title: C-H...O hydrogen bonding in 4-phenyl-benzaldehyde: a comprehensive crystallographic, spectroscopic and computational study.
abstract: The crystal structure of 4-phenyl-benzaldehyde reveals the presence of a dimer linked by the C=O and C9-H groups of adjacent molecules. In the liquid phase, the presence of C-H...O bonded forms is revealed by both vibrational and NMR spectroscopy. A DeltaH value of -8.2 +/- 0.5 kJ mol(-1) for the dimerisation equilibrium is established from the temperature-dependent intensities of the bands assigned to the carbonyl-stretching modes. The NMR data suggest the preferential engagement of the C(2,6)-H and C(10/12)/C(11)-H groups as hydrogen bond donors, instead of the C(9)-H group. While ab initio calculations for the isolated dimers are unable to corroborate these NMR results, the radial distribution functions obtained from molecular dynamics simulations show a preference for C(2,6)-H and C(10/12)/C(11)-H...O contacts relative to the C(9)-H...O ones.
authors.affiliation: CICECO, Departamento de Química, Universidade de Aveiro, P-3810-193 Aveiro, Portugal.
authors.forename: Pedro D
authors.initials: PD
authors.lastname: Vaz
authors.forename: Mariela
authors.initials: M
authors.lastname: Nolasco
authors.forename: Nelson
authors.initials: N
authors.lastname: Fonseca
authors.forename: Ana M
authors.initials: AM
authors.lastname: Amado
authors.forename: António M Amorim da
authors.initials: AM
authors.lastname: Costa
authors.forename: Vitor
authors.initials: V
authors.lastname: Félix
authors.forename: Michael G B
authors.initials: MG
authors.lastname: Drew
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Goodfellow
authors.forename: Paulo J A
authors.initials: PJ
authors.lastname: Ribeiro-Claro
mesh_terms: D001547:Benzaldehydes / Q000032:analysis / Q000737:chemistry*; D001665:Binding Sites; D002244:Carbon / Q000737:chemistry*; D003198:Computer Simulation; D018360:Crystallography, X-Ray / Q000379:methods*; D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D010100:Oxygen / Q000737:chemistry*
chemical_list: D001547:Benzaldehydes; D002244:Carbon; D006859:Hydrogen; D010100:Oxygen