A new series of 3D lanthanide phenoxycarboxylates: synthesis, crystal structure, magnetism and photoluminescence studies

• Type: Article in International Scientific Journal
• Date: 2021

Authors

Sen, R (Author) Other; Paul, S (Author) Other; Sarkar, A (Author) Other; Botas, AMP (Author) Other; Neto, ACN (Author) Other; Brandao, P (Author) Other; Lopes, AML (Author) FCUP; Ferreira, RAS (Author) Other; araujo, j. p. (Author) FCUP; Lin, Z (Author) Other

Journal

Title: CrystEngComm

Vol. 227

Pages: 4143-4151

ISSN: 1466-8033

Publisher: Royal Society of Chemistry

Indexing

ISI Web of Knowledge - 14 Citations

Other information

Authenticus ID: P-00T-Z93

DOI: 10.1039/d1ce00228g

Abstract (EN): A new series of 3D lanthanide (Ln) frameworks has been synthesized with the general formula [{Ln(L)(H2O)}center dot H2O](n) (where Ln = La(1), Tb(2) and Dy(3); L = (HO)OC6H2(CH2COO)(2); H3L = 2,5-dihydroxy-1,4-benzenediacetic acid = DHBDA). All the crystals were analyzed by single crystal X-ray diffraction. The Ln ions are octa-coordinated having the square antiprism geometry with the D-4d symmetry and connected along the crystallographic a-axis forming a zigzag chain. These chains are further connected by the ligands in three-dimensional crystallographic space. Compounds 2 and 3 were subjected to variable temperature magnetic susceptibility measurements and photoluminescence studies. Magnetic studies reveal that compound 2 possesses antiferromagnetic coupling whereas compound 3 shows ferromagnetic interaction at temperatures above ca. 40 K. The emission spectra of compounds 2 and 3 combine the intra-4f emission of the Ln ions with that of the ligand, depending on the selected temperature, pointing out that the energy transfer processes are thermally activated. In addition, compound 2 presented an invariant D-5(4) lifetime behaviour at temperatures between 15 and 300 K. Theoretical analysis showed that the long-lived lifetimes of the free ligand's excited states and the intramolecular energy transfer rate invariability are responsible for such abnormal behaviour.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9