Modulation of the luminescence quantum efficiency for blue luminophor {Al(salophen)}+ by ester-substituents

Abstract

A series of Al(III) complexes of a salophen (N,N'-bis(salicylidene)-o-phenylenediamine) derivative with an ester substituent at the C5 position of the salicylidene rings have been prepared and their luminescence properties investigated. All exhibit a bright blue emission (lambda(em) = 478 nm) that is observed neither for other metal ions nor with the non-functionalized ligand. Moreover, the ester-R group (Me, (t)Bu, Ph) was found to significantly affect the quantum yields (varphi = 12 to 20%) of the luminophor. DFT calculations have been undertaken to reveal the influence of the ester and its R-group on the frontier molecular orbitals. Preparation and photoluminescence properties in solution and solid state are reported. The crystal structure of a pyridine oxide adduct [L(tBu)Al(PyO)(2)].NO(3), where L(tBu) stands for the tButyl-ester functionalized Schiff base, has been solved.

Functional Hybrid Materials Based on Layered Simple Hydroxide Hosts and Dicarboxylate Schiff Base Metal Complex Guests

“…[48] In the hybrid structures, the luminescence was apparently quenched as a result of absorption by the inorganic layers. [48] In the hybrid structures, the luminescence was apparently quenched as a result of absorption by the inorganic layers.…”

“…[48] In a 500 mL flask, p-hydroxybenzoic acid (15 g, 108 mmol) was added to trifluoroacetic acid (40 mL) to form a suspension. [48] In a 500 mL flask, p-hydroxybenzoic acid (15 g, 108 mmol) was added to trifluoroacetic acid (40 mL) to form a suspension.…”

Supramolecular control over recognition and efficient detection of picric acid

“…10 The luminescence quantum yields found for 1 (F = 0.67) and 2 (F = 0.56) are among the highest known for this class of materials. 7b, 10,11 They are also significantly higher than that found for 3 (F = 0.20), as anticipated for the ester-functionalized ligands. The higher efficiency obtained for 1 is ascribed to the aromaticity in the ester group, which has been shown to improve the efficiency of the molecule to re-emit the absorbed photons.…”

Investigation of VO–salophen complexes electronic structure

“…Recently, Schiff base derivatives are emerging as tunable and adaptable chromophore ligands to such an extent that they are tested, for example, as luminescent labeling agent [13], as materials for OLED (organic-light-emitting-diode) technology [14], as probes for cell imaging systems [15]. In this field, the possibility to modulate the ligand substitution is a powerful tool to tune the light absorption and emission behavior of the metal complex [16].…”