Binuclear Gadolinium(III) Pivalates with 4,7-Diphenyl-1,10-Phenanthroline: Synthesis, Structure, Thermal Behavior, Magnetic and Photoluminescence Properties

Complexes [Gd-2(piv)(6)(bath)(2)].2EtOH (1a.2EtOH), [Gd-2(piv)(6)(bath)(2)].1.5EtOH.0.5H(2)O (1b.1.5EtOH.0.5H(2)O), and [Gd-2(piv)(6)(bath)(2)].H2O (1c.H2O), where piv is (CH3)(3)CCO2- and bath is 4,7-diphenyl-1,10-phenanthroline, which have different molecular and crystal structures, were synthesized and studied by X-ray diffraction. A unique feature of polymorphs 1a, 1b, and 1c is that they exhibit first-order phase transitions, namely, structural phase transitions, or melting before thermal decomposition. Magneto-structural data for binuclear gadolinium pivalates with bath (1), bpy (2), phen (3), and Hpiv (4) ligands and the polymeric complex [Gd(piv)(3)](n) (5) are presented. The complexes were characterized by ESR spectroscopy. The energies of the excited singlet S-1 and triplet T-1 states of the bath ligand in carboxylates 1a.2EtOH, 1b.1.5EtOH.0.5H(2)O, and 1c.H2O were determined.

Automated summary

The synthesis and study of three gadolinium pivalate complexes with different molecular and crystal structures were conducted, revealing first-order phase transitions or melting behavior before thermal decomposition. Magneto-structural data and the energies of excited states of ligands were also determined and characterized using ESR spectroscopy.