Near-Infrared Lanthanide-Based Emission from Fused Bis[Ln(III)/Zn(II) 14-metallacrown-5] Coordination Compounds

Inorg Chem. 2022 Apr 18;61(15):5691-5695. doi: 10.1021/acs.inorgchem.2c00084. Epub 2022 Apr 4.

Abstract

A set of (Ln[14-MCZn(II)N(quinHA)-5])2Ln2Zn2(quinHA)2(ph)2(Hph)4(OH)8(H2O)4 metallacrowns (Ln-1, Ln = Tb, Gd, or Yb; H2quinHA = quinaldic hydroxamic acid, H2ph = phthalic acid) have been synthesized via solution-state self-assembly. The metallacrowns possess an uncommon topology within the metallacrown family where two rarely seen 14-metallacrown-5 moieties are fused by a Yb2Zn2(quinHA)2 bridge. Moreover, Yb-1 analyzed in the solid state exhibits a characteristic near-infrared luminescence signal arising from Yb3+ 2F5/22F7/2 transition despite the proximity of high energy O-H oscillators.