Qing-An Wu

Unique Tetradentate Coordination of 2,2′-Bipyridyl-3,3′-Dicarboxylate (bpdc). Hydrothermal Synthesis and Crystal Structure of A Novel Polymeric Supramolecule [Co(bpdc)(H2O)2]n

The title complex has been synthesized using hydrothermal methods and its structure determined by X-ray diffraction. It consists of polymeric chains of [Co(bpdc)(H2O)2] units (bpdc = 2,2′-bipyridyl-3,3′-dicarboxylate) which are linked by intermolecular hydrogen bonds to form two-dimensional layer-shaped supramolecules. Each bpdc ligand bridges two cobalt(II) centers in a rare tetradentate fashion through its two pyridyl nitrogen atoms chelating to one cobalt and two carboxyl oxygen atoms to the other in the equatorial plane. The octahedral coordination of cobalt is completed by two axial water molecules.

Hydrothermal Synthesis, Crystal Structure, and Properties of Nickel(II) Coordination Polymer with 2,2′‐Bipyridyl‐3,3′‐dicarboxylate

Abstract The polymeric complex [Ni(bpdc)(H2O)2] n (bpdc, 2,2′‐bipyridyl‐3,3′‐dicarboxylate dianion) which consist of [Ni(bpdc)(H2O)2] units was synthesized using a hydrothermal method. Its crystal structure was determined by x‐ray crystal diffraction as 1‐D chain‐like polymer. In [Ni(bpdc)(H2O)2] n , each bpdc bridges a Ni(II) pair in a unique tetradentate fashion through its two pyridine nitrogen atoms and two oxygen atoms of two carboxyl groups. Each Ni(II) cation has a slightly distorted octahedral coordination environment where the equatorial plane includes the two nitrogen atoms of one bpdc ligand and two oxygen atoms of another bpdc anion, while the axial positions are occupied by two oxygen atoms of two coordinated water molecules. In the polymeric complex the complicated hydrogen‐bonding network and π–π stacking interaction play an important role for its thermostability.

Studies on Synthesis and Crystal Structures of Heteronuclear Complexes of Tartarate with Na(I), K(I) and Cu(II)

A unique heteronuclear tartaric coordination complex [C12H20Cu2KNaO24] was synthesized by the interaction of potassium‐sodium tartarate with CuCl2. Its X‐ray crystal structure shows that the new coordination complex belongs to a monoclinic system, P2(1) space group. The crystallographic data are: a=7.6429(15)Å, b=20.753(4) Å, c=8.1058(16)Å, α=90°, β=112.06(3)°, γ=90°. In this complex, two Cu(II) ions that are in different coordination environments and 2 tartarate ligands exist in cyclic forms. These cyclic structures are connected by Na(I)–K(I) ion pairs and then form the complicated crystal structure through the hydrogen‐bond network.

SYNTHESES AND CHARACTERIZATION OF THE N,N′-BIS(FERROCENYLMETHYLENE)-ETHYLENEDIAMINE SCHIFF BASE AND ITS TRANSITION METAL COMPLEXES

The N,N′-bis(ferrocenylmethylene)ethylenediamine Schiff base was synthesized by condensing ferrocenylaldehyde with ethylenediamine. The complexes of the Schiff base with Zn(II), Co(II), Ni(II) and Fe(III) ions were synthesized. The compositions and properties of the ligand and its complexes were established by elemental analyses, IR, 1H NMR, UV-Vis. spectra and molar conductances.

SYNTHESIS OF THE N,N′-BIS(FERROCENYLMETHYLENE)-1,2-PHENYLENEDIAMINE SCHIFF BASE AND SIX RARE EARTH METAL COMPLEXES

The N,N′-bis(ferrocenylmethylene)-1,2-phenylenediamine Schiff base (BFPDA) was synthesized by the condensation of ferrocenylaldehyde with 1,2-phenylenediamine. The complexes of BFPDA with Gd(III), Pr(III), Nd(III), Yb(III), Eu(III) and Er(III) were synthesized by template synthesis. The composition and properties of BFPDA and six rare earth metal complexes were determined by elemental analyses, IR, 1H NMR, UV-Vis spectra and molar conductance.

