Tailoring the Solid-State Fluorescence of BODIPY by Supramolecular Assembly with Polyoxometalates

Abstract

A cationic boron dipyrromethene (BODIPY) derivative (1 + ) has been successfully combined with two polyoxometalates (POMs), the Lindqvist-type [W6O19] 2and the β-[Mo8O26] 4units, into three new supramolecular fluorescent materials(1)2[W6O19]⋅2CH3CN, (1)2[W6O19] and (1)4[Mo8O26]⋅DMF⋅H2O. The resulting hybrid compounds have been fully characterized by a combination of single-crystal X-ray diffraction, IR and UV-Vis spectroscopies and photoluminescence analyses. This self-assembly approach prevents any π-π stacking interactions between the BODIPY units, responsible for aggregation-caused quenching (ACQ) effects, but also between the BODIPY and the POMs, avoiding intermolecular charge-transfer effects. Noticeably, the POM units do not only act as bulky spacers but their negative charge density drives the molecular arrangement of the 1 + luminophore, strongly modifying its fluorescence in the solid state. As a consequence, the 1 + cations are organized into dimers in (1)2[W6O19]⋅2CH3CN and (1)2[W6O19], which are weakly emissive at room temperature, and in a more compact layered assembly in (1)4[Mo8O26]⋅DMF⋅H2O which exhibits a redshifted and intense emission upon similar photoexcitation.

Imidazole-Dependent Assembly of Copper Polymolybdate Frameworks for One-Pot Sulfide Oxidation and C–H Activation

“…The Cu1 atom is six-coordinated with four nitrogen atoms ( S2). 35,36 In addition, the supramolecular structure of Im-Cu-PMoFs-3 is formed along the crystallo 3.3. Selective Oxidation of Benzylic Hydrocarbons.…”

“…All Mo­(VI) sites in Im-Cu-PMoFs-3 show distorted MoO 6 octahedrons with Mo–O distances, in agreement with known polyoxomolybdate compounds (Table S2). , In addition, the supramolecular structure of Im-Cu-PMoFs-3 is formed along the crystallographic bc plane by Cu–O–Mo bond bridges between [Cu­(1-bIM) 4 ] 2+ and [β-Mo 8 O 26 ] 4– subunits, and the 2D sheet is shown in Figure .…”

Design strategies and applications of novel functionalized phenazine derivatives: a review

“…[3][4][5][6][7][8][9][10] Phenazine is a rigid planar, redox-active and electrondeficient aromatic compound, which could be easily modified with functional groups or combined with some ligands to create novel functional materials. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] In the design of photoelectric functional materials, it becomes one of the most attractive and appropriate structures. [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] Typically, the functionalization of nitrogen atoms on the phenazine skeleton leads to the formation of a series of phenazine derivatives with variable absorption and fluorescence properties.…”

Aryl-Boron-Substituted BODIPYs: Direct Access via Aluminum-Chloride-Mediated Arylation from Arylstannanes and Tuning the Optoelectronic Properties

“…Therefore, BODIPY dyes have played increasingly important roles in many fields involving fluorescent probes, labeling reagents, photosensitizers, and energy-transfer cassettes . Nevertheless, most BODIPY derivatives have a rigid and planar structure, which render them with very small Stokes shifts (5–20 nm) and aggregation-caused quenching (ACQ) of fluorescence in a high concentration and in the solid state …”