethyl Sulfoxide