Effect of alkyl substituents in BODIPYs: a comparative DFT computational investigation

Abstract

A detailed computational investigation encompassing the effects of alkyl groups in the structural and electronic properties of BODIPY dyes is presented. Abstract:Random changes in the alkyl substitution patterns in fluorescent dyes e.g. BODIPYs often accompany with significant changes in their photophysical properties. To understand such alteration of properties in closely related molecular systems, a comparative DFT (density functional theory) computational investigation was performed in order to comprehend the effects of alkyl substitutions in controlling the structural and electronic nature of BODIPY dyes. In this context, a systematic strategy was utilized considering all possible outcomes of constitutionally-isomeric molecules to understand the alkyl groups' effects on the BODIPY molecules. The usage of four different computational methods {i.e. B3LYP/6-31G(d); B3LYP/6-311++G(d, p); wb97xd/6-311++G(d, p) and mpw1pw91/6-311++G(d, p)} was employed to rationalized the unanimity of the trends associated with the molecular properties. In line with experimental observations, it was found that alkyl substituents in BODIPY dyes situated at 3/5-positions effectively participate in stabilization as well as planarization of such molecules. Screening of all the possible isomeric molecular systems was used to understand the individual properties and overall effects of the typical alkyl substituents in controlling several basic properties of such BODIPY molecules.

Effect of the substitution position (2, 3 or 8) on the spectroscopic and photophysical properties of BODIPY dyes with a phenyl, styryl or phenylethynyl group

“…Mukherjee and Thilagar investigated substitutions around the BODIPY core with respect to relative stability of the electronic ground states. 46 They found that alkyl substitutions at the 3/5-positions contributed to a stabilization of the ground-state energy coupled with planar relaxed S0 geometries.…”

Density Functional Theory Based Analysis of Photoinduced Electron Transfer in a Triazacryptand Based K+ Sensor

“…6,9,10 Substituted BOD-IPY molecules are of considerable interest since the observed photophysical properties are highly sensitive to the nature of the substitution, and there have been several recent computational studies concerned with the calculation of the absorption and emission properties of BODIPY based systems. [11][12][13][14][15][16] These include the incorporation of solvent via a polarised continuum model. 12,15 In this work we focus on a triazacryptand-based fluorescent sensor with a 4-amino-naphthalimide fluorophore reported by Zhou et.…”

The Photostability of Two Optical Materials Based on Perylene Diimide Substituted by Different Aromatic Groups at the Bay Area

“…Calculations of electronic absorption spectra were done with the TD‐DFT method at the B3LYP/6‐31G(d) level on the basis of the optimized ground‐state structures. As this method has been widely used and given reliable results in the past reports . The results were given in Table .…”