title: Synthesis, characterization, MCD spectroscopy, and TD-DFT calculations of copper-metalated nonperipherally substituted octaoctyl derivatives of tetrabenzotriazaporphyrin, cis- and trans-tetrabenzodiazaporphyrin, tetrabenzomonoazaporphyrin, and tetrabenzoporphyrin.
abstract: Synthesis of the title compounds has been achieved through refinement of a recently reported synthetic protocol whereby varying equivalents of MeMgBr are reacted with 1,4-dioctylphthalonitrile to produce mixtures favoring specific hybrid structures. The initially formed magnesium-metalated compounds are obtained as pure materials and include, for the first time, both isomers (cis and trans) of tetrabenzodiazaporphyrin. The compounds were demetalated to the metal-free analogues, which were then converted into the copper-metalated derivatives. The X-ray structure of the copper tetrabenzotriazaporphyrin derivative is reported. The metal-free and copper-metalated macrocycles exhibit columnar mesophase behavior, and it is found that the mesophase stability is unexpectedly reduced in the diazaporphyrin derivatives compared to the rest of the series. The results of time-dependent density functional theory calculations for the copper complexes are compared to the observed optical properties. Michl's perimeter model was used as a conceptual framework for analyzing the magnetic circular dichroism spectral data, which predicted and accounted for trends in the observed experimental spectra.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
authors.forename: John
authors.initials: J
authors.lastname: Mack
authors.forename: Lydia
authors.initials: L
authors.lastname: Sosa-Vargas
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Coles
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Tizzard
authors.forename: Isabelle
authors.initials: I
authors.lastname: Chambrier
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Cammidge
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Cook
authors.forename: Nagao
authors.initials: N
authors.lastname: Kobayashi
mesh_terms: D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D011166:Porphyrins / Q000138:chemical synthesis* / Q000737:chemistry*; D011789:Quantum Theory; D013237:Stereoisomerism
chemical_list: D009942:Organometallic Compounds; D011166:Porphyrins; D003300:Copper