Indexing Non-merohedrally Twinned Crystals by Bruker'sAPEX2 and Agilent's CrysAlis~(PRO), an Example of a Crystal Structure That Can Be Refined through Either the PLATONRoute or the ‘HKLF 5' Route,and, Simultaneous Data Collection of Two Crystals in a Tw

The first part of this report describes the data reduction of non-merohedrally twinned crystals measured on Bruker and Agilent area-detector diffractometers. The image frames of methyl-2-aminopyrazine-3-carboxylate were processed with APEX2 to furnish a set of overlapping diffraction indices that were used for solution and refinement. CrysAlisPRO was used for processing the frames of bis(diethyldicarbamato)nickel, which exists in monoclinic and tetragonal polymorphs, and in untwinned and twinned forms. In the second part, the crystal structure of [(3-formyl-4- hydroxyphenyl)methyl]triphenylphosphanium chloride was refined through the ‘HKLF 5'(based on a combined set of diffraction indices) and PLATON(based on one set of diffraction indices) routes to give identical outcomes because the amount of overlap of the twin domains is small. For the third part, in a proof-of-concept investigation, the diffraction pattern of untwinned and twinned 4-{(E)-(4-aminophenyl)diazenyl]phenylamine was recorded simultaneously in one run; the three domains could be indexed and the crystal structure satisfactorily refined. The refinement was identical to those derived from independent measurements; the crystal structure features two independent centrosymmetric molecules, one of which is ordered and the other whole-molecule-disordered. This two-in-one run opens up the possibility that two or more crystals having different atomic compositions can be measured simultaneously if their reciprocal lattices do not overlap significantly.     

Phosphonium-Ring-Fused Bicyclic Metallafuran Complexes of Ruthenium and Osmium

Metallafuran complexes with a fused five-membered phosphonium ring were synthesized from reactions between terminal ynones HC≡C(C=O)R and cis-[Ru/Os(dppm)₂Cl₂] (dppm=1,1-bis(diphenylphosphino)methane). A metal–vinylidene-involving pathway was found to be an energetically feasible formation mechanism for these complexes. These phosphonium-containing metallafurans, like many phosphonium-functionalized drugs, have the ability to induce mitochondrial dysfunction. They also exhibit stronger cytotoxicity against several human cancer cell lines in comparison with their metal precursors and the classic anticancer drug cisplatin. Overall, this work provides structural and mechanistic insights for the rational design of functional metallacycles via activation of alkynes by Ru^II and Os^II centers.     

A novel polyethyleneimine-decorated FeOOH nanoparticle for efficient siRNA delivery

Despite the promising prospect of small interfering RNA(siRNA) for the treatment of diverse diseases,it remains challenging to develop novel delive ry materials to desired tissues and cells.In this study,a novel iron oxyhydroxide(FeOOH) nanoparticle(NP) whose surface was modified with branched polyetherimide(PEI) was developed to deliver siRNA into the cancer cells.It was demonstrated that PEI-FeOOH(PFeOOH) efficiently complexed siRNA,mediated effective cellular uptake and endosomal escape,thereby triggering robust gene silencing in vitro.In addition,PFeOOH/siRNA formulation loading with anti-RRM2 siRNA effectively inhibited the growth of tumor tissues,and exhibited excellent safety profiles in vivo.Therefore,this study conceptually provided a FeOOH-based nucleic acid delivery vesicle which can potentially use to achieve diagnosis and therapy simultaneously.     

Synthesis of propargylic and allylic trifluoromethyl selenoethers by copper-mediated trifluoromethylselenolation of propargylic chlorides and allylic bromides

The copper-mediated trifluoromethylselenolation of propargylic chlorides and allylic bromides is described. This approach provides a wide range of propargylic and allylic trifluoromethyl selenoethers in moderate to good yields. These results open the way to synthesis strategies for various trifluoromethylselenolated compounds.     

MHD flow and mass transfer of chemically reactive upper convected Maxwell fluid past porous surface

The magnetohydrodynamic (MHD) flow and mass transfer of an electrically conducting upper convected Maxwell (UCM) fluid at a porous surface are studied in the presence of a chemically reactive species. The governing nonlinear partial differential equations along with the appropriate boundary conditions are transformed into nonlinear ordinary differential equations and numerically solved by the Keller-box method. The effects of various physical parameters on the flow and mass transfer characteristics are graphically presented and discussed. It is observed that the order of the chemical reaction is to increase the thickness of the diffusion boundary layer. Also, the mass transfer rate strongly depends on the Schmidt number and the reaction rate parameter. Furthermore, available results in the literature are obtained as a special case.     

Efficient evaluation of Casimir force in arbitrary three-dimensional geometries by integral equation methods

In this Letter, we generalized the surface integral equation method for the evaluation of Casimir force in arbitrary three-dimensional geometries. Similar to the two-dimensional case, the evaluation of the mean Maxwell stress tensor is cast into solving a series of three-dimensional scattering problems. The formulation and solution of the three-dimensional scattering problems are well-studied in classical computational electromagnetics. This Letter demonstrates that this quantum electrodynamic phenomenon can be studied using the knowledge and techniques of classical electrodynamics.