Diaminodicyanoquinones: Fluorescent Dyes with High Dipole Moments and Electron‐Acceptor Properties

Abstract

Fluorescent dyes are applied in various fields of research, including solar cells and light-emitting devices,and as reporters for assays and bioimaging studies.F luorescent dyes with an added high dipole moment pave the way to nonlinear optics and polarity sensitivity.Redox activity makes it possible to switch the moleculesp hotophysical properties.D iaminodicyanoquinone derivatives possess high dipole moments,y et only low fluorescence quantum yields,and have therefore been neglected as fluorescent dyes.H ere we investigate the fluorescence properties of diaminodicyanoquinones using acombined theoretical and experimental approach and derive molecules with af luorescence quantum yield exceeding 90 %. The diaminodicyanoquinone core moiety provides chemical versatility and can be integrated into novel molecular architectures with unique photophysical features.

Identification of the Irreversible Redox Behavior of Highly Fluorescent Benzothiadiazoles

“…[13] Furthermore, BTDs can act as ortho-diamine protecting groups and can thus be used as precursors for other molecular compounds, e. g. diaminodicyanoquinones and quinoxalines. [14,15] Although, those applications involve redox processes, there are few publications where the BTD unit was considered as a redox switch. [16] In this regard, most currently used redox switches are based on, e. g. organometallic motives or complex organic structures such as perylenediimide-dithienylethene dyads.…”

“…Accordingly, from ethanol to 1decanol τ increases by 12.5 % and Φ fl by 47 %. Since Φ fl and τ increase with increasing viscosity are well known phenomena, [15,35,36] we compared our results with solutions of 4 in mixtures of EtOH-PEG with increasing viscosity but only slightly changing polarity ( Figure S11). Here, both values increase as well, 1.2 % for τ and 7.8 % for Φ fl (Table S7).…”

Regioselective Functionalization of Stable BN‐Modified Luminescent Tetraphenes for High‐Resolution Fingerprint Imaging

“…These compounds were obtained as solid powders by chromatography on silica gel and could be stored in air for several months without any noticeable decomposition, as determined by 1 HNMR spectroscopy.A ll compounds were characterized by 1 H, 13 C, and 11 BNMR and HRMS spectroscopy.T he structures of 5 and 8 were confirmed by X-ray single-crystal analysis ( Figure 1, Figure S1, Table S1). Compound 8 adopts as lightly twisted configuration, with as mall Scheme 1.…”

“…Therefore, 5 and 6 show redshifted emission in CH 2 Cl 2 compared to 1,exhibiting emission ranging from blue to yellow with l em shifting from 430 to 537 nm ( Figure S5 in the Supporting Information). [13] Thef luorescence properties of these compounds were also investigated in n-hexane and toluene,and the results indicate that their fluorescence properties are also affected by the solvent polarity.W ith high solvent polarity,t he emission spectra of the compounds are broadened and exhibit as ignificant redshift from 488 to 537 nm ( Figure 2). [13] Thef luorescence properties of these compounds were also investigated in n-hexane and toluene,and the results indicate that their fluorescence properties are also affected by the solvent polarity.W ith high solvent polarity,t he emission spectra of the compounds are broadened and exhibit as ignificant redshift from 488 to 537 nm ( Figure 2).…”

“…It is noted that the quantum yields in CH 2 Cl 2 were affected significantly by the electronic effects of the substituents on the main backbone.F or example,attaching two diphenylamino groups dramatically improved the quantum yield of compound 6 up to 84 %, because the two nonplanar diphenylamine groups restrict the internal rotations of 6 in solution and therefore improve its quantum yield;t his is in agreement with the proposal that the restricted internal rotation of compounds can improve their quantum yields in solution significantly. [13] Thef luorescence properties of these compounds were also investigated in n-hexane and toluene,and the results indicate that their fluorescence properties are also affected by the solvent polarity.W ith high solvent polarity,t he emission spectra of the compounds are broadened and exhibit as ignificant redshift from 488 to 537 nm (Figure 2). This can be attributed to ah ighly polarized intramolecular charge-transfer (ICT) excited state,typical for donor-(p-spacer)-acceptor (D-p-A) compounds.…”