Wydział Chemii

C. Seidel

Chantal Lorbeer

Joanna Cybińska

Anja Verena Mudring

U. Ruschewitz

2012

Inorganic Chemistry

51

4679-4688

10.1021/ic202655d

Naukowa

Angielski

Artykuł

By slow diffusion of triethylamine into a solution of 2,3,5,6-tetrafluoroterephthalic acid (H₂tfBDC) and the respective lanthanide salt in EtOH/DMF single crystals of seven nonporous coordination polymers, _∞²[Ln(tfBDC)(NO₃)(DMF)₂]·DMF (Ln³⁺ = Ce, Pr, Nd, Sm, Dy, Er, Yb; C2/c, Z = 8) have been obtained. In the crystal structures, two-dimensional square grids are found, which are composed of binuclear lanthanide nodes connected by tfBDC^2– as a linking ligand. The coordination sphere of each lanthanide cation is completed by a nitrate anion and two DMF molecules (CN = 9). This crystal structure is unprecedented in the crystal chemistry of coordination polymers based on nonfluorinated terephthalate (BDC^2–) as a bridging ligand; as for tfBDC^2–, a nonplanar conformation of the ligand is energetically more favorable, whereas for BDC^2–, a planar conformation is preferred. Differential thermal analysis/thermogravimetric analysis (DTA/TGA) investigations reveal that the noncoordinating DMF molecule is released first at temperatures of 100–200 °C. Subsequent endothermal weight losses correspond to the release of the coordinating DMF molecules. Between 350 and 400 °C, a strong exothermal weight loss is found, which is probably due to a decomposition of the tfBDC^2– ligand. The residues could not be identified. The emission spectra of the _∞²[Ln(tfBDC)(NO₃)(DMF)₂]·DMF compounds reveal intense emission in the visible region of light for Pr, Sm, and Dy with colors from orange, orange-red, to warm white.

https://doi.org/10.1021/ic202655d

https://www.acs.org/content/acs/en.html