Energy Transfer between CNT Surface and −Re(CO)₃(phen)⁺* Pendants Grafted to P4VP in Nanohybrid Shish-Kebob-like Structures

Abstract

The adsorption of a Re­(CO)3(phen)-poly­(4-vinylpyridine) polymer, RePVP, on multiwall carbon nanotubes surfaces is studied by transmission electron microscopy and absorption spectroscopy in combination with chemometric techniques in MeOH/H2O solvent mixture. Nanohybrid structures like a shish-kebab (NHSK) are observed by TEM when RePVP is wrapped around carbon nanotubes (CNTs) surfaces. The association between RePVP and CNTs studied by absorption spectroscopy suggests the coexistence of CNTs with a high or low content of adsorbed RePVP on their surface. In the absence of CNTs, the photophysical properties of RePVP (i.e., luminescence quantum yield, ΦL, and amplitude-weighted average lifetimes, ⟨τ⟩) are strongly dependent on the morphology of the polymer as witnessed by the dependence of ΦL on the concentration of RePVP (C RePVP) and the fact that in CH3CN ΦL and ⟨τ⟩ are sensitive to O2 while in a MeOH/H2O solvent mixture they are not. In the NHSK, an energy-transfer process between excited −[Re­(CO)3(phen)]+* pendent chromophores and the CNTs surface, with static and dynamic components, is responsible for the quenching of the RePVP luminescence by CNTs.

The effect of water in THF/water mixtures on CMC, aggregation sizes, and fluorescence quenching of a new calix[4]resorcinarene macrocycle

“…The indexes i , n , and j denote the samples, absorbing factors, and recorded wavelengths, respectively. 41 To perform the MCR-ALS analysis, we took into account the non-negative absorption spectra and non-negative concentration constraints. It was necessary to consider three independent factors ( n = 3) to accurately replicate all of the experimental data.…”

Superparamagnetic Nanoparticles with Phosphorescent Complexes as Hybrid Contrast Agents: Integration of MRI and PLIM

“…In addition, such triplet emitters can also be implemented as oxygen sensors, as their excited-state lifetime and luminescence intensity are quenched by diffusion-controlled Dexter-like energy transfer to triplet molecular dioxygen ( 3 O 2 ); in turn, singlet oxygen can be photogenerated, which is used in photodynamic therapy. Recently, we have shown that both PtCx [34,35,38] and Re(I) [39] complex can potentially perform as oxygen sensors and luminescent labels for biomedical applications.…”