Pan-Pan Shen

A series of lanthanide complexes with different N-donor ligands: synthesis, structures, thermal properties and luminescence behaviors

Four novel lanthanide complexes, [Ln(2,4-DClBA)3(terpy)(H2O)]·H2O (Ln = Eu(1), Tb(2)); [Ln(2,4-DClBA)3(5,5′-DM-2,2′-bipy)(C2H5OH)]2 (Ln = Eu(3), Tb(4); 2,4-DClBA: 2,4-dichlorobenzoate; terpy: 2,2′:6′,2′′-terpyridine; 5,5′-DM-2,2′-bipy: 5,5′-dimethyl-2,2′-bipyridine) have been synthesized via a conventional solution method at room temperature and structurally characterized by single crystal and powder X-ray diffraction. Complexes 1–2 exhibit mononuclear lanthanide architectures and each Ln3+ ion is nine-coordinated adopting a distorted monocapped square antiprismatic molecular geometry, while complexes 3–4 exhibit binuclear lanthanide architectures in which each Ln3+ ion is eight-coordinated adopting a distorted square antiprismatic molecular geometry. Mononuclear complexes 1–2 are stitched together via Cl–π and hydrogen bonding interactions to form the 1D, 2D, 3D supramolecular structures. While complexes 3–4 are packed together through Cl–Cl, π–π, and hydrogen bonding interactions to form 1D, 2D supramolecular structures. Luminescence investigation reveals that complexes 1, 3 and 2, 4 display strong red and green emission respectively, showing that terpy and 5,5′-DM-2,2′-bipy can act as sensitizing chromophores, but the former is more effective. The IR, TG-DTG, and the heat capacities of complexes 1–4 were also measured.

Rare earth compounds with 3-methoxybenzoic acid and terpyridine ligands: Structures, thermal and spectroscopic properties

Two trivalent rare earth compounds [Ln(3-MOBA)3(terpy)(H2O)]2 (Ln = Tb (1), Eu (2); 3-MOBA = 3-methoxybenzoate, terpy = 2,2′:6′,2″-terpyridine) were obtained in solid state, and the structure of 1 was determined by X-ray diffraction. The analysis of characterization was performed by elemental analysis, IR spectra, X-ray powder diffraction, thermogravimetric and differential scanning calorimetry coupled to infrared spectrometer (TG/DSC–FTIR). Besides that the luminescent properties and antibacterial activities were discussed. The crystal structure of 1 revealed that the asymmetric units were further stitched together to form 1D chain along the x-axis direction through the offset face-to-face π···π weak stacking interactions. Luminescence investigation revealed that compounds exhibited strong green and red emissions and the fluorescence quantum yield of two compounds were measured. What’s more, the Commission Internationale de L’Eclairage chromaticity diagrams were presented. The antibacterial activity studies show that two compounds had good antibacterial actions on E. coli, S. aureus and no antibacterial activities on C. albicans.

CCDC 1481080: Experimental Crystal Structure Determination

Related Article: Ye Wang, Pan-Pan Shen, Ning Ren, Jian-Jun Zhang,||J.Coord.Chem.|||doi:10.1080/00958972.2017.1339033

Syntheses, structures, thermal stabilities and bacteriostatic activities of four lanthanide complexes

Abstract Four lanthanide complexes, [La2(2,4-DClBA)6(5,5′-DM-2,2′-bipy)2(H2O)2]·2C2H5OH (1) and [Ln(2,4-DClBA)3(5,5′-DM-2,2′-bipy)(C2H5OH)]2 (Ln = Pr(2), Sm(3), Gd(4); 2,4-DClBA = 2,4-dichlorobenzoate; 5,5′-DM-2,2′-bipy = 5,5′-dimethyl-2,2′-bipyridine), were synthesized and characterized via elemental analysis, infrared spectra and thermogravimetric analysis (TG). The crystal structures of 1 and 2–4 are different; Each La3+ is nine-coordinate adopting a distorted mono-capped square antiprism, while the Ln3+ ions of 2–4 are all eight-coordinate with a distorted square antiprismatic molecular geometry. There are subtle changes in the local coordination geometry of the lanthanide–5,5′-DM-2,2′-bipy complexes. Binuclear 1 complexes are stitched together via two kinds of hydrogen bonding interactions (OH⋯O and CH⋯O) to form 1-D chains along the y axis, while the units of 2–4 are stitched together via CH⋯O to form 1-D chains along the x axis. TG analysis revealed thermal decomposition processes and thermal stabilities of the complexes. The bacteriostatic activities of the complexes were evaluated against Candida albicans, Escherichia coli, and Staphylococcus aureus.