Synthesis and crystal structures of Cu(II) and Pb(II) aroylhydrazone complexes and magnetic properties of [Cu2(L)2(Cl)2(HO)6] n (HL=2-pyridylaldehyde isonicotinoylhydrazone)

Two novel aroylhydrazones complexes {[Cu2(L)2(Cl)2](H2O)6} n (1), [Pb(L)(CH3COO)] (2), (HL = 2-pyridylaldehyde isonicotinoylhydrazone), were synthesized and structurally characterized by means of X-ray single-crystal diffraction. In complex 1, HL coordinates to Cu(II) using the normal coordination of aroylhydrazone, and also two pyridyl nitrogens forming a coordination polymer. There are strong intermolecular π–π stacking interactions in 2. Magnetism of complex 1 was studied in the temperature range 5–300 K. The results reveal the occurrence of a weak ferromagnetic coupling with J = 0.29 cm−1.

SYNTHESIS AND CHARACTERIZATION OF HEAVY METAL COMPLEXES OF 1,5-BIS(2-CARBOXYPHENYL)-3-(2-FURYL)FORMAZAN AND ITS MIXED-LIGAND COMPLEXES WITH 2,2′-DIPYRIDYL

1,5-Bis(2-carboxyphenyl)-3-(2-furyl)formazan (H2BCFF) and its complexes with Zn(II), Cd(II), Hg(II) and Pb(II) and its mixed ligand complexes with 2,2′-dipyridyl with Cd(II), Hg(II) and Pb(II) have been synthesized. The structures, compositions and properties of these compounds were determined by elemental analyses, IR, 1H NMR and UV-Vis. Spectra, molar conductivities and thermal analyses.

Synthesis and Crystal Structure of a Novel Supra‐Molecular Compound [Co(tsc)2][NPA]2 · 4H2O (tsc=Thiosemicarbazide, H2NPA=3‐Nitro‐Phthalic Acid)

The supramolecular compound [Co(tsc)2][NPA]2 · 4H2O has been synthesized, with its crystal structure characterized by IR spectrum and X‐ray crystallography diffraction. It belongs to triclinic crystal with p‐1 space group. Unit cell dimensions are a=6.6585(13) Å, b=6.6585(13) Å, c=13.871(3) Å; α=86.64(3)°, β=89.78(3)°, γ=75.42(3)°, V=717.9(2) Å3. Characterization reveals that 3‐nitro‐hphthalate anions as hydrogen bond acceptor bonds to two different cations in parallel and vertical directions, respectively. All of the potential hydrogen bond donors and acceptors are involved in hydrogen bonds, leading to a 2D supramolecular layer structure.

SYNTHESIS AND CHARACTERIZATION OF MIXED-LIGAND COMPLEXES OF FERROCENYLACRYLIC ACID, 1,10-PHENANTHROLINE, AND 8-QUINOLINOL WITH TRANSITION METALS AND LEAD(II)

Seven complexes of ferrocenylacrylic acid (HL) with selected transition metals and lead(II), five mixed-ligand complexes of HL and 1,10-phenanthroline (phen) with Zn(II), Cd(II), Hg(II), Co(II) and Pb(II) and three mixed-ligand complexes of HL and 8-quinolinol (HOX) with Zn(II), Cd(II) and Pb(II) have been synthesized and characterized. The carboxylic group of HL can coordinate to metal ions in a symmetrical bidentate manner in the mono-complexes or mixed-ligand complexes. HL coordinates with a metal ion in a 2:1 molar ratio, while the ligands HL, phen and HL, HOX coordinate with a metal ion in 2:1:1 and 1:1:1 ratios, respectively. For each complex in the three series, the thermal stabilities are higher than those of the corresponding ligands, and the mono-complexes of the metal ion with HL are more stable than the mixed-ligand complexes of the metal ions with phen or HOX.