title: Stiffness tunable molecular spring washers: high-pressure Raman investigations on porphyrin self-assemblies.
abstract: The Raman spectra of a series of meso-substituted porphyrin self-assemblies have been measured as a function of pressure up to 13 GPa. In comparison with that for Tpp J-aggregates in our previous investigation [J. Phys. Chem. B, 2008, 112, 15562], a similar phenomenon has been observed in all meso-substituted self-assemblies, such as peaks in the spectrum which show positive linear pressure dependence which provides no evidence of the phase transition and the intensity enhancement of aromatic Psi(3) C-C stretching vibration with pressure. The different slopes of intensity ratios between Psi(3) C-C and C(a)-C(m) stretching vibration to pressure in these meso-substituted porphyrin self-assemblies indicate that the stiffness of molecular spring washers is tunable.
authors.affiliation: State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Chang Chun, 130023, P. R. China. mzhou06@mails.jlu.edu.cn
authors.forename: Mi
authors.initials: M
authors.lastname: Zhou
authors.forename: Zuowei
authors.initials: Z
authors.lastname: Li
authors.forename: Tiecheng
authors.initials: T
authors.lastname: Liu
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Dapeng
authors.initials: D
authors.lastname: Xu
authors.forename: Shuqin
authors.initials: S
authors.lastname: Gao
mesh_terms: D000042:Absorption; D011166:Porphyrins / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman; D016709:Yin-Yang
chemical_list: D011166:Porphyrins