Luminescence Enhancement Induced by Aggregation of Alkoxy-Bridged Rhenium(I) Molecular Rectangles

Abstract

Self-assembly of rhenium(I)-based molecular rectangles containing long alkyl chains has been achieved in one-pot synthesis by solvothermal methods. An enormous enhancement in the emission intensity, quantum yield, and lifetime of the rectangles has been observed when the solvent medium is changed from organic to aqueous. Addition of water favors the aggregation of Re(I) molecular rectangle resulting in the luminescence enhancement, and this phenomenon has been traced out using light scattering techniques.

Synergistic π–π and Pt–Pt interactions in luminescent hybrid inorganic/organic dual columnar liquid crystals

“…Solid materials with aggregation-induced emission or aggregation-induced enhanced emission have been reported. 52 Among them a particularly interesting case is found in a few organometallic complexes of Re I , 53 Pt II , 22,54,55 and Ir III , 56 which show aggregation induced phosphorescence based on weak metallophilic interactions in the solid state. Our compounds are hoped to be related to those but are uncommon because this aggregation-induced emission occurs in a fluid mesophase.…”

MHD Unsteady Flow of a Williamson Nanofluid in a Vertical Porous Space With Oscillating Wall Temperature

“…These fluids are engineered colloidal suspensions of nanoparticles in a base fluid. Previous studies indicate that an enormous enhancement in the emission intensity, quantum yield, and lifetime of the molecular rectangles has been observed when the solvent medium is changed from organic to aqueous (Manimaran et al, 2002;Manimaran et al, 2003). In particular, Alkoxy-bridged rhenium (I) rectangles (1,R = 4 9 C H ; 2, R = 8 17 C H ; 3, R = 12 25 C H ; bpy=4, 4' -bipyridine) comprising long alkyl chains form optically transparent aggregates and exhibit luminescence enhancement in the presence of water.…”

“…Generally, the nanoparticles used in nanofluids are typically made of metals, oxides, carbides, or carbon nanotubes and the base fluids used are usually water, ethylene glycol and oil. Moreover, the study of nanofluid is of growing interest for the observation of enhanced thermal conductivity which may throw light on the urgent cooling problems in engineering, for instance, the cooling of integrated circuits and micro-electromechanical systems (See Lee et al, 1999, Manimaran et al, 2002Manimaran et al, 2003;Xuan and Li, 2003;Buongiorno, 2006;Thanasekaran, et al, 2007, Marga et al, 2005Kakac, Pramuanjaroenkij, 2009). Vajravelu et al (2011) presented the detailed analysis of convective heat transfer in the flow of viscous Agwater and Cu-water nanofluids over a stretching surface.…”

Multisubstituted Olefins: Platform Synthesis and Applications to Materials Science and Pharmaceutical Chemistry

“…If this is the case, aggregation (solidification) should lead to a reduction in the probability and amplitude of molecular motions such as twisting and out-of-plane bending motion, which might trigger radiationless transitions, thereby enhancing the fluorescence efficiency as a whole. Such an aggregation-induced enhanced emission [35][36][37][38][39][40][41][42][43] was also found during the measurements of the photophysical properties of arylethene-based -systems in dioxane/water mixtures. The following example of 14e is typical (Fig.…”

“…26). 18,[35][36][37][38][39][40][41][42][43] For example, as well as highly fluorescent 14, otherwise nonfluorescent -systems such as 15 and 16 also became fluorescent in the solid state. The max values of the solid-state emission were found to be similar to those obtained in chloroform solution.…”