Tuning Structural Topologies of Two Cadmium(II) Coordination Polymers via Isomeric Dipyridyl Ligands: Syntheses,Crystal Structures,and Luminescent Properties

Abstract. Two new coordination polymers {[Cd₂(BDC)₂(3‐bpmp)(H₂O)₂] · 2H₂O}_n ( 1 ) and [Cd₂(BDC)₂(4‐bpmp)]_n ( 2 ) [H₂BDC = 5‐hydroxy‐isophthalic acid, 3‐bpmp = 1,4‐bis(3‐pyridylmethy)piperazine, and 4‐bpmp = 1,4‐bis(4‐pyridylmethy) piperazine] were synthesized via hydrothermal synthesis, and further characterized by IR spectroscopy, elemental analysis, XRD, and X‐ray crystallography. Complex 1 shows a two‐dimensional (4,4) sql topology and complex 2 features an 8‐connected hex topology. Moreover, the luminescent properties of complexes 1 and 2 were investigated in the solid state at room temperature.     

C?H Functionalization/Asymmetric Michael Addition Cascade Enabled by Relay Catalysis: Metal Carbenoid Used for C?C Bond Formation

A combination of either ruthenium(II) or rhodium(II) complexes and quinine‐derived squaramide enables 3‐diazooxindoles, indoles, and nitroalkenes to undergo highly efficient asymmetric three‐component reactions, thus affording optically active 3,3′‐bis(indole)s through a consecutive C C bond‐forming sequence, which turned out to be applicable to the facile total synthesis of (−)‐folicanthine.     

Multi‐Colored Fibers by Self‐Assembly of DNA,Histone Proteins,and Cationic Conjugated Polymers

The development of biomolecular fiber materials with imaging ability has become more and more useful for biological applications. In this work, cationic conjugated polymers (CCPs) were used to construct inherent fluorescent microfibers with natural biological macromolecules (DNA and histone proteins) through the interfacial polyelectrolyte complexation (IPC) procedure. Isothermal titration microcalorimetry results show that the driving forces for fiber formation are electrostatic and hydrophobic interactions, as well as the release of counterions and bound water molecules. Color‐encoded IPC fibers were also obtained based on the co‐assembly of DNA, histone proteins, and blue‐, green‐, or red‐ (RGB‐) emissive CCPs by tuning the fluorescence resonance energy‐transfer among the CCPs at a single excitation wavelength. The fibers could encapsulate GFP‐coded Escherichia coli BL21, and the expression of GFP proteins was successfully regulated by the external environment of the fibers. These multi‐colored fibers show a great potential in biomedical applications, such as biosensor, delivery, and release of biological molecules and tissue engineering.     

Genetic profile characterization and population study of 21 autosomal STR in Chinese Kazak ethnic minority group

Short tandem repeat loci have been recognized as useful tools in the routine forensic application and in recent decades, more and more new short tandem repeat (STR) loci have been constantly discovered, studied, and applied in forensic caseworks. In this study, we investigated the genetic polymorphisms of 21 STR loci in the Kazak ethnic minority as well as the genetic relationships between the Kazak ethnic minority and other populations. Allelic frequencies of 21 STR loci were obtained from 114 unrelated healthy Kazak individuals in the Ili Kazak Autonomous Prefecture, Xinjiang Uigur Autonomous Region of China. We observed a total of 159 alleles in the group with the allelic diversity values ranging from 0.0044 to 0.5088. The highest polymorphism was found at D19S433 locus and the lowest was found at D1S1627. Statistical analysis of the generated data indicated no deviation from Hardy–Weinberg equilibriums at all 21 STR loci. In order to estimate the population differentiation, allelic frequencies of all STR loci of the Kazak were compared with those of other neighboring populations using analysis of molecular variance method. Statistically significant differences were found between the studied population and other populations at 2–7 STR loci. A neighbor‐joining tree was constructed based on allelic frequencies of the 21 STR loci and phylogenetic analysis indicates that the Kazak has a close genetic relationship with the Uigur ethnic group. The present results may provide useful information for forensic sciences and population genetics studies, and can also increase our understanding of the genetic background of this group. The present findings showed that all the 21 STR loci are highly genetically polymorphic in the Kazak group, which provided valuable population genetic data for the genetic information study, forensic human individual identification, and paternity tests.     

