One-dimensional Zn(II) oligo(phenyleneethynylene)dicarboxylate coordination polymers

Synthesis, crystal structures, thermal and photoluminescent properties

authored by: Andreas Schaate, Miriam Schulte, Michael Wiebcke, Adelheid Godt, Peter Behrens
Abstract: The rigid, π-conjugated dicarboxylic acid 1,4-bis-[2-(4-carboxyphenyl)ethynyl]-2,5-dihexylbenzene {HO₂C[PEP(hexyl)₂EP]CO₂H} has been used to synthesise the new crystalline coordination polymers {Zn(O₂C[PEP(hexyl)₂EP]CO₂)(DMF)₂} (1) and {Zn(O₂C[PEP(hexyl)₂EP]CO₂)(DEF)₂} (2) in N,N-dimethylformamide (DMF) and N,N-diethylformamide (DEF), respectively, under mild conditions. Single-crystal X-ray crystallography revealed that 1 and 2 are isostructural and consist of uncharged zigzag coordination chains in which [Zn(formamide)₂]²⁺ fragments are bridged by (O₂C[PEP(hexyl)₂EP]CO₂)^2- ligands. The zigzag chains possess different intra-chain Zn⋯Zn⋯Zn angles due to the different volumes of the coordinating formamide molecules and subtle differences in the hydrophobic inter-chain interactions. Upon heating 1 and 2 to 200 °C, removal of the coordinating formamide molecules occurs, yielding the formamide-free compounds 1-DMF and 2-DEF of composition {Zn(O₂C[PEP(hexyl)₂EP]CO₂)}. According to powder X-ray diffraction and FT-IR spectroscopy studies, these materials are not crystalline but still possess partial ordering of intact, yet modified coordination chains in a structural arrangement which appears to be related to the respective parent compounds. Compounds 1, 2, 1-DMF and 2-DEF exhibit blue photoluminescence. The emission maxima of 1-DMF and 2-DEF are red-shifted by ca. 25 nm with respect to λ_max of 1 and 2, respectively.
Organisation(s): Institute of Inorganic Chemistry
Center for Solid State Chemistry and New Materials (ZFM)
External Organisation(s): Bielefeld University
Type: Article
Journal: Inorganica chimica acta
Volume: 362
Pages: 3600-3606
No. of pages: 7
ISSN: 0020-1693
Publication date: 10.04.2009
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Physical and Theoretical Chemistry, Inorganic Chemistry, Materials Chemistry
Electronic version(s): https://doi.org/10.1016/j.ica.2009.04.004 (Access: Unknown)

BibTeX

@article{af5bcc55fd3247979f8011e0414646af,
title = "One-dimensional Zn(II) oligo(phenyleneethynylene)dicarboxylate coordination polymers: Synthesis, crystal structures, thermal and photoluminescent properties",
abstract = "The rigid, π-conjugated dicarboxylic acid 1,4-bis-[2-(4-carboxyphenyl)ethynyl]-2,5-dihexylbenzene {HO2C[PEP(hexyl)2EP]CO2H} has been used to synthesise the new crystalline coordination polymers {Zn(O2C[PEP(hexyl)2EP]CO2)(DMF)2} (1) and {Zn(O2C[PEP(hexyl)2EP]CO2)(DEF)2} (2) in N,N-dimethylformamide (DMF) and N,N-diethylformamide (DEF), respectively, under mild conditions. Single-crystal X-ray crystallography revealed that 1 and 2 are isostructural and consist of uncharged zigzag coordination chains in which [Zn(formamide)2]2+ fragments are bridged by (O2C[PEP(hexyl)2EP]CO2)2- ligands. The zigzag chains possess different intra-chain Zn⋯Zn⋯Zn angles due to the different volumes of the coordinating formamide molecules and subtle differences in the hydrophobic inter-chain interactions. Upon heating 1 and 2 to 200 °C, removal of the coordinating formamide molecules occurs, yielding the formamide-free compounds 1-DMF and 2-DEF of composition {Zn(O2C[PEP(hexyl)2EP]CO2)}. According to powder X-ray diffraction and FT-IR spectroscopy studies, these materials are not crystalline but still possess partial ordering of intact, yet modified coordination chains in a structural arrangement which appears to be related to the respective parent compounds. Compounds 1, 2, 1-DMF and 2-DEF exhibit blue photoluminescence. The emission maxima of 1-DMF and 2-DEF are red-shifted by ca. 25 nm with respect to λmax of 1 and 2, respectively.",
keywords = "Coordination polymer, Crystal structure, Oligo(phenyleneethynylene)dicarboxylic acid, Photoluminescence, Zinc",
author = "Andreas Schaate and Miriam Schulte and Michael Wiebcke and Adelheid Godt and Peter Behrens",
year = "2009",
month = apr,
day = "10",
doi = "10.1016/j.ica.2009.04.004",
language = "English",
volume = "362",
pages = "3600--3606",
journal = "Inorganica chimica acta",
issn = "0020-1693",
publisher = "Elsevier BV",
number = "10",
}