Quantum Chemical Study Aimed at Modeling Efficient Aza-BODIPY NIR Dyes: Molecular and Electronic Structure, Absorption, and Emission Spectra

Abstract

A comprehensive study of the molecular structure of aza-BODIPY and its derivatives, obtained by introduction of one or more substituents, was carried out. We considered the changes in the characteristics of the electronic and geometric structure of the unsubstituted aza-BODIPY introducing the following substituents into the dipyrrin core; phenyl, 2-thiophenyl, 2-furanyl, 3-pyridinyl, 4-pyridinyl, 2-pyridinyl, and ethyl groups. The ground-state geometries of the unsubstituted Aza-BODIPY and 27 derivatives were computed at the PBE/6-31G(d) and CAM-B3LYP/6-31+G(d,p) levels of theory. The time-dependent density-functional theory (TDDFT) together with FC vibronic couplings was used to investigate their absorption and emission spectra.

Analysis of the Sensitivity of the Gas Electron Diffraction Method to the Determination of the Conformational Composition of Phenyl and Thiophenyl Substituted Aza-Bodipy: Theoretical Study

“…Conformational multiformity of 1 and 2 is associated with the possible rotation of substituent groups around the C-C bonds. Rotation barriers of phenyl and thiophenyl are around 23 and 35 kJ•mol -1 , respectively [34]. The molecules are non-planar due to the movement of the substituents out of the heterocycle plane.…”

“…BODIPY derivatives are studied by almost all physicochemical methods: a variety of spectroscopies in the visible region, including UV-Vis spectroscopy [3][4][5], transient absorption [6][7][8] and multiphoton absorption [9][10][11][12], as well as IR spectroscopy [13][14][15][16], NMR spectroscopy [17][18][19][20], EPR spectroscopy [21][22][23], differential scanning calorimetry [24][25][26], cyclic voltammetry [27][28][29] and X-ray diffraction (XRD) analysis [30][31][32]. Moreover, a large number of works [13,33,34] are devoted to the quantum chemical (QC) calculations of BOD-IPYs structures. At the same time, it is surprising that there are no data on the structure of these molecules in the gas phase.…”

Data-Driven Modeling of S0 -> S1 Excitation Energy in the BODIPY Chemical Space: High-Throughput Computation, Quantum Machine Learning, and Inverse Design

“…On an asymmetric framework, the total number of molecules that can be formed by introducing 46 groups in 7 sites should be 46 7 = 435.8×10 9 . However, since the unsubstituted BODIPY framework has the C 2v point group symmetry [82,83], this number drops when redundant entries are eliminated. For such symmetry constrained enumerations, Pólya [84][85][86] has suggested an algebraic strategy that has been used for non-constructive enumeration of chemical compound spaces [87].…”

XPS and quantum chemical analysis of 4Me-BODIPY derivatives

“…Currently, a limited number of articles are devoted to a thorough study of the electronic structure of BODIPY. [16][17][18] In this article, we decided to evaluate the influence of such electronic effects of substituents (by 2, 6 positions of the pyrrole rings of BODIPY, see Scheme 1) as the ''heavy atom effect'', ÀI (negative inductive) and +M (positive mesomeric) (using the example of BODIPY III), +I (positive inductive) (using BODIPY IV as an example), +I (positive inductive) and +M (positive mesomeric) (using Scheme 1 BODIPY molecules studied in the present work.…”