Synthesis, crystal structures and, magnetic and photoluminescence properties of lanthanide-based metal-organic frameworks constructed with 2,5-dihydroxybenzene-1,4-dicarboxylic acid

• Published in: RSC advances 2020-03, Vol.1 (22), p.12841-1285
• Main Authors: Hussain, Sajjad, Chen, Xuenian, Harrison, William T. A, Ahmad, Saeed, Sharif, Shahzad, Su, Jian, Muhammad, Shabbir, Li, Shujun
• Format: Article
• Language: English
• Subjects: Antiferromagnetism; Cerium; Chemical analysis; Chemical bonds; Chemistry; Chloride ions; Coordination polymers; Coupling (molecular); Crystal structure; Crystallography; Dicarboxylic acids; Differential scanning calorimetry; Ethanol; Fluorescence; Gadolinium; Hydrogen bonds; Infrared analysis; Infrared spectroscopy; Ligands; Magnetic materials; Magnetic properties; Photoluminescence; Single crystals; Spectrum analysis; Structural analysis; Thermogravimetric analysis
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d0ra01294g

Four new lanthanide( iii ) coordination polymers ( 1-4 ) have been synthesized by using 2,5-dihydroxybenzene-1,4-dicarboxylate (Dhbdc, C 8 H 6 O 6 2− ) as a ligand and characterized by elemental analysis, infrared spectroscopy, TGA-DSC (Thermogravimetric Analysis-Differential Scanning Calorimetry) and single crystal X-ray diffraction studies. The isolated complexes include; [Ce(Dhbdc)(H 2 O) 3 Cl] n ( 1 ) and [Ln(Dhbdc) 1.5 (H 2 O) 2 ] n ·3 n (C 2 H 6 O)· n H 2 O [Ln = Eu ( 2 ), Gd ( 3 ) and Tb ( 4 )]. The structural analysis reveals that compound 1 is a two-dimensional polymer in which the cerium atoms are coordinated by six oxygen and two bridging chloride ions adopting a dodecahedral geometry. The compounds 2-4 are isomorphous and their extended structures consist of three-dimensional supramolecular frameworks encapsulating [001] channels occupied by the guest water and ethanol molecules. The metal atoms in 2-4 exhibit a square antiprism geometry. All these compounds have O-H O hydrogen bonds originating from the coordinated water and solvent molecules that help to consolidate the structures. The compounds 1 , 3 and 4 were investigated for magnetic properties and they exhibited weak antiferromagnetic coupling interactions between the lanthanides as per the Curie Weiss law. Anisotropic nature of 3 and 4 has been depicted as per magnetization versus field plots. Complex 4 behaves as a soft magnetic material as compared to 3 . The luminescence studies indicate that compounds 2 , 3 and 4 show ligand-centred fluorescence, which is significantly enhanced in the case of 4 . Four new lanthanide( iii ) coordination polymers ( 1-4 ) have been synthesized by using 2,5-dihydroxybenzene-1,4-dicarboxylate as a ligand and investigated for magnetic and photo-luminescence properties.