title: Solvent dependent supramolecular self-assembly and surface reversal of a modified porphyrin.
abstract: In this paper, a novel core-modified porphyrin with meso-aryl substituents and phenanthrene-fused pyrrole rings (N2S2-OR) is synthesized. Scanning tunneling microscopy (STM) has been used to probe its self-assembly behavior on a highly-oriented pyrolytic graphite (HOPG) surface. Our STM results have shown that there is an obvious solvent-dependent self-assembly for the surface-confined target molecules. In n-tetradecane, N2S2-OR assembles into a perfect alternating structure. At the 1-phenyloctane-graphite interface, disordered structures are formed and nonperiodic alternation is observed, whereas the target molecule in 1-heptanoic acid is assumed to form homogeneous close-packed monolayers with no alternating. Interestingly, such solvent-dependent supramolecular assembled behavior also involves the structural transformation of the backbone of the core-modified porphyrin derivative from saddle to reversed-saddle in these three solvents with different polarities.
authors.affiliation: National Center for Nanoscience and Technology (NCNST), Beijing 100190, P R China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Zhang
authors.forename: Haijun
authors.initials: H
authors.lastname: Xu
authors.forename: Yongtao
authors.initials: Y
authors.lastname: Shen
authors.forename: Yibing
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Shen
authors.forename: Qingdao
authors.initials: Q
authors.lastname: Zeng
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
mesh_terms: D000473:Alkanes; D006108:Graphite / Q000737:chemistry; D016252:Microscopy, Scanning Tunneling; D010616:Phenanthrenes / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000473:Alkanes; D010616:Phenanthrenes; D011166:Porphyrins; D011758:Pyrroles; D012997:Solvents; C024713:n-tetradecane; D006108:Graphite