Publication
Mesomorphism and luminescence in coordination compounds and ionic salts based on pyridine-functionalized β-diketones. Influence of the pyridine nitrogen position
| Summary: | Pyridine-functionalized β-diketones with the pyridine nitrogen atom at 3 or 4 position (L3N and L4N, respectively) have been used as building blocks to obtain two new families of compounds with mesomorphic and luminescent behaviors. The N-pyridine coordination of the β-diketones to zinc(II), palladium(II) and platinum(II) metal centers has allowed to synthesize neutral coordination compounds of the type [MCl2(LZN)2] (M = Zn(II), Pd(II), Pt(II); Z = 3, 4). Particularly, coordination of L4N towards Pt(II) gives rise to the cationic species [Pt(NH3)2(L4N)2]2+. Otherwise, protonation of the pyridine moiety was strategically used to obtain a novel series of pyridinium ionic salts of the type (HLZN)nA (n = 1, A = Cl; n = 2, A = MCl4, M = Zn(II), Pd(II), Pt(II); Z = 3, 4). The neutral or ionic nature of the complexes, as well as the β-diketone ligands and the metal center in both the neutral and anionic complexes, has a great influence on the mesomorphic behavior. Thus, columnar or smectic mesophases can be selectively formed. Single-crystal and temperature-dependent powder X-ray diffraction studies have been performed to analyze the molecular packing in the crystal and the supramolecular ordering in the mesophase. All the aforementioned factors also play a key role on the luminescence properties, the Zn(II) coordination compounds and ionic salts being the best candidates as bifunctional materials. |
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| Main Authors: | Martínez-Ceberio, Carlos |
| Other Authors: | Carmen Torralba, M.; Duarte, Frederico; Herrero, Santiago; Cano, Mercedes; Lodeiro, Carlos; Cuerva, Cristián |
| Subject: | Diketones Ionic salts Liquid crystals Luminescence Metallomesogens Electronic, Optical and Magnetic Materials Atomic and Molecular Physics, and Optics Condensed Matter Physics Spectroscopy Physical and Theoretical Chemistry Materials Chemistry |
| Year: | 2023 |
| Country: | Portugal |
| Document type: | article |
| Access type: | open access |
| Associated institution: | Universidade Nova de Lisboa |
| Language: | English |
| Origin: | Repositório Institucional da UNL |
| Summary: | Pyridine-functionalized β-diketones with the pyridine nitrogen atom at 3 or 4 position (L3N and L4N, respectively) have been used as building blocks to obtain two new families of compounds with mesomorphic and luminescent behaviors. The N-pyridine coordination of the β-diketones to zinc(II), palladium(II) and platinum(II) metal centers has allowed to synthesize neutral coordination compounds of the type [MCl2(LZN)2] (M = Zn(II), Pd(II), Pt(II); Z = 3, 4). Particularly, coordination of L4N towards Pt(II) gives rise to the cationic species [Pt(NH3)2(L4N)2]2+. Otherwise, protonation of the pyridine moiety was strategically used to obtain a novel series of pyridinium ionic salts of the type (HLZN)nA (n = 1, A = Cl; n = 2, A = MCl4, M = Zn(II), Pd(II), Pt(II); Z = 3, 4). The neutral or ionic nature of the complexes, as well as the β-diketone ligands and the metal center in both the neutral and anionic complexes, has a great influence on the mesomorphic behavior. Thus, columnar or smectic mesophases can be selectively formed. Single-crystal and temperature-dependent powder X-ray diffraction studies have been performed to analyze the molecular packing in the crystal and the supramolecular ordering in the mesophase. All the aforementioned factors also play a key role on the luminescence properties, the Zn(II) coordination compounds and ionic salts being the best candidates as bifunctional materials. |
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