Substituted Position Effect on Twisted intramolecular Charge Transfer of 1- and 2-anthracene aromatic Carboxamides as Chemosensors Based on Linear Polyether

Abstract

Bi-chromophoric compounds linked to linear polyether N, N′-[oxybis(3-oxapentamethyleneoxy-2-phenyl)]-bis(1-anthracenecarboxamide) (14) and its analogues (15, 24 and 25) were synthesized. Their photochemical properties and complexation actions were investigated in acetonitrile. These fluoroionophores have shown weak emissions in the absence of guest ions, resulting in a twisted intramolecular charge transfer (TICT) quenching process (off state) of an anthracene aromatic amide moiety. After the formation of a complex with alkaline earth metal ions, a large enhancement of fluorescent intensities was obtained (on state). The efficiencies of controlling an off-on fluorescent signal using 14 and its analogues (15, 24 and 25) were larger than that of the 9-positioned analogue. These results suggested that the TICT relaxation process was effectively able to control using 14 and its analogues (15, 24 and 25) by complex formations.

Recent advances in twisted intramolecular charge transfer (TICT) fluorescence and related phenomena in materials chemistry

“…As a consequence, (11) exhibited a 50-70-fold increase in its fluorescence intensity by the addition of Ca 2+ , Sr 2+ or Ba 2+ ions. 42 This strategy, wherein complexation prevents TICT formation by imposing steric restriction, is also effective for the detection of neutral molecules such as surfactants. 43…”

Two-Dimensional Electronic Spectroscopy Reveals Vibrational Modes Coupled to Charge Transfer in a Julolidine–BODIPY Dyad

“…In model compounds, D and A are often linked by a single covalent bond such that photoexcitation of the system results in torsional motion about that bond as CT occurs. − Indeed, many examples of twisted intramolecular CT (TICT) states have been studied. ,,− In these cases, when the photoexcited D–A system relaxes from its local exciton (LE) state, CT is favored when the two π systems have large dihedral angles relative to one another, while conversely, maintaining planarity between the D and A π systems favors relaxation of the LE state, often via radiative decay by fluorescence. , TICT states have proven useful in developing optimized organic light-emitting diodes, − high-efficiency organic photovoltaics, − finely tuned aggregation-induced emission luminogens (AIEgens), , and techniques for sensing chemical species, − microenvironmental viscosity, − and environmental polarity . For example, Sunahara and co-workers took advantage of this architecture to develop a library of BODIPY-containing compounds exhibiting different degrees of TICT state formation to be utilized for solvent polarity sensing.…”

Determination of SDS Using Fluorescent γ-Cyclodextrin Based on TICT in Aqueous Solution

“…14 To address the problem described above, we introduced twisted intramolecular charge transfer (TICT) as a fluorescence-related switching mechanism. [15][16][17][18] The utilization of the TICT process enables fluorescence switching of a chemosensor by a degree of the steric barrier. It was reported that TICT was controlled by micellar aggregation 19 and the use of a viscous solvent.…”