Emission and theoretical studies of Schiff-base [2+2] macrocycles derived from 2,2′-oxydianiline and zinc complexes thereof

Kuiyuan Wang, Kai Chen, Tiezheng Bian, Yimin Chao, Takehiko Yamato, Feng Xing, Timothy J. Prior, Carl Redshaw

Research output: Contribution to journalArticle

Abstract

The emission properties of a number of solvates of the [2 + 2] Schiff-base macrocycles {[2-(OH)-5-(R)–C 6H 2–1,3-(CH) 2][O(2-C 6H 4N) 2]} 2 (Me L 1H 2, tBu L 2H 2, Cl L 3H 2), formed by reacting 2,6-dicarboxy-4-R-phenol with 2,2′-oxydianiline (2-aminophenylether), (2-NH 2C 6H 4) 2O, have been investigated. Macrocycles L 1−3H 2 exhibited different maximum emission wavelengths in different solvents, from λ max at 508 nm (in acetonitrile) to 585 nm (in dichloromethane). DFT studies on systems L 1−3H 2 involving solvents of different polarity (DMF versus n-hexane) indicated that the energy level gap increases with solvent polarity in line with the observed hypochromic shifts. Reaction of macrocycle L 1H 2 with three equivalents of ZnBr 2, in the presence of Et 3N, affords the complex [(ZnBr)(ZnNCMe)L 1] 2[ZnBr 4]·2.5MeCN (1·2.5MeCN). In the case of L 2H 2, reaction with two equivalents of ZnBr 2 affords [(ZnBr)L 2H 2][ZnBr 3NCMe]·3MeCN (2·3MeCN), whilst in the presence of two equivalents of Et 3N, work-up led to the isolation of the complex [(ZnBr) 2L 2]·4.5MeCN (3·4.5MeCN). The molecular structures of 1, 2 and 3 are reported, together with their emission behaviour.

Original languageEnglish
Article number109300
JournalDyes and Pigments
Volume190
Early online date18 Mar 2021
DOIs
Publication statusPublished - Jun 2021

Keywords

  • DFT studies
  • Emission
  • Macrocycle
  • Schiff-base
  • Solvents

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