A new series of lanthanide-based complexes with a bis(hydroxy)benzoxaborolone ligand: synthesis, crystal structure, and magnetic and optical properties

摘要

Reactions, under hydrothermal conditions, between lanthanide chlorides and the sodium salt of 2-carboxyphenylboronic acid lead to a series of lanthanide-based complexes with general chemical formula [Ln(2)(C7H5O2)(4)(C7O4H6B)(2)4H(2)O] with Ln = Eu-Dy. During the synthetic process, the 2-carboxyphenylboronate ligand decomposes leading to benzoate (C7H5O2) and bis(hydroxy)benzoxaborolone (C7O2H6B). The crystal structure was solved on the basis of the Tb-derivative. It crystalizes in the triclinic system, space group P1 (n degrees 2) with a = 9.3329(13) angstrom, b = 16.012(2) angstrom, c = 16.212(2) angstrom, alpha = 107.789(5)degrees, beta = 90.226(5)degrees, gamma = 97.585(5)degrees, V = 2284.16(52) angstrom(3) and Z = 2. Its crystal structure can be described on the basis of di-lanthanides entities surrounded by ligands. Compounds that constitute this series are thermally stable up to 190 degrees C. Solid-state luminescence properties have been studied in detail. The magnetic properties of the Dy-derivative have also been explored. It exhibits single molecule magnet behavior. Single crystals of the sodium salt of 2-carboxyphenylboronic acid with chemical formula [Na(C7O4H6B)(H2O)](infinity) have also been obtained during this study. This compound crystallizes in the orthorhombic system, space group P2(1)2(1)2(1) (n degrees 19) with a = 4.5881(13) angstrom, b = 6.5905(16) angstrom, c = 29.644(8) angstrom, V = 897.0(4) angstrom(3) and Z = 4. Its crystal structure is 2D and can be described as zigzag chains of sodium 2-carboxyphenylboronate bound to each other by coordination water molecules.