Luminescent coordination polymers for the VIS and NIR range constituting LnCl₃ and 1,2-bis(4-pyridyl)ethane

A series of 14 lanthanide containing coordination polymers LnCl3 with 1,2-bis(4-pyridyl)ethane (bpe) was synthesized from either thiazole or pyridine. Depending on the ligand content, a structural diversity from 3D-frameworks [LnCl3(bpe)2]·thz, Ln = Ce-Lu, to 1D-strands [La2Cl6(bpe)2(thz)6] and [LnCl3(bpe)(py)2]·(bpe/py), Ln = Gd, Er, was obtained and characterized by X-ray single crystal diffraction, powder diffraction, differential thermal analysis and thermogravimetry (DTA/TG), IR-spectroscopy and photoluminescence spectroscopy. The compounds exhibit a variety of luminescence properties and different phenomena. This includes ligand centred fluorescence, metal-centred 5d-4f/4f-4f emission in the visible and the NIR range, antenna effects via Dexter and Förster energy transfer mechanisms, excitation dependent emission with a correlating shift of the chromaticity coordinates and inner filter effects by combined re-absorption/emission.