title: Spectroscopic probe on N-H⋯N, N-H⋯O and controversial C-H⋯O contact in A-T base pair: a DFT study.
abstract: DNA base pair A-T has been investigated by IR and NMR spectroscopy using DFT methods. The results have been analyzed in terms of infrared vibrational frequencies and (1)H NMR chemical shifts. Different types of interactions N-H⋯N, N-H⋯O and C-H⋯O types have been investigated in DNA base pairs. Although, previous reports argued about the third C-H⋯O type interaction in A-T base pair, such typical interaction has been analyzed thoroughly by IR and NMR spectroscopy using DFT methods. Our results show that the CH⋯O interaction in the A-T base pair is a weak interaction compared to normal hydrogen bond interactions.
authors.affiliation: Department of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi, Taiwan.
authors.forename: Venkatesan
authors.initials: V
authors.lastname: Srinivasadesikan
authors.affiliation: Department of Chemistry, National Institute of Science and Technology, Berhampur 761008, India.
authors.forename: Prabhat K
authors.initials: PK
authors.lastname: Sahu
authors.affiliation: Department of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi, Taiwan. Electronic address: chesll@ccu.edu.tw.
authors.forename: Shyi-Long
authors.initials: SL
authors.lastname: Lee
mesh_terms: D000225:Adenine / Q000737:chemistry*; D020029:Base Pairing; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013941:Thymine / Q000737:chemistry*
chemical_list: D000225:Adenine; D013941:Thymine
keywords: A–T base pair; C–H⋯O interaction; DFT; Hydrogen bond; Spectroscopy; Van der Waals interaction