Two cadmium(II) complexes with polymeric 2D layer and discrete mononuclear motifs: Syntheses,crystal structures,and fluorescent properties

Two new 1,3-bi(4-pyridyl)propane-based cadmium(II) complexes, [Cd(Bpp)₂(Nas)₂] _n (I) and [Cd(Bpp)₂(Na)₂(H₂O)₂] (II) (Bpp = 1,3-bi(4-pyridyl)propane, Nas^– = 2-aminonaphthalene-1-sulfonate, and Na^– = 1-naphthoate) (CIF files CCDC nos. 1429589 (I), 1429590 (II)) have been hydrothermally synthesized by varying carboxylate- or sulfonate-containing coligands. Structural analyses reveal that, complex I with monodentate Nas^– ligands exhibits a two-dimensional (2D) layered motif extended by equatorial Bpp connectors. By contrast, complex II modified by monodentate Na^– ligands exhibit discrete mononuclear structure. Althouth the Nas^–/Na^– coligands showed the same monodentate binding modes, the Bpp ligand exhibits bridging or terminal binding modes in I and II, respectively. So it is obvious that the competitive coordination in the present mixed-ligands system is responsible for the aggregation or dissociation of mononuclear structural units. Furthermore, both of the two compounds are linked to 3D supramolecular architecture by intermolecular C–H···O hydrogen bonding or C–H···π stacking interactions, exhibiting strong fluorescent emissions resulting from the ligand-to-metal or Na^?-based intraligand charge transfer at room temperature, which can be hopefully used as fluorescent materials.     

Hydrothermal reactions from sodium hydrogen carbonate to phenol

We report here experimental evidence for the hydrothermal formation of a pure organic molecule, phenol, from the reaction of carbonate with water in the presence of iron powders.     

Mononuclear and binuclear sandwich copper(II) complexes with poly(pyrazolyl)borate ligands: syntheses, structures and properties

A series of Cu(II) complexes Cu(2)[micro-pz](2)[HB(pz)(3)](2) (1), Cu[H(2)B(pz)(2)](2) (2), Cu[HB(pz)(3)](2) (3), Cu[HB(pz(Me2))(3)](2) (4), Cu[B(pz)(4)](2) (5) (pz=pyrazole), have been synthesized and characterized by elemental analysis, IR, UV-vis, X-ray diffraction, thermal analysis and theoretical analysis. The IR spectra give the Cu-N vibration modes at 322, 366, 344, 387, and 380 cm(-1) in complexes 1-5, respectively. The UV spectra show all the complexes have same UV absorption at 232 nm; there is another band at 332 nm for complexes 1, 2 and 4, while for complexes 3 and 5, the bands are at 272 and 308 nm, respectively. Complex 1 has a binuclear structure in which two pyrazole ligands bridge two Cu-Tp units. In 2-5, the Cu(II) centers are coordinated with dihydrobis(pyrazolyl)borate (Bp), hydrotris(pyrazolyl)borate (Tp), hydrotris(3,5-Me2pyrazolyl)borate (Tp'), tetrakis(pyrazolyl)borate (Tkp) respectively to form a mononuclear structure. The results of thermal analysis for complexes 1-5 are discussed too.     

One-step synthesis of highly water-soluble magnetite colloidal nanocrystals

A high-temperature solution-phase hydrolysis approach has been developed for the synthesis of colloidal magnetite nanocrystals with well-controlled size and size distribution, high crystallinity, and high water solubility. The synthesis was accomplished by the hydrolysis and reduction of iron(III) cations in diethylene glycol with a rapidly injected solution of sodium hydroxide at an elevated temperature. The high reaction temperature allows for control over size and size distribution and yields highly crystalline products. The superior water solubility is achieved by using a polyelectrolyte, that is, poly(acrylic acid) as the capping agent, the carboxylate groups of which partially bind to the nanocrystal surface and partially extend into the surrounding water. The direct synthesis of water-soluble nanocrystals eliminates the need for additional surface modification steps which are usually required for treating hydrophobic nanocrystals produced in nonpolar solvents through the widely recognized pyrolysis route. The abundant carboxylate groups on the nanocrystal surface allow further modifications, such as bioconjugation, as demonstrated by linking cysteamine to the particle surface. The monodisperse, highly water-soluble, superparamagnetic, and biocompatible magnetite nanocrystals should find immediate important biomedical applications.     

M2Ba2Sn6 (m =yb, ca): metallic zintl phases with a novel tin chain substructure

The compounds M2Ba2Sn6 (M = Yb, Ca) have been synthesized by solid-state reactions in welded Ta tubes at high temperature. Their structures were determined by single-crystal X-ray diffraction studies to be orthorhombic; space group Cmca (No. 64); Z = 8; a = 15.871(3), 15.912 (3) A; b = 9.387(2), 9.497(2) A; c = 17.212(3), 17.184(3) A; and V = 2564.3(9), 2597.0(9) A3, respectively. These contain infinite tin chains along constructed from butterflylike 3-bonded Sn tetramers interconnected by pairs of 2-bonded Sn. The chains are further interconnected into corrugated layers by somewhat longer Sn-Sn bonds along c. The compounds with the chains alone would be Zintl phases, but the interchain bonding makes them formally one-electron rich per formula unit. The electronic structures calculated by extended Hückel and TB-LMTO-ASA methods indicate that these compounds are metallic but with a deep pseudogap at the Fermi level. States that bind the extra electrons lie just below EF and involve important Yb(Ca)-Sn contributions. The origin of metallic Zintl phases is briefly discussed.     

Experimental and theoretical studies of the electronic structure and the ionization and dissociation processes of trifluoromethyl peroxynitrate

In this work, we present a complete study of the ionization and dissociation processes for trifluoromethyl peroxynitrate (CF3OONO2). CF3OONO2 was generated by UV photolysis of a mixture of (CF3CO)2O, NO2, and O2. The product was detected and characterized by the photoelectron spectroscopy (PES) and photoionization mass spectroscopy (PIMS). The geometric and electronic structures of CF3OONO2 were investigated by the combination of experiments and the density functional and ab initio calculations. It is worthwhile mentioning that drastic changes occur in the geometry of CF3OONO2 after ionization. Due to the removal of one electron from the O-N sigma bond, the COON dihedral angle changes to 180 degrees and as a result, the nonplanar structure becomes planar. And the O-N single bond length increases remarkably, with the positive charge most localized on the NO2 moiety. The experimental first vertical ionization potential is 12.39 eV. Based on the calculated bond dissociation energies, the dissociation pathway was predicted. The calculated results explain the ion intensities observed in the photoionization mass spectrum. The dissociation of O-N single bond is found to be the most favored of the possible dissociation paths for CF3OONO2+.     

Study on Radiation of the Rrest color Electric Wave of Quarks in QGP

Using the Debye screening in QGP, the disbibudon function and the color electric potential of the quarks at high temperature, the radiated power of the rest color electric wave of the quarks in QGP are obtained. The relation between the radiated power of the rest color electric wave of the quarks and the Dedbye length λ_D is discussed. This will help to study the Debye screening potendal using the radiated Power.