title: A spectroscopic and theoretical investigation of a free-base meso-trithienylcorrole.
abstract: The unique optical properties of free-base meso-tris(5-methylthien-2-yl)corrole were compared to those of the widely investigated meso-triphenyl-substituted analogue. A combination of spectroscopic and computational experiments was undertaken to elucidate the relationship between structural features of the neutral, mono-anionic and mono-cationic forms of the corroles and their corresponding optical properties. A general bathochromic shift was measured for the thienyl-substituted corrole. The experimental spectra are supported by excited state calculations. A systematic series of ground state minimizations were performed to determine energy minima for the flexible and solvent-sensitive molecules. Trithienylcorrole was found to have a more nonplanar macrocycle in conjunction with a high degree of π-overlap with the meso-substituents. Both structural features contribute to their bathochromically shifted optical spectra. The configurational character of the thienyl-substituted corrole is shown to have a larger degree of molecular orbital mixing and doubly excited character, which suggest a more complex electronic structure that does not fully adhere to the Gouterman four-orbital model. The reactivity of the thienyl groups, particularly with respect to their ability to be (electro)-polymerized, combined with the tight coupling of the meso-thienyl groups with the corrole chromophore elucidated in this work, recommends the meso-thienylcorroles as building blocks in, for instance, organic semiconductor devices.
authors.affiliation: Department of Chemistry, University of Connecticut, Storrs, CT.
authors.forename: Jordan A
authors.initials: JA
authors.lastname: Greco
authors.forename: Alison
authors.initials: A
authors.lastname: Rossi
authors.forename: Robert R
authors.initials: RR
authors.lastname: Birge
authors.forename: Christian
authors.initials: C
authors.lastname: Brückner
mesh_terms: D011166:Porphyrins / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011166:Porphyrins; C431863:corrole