title: Determination of 3(1)-stereochemistry in synthetic bacteriochlorophyll-d homologues and self-aggregation of their zinc complexes.
abstract: Zinc complex of methyl 3(1)-octadecyl-bacteriopheophorbide-d was prepared from modification of naturally occurring chlorophyll-a. The 3(1)-epimerically pure samples were obtained by HPLC separation and their stereochemistry including the absolute configuration at the secondary alcoholic 3(1)-position was determined by combination of esterification to methoxy(trifluoromethyl)phenylacetate and NMR spectroscopy (Mosher's method). Both the epimers were monomeric in a polar organic solvent and self-aggregated in a non-polar solvent to give oligomers as well as dimers possessing red-shifted visible absorption bands. Visible spectra of the non-polar organic solutions were dependent upon the 3(1)-chirality and such a diastereoselective control on the self-aggregation led to the formation of self-aggregates with different supramolecular structures.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan. tamiaki@se.ritsumei.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tamiaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kitamoto
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Nishikawa
authors.forename: Takuya
authors.initials: T
authors.lastname: Hibino
authors.forename: Reiko
authors.initials: R
authors.lastname: Shibata
mesh_terms: D001429:Bacteriochlorophylls / Q000138:chemical synthesis* / Q000737:chemistry; D008670:Metals / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
chemical_list: D001429:Bacteriochlorophylls; D008670:Metals; D009942:Organometallic Compounds; D011108:Polymers; C459779:bacteriochlorophyll d; D015032:Zinc