Heterometallic, Hybrid, Heavy Main‐Group Iodometallates Containing Lanthanide Complexes: Template Synthesis, Structures, Thermal, Optical, Luminescent and Magnetic Properties

Abstract

Abstract Using [Ln(L) 8 ] 3+ [Ln = Tb, Y; L = dimethyl sulfoxide (DMSO), N , N ‐dimethylformamide (DMF)] cations as templating reagents, the syntheses and crystal structures of the following new metal organic–inorganic hybrid complexes based on either discrete clusters or 1D chains of an iodoplumbate or‐bismuthate moiety are reported: [Tb(DMSO) 8 ] 2 [(DMSO) 2 Pb 5 I 16 ] ( 1 ), [Tb(DMF) 8 ][Pb 3 I 9 ] 1∞ · DMF ( 2 ) and [Ln(DMF) 8 ][Bi 2 I 9 ] [Ln = Y ( 3 ), Tb ( 4 )]. These derivatives were characterized by thermogravimetric analysis (TGA), diffuse‐reflectance spectroscopy, luminescence spectroscopy and magnetic studies. TGA studies show that the thermal stability of these complexes decreases in the order 2 > 3 ≈ 4 > 1 . An optical band‐gap in the range 1.90–2.15 eV in the diffuse‐reflectance spectra of 1 – 4 indicate their potential use as semiconductors, 3 and 4 being the most promising because of their low band gap values. Compared to the precursors [Tb(DMSO) 8 ]I 3 and [Tb(DMF) 8 ]I 3 , the high energy transitions in the excitation spectra of 1 , 2 and 4 are quenched by a process that is best attributed to the autoionization of the carriers in the material. The temperature dependence of the magnetic susceptibilities of 1 , 2 and 4 was reproduced well by a Curie–Weiss plot at 2–300 K.