title: Temperature-dependent Raman spectroscopic study of the nematic liquid crystal 4-n-pentyl-4'-cyanobiphenyl.
abstract: The spectral behaviors of 4-n-pentyl-4'-cyanobiphenyl (5 CB) have been studied by means of temperature-dependent Raman spectros-copy in the range between --70 and 70 degrees C. The nu(C identical with N) bands in the Raman spectra were found splitting below the transition temperature from the solid to the nematic liquid crystalline phase at approximately 24 degrees C, suggesting the existence of solid crystalline polymorphism. The interfacial structures of 5 CB on metal plate surfaces have been reexamined by surface-enhanced Raman scattering (SERS) at different temperatures. On Ag and Au, the asymmetric shapes of the nu(C identical with N) bands suggest that there should exist different binding schemes for 5 CB on metal surfaces. These asymmetric bands in the nu(C identical with N) stretching region were found to vary in changing temperature.
authors.affiliation: School of Electrical Engineering, Soongsil University, Seoul 156-743, Korea.
authors.forename: Dae Seung
authors.initials: DS
authors.lastname: Kang
authors.forename: Ki-Sun
authors.initials: KS
authors.lastname: Kwon
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Kim
authors.forename: Myoung-Seon
authors.initials: MS
authors.lastname: Gong
authors.forename: Sung Seok A
authors.initials: SS
authors.lastname: Seo
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Noh
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Joo
mesh_terms: D001713:Biphenyl Compounds / Q000032:analysis / Q000737:chemistry*; D005818:Genetic Engineering / Q000379:methods*; D008859:Microscopy, Polarization; D009570:Nitriles / Q000032:analysis / Q000737:chemistry*; D011108:Polymers / Q000032:analysis / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013696:Temperature
chemical_list: D001713:Biphenyl Compounds; D009570:Nitriles; D011108:Polymers; C422409:liquid crystal polymer; C433919:4-cyano-4'-pentylbiphenyl