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.

Flexible interlocked porous frameworks allow quantitative photoisomerization in a crystalline solid

“…As illustrated above, the reversible modulation of CO 2 sorption by photoirradiation is realized by the photoreactive flexible PCP. Our study not only clearly showed the correlation between photoisomerization efficiency and porous properties, which was not reported for pioneering works 22, 23 with a photomodulable CO 2 sorption, but also enables a material designed from the viewpoint of structural flexibility in a crystalline state. Our preliminary results in sorption experiments of PCP 1′ with other gases such as N 2 (Supplementary Fig.…”

Concentration Dependent Dimensionality of Resonance Energy Transfer in a Postsynthetically Doped Morphologically Homologous Analogue of UiO-67 MOF with a Ruthenium(II) Polypyridyl Complex

“…[1][2][3] Recently, a great deal of interest has been spent on incorporating photoactive ligands as guest molecules in MOFs for potential photovoltaic and photocatalytic applications. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] For example, a series of Re(II), Ir(III), and Ru(II) metal 5,5′-dicarboxy-2,2′-bipyridine, DCBPY, coordination complexes have been incorporated into the Zr(IV) 4,4'-biphenyldicarboxylic acid, BPDC, MOF UiO-67 for the purpose of carbon dioxide reduction, water oxidation, and organic conversion reactions. 11 The UiO-67 MOF is comprised of Zr 6 (µ 3 -O) 4 (µ 3 -OH) 4 metal nodes connected by twelve BPDC ligand resulting in two distinct cavity-types: a tetrahedral cavity having a diameter of approximately 12 Å, and an octahedral cavity approximately 23 Å in diameter.…”

Two-Photon Responsive Metal–Organic Framework

“…Light responsive MOFs, whose chemical and structural changes can be controlled merely by mild condition-light irradiation, have shown intriguing properties, and thus recently received great interest. [17][18][19][20][21][22][23][24][25][26][27][28] For example, light can induce configuration transformations of the linkers/guests, thus to tune the pores of MOFs and enhance their gas separation performances. [18][19][20][21] Photochemical reactions can also provide an alternative way to introduce functional groups/moieties and thus to develop smart MOFs with switchable optical absorption and fluorescence properties.…”

“…[18][19][20][21] Photochemical reactions can also provide an alternative way to introduce functional groups/moieties and thus to develop smart MOFs with switchable optical absorption and fluorescence properties. [21][22][23][24][25] Because the light triggers the reactions in a one-photon process in these examined systems, we were not able to develop their spatial selectivity: the photochemical responses take place either on the surfaces or in the whole crystals of MOFs. It is essential to engineer the properties of MOFs using the light or laser in 3-dimensional (3D) structure, which would create functional patterns inside the MOF crystals and find applications in chemical sensors, optical switches, data storage and circuits.…”