title: Dangling OD confined in a Langmuir monolayer.
abstract: Novel structural features of water confined in lipid Langmuir monolayers are revealed. Using vibrational sum frequency generation spectroscopy at the air/D2O/monolayer interface, dangling OD bonds were investigated. Upon increasing the monolayer surface coverage, the dangling OD stretching mode showed a marked frequency red-shift as well as spectral structure. Furthermore, the dangling OD was found to exist even when a D2O surface was fully covered by the lipid molecules. This phenomenon was observed in monolayers formed with dipalmitoylphosphatidylcholine and with palmitic acid. The frequency red-shift of the dangling OD is interpreted to be due to the perturbation imposed by the lipid hydrophobic tail groups. The observed persistence of the dangling OD at full surface coverage is related to hydrophobicity-induced drying.
authors.affiliation: Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Ma
authors.forename: Xiangke
authors.initials: X
authors.lastname: Chen
authors.forename: Heather C
authors.initials: HC
authors.lastname: Allen
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D000388:Air; D017666:Deuterium Oxide / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008567:Membranes, Artificial; D019308:Palmitic Acid / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D008567:Membranes, Artificial; D015060:1,2-Dipalmitoylphosphatidylcholine; D019308:Palmitic Acid; D017666:Deuterium Oxide