The first synthesis, isolation and X-ray structure of a phosphonium phosphide, (Ph3PMe){[C6H2(CF3)3-2,4,6]2P}

The synthesis of a bulky secondary phosphine, Ar₂PH [Ar=C₆H₂(CF₃)₃-2,4,6], and its use in the first synthesis and isolation of a phosphonium phosphide, (Ph₃PMe)+(Ar₂P)⁻, via the deprotonation of Ar₂PH with a nonstabilised phosphorus ylide, Ph₃P=CH₂, are reported. An X-ray structure of this salt reveals that cations and anions are weakly associated in the solid state through C–HP interactions.     

Synthesis of unsymmetrically substituted 2,5-piperazinediones: regioselective alkylation of piperazinedione derivatives

A variety of unsymmetrically substituted 2,5-piperazinediones have been synthesized by regioselective alkylation of piperazinedione derivatives.     

Functionalizing Designer DNA Crystals with a Triple‐Helical Veneer

DNA is a very useful molecule for the programmed self‐assembly of 2D and 3D nanoscale objects. 1 The design of these structures exploits Watson–Crick hybridization and strand exchange to stitch linear duplexes into finite assemblies. 2 – 4 The dimensions of these complexes can be increased by over five orders of magnitude through self‐assembly of cohesive single‐stranded segments (sticky ends). 5 , 6 Methods that exploit the sequence addressability of DNA nanostructures will enable the programmable positioning of components in 2D and 3D space, offering applications such as the organization of nanoelectronics, 7 the direction of biological cascades, 8 and the structure determination of periodically positioned molecules by X‐ray diffraction. 9 To this end we present a macroscopic 3D crystal based on the 3‐fold rotationally symmetric tensegrity triangle 3 , 6 that can be functionalized by a triplex‐forming oligonucleotide on each of its helical edges.     

Intramolecular Pd(II)-catalyzed oxidative biaryl synthesis under air: reaction development and scope

New reaction conditions for intramolecular palladium(II)-catalyzed oxidative carbon-carbon bond formation under air are described. The use of pivalic acid as the reaction solvent, instead of acetic acid, results in greater reproducibility, higher yields, and broader scope. This includes the use of electron-rich diarylamines as illustrated in the synthesis of three naturally occurring carbazole products: Murrayafoline A, Mukonine, and Clausenine. A variety of side products have also been isolated, casting light on competing reaction pathways and revealing new reactivity with palladium(II) catalysis.     

A priori estimate for convex solutions to special Lagrangian equations and its application

We derive a priori interior Hessian estimates for special Lagrangian equations when the potential is convex. When the phase is very large, we show that continuous viscosity solutions are smooth in the interior of the domain. © 2008 Wiley Periodicals, Inc.     

Preparation and benchmarking of novel cellulose nanopaper

Cellulose - Synthetic polymers and plastics which are currently used as barrier materials in packaging applications are neither renewable nor biodegradable. Nanopaper, which is obtained by breaking...     

Varieties whose finitely generated members are free

We prove that a variety of algebras whose finitely generated members are free must be definitionally equivalent to the variety of sets, the variety of pointed sets, a variety of vector spaces over a division ring, or a variety of affine vector spaces over a division ring.