Hailou Li

Lanthanide-Connecting and Lone-Electron-Pair Active Trigonal-Pyramidal-AsO3 Inducing Nanosized Poly(polyoxotungstate) Aggregates and Their Anticancer Activities.

By virtue of the stereochemical effect of the lone-electron pair located on the trigonal-pyramidal-AsO3 groups and the one-pot self-assembly strategy in the conventional aqueous solution, a series of novel lanthanide-bridging and lone-electron-pair active trigonal-pyramidal-AsO3 inducing nanosized poly(polyoxotungstate) aggregates [H2N(CH3)2]6 Na24H16{[Ln10W16(H2O)30O50](B-α-AsW9O33)8}·97H2O [Ln = EuIII (1), SmIII (2), GdIII (3), TbIII (4), DyIII (5), HoIII (6), ErIII (7), TmIII (8)] were prepared and further characterized by elemental analyses, IR spectra, UV spectra, thermogravimetric (TG) analyses and single-crystal X-ray diffraction. The most remarkable structural feature is that the polyanionic skeleton of {[Ln10W16(H2O)30O50](B-α-AsW9O33)8}46− is constructed from eight trivacant Keggin [B-α-AsW9O33]9− fragments through ten Ln centers and sixteen bridging W atoms in the participation of fifty extraneous oxygen atoms. Notably, 4 and 8 can be stable in the aqueous solution not only for eight days but also in the range of pH = 3.9–7.5. Moreover, the cytotoxicity tests of 4 and 8 toward human cervical cancer (HeLa) cells, human breast cancer (MCF–7) cells and mouse fibroblast (L929) cells were performed by the 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and the cell apoptosis processes were characterized by calcein AM/PI staining experiments, annexin V-FITC/PI staining experiments and morphological changes.

Synthesis, structure, spectroscopic and ferroelectric properties of an acentric polyoxotungstate containing 1:2-type [Sm(α-PW11O39)2]11− fragment and d-proline components

An organic-inorganic hybrid mono-Sm(III) substituted phosphotungstate KNa3[HPro]₇[Sm(α-PW₁₁O₃₉)₂]·Pro·₁₈H₂O (1) (Pro=D-proline) has been synthesized in the conventional aqueous solution and structurally characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses, IR spectra, UV spectra, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. The molecule of 1 consists of a classical 1:2-type [Sm(α-PW₁₁O₃₉)₂](11-) fragment and free D-proline components. It should be pointed out that the synergistic action between the in-situ formed chiral [Sm(α-PW₁₁O₃₉)₂](11-) fragment and chiral D-proline components results in the formation of the chiral 1. The luminescence emission of 1 reveals three characteristic bands that derive from the (4)G₅/₂→(6)H₅/₂, (4)G₅/₂→(6)H₇/₂ and (4)G₅/₂→(6)H₉/₂ transitions of the Sm(III) cation as well as the synergistic contribution of the O→W transitions of [α-PW₁₁O₃₉](7-) moieties and a π(*)-n or π(*)-π transitions of Pro. Its ferroelectric behavior has been measured.

Syntheses, structures and fluorescence properties of three rare-earth containing docosatungstates.

Three rare-earth containing docosatungstates Na3H2[RE(H2O)4][RE(H2O)5]2[W22O74H2]·36H2O [RE=DyIII (1), HoIII (2), YIII (3)] have been synthesized by reaction of Na2WO4·2H2O, dimethylamine hydrochloride (DMAHC) and RE(NO3)3·6H2O in the aqueous solution and characterized by elemental analyses, IR spectra, thermogravimetric (TG) analysis, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. 1-3 are isomorphous and each molecular unit consists of a S-shaped docosatungstate [W22O74H2]14- polyoxoanion with two supporting [RE(H2O)5]3+ cations and one disordered [RE(H2O)4]3+ cation. The [W22O74H2]14- polyoxoanion can be viewed as combination of two hendecatungstate [W11O38H]9- subunits in the staggered fashion by sharing two μ2-O atoms. The TG curves of 1-3 reveal the one-step weight loss between 25°C to 700°C. Moreover, both 1 and 2 demonstrate the characteristic luminescence emission behaviors of the corresponding RE3+ ions and their lifetime decay curves can be well fitted to the double exponential function. In addition, the CIE chromaticity coordinates of 1 and 2 have been obtained based on their corresponding emission spectra, and their dominant wavelengths and color purities have been also calculated.

Syntheses and Structures of Two Organic–Inorganic Composite Vanadoborates Na2(Hen)4[B18V12O60]·16H2O and (H2en)6[B18V12O60]2·2tepa·11H2O

Two organic–inorganic composite vanadoborates Na2(Hen)4[B18V12O60]·16H2O (1) (en = ethylenediamine) and (H2en)6[B18V12O60]2·2tepa·11H2O (2) (tepa = tetraethylenepentamine) have been hydrothermally synthesized and characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses, IR spectra, and X-ray crystallography. Single-crystal structural analyses show that 1 exhibits a 2-D polyoxovanadium borate sheet architecture with a four-connected topology established by [B18V12O60]6− units via Na+ bridges whereas the molecular unit of 2 consists of two discrete [B18V12O60]6− clusters, six diprotonated [H2en]2+ cations, two tepa molecules, and 11 lattice water molecules.