New heterocyclic metallomesogens: synthesis,mesomorphic and thermal behaviours of Cu(II) complexes with 1,2,3-triazole-based Schiff bases ligands

Two series of new Cu(II) complexes derived from the reaction of copper acetate with the non-linear 1,2,3-triazole-based Schiff bases have successfully been synthesised. The structures of the ligands and its complexes were elucidated by elemental analysis, FT-IR, ¹H-NMR and UV–visible spectroscopic techniques. The differential scanning calorimetry and polarizing optical microscopy supported the anisotropic properties of uncoordinated ligands in which the focal conic fan-shaped texture and/or broken fan-shaped texture characteristics of respective SmA and SmC phases were recorded. However, not all of their corresponding Cu(II) complexes are mesogenic. Although the iodo-substituted ligands with even parity C₁₀H₂₉ to C₁₄H₃₃ are non-stable and exhibit SmA phase which is not reproducible, the ultimate Cu(II) complexes show exclusively stable SmA phase. This observation can be ascribed to the enhanced colinearity and molecular anisotropic by the presence of Cu-N and Cu-O coordination modes. On the other hand, the comparison studies show that different positions of ortho-hydroxyl group affect the mesomorphic and thermal behaviour of ligands and Cu(II) complexes.     

Diffraction effects in planar wave-sphere interaction

Using the classical Mie scattering theory,we compute the energy density of an arbitrary partial wave(e.g.,the nth order) and then determine that the interaction between an incident planar wave and a sphere of radius a is the one between the sphere and those partial waves the order of which satisfies n≤ka.We also provide a simple expression to describe the diffracted wave in which the angle-dependent functions are employed.The difference between the accurate and the approximate expressions is demonstrated by numerical calculation.     

Electron Spin Resonance Study of the Solvent Effect on the Conformation of Some Iminoxy Radicals

The reaction of nitrogen dioxide with carbonyl compounds having a methylene or vinyl group adjacent to the corbonyl leads to the formation of stable iminoxy radicals^1-3. Evidence^1,2,4 has been presented that the precursor of these iminoxy radicals is probably the corresponding oxime formed by rearrangements of the intermediate nitroso compounds. There have also been reports on the e.s.r. detection of some cis-trans isomers of some iminoxy radicals in methanol or in neat liquid^1,5. We wish to report here a drastic solvent effect on the conformations of some iminoxy radicals formed by the reaction of NO₂ with trifluoroacetylacetone.     

Elastic and Transition Form Factors of the Δ(1232)

Predictions obtained with a confining, symmetry-preserving treatment of a vector ? vector contact interaction at leading-order in a widely used truncation of QCD’s Dyson–Schwinger equations are presented for Δ and Ω baryon elastic form factors and the γN → Δ transition form factors. This simple framework produces results that are practically indistinguishable from the best otherwise available, an outcome which highlights that the key to describing many features of baryons and unifying them with the properties of mesons is a veracious expression of dynamical chiral symmetry breaking in the hadron bound-state problem. The following specific results are of particular interest. The Δ elastic form factors are very sensitive to m _Δ. Hence, given that the parameters which define extant simulations of lattice-regularised QCD produce Δ-resonance masses that are very large, the form factors obtained therewith are a poor guide to properties of the Δ(1232). Considering the Δ-baryon’s quadrupole moment, whilst all computations produce a negative value, the conflict between theoretical predictions entails that it is currently impossible to reach a sound conclusion on the nature of the Δ-baryon’s deformation in the infinite momentum frame. Results for analogous properties of the Ω baryon are less contentious. In connection with the N → Δ transition, the Ash-convention magnetic transition form factor falls faster than the neutron’s magnetic form factor and nonzero values for the associated quadrupole ratios reveal the impact of quark orbital angular momentum within the nucleon and Δ; and, furthermore, these quadrupole ratios do slowly approach their anticipated asymptotic limits.     

A new MnxOy/carbon nanorods derived from bimetallic Zn/Mn metal–organic framework as an efficient oxygen reduction reaction electrocatalyst for alkaline Zn-Air batteries

Journal of Solid State Electrochemistry - In this work, nanorods like bimetallic Zn/Mn metal–organic-frameworks (MOFs) are proposed as the precursor for preparing MnxOy/porous carbon...     

Pd nanoparticles supported on amphiphilic porous organic polymer as an efficient catalyst for aqueous hydrodechlorination and Suzuki-Miyaura coupling reactions

Developing efficient and recyclable heterogeneous catalysts for organic reactions in water is important for the sustainable development of chemical industry. In this work, Pd nanoparticles supported on DABCO-functionalized porous organic polymer was successfully prepared through an easy copolymerization and successive immobilization method. Characterization results indicated that the prepared catalyst featured big surface area, hierarchical porous structure, and excellent surface amphiphilicity. We demonstrated the use of this amphiphilic catalyst in two case reactions, i.e. the aqueous hydrodechlorination and Suzuki-Miyaura coupling reactions. Under mild reaction conditions, the catalyst showed high catalytic activities for the two reactions. In addition, the catalyst could be easily recovered and reused for several times. Also, no obvious Pd leaching and aggregation of Pd nanoparticles occurred up during the consecutive reactions.     

Rapid Interception of CnF2n+1(O)SO. Radical with Copper-Based Carbene: A Novel Access to Perfluoroalkanesulfinate Ester

In this communication, an unprecedented interception of C_nF_2n+1(O)SO^. radical with a copper-based carbene has been established. Distinguished by wide substrate scopes and mild reaction conditions, this novel radical–carbene coupling reaction (RCC reaction) provides a fundamentally different and mechanistically interesting strategy for the synthesis of perfluoroalkanesulfinate esters.