Solvent-controlled intramolecular excimer emission from organosilicon derivatives of naphthalene

New mono-, bis-and tetra-fluorophoric organosilicon naphthalene derivatives, that are able to form intramolecular excimers have been synthesized and characterized. The synthesized compounds show only monomeric fluorescence in dilute solutions of common organic solvents, but exhibit relatively strong excimer-like emission in DMSO-water and THF-water mixtures. In all cases, the intensity of excimer fluorescence increases with increasing water content and decreases with increasing temperature. Fully and partially overlapping excimer conformations have been modeled by DFT-based calculations. Properties of different intramolecular excimers in an ensemble of four naphthalene molecules linked to a cyclotetrasiloxane ring in an all -cis arrangement are considered. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

New mono-, bis- and tetra-fluorophoric organosilicon naphthalene derivatives capable of forming intramolecular excimers have been synthesized and characterized. These compounds exhibit strong excimer-like emission in certain solvent mixtures, with fluorescence intensity increasing with water content and decreasing with temperature. Different intramolecular excimers in an ensemble of four naphthalene molecules linked to a cyclotetrasiloxane ring have been modeled using DFT-based calculations.