Dual‐emissive polydiphenylsilane nanocomposite: effect of N,N′‐bis(4‐hydroxysalicylidene)‐1,2‐phenylenediamine‐Zn complex

Abstract

The fluorescence properties of polysilane can be strongly influenced by creating new excited states that involve electronic transitions and the relaxation to the ground state. This work presents the optical effects obtained by doping a specially designed polydiphenylsilane copolymer with Zn complex of N,N′-bis(4-hydroxysalicylidene)-1,2-phenylenediamine. The nanocomposites have been prepared in solution by mixing the polymer with low amounts of Zn-salophen and using tetrahydrofuran as solvent. The ultraviolet-visible spectrum has shown the occurrence of an intermolecular charge transfer between polysilane and the metal complex. Photoluminescence studies have revealed an interesting dual emission profile of nanocomposite. The origin of this phenomenon has been evidenced by molecular modeling and simulation of the electronic transitions. The modeling results have unveiled a new low-lying excited state due to intermolecular interactions. The thin films of nanocomposites have been drop-casted from solutions. The obtained films have been studied by Transmission Electron Microscopy (TEM)-Scanning Transmission Electron Microscopy (STEM)-Energy Dispersive X-ray analysis (EDX) to gain information on the film-forming capacity and surface morphology. The results have revealed a high potential of such materials for fluorescence sensing applications.

Cobalt Ferrite Particles Produced by Sol-Gel Autocombustion and Embedded in Polysilane: An Innovative Route to Magnetically-Induced Fluorescence Composites

“…It should be noticed that typically the first excited states in polysilanes are attributed to σ → σ* electronic transition owing to σ -electronic systems in the Si–Si backbone chain. In the experimental UV–Vis spectra of the polysilanes solution, these σ → σ* electronic transitions normally appear in the region of 300–400 nm, due to the long conjugated Si–Si chains [ 52 ]. In the theoretical UV-Vis spectra, the σ → σ* electronic transitions might appear below 300 nm due to the fact that much shorter Si–Si chains are subjected to the modeling procedure.…”