Portable paper‐based device for quantitative colorimetric assays relying on light reflectance principle

This paper presents a novel paper‐based analytical device based on the colorimetric paper assays through its light reflectance. The device is portable, low cost (<20 dollars), and lightweight (only 176 g) that is available to assess the cost‐effectiveness and appropriateness of the original health care or on‐site detection information. Based on the light reflectance principle, the signal can be obtained directly, stably and user‐friendly in our device. We demonstrated the utility and broad applicability of this technique with measurements of different biological and pollution target samples (BSA, glucose, Fe, and nitrite). Moreover, the real samples of Fe (II) and nitrite in the local tap water were successfully analyzed, and compared with the standard UV absorption method, the quantitative results showed good performance, reproducibility, and reliability. This device could provide quantitative information very conveniently and show great potential to broad fields of resource‐limited analysis, medical diagnostics, and on‐site environmental detection.     

Organocatalytic asymmetric one-pot sequential reaction: synthesis of highly substituted spirocyclohexanepyrazolones with six contiguous stereogenic carbons

An atom-economical synthesis of chiral polyfunctionalized spiropyrazolone derivatives based on the development of a new organocatalytic enantioselective one-pot sequential Michael/Michael/Aldol reaction of 1,3-dicarbonyl compounds with unsaturated pyrazolones and α,β-unsaturated aldehydes has been developed. The notable features of this one-pot sequential process include the generation of up to six consecutive stereogenic carbon centers including one quaternary stereocenter and five tertiary stereocenters with high enantioselectivities (up to 95% ee) and excellent diastereoselectivities (>99:1 d.r.).     

Synthesis and properties of novel crown ether-annelated 4′,5′-diaza-9′-(1,3-dithiole-2-ylidene)-fluorenes and their ruthenium(II) complexes

Two novel redox-active 1,3-dithiole (DT) ring-fused 4,5-diazafluorene ligands with crown ether moieties (L1 and L2) were synthesized and characterized. The crystal structure of L1 was studied. The electrochemical and spectroscopic properties of these new ligands, as well as the corresponding bis(bipyridine)ruthenium(II) complexes [4: Ru L1(bpy)₂ and 5: Ru L2(bpy)₂], were also been investigated.     

A new size extensive multireference perturbation theory

A new multireference perturbation series is derived based on the Rayleigh–Schrödinger perturbation theory. It is orbitally invariant. Its computational cost is comparable to the single reference Møller–Plesset perturbation theory. It is demonstrated numerically that the present multireference second‐ and third‐order energies are size extensive by two types of supermolecules composed of H₂ and BH monomers. Spectroscopic constants of as well as the ground state energies of H₂O, NH₂, and CH₂ at three bond lengths have been calculated with the second multireference perturbation theory. The dissociation behaviors of CH₄ and HF have also been investigated. Comparisons with other approximate theoretical models as well as the experimental data have been carried out to show their relative performances. © 2013 Wiley Periodicals, Inc.     

Monte Carlo simulation of PGNAA system for determining element content in the rock sample

The element content in rock sample can be determined by prompt gamma ray activation analysis technology. The neutron distributions under the conditions with different moderating materials, moderator size and distance from neutron source to lead-out hole were simulated using Monte Carlo method, and then the optimal structure parameters to get the highest thermal neutron flux was obtained. The PGNAA system with optimal parameters based on ²⁵²Cf neutron source was founded. In addition, the rock and element standard samples were irradiated by thermal neutron in this system. Moreover, the element content was calculated by processing gamma ray spectroscopy recorded, and it is in agreement with result of XRF method.     

Modified 2-window approach for rapid determination of 90Sr and 90Y at low quench level using liquid scintillation counting

⁹⁰Sr is a product of nuclear fission, the radioactivity of which can be determined by liquid scintillation counting (LSC). Because the LSC spectra of ⁹⁰Sr and its daughter ⁹⁰Y overlap each other, the following methods are usually used: (1) measuring immediately after ⁹⁰Sr/⁹⁰Y separation; (2) waiting to reach radioactive equilibrium; (3) adopting the conventional 2-window approach; and (4) using the spectra deconvolution technique. The first one requires ⁹⁰Sr/⁹⁰Y separation and immediate measurement; the second one is time-consuming; the third one is valid only for samples with the same quench level as the calibration standard; the last one is somewhat complicated, and in some cases it is not convenient to export the experimental data to some deconvolution software. Therefore, we have developed a modified 2-window approach to rapidly determine ⁹⁰Sr and ⁹⁰Y in either equilibrium or disequilibrium at low quench level. The key modification of the approach is to provide an LSC spectrum of pure ⁹⁰Y with the same quench level as the sample to be determined. This modification eliminates the need to conduct ⁹⁰Sr/⁹⁰Y separation for the sample itself, to prepare the quench curves, and to fit the LSC spectra with some deconvolution software.