Shu-Yun Niu

Synthesis, structure and luminescent properties of coordination polymers with 1,2-benzenedicarboxylic acid and a series of flexible dicarboxylate ligands

A series of lanthanide coordination polymers, namely, [Ln(ox)0.5(phth)(H2O)2]·0.5H2O (Ln = Tb (1), Sm (2); H2ox = oxalic acid; H2phth = 1,2-benzenedicarboxylic acid), [Ln(mal)0.5(phth)(H2O)2]·H2O (Ln = Eu (3), Sm (4); H2mal = maleic acid), [Pr3(mal′)(phth)3(H2O)3]·H2O (5) (H2mal′ = malic acid) [Eu(ad)0.5(phth)(H2O)2] (Ln = Eu (6), Sm (7); H2ad = adipic acid), [Pr2(ad)(phth)2(H2O)4] (8) have been synthesized hydrothermally from the self-assembly of the lanthanide ions (Ln3+) with different types of flexible dicarboxylate ligands and the rigid 1,2-benzenedicarboxylate ligand. All coordination polymers were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Structural analyses reveal that the networks of all eight complexes exhibit a variety of coordination modes at the metal centers. The thermal stabilities for 1, 3, 5, 6, 8, photoluminescent properties for 1–4 and 6–7 were examined, and the results show that the complexes seem to be good candidates for novel hybrid inorganic–organic photoactive materials with excellent thermal stability.

New scorpionate oxovanadium complexes : syntheses and crystal structures of a series of vanadium (IV) complexes with mixed ligands of polypyrazolylborates and substituted acetylacetonates

The reaction of [VO(R1-acac)2] (R1 = Me or Et; acac = acetylacetonate) with Na[HB(pz)3] (pz = pyrazole) or Na[HB(3,5-Me2pz)3] in MeOH gave a series of new oxovanadium (IV) complexes: [VO{HB(pz)3}(Me-acac)] (1), [VO{HB(3,5-Me2pz)3}(Me-acac)] (2), [VO{HB(pz)3}(Et-acac)] (3) and [VO{HB(3,5-Me2pz)3}(Et-acac)] (4), respectively. All complexes have similar distorted octahedral coordination about vanadium, [VO(N3O2)], in which the basal plane is defined by the N4, N6 atoms from the tridentate ligand and the O2, O3 atoms from the R1-acac ligand. However, the dihedral angles between the plane formed by O2, V and O3, and the plane of the pentane-2, 4-dionato ligand (O2, C1, C2, C3 and O3) are variously different; 3.59° for 1, 74.54° for 2, 0.92° for 3, and 29.50° for 4, respectively. In addition, ab initio calculations on 1, 2, 3 and 4 have given the energies and characters of the selected MOs, the atomic net charge and the NBO bond order. The order of stability of the complexes is 1 ≅ 2 ≅ 4 > 3.