Optical properties of binuclear zinc (II) macrocyclic complexes derived from 4-methyl-2,6-diformylphenol and 1,2-diaminobenzene

In this work, we present the synthesis and optical study of the binuclear zinc(II) macrocyclic complexes, derived from 4-methyl-2,6-diformylphenol and 1,2-diaminobenzene (H2L). Two zinc macrocyclic complexes with different anions were prepared and characterized: [Zn2LCl2]·H2O (1) and [Zn2L](NO3)2 (2).The complexes are emissive, both in the solid state and in solution at room temperature. Spectroscopic properties of the macrocyclic complexes were investigated using stationary and time resolved methods in solutions of dimethylsulfoxide (DMSO), and in solid state. DMSO solutions show two emission bands centered at 480 and 521 nm for complex (1), and at 527 nm with a shoulder at 480 nm for (2). The emission spectra of these compounds in solid state show a red shifted band, presenting the maxima at 565 nm for (1) and 575 nm for (2). The emission lifetimes for these compounds are very short, viz. 650 and 480 ps for macrocycles (1) and (2), respectively.

Graphical abstractDMSO solutions of [Zn2LCl2]·H2O (1) and [Zn2L](NO3)2 (2) show emission bands centred at 480 and 521 nm for (1), and at 527 and 480 nm for (2). The emission spectra in the solid state show a red shifted band at 565 nm (1), and 575 nm (2), respectively.Figure optionsDownload full-size imageDownload as PowerPoint slide