A series of new lanthanide complexes with 2 ‐bromo‐5‐methoxybenzoic acid and 5,5′‐dimethyl‐2,2′‐bipyridine: Crystal structures, thermal behavior, luminescent and magnetic properties

Complexes1–3 are isostructural and each metal center is nine ‐coordinated, while complex4 is eight ‐coordinated exhibiting a different structure. All binuclear units are assembled into 1D, 2D and 3D supramolecular structures via π–π stacking and hydrogen bonding interactions. The luminescent properties were studied, and the lifetime of complex2 is 0.693 ms. Four new binuclear lanthanide complexes [Ln(2 ‐Br‐5‐MOBA)3(5,5 ′‐DM‐2,2′‐bipy)]2 (Ln  = Gd(1), Tb(2), Dy(3), Er(4); 2 ‐Br‐5‐MOBA = 2‐bromo‐5‐methoxybenzoate; 5,5′‐DM‐2,2′‐bipy = 5,5′‐dimethyl‐2,2′‐bipyridine) have been successfully synthesized and then further characterized by infrared spectra, single‐crystal X‐ray diffraction, elemental analyses and Powder X‐ray diffractio n (PXRD). Complexes1 –3 are isostructure with the coordination number of nine, while the complex4 is eight ‐coordinated exhibiting a different structure. Nevertheless, the complexes1 –4 form the same 1D, 2D and 3D supramolecular structures by hydrogen bonding (C ‐H···Br and C‐H···O) and π–π stacking interactions. Thermal behavior of complexes1 –4 was studied by TG/DSC ‐FTIR techniques. The luminescent spectra of complexes2 and3 were investigated at room temperature, which exhibits characteristic luminescence of Tb3+ and Dy3+ ions, respectively. The luminescence decay curve of the complex2 was measured, which follows double ‐exponential decay law. The luminesc...

Source: Applied Organometallic Chemistry - October 23, 2018 Category: Chemistry Authors: Wu Xiao ‐Hui, Ren Ning, Zhang Jian‐Jun Tags: FULL PAPER Source Type: research