Tuning the Photophysical Properties of BODIPY Molecules by π‐Conjugation with Fischer Carbene Complexes

Abstract

The synthesis, structure, and photophysical properties of novel BODIPY-Fischer alkoxy-, thio-, and aminocarbene dyads are reported. The BODIPY chromophore is directly attached to the carbene ligand by an ethylenic spacer, thus forming donor-bridge-acceptor π-extended systems. The extension of the π-conjugation is decisive in the equilibrium geometries of the dyads and is clearly reflected in the corresponding absorption and emission spectra. Whereas the BODIPY fragment is mainly isolated in aminocarbene complexes, it is fully conjugated in alkoxycarbene derivatives. The former thus exhibit the characteristic photophysical properties of BODIPY units, whereas complete suppression of the BODIPY fluorescence emission is observed in the latter, as a direct consequence of the strong electron-accepting character of the (CO)5M=C moiety. As the π-acceptor character of the metal-carbene group can be modified, the electronic properties of the conjugated BODIPY can be tuned. Density functional calculations have been carried out to gain insight into the photophysical properties.

Fine‐Tuning the Fluorescence Gain of FRET‐Type (Bodipy)(Bodipy′)‐NHC‐Iridium Complexes for CO Detection with a Large Virtual Stokes Shift

“…Based on the predominance of PET quenching, we had determined that the electron density at the transition metal influences the fluorescenceb rightness. [30] An increase in the electron density at the transition metal increases the quenching effect of the metal and leads to ad ecrease in the fluorescencei ntensity. [30a] Based on this, am ore detailed investigation of the electronic factors controlling the brightness of the iridium complexes is required.…”

Chiral‐at‐Metal BODIPY‐Based Iridium(III) Complexes: Synthesis and Luminescence Properties

“…[11] On the other hand, our work in push-pull systems containing a Cr(0) and W(0) Fischer metal carbene moiety, I, clearly demonstrated that the system geometry is reflected in the deactivation of the fluorescence. [12] Analogously, complexes BODIPY-metal carbene II, having remote π-conjugation, allowed to determine the influence of electronic factors in the emission properties of the BODIPY moiety. [13] A similar study was carried out in BODIPYs having remote half-sandwich Ir(III) and Rh(III) moieties, III (Figure 1).…”

Joint Isotherm Calorimetric Titration–DFT Investigation of the Demethoxy-Amination of Fischer Carbenes

“…Fischer carbenes possess a few potential reactive sites that directly stem from the electrophilic character of the carbenic carbon. [9][10][11][12][13][14][15] As a consequence of possessing versatile chemical properties, accompanied with the adjustable electronic characteristics of the substituents (X, R) on the carbene carbon atom, Fischer carbenes were found to be very important precursors in both organic and inorganic synthesis [16][17][18][19][20][21][22][23][24][25][26][27][28][29] as well as in the synthesis of biological active compounds [30][31][32][33][34].…”