title: Energy transfer on demand: photoswitch-directed behavior of metal-porphyrin frameworks.
abstract: In this paper, a photochromic diarylethene-based derivative that is coordinatively immobilized within an extended porphyrin framework is shown to maintain its photoswitchable behavior and to direct the photophysical properties of the host. In particular, emission of a framework composed of bis(5-pyridyl-2-methyl-3-thienyl)cyclopentene (BPMTC) and tetrakis(4-carboxyphenyl)porphyrin (H4TCPP) ligands anchored by Zn(2+) ions can be altered as a function of incident light. We attribute the observed cyclic fluorescence behavior of the synthesized porphyrin-BPMTC array to activation of energy transfer (ET) pathways through BPMTC photoisomerization. Time-resolved photoluminescence measurements show a decrease in average porphyrin emission lifetime upon BPMTC insertion, consistent with an ET-based mechanism. These studies portend the possible utilization of photochromic ligands to direct chromophore behavior in large light-harvesting ensembles.
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina , Columbia, South Carolina 29208, United States.
authors.forename: Derek E
authors.initials: DE
authors.lastname: Williams
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Rietman
authors.forename: Josef M
authors.initials: JM
authors.lastname: Maier
authors.forename: Rui
authors.initials: R
authors.lastname: Tan
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Greytak
authors.forename: Mark D
authors.initials: MD
authors.lastname: Smith
authors.forename: Jeanette A
authors.initials: JA
authors.lastname: Krause
authors.forename: Natalia B
authors.initials: NB
authors.lastname: Shustova
mesh_terms: D004735:Energy Transfer; D008027:Light; D008665:Metalloporphyrins / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D055668:Photochemical Processes; D011166:Porphyrins / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013237:Stereoisomerism; D013876:Thiophenes / Q000737:chemistry*; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry*
chemical_list: D008665:Metalloporphyrins; D009942:Organometallic Compounds; D011166:Porphyrins; D011725:Pyridines; D013876:Thiophenes; D015032:Zinc