Synthesis, molecular structure and emission properties of benzoato-bridged lanthanide complexes with hydrotris(pyrazolyl)borate

Abstract

Reaction of GdCl3 and TbCl3 with one equivalent of the potassium salt of the tridentate ligand hydrotris(pyrazol-1- yl)borate [K(tp)] and two equivalents of sodium p-X-benzoate (X = H, Cl, Br and NO2) yielded the complexes 1-6 of composition [(tp)Ln(mu-p-X-OBz)(2)}(2)] (Ln = Gd, Tb) whereas the reaction of TbCl3 with 2 equivalents of [K(tp)] and one equivalent of sodium azide, gave the tetranuclear complex [{tp)(2)Tb(mu-N- 3)}(4)] (7). The crystal structures of the benzoate complexes (X = H) of Gd (1) and Tb (2) and their analogous p-Cl-benzoate derivatives with Gd (3) and Tb (4) have been determined. The compounds consist of a seven-coordinate tetrakis carboxylato bridged dimetal unit with two capping hydrotris(pyrazolyl)borate ligands. Unit cell determinations suggested that [{tp)Tb(mu-p-Cl-OBZ)(2)}(2)] (5), and [{(tp)Tb(mu-p-NO2-OBz)(2)}(2)] (6), are isostructural with (3) and (4). Single crystal X-Ray analysis of (7) revealed its tetranuclear structure comprising a cyclic 16-membered Tb-4(mu- N-3)(4)-unit with two hydrotris(pyrazol-1-yl)borate ligands bound to each of the terbium ions resulting in a tetragonal antiprismatic N-8-coordination sphere. The luminescence properties of the unsubstituted and para-substituted Gd and Tb benzoate complexes have been studied in solution at room temperature

Octaammine EuII and YbII Azides and Their Thermal Decompositions to the Nitrides

“…Bulky ligands on lanthanoid atoms have been frequently employed to lend lanthanoid azides more stability towards mechanical shock or temperature changes, and also to increase the solubility in organic and unipolar solvents. Targets of these works are the preparation of phosphors or of molecular nitrides of the lanthanoids, which still seem to be elusive …”

Di-μ-benzoato-κ3O,O′:O′;κ3O:O,O′-bis[aquabis(benzoato-κ2O,O′)(dimethylformamide-κO)europium(III)]

“…For properties of rare earth compounds derived from carboxylic acids, see: Chin et al (1994); Singh et al (2002). For related compounds, see: Jin et al (1996); Gubina et al (2000); Wang et al (2003); Qiu et al (2007); Ooi et al (2010).…”

“…Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL97. Because of their excellent luminescent properties (Chin et al, 1994;Singh et al, 2002), rare earth-carboxylic acid complexes have been widely studied and applied in many fields. Distinct structure features with various rare earths (Qiu et al, 2007;Gubina et al, 2000) or ligands (Jin et al, 1996;Wang et al, 2003) have been reported.…”

Synthesis, X-ray structures and NIR chiroptical properties of a series of dinuclear lanthanide(iii) complexes [Ln2{μ-(S- or RS-pba)}4(HBpz3)2]; novel configurational chirality due to non-bonding Ln⋯O interactions

“…5b Over the last 15 years, dinuclear Ln-Ln complexes with bridging carboxylate type ligands have been studied from different view points. [6][7][8][9][10] The latest study on the benzoate bridged Ln() complexes focused on the synthesis, X-ray structures and emission properties, but the targeted lanthanide ions were limited to only three Gd and Tb complexes. 10 Though the metal-metal interactions and chiroptical properties for the tetracarboxylate bridged dinuclear transition metal complexes of the type, M 2 (O 2 CR) 4 L 2 have been studied (showing only vicinal chirality due to optically active RCO 2 ) for a few decades, 11 there are no systematic chiroptical studies on this type of Ln 2 (O 2 CR) 4 L 2 complexes with configurational chirality.…”