Caixia Yin

Extended Metal-Atom Chains with an Inert Second Row Transition Metal : [Ru5(μ5-tpda)4X2] (tpda2-= tripyridyldiamido dianion, X = Cl and NCS)

EMACs (extended metal-atom chains) offer a unique platform for the exploration of metal-metal interactions. There has been significant advances on the synthesis of EMACs, such as lengthening the chains up to 11 metal atoms thus far, integrating naphthyridine moieties for tuning the charge carried at metal centers, and manipulation of metal-metal interactions. However, the metal centers in EMACs hitherto are limited to first row transition metals which are more labile than those relatively inert ones with electrons filled in the 4d and 5d shells. In this Communication, the synthesis, crystallographic, magnetic, and electrical conducting studies of [Ru5(mu5-tpda)4Cl2] and [Ru5(mu5-tpda)4(NCS)2], the first pentanuclear EMACs of second-row transition metal, are reported.

The First Heteropentanuclear Extended Metal‐Atom Chain: [Ni+Ru25+Ni2+Ni2+(tripyridyldiamido)4(NCS)2]

This study develops the first heteropentametal extended metal atom chain (EMAC) in which a string of nickel cores is incorporated with a diruthenium unit to tune the molecular properties. Spectroscopic, crystallographic, and magnetic characterizations show the formation of a fully delocalized Ru2(5+) unit. This [Ru2]-containing EMAC exhibits single-molecule conductance four-fold superior to that of the pentanickel complex and results in features of negative differential resistance (NDR), which are unobserved in analogues of pentanickel and pentaruthenium EMACs. A plausible mechanism for the NDR behavior is proposed for this diruthenium-modulated EMAC.

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.

Coordination chemistry mimics of nuclease-activity in the hydrolytic cleavage of phosphodiester bond

In vivo, there occurs the synthesis and degradation of the nucleic acids, involving the formation and cleavage of phosphodiester bond. The cleavage modes of phosphodiester bond can be divided into two types, oxidative and hydrolytic, only the hydrolytic products are sticky and connectable, allowing to be religated by ligases. In recent years, great progresses have been made in chemical mimics in the hydrolytic cleavage of phosphodiester bond. Among the found metal complexes with the activity of nucleic acid cleavage, there are mononuclear and dinuclear metal complexes, the adopted metal ions including transitional and lanthanide metal ions. However, the reaction rates are still several orders less than those of the natural enzymes. It should be a prosperous and expedient direction to mimic the hydrolytic cleavage of phosphodiester bond by taking the advantages of dinuclear metal complexes.

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.

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.