title: Broad hexagonal columnar mesophases formation in bioinspired transition-metal complexes of simple fatty acid meta-octaester derivatives of meso-tetraphenyl porphyrins.
abstract: A series of meta-substituted fatty acid octaester derivatives and their transition-metal complexes of meso- tetraphenyl porphyrins (TPP-8OOCR, with R = C(n-1)H(2n-1), n = 8, 12, or 16) have been prepared through very simple synthesis protocols. The thermotropic phase behavior and the liquid crystalline (LC) organization structures of the synthesized porphyrin derivatives were systematically investigated by a combination of differential scanning calorimetry (DSC), polarized optical microscopy (POM), and variable-temperature small-angle X-ray scattering/wide-angle X-ray scattering (SAXS/WAXS) techniques. The shorter octanoic acid ester substituted porphyrin (C8-TPP) did not show liquid crystallinity and its metal porphyrins exhibited an uncommon columnar mesophase. The lauric acid octaester (C12-TPP) and the palmitic acid octaester (C16-TPP) series porphyrins generated hexagonal columnar mesophase Colh. Moreover, the metal porphyrins C12-TPPM and C16-TPPM with M = Zn, Cu, or Ni, exhibited well-organized Colh mesophases of broad LC temperature ranges increasing in the order of TPPNi<TPPCu≤TPPZn with their increased effective ionic radii in the square-planar coordination. The simplicity in synthesis, the well intercolumnar organization of Colh mesophase, the broadness of the discotic LC range, and the specific UV/Vis absorption and fluorescence emission behaviors make the symmetrically substituted fatty acid octaester porphyrins and their metal complexes very attractive for variant applications.
authors.affiliation: Key Laboratory of High Performance Polymer Materials and Technology of Ministry of Education, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (P.R. China).
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.forename: Keyang
authors.initials: K
authors.lastname: Chen
authors.forename: Yuchen
authors.initials: Y
authors.lastname: Deng
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.forename: Chengjie
authors.initials: C
authors.lastname: Liu
authors.forename: Rongshi
authors.initials: R
authors.lastname: Cheng
authors.forename: Dongzhong
authors.initials: D
authors.lastname: Chen
mesh_terms: D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D004952:Esters; D005227:Fatty Acids / Q000737:chemistry*; D007850:Lauric Acids / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D015394:Molecular Structure; D019308:Palmitic Acid / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D028561:Transition Elements / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D056831:Coordination Complexes; D004952:Esters; D005227:Fatty Acids; D007850:Lauric Acids; D008670:Metals; D011166:Porphyrins; D028561:Transition Elements; C030358:lauric acid; D019308:Palmitic Acid
keywords: fatty acids; hexagonal columnar mesophases; liquid crystals; porphyrinoids; transition metals