Near Infrared Luminescence and Supramolecular Structure of a Helical Triple-Decker Yb(III) Schiff Base Cluster

The triple-decker complex [Yb3L3(OAc)2Cl](H2O)3(CH3OH)1.5(CH3CN)0.5 (1) is formed from the reaction of H2L,
YbCl3·6H2O, and Zn(OAc)2·2H2O in 25% yield (H2L = N,N‘-bis(5-bromo-3-methoxysalicylidene)phenylene-1,2-diamine). The single-crystal X-ray structure of 1 revealed the presence of two independent, chiral molecules of 1 in the asymmetric unit. Intermolecular
π−π stacking and C−H···π interactions between both sets of Yb3L3 units create two one-dimensional strands, A and B. Strands of
A are cross-linked via Br···H−C hydrogen bonds creating a three-dimensional network that encloses the B strands. Near-infrared
(NIR) lanthanide luminescence in both the solid state and the solution is observed in 1.