Influence of the electron donor groups on the optical and electrochemical properties of borondifluoride complexes of curcuminoid derivatives: a joint theoretical and experimental study

Abstract

(50 mV per unit of s), which we relate to the twisted ground-state geometry of the meso aryl substituent. The correlation models established in this study may be useful to anticipate the optical and electrochemical properties of borondifluoride complexes of curcuminoids with good reliability.

Exciton Interactions, Excimer Formation, and [2π+2π] Photodimerization in Nonconjugated Curcuminoid‐BF2 Dimers

“…The cyclic voltammograms (CVs) of the five compounds were recorded in DCMc ontaining 0.1 m of (nBu) 4 NPF 6 and display two-electron irreversible oxidation and reduction wavesc onsistent with the electrochemical properties of curcuminoids-BF 2 ( Figure S2). [23] The oxidation and reduction half-wavep otential values (Table S1) are very close to those obtained fort he reference compounds,s howingt hat tethering two curcuminoid-BF 2 units does not change significantly their electrochemical behavior in solution.…”

D–π–A–π–D Dyes with a 1,3,2‐Dioxaborine Cycle in the Polymethine Chain: Efficient Long‐Wavelength Fluorophores

“…However, the difluoroboron complex of acetylacetone provides a pathway to dyes with the dioxaborine core incorporated into the polymethine chain as the central electron acceptor group of the D–π–A–π–D system. Only bis‐styryls of this type ― borondifluoride complexes of curcumin analogues ― have been reported hitherto (Figure ) . Their absorption maximum ranges from 450 to 650 nm, shifting bathochromically and gaining intensity with increasing electron‐donating ability of a substituent in the benzene rings , .…”

“…Their absorption maximum ranges from 450 to 650 nm, shifting bathochromically and gaining intensity with increasing electron‐donating ability of a substituent in the benzene rings , . Their photophysical, NLO, and electrochemical properties were studied in detail by a group of French scientists . The NIR emission of difluoroborinated curcuminoids makes them suitable candidates for NIR imaging, which has attracted considerable attention because it allows deep tissue penetration, shows low auto‐fluorescence background, and causes less damage to biological samples.…”

Searching for new borondifluoride β -diketonate complexes with enhanced absorption/emission properties using ab initio tools

“…Nevertheless, we test three protocols here, in order to pinpoint the best option for the investigated dyes. We can classify the studied systems as: curcuminoids (1) 40 , characterized by two donor groups attached to a dioxaborine moiety through π-conjugated chains, hemicurcuminoids (2) 41,42 , with one donor group connected to the dioxaborine fragment by a π-connector while the other one is linked through a single bond; their ethynylene analogues (3) 41 , and 2'-hydroxy-chalcones (4) [43][44][45] . In Scheme 2, we can observe the complete panel of borondifluoride β-diketonate complexes studied in the first stage of this work.…”

“…Herein we perform a detailed TD-DFT study of the relationships between absorption/emission properties and structural features of a large set of borondifluoride βdiketonate complexes based on four families of dyes: curcuminoids 40 , hemicurcuminoids 41,42 , their ethynylene analogues 41 and 2'-hydroxy-chalcones (Scheme 2) [43][44][45] . As a first step, we…”