title: Axial ligand exchange reactions of meso-aryl subporphyrins-axially fluoro-substituted subporphyrin and a mu-oxo dimer and trimer of subporphyrins.
abstract: High reactivity of the boron atom of meso-aryl subporphyrins enables the introduction of a broad range of functional groups to its axial position. Axially fluoro-substituted subporphyrins were easily synthesized upon treatment of axially hydroxyl-substituted subporphyrins with BF(3).OEt(2). Homogeneous mu-oxo dimers of subporphyrins were formed by heating monomers in the presence of triethylamine under a high vacuum. A heterogeneous subporphyrin-phthalocyanine-subporphyrin trimer was selectively formed from the respective monomers under similar reaction conditions. Structures of these molecules were elucidated by (1)H NMR spectra and a single-crystal X-ray diffraction analysis, and the interactions between neighboring chromophores in the dimeric systems were estimated from absorption and magnetic circular dichroism spectra.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
authors.forename: Soji
authors.initials: S
authors.lastname: Shimizu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Matsuda
authors.forename: Nagao
authors.initials: N
authors.lastname: Kobayashi