Two-Photon Responsive Metal–Organic Framework

Abstract

Two-photon processing presents a facile means to tailor the properties of materials in three-dimensions. A two-photon responsive metal-organic framework (MOF) has been realized through the incorporation of a photoactive linker into a MOF via a multivariate strategy. The resulting MOF exhibits a significant one-photon and two-photon excited fluorescence change in response to UV light and infrared femtosecond laser, enabling spatial modulation of the fluorescence property of the MOF. It thus demonstrates the capacity of two-photon patterning and imaging inside the crystal, and the formation of three-dimensional two-photon excited fluorescent structure in a high resolution.

Photoactive and Physical Properties of an Azobenzene-Containing Coordination Framework

“…Several studies of asymmetric azobenzenes have suggested that the decrease in relative intensity of peaks between 1400 and 1550 cm À1 is indicative of an isomerisation process. [51,52] Crystal Structure and Thermophysical Properties of [Zn 4 (tbazip) 3 (Fig. S3, Supplementary Material).…”

“…The spaces occupied by these solvent molecules are connected to neighbouring solvent spaces to form channels along the a-axis. The observed porosity in [Zn 4 (tbazip) 3 attributable to the partial retention of these channels upon evacuation of the solvent molecules. PXRD analysis was employed to confirm the bulk purity of [Zn 4 (tbazip) 3 (bpe) 2 (OH) 2 ]ÁbpeÁ2H 2 O (Fig.…”

“…Functional inorganic materials that may be altered by the application of an external stimulus, such as pressure, [1] temperature, [2] or light, [3] have been rapidly developing over the past decade. Light stimulus is of particular interest because it is highly accessible, tunable, and may be used as a way to modify the structure of a functional inorganic material to induce a response (referred to as photoresponsivity).…”

“…[41] Lyndon et al [8] investigated the framework [Zn(abdc)(bpe)], previously reported by Chen et al [42] Here, a photoresponse was observed in the framework for the first time, where the azobenzene underwent cis-trans isomerisation in the pillars of the MOF, which led to measurable variations in the uptake and release of CO 2 . More recently, an azo-based MOF, Co 3 (dpia) 2 (azdc) 3 …”

“…Presumably, the densely packed nature of [Zn 4 (tbazip) 3 (bpe) 2 (OH) 2 ]Ábpe precludes the effect of isomerisation on the gas adsorption properties.…”