Synthesis and Spectroscopic Properties of Selenophene[3, 2-b]-Fused BODIPYs

Abstract

Fusion selenophene endows the chromophore with more intrinsic and special functions. Herein, nonsymmetric selenophene-fused BODIPYs were designed and synthesized starting from the selenophene unit. The fused ring of selenophene not only maintains the rigid structure of BODIPY but also further modulates its spectral properties. The newly prepared dyes possessed many promising properties including large molar extinction coefficients, low fluorescence quantum yields, and moderate singlet oxygen generation. Quantum calculations affirmed that the smaller singlet-triplet energy gap and larger spin–orbit coupling cause efficient intersystem crossing, thus enhancing the singlet oxygen generation yield. Furthermore, selenophene-fused BODIPY exhibited significant phototoxicity with negligible dark cytotoxicity, based on the fluorescence imaging of the reactive oxygen species detection experiment.

Synthesis, Properties, and Semiconducting Characteristics of Bisbenzothieno[b]-Fused BODIPYs

“…The suitable X-ray crystals of BTB 1d for X-ray analysis were formed by slowly diffusing hexane into its dichloromethane solution. Similar to those reported BODIPYs, − BTB 1d maintains an almost planar core structure (Figures and S1). The dihedral angle of 5.1° between the two thiophene rings reveals that this kind of ring-fusion leads to little structural disruption, which might be influenced by the steric and crystal packing considerations.…”

Rational Design of Selenophene‐infused BODIPY Molecules as Fluorogenic Probes for Lung Tumor Imaging – A Computational Approach

“…These transitions primarily involved HOMO!LUMO transitions. Furthermore, the study investigated the singlet-triplet transitions of the TTB derivatives, as introducing selenium in BODIPY has been shown to improve the Intersystem Crossing rate (ISC) [18,60] , leading to very low singlet-triplet (ΔES1-T3) energy gaps. This property makes these molecules show excellent emission and can be used as bio-imaging probes.…”

“…[26] In this context, a recent work by Hua Lu et al introduced selenophene-fused BODIPYs, exhibiting reduced energy gaps, enhanced electron distribution, and heightened intersystem crossing (ISC) compared to their heteroatom-fused counterparts. [18] Leveraging selenophene's unique attributes -larger atomic radius, heightened polarizability, and diminished electronegativity relative to Sulphur and Oxygen -these derivatives show promise as photosensitizers for photodynamic therapy (PDT) in cancer treatment. [27,28] However, the quest for identifying an optimized BODIPY structure with desirable absorption and emission properties is still continuing.…”

“…[16,17] Among these strategies, literature reveals that the incorporation of heterocyclic units has demonstrated the capacity to broaden the spectrum through expanded system conjugation, with heteroatoms further modulating frontier orbital electron distribution. [18] For instance, the fusion of BODIPY with heterocyclic rings like furan and thiophene has yielded improved absorption and emission attributes.…”

“…Diverse adaptations have extended BODIPY′s utility across diverse domains, encompassing optoelectronics, photodynamic therapy (PDT), bioimaging, metal ion detection, and theranostic roles in biomedicine [16,17] . Among these strategies, literature reveals that the incorporation of heterocyclic units has demonstrated the capacity to broaden the spectrum through expanded system conjugation, with heteroatoms further modulating frontier orbital electron distribution [18] . For instance, the fusion of BODIPY with heterocyclic rings like furan and thiophene has yielded improved absorption and emission attributes.…”