Fangjun Huo

Applying the Yb3+ ion as a simple and sensitive probe to detect phosphate-containing derivatives in aqueous solution.

A simple and sensitive detection method for HPO(4)(2-) and phosphate-containing derivatives in aqueous solution with a new ensemble which is prepared by mixing ytterbium chloride and pyrocatechol violet in a 2:1 molar ratio in 10 mM HEPES buffer at pH 7.0.

DNA-binding spectra and cleavage studies on Ce(III) complex of 2-[(Trifluoroaceto)aceto]thinophene-piperidine ligands

A kind of complex of CeTTA4 · HP (TTA = 2-[(Trifluoroaceto)aceto]thinophene, HP = piperidine) has been synthesized and characterized, and its DNA-binding properties of CeTTA4 · HP using UV spectra, fluorescent spectra, thermal denaturation, viscometry, molecular modeling and CV (cyclic voltammetry). The results show that the binding-mode between CeTTA4 · HP and DNA is intercalation. The interaction between the complex and DNA has also been investigated by gel electrophoresis. Interestingly, we found that the CeTTA4 · HP complex can cleave circular plasmid pBR322 DNA at pH 7.2 and 37°C. In addition, BDNPP was chosen (bis(2,4-dinitrophenyl)-phosphate) as a model compound to further study its cleavage mechanism for pBR322 DNA. From the first-order kinetics equation, we prove indirectly the mechanism may be hydrolytic cleavage.

An oxonium hydrogen sulfate of 3a,6a-diphenylglycoluril.

In the title compound, (5-oxo-3a,6a-diphenylperhydroimidazo[4,5-d]imidazol-2-ylidene)oxonium hydrogen sulfate, C16H15N4O2+ x HSO4-, the asymmetric unit contains a hydrogen sulfate anion and a 3a,6a-diphenylglycoluril oxonium cation. The hydrogen sulfate anion is joined to the oxonium cation via a strong O-H...O hydrogen bond (H...O = 1.69 A). The crystal packing is mainly dominated by interactions involving the hydrogen sulfate anion. The diphenylglycoluril oxonium cations also self-assemble through N-H...O hydrogen bonds, forming molecular chains along the [001] vector. Four intramolecular C-H...N hydrogen bonds are observed, having an S(5) motif.

A novel O-Zn bridging polymer complex of 2,6-bis[bis(carboxylatomethyl)aminomethyl]-4-methylphenolate.

A new one-dimensional coordination polymer, catena-poly[[acetatohexaaqua{mu4-2,6-bis[bis(carboxylatomethyl)aminomethyl]-4-methylphenolato}trizinc(II)] octahydrate], [Zn3(C17H17N2O9)(C2H3O2)(H2O)6] x 8 H2O, is a trinuclear complex consisting of three zinc centers joined by a phenolate bridge and Zn(H2O)4 units. In each complex polymer unit, the three Zn atoms have different coordination modes. Of the two phenolate-bridged Zn ions, one adopts a distorted octahedral coordination composed of two carboxylate ligands, one tertiary N atom, two water molecules and the bridging phenolate ligand, while the other adopts a pyramidal geometry composed of two carboxylate ligands, one tertiary N atom from another coordination arm, one acetate anion as the counter-anion and the bridging phenolate ligand. The third type of Zn centre is represented by two independent Zn atoms lying on inversion centres. They both have an octahedral coordination consisting of four O atoms from four water molecules and two acetate carbonyl O atoms from the ligand. The latter Zn atoms join the above-mentioned binuclear complex units through O atoms of the carboxylate groups into an infinite chain. Neighboring aromatic rings are distributed above and below the chain in an alternating manner. Between the coordination chains, the Zn...Zn separations are 5.750 (4) and 6.806 (4) A. The whole structure is stabilized by hydrogen bonds formed mainly by solvent water molecules.

3,3a-dihydrocyclopenta[b]chromen-1 (2H)-ones from the reaction of salicylaldehyde and 2-cyclopenten-1-one

The two title chromene compounds, 3,3a-dihydrocyclopenta[b]chromen-1(2H)-one, C16H12O2, (I), and 2-(2-hydroxybenzylidene)-3,3a-dihydrocyclopenta[b]chromen-1(2H)-one, C19H14O3, (II), have been determined in the monoclinic space group P2(1)/n. Compound (I) is mainly stabilized by C-H...pi interactions. Compound (II) is linked into infinite one-dimensional chains with a C(3) motif via intermolecular O-H...O hydrogen bonds. The intermolecular C-H...pi and pi-pi interactions also play key roles in stabilizing the crystal packing. Two intramolecular C-H...O hydrogen bonds with S(5) motifs were detected in (II).

2,6-Bis(hydroxy­methyl)-4-methyl­phenol benz­ylidene 1,2-acetal

The title compound, C16H16O3, is an intermediate compound in the synthesis of polypodal binucleating ligands which are suited for the preparation of dinuclear complexes, employing two non-equivalent complexation sites. There are two weak intramolecular C—H⋯O hydrogen bonds generating a ring of pattern S(5), and an intermolecular O—H⋯O hydrogen bond.