Luminescent Materials: Locking π‐Conjugated and Heterocyclic Ligands with Boron(III)

Abstract

Multidisciplinary research on novel organic luminescent dyes is propelled by potential applications in plastic electronics and biomedical sciences. The construction of sophisticated fluorescent dyes around a tetrahedral boron(III) center is a particular approach that has fueled the creativity of chemists. Success in this enterprise has been readily achieved with simple synthetic protocols, the products of which display unusual spectroscopic behavior. This account is a critical review of recent advances in the field of boron(III) complexes (excluding BODIPYs and acetylacetonate boron complexes) involving species displaying similar coordination features, and we outline their potential development in several disciplines.

Strongly Emissive and Photostable Four‐Coordinate Organoboron N,C Chelates and Their Use in Fluorescence Microscopy

“…Hence, the extension of the aryl -conjugation alone seems not to improve the photostability. However, the substitution with electron-donating groups provides very photostable dyes (2)(3)(4)(5). It is reasonable to assume that the electron-donor substitution stabilizes the excited ICT state which serves as an energy sink and thereby disfavors competing photoreaction channels.…”

“…[1][2][3][4] The structural scope includes N,O-and N,Nchelates with five-and six-membered rings as most common binding motifs [3,5] as well as bi-nuclear boron complexes. [6] Prominent examples are boron 8-hydroxyquinolinate complexes, [7,8] boron dipyrromethene (Bodipy) dyes, [9][10][11] boranils, [12,13] and boron iminocoumarins (Boricos).…”

Influence of Substituent and Benzoannulation on Photophysical Properties of 1-Benzoylmethyleneisoquinoline Difluoroborates

“…4 On the other hand, studies for the BF 2 -carrying fluorescent dyes different from BODIPYs are rare. Very recently the first survey on these molecules has been published by Ziessel et al 5 Moreover, there are some attempts to clarify their properties by computational approaches. [6][7][8] Thus there is still a need to investigate, how their properties can be tuned in order to obtain desired photophysical characteristics.…”

Fluorescent benzene-centered mono-, bis- and tris-triazapentadiene–boron complexes

“…Especially boron seems of interest to us, since boron-nitrogen compounds are known to exhibit intense fluorescence properties 10,11 and are also used in modern applications like OLEDs. 12 In 1962 the first neutral 1 : 1 triazapentadiene-boron complex was synthesized by Milks et al 13 and, a decade later, Mikhailov et al started to intensively study the synthesis of similar complexes.…”