Polydentate phosphines

Phosphines are one of the most important classes of ligands in chemistry, in both the industrial and academic spheres. This review deals with the design and properties of polydentate phosphines, an original and broad class of multidentate ligands. The multidentate nature of these species has led to special properties, in which the spatial proximity of phosphorus atoms is crucial. The first part gives an overview of oligodentates polyphosphines in which is discussed the types and the basic routes for their synthesis. The review continues with the most important synthetic routes for obtaining complexes. Because of huge amount of literature data this review is not exhaustive, but it collects the most relevant findings in this area. The restriction to structural and spectroscopic properties allows us for a well organized handling of the complex material.     

Why magnesium is five‐coordinate in methanol(phthalocyaninato)magnesium(II)

The square‐pyramidal Mg center in the title compound, [Mg(C₃₂H₁₆N₈)(CH₄O)], is five‐coordinate due to the formation of back‐to‐back π–π dimers that saturate the vacant apical site of the metal coordination sphere. Each complex is a member of a back‐to‐back and a face‐to‐face dimer; the latter are tethered by two strong O—H⋯N hydrogen bonds. The dimers form columns that likely determine the solid‐state packing. The phthalocyaninate ligands are essentially planar, with a slight `hat visor' conformation character.     

A versatile synthesis of a new bisiminophosphorane

The iminophosphorane CH₂CH₂[P{NP(O)(OPh)₂}Ph₂]₂ is synthesized in high yields (80–97%) via a very convenient procedure using diphenylphosphoryl azide (DPPA) and 1,2-bis(diphenylphosphino)ethane.     

The bis(η5‐cyclo­penta­dienyl)­methyl­zirconium(IV) methyl­tris­(penta­fluoro­phenyl)­borate ion pair

The title complex, [Zr(CH₃)(C₅H₅)₂][CH₃B(C₆F₅)₃], crystallizes as an ion pair linked through an unsymmetrical methyl bridge. The bridging Zr—Me distance [2.556 (2) Å] is significantly longer than the terminal Zr—Me distance [2.251 (3) Å], while the Zr—C—B angle approaches linearity [169.1 (2)°].     

[Ferrocene‐1,1′‐diyl­bis­(diiso­propyl­phosphine‐P)]bis(phenylthio)palladium(II)

The Pd atom in the title compound, [Pd(C₆H₅S)₂(C₂₂H₃₆FeP₂)], possesses a distorted square‐planar geometry. The phenyl rings attached to the S atoms are located on opposite sides of the plane defined by the Pd and two S atoms. The Pd—S bonds are statistically significantly different, with values of 2.3703 (7) and 2.3887 (7) Å.     

Study of the deformation characteristics of window security film by digital image correlation techniques

This paper presents a speckle-displacement measurement technique based on the digital image correlation to study the notch sensitivity and crack bridging of window security film. It is used to protect existing glazing against hurricanes, blast and terrorist explosions. The window security film is laminated to the interior side of the glass window by means of a special adhesive. When the glass is breaking, the window film keeps all glass fragments together.The proposed sub-pixel registration of the displacement field is achieved using a calculation technique based on the centre of mass localization of the complex spectrum. This approach increases the computational efficiency for displacements smaller than one pixel and performs with high precision when optimal values of the input correlation parameters are used. In order to achieve a high accuracy of the algorithm, optimization of these input image correlation parameters is offered. For larger displacements an iterative procedure which preserves the precision is successfully implemented.The speckle pattern is created by small white dots sprayed on the previously black painted film surface. As a result, white light illumination can be used which significantly simplifies the experiments.     

NMSSM and seesaw physics at LHC

We consider extensions of the next-to-minimal supersymmetric model (NMSSM) in which the observed neutrino masses are described in terms of effective dimension six (or seven) rather than dimension five operators. All such operators respect the discrete symmetries of the model. The new particles associated with the double (or triple) seesaw mechanism can have sizable couplings to the known leptons, even with a TeV seesaw scale. In the latter case some of these new short-lived particles could be produced and detected at the LHC.     

Synthesis of Nitro‐Octaaza Derivatives of Reduced Anthracene

Nitro compounds of octaaza derivatives of reduced anthracene were synthesized for the first time by reaction of 2,3,4a,6,7,8a,9,10‐octaaza‐4,8‐dioxo‐3,4,4a,7,8,8a,9,9a,10,10a‐decahydroanthracene with nitric acid, mixed nitric acid/sulfuric acid, and nitric acid/acetic anhydride at between –20 and –30 °C. In addition, 1,2,4,5‐tetrazine azido derivatives were obtained by hydrolytic decomposition of the starting compound by nitrous acid. All the resultant compounds exhibit high thermal stability.     

Dissociation Energy Computations for Saline Bonds Implied in Interactions Mediated by Peptidoglicans

Summary: Dissociation energy and hydration energy calculations, in water solution, are presented for saline bonds mediated by Ca²⁺ and Mg²⁺ ions with Brőnstedt type bases ( COO ,  OSO₃ ,  OH). A computationally intensive method, Polarisable Continuum Model (PCM) using 6-31G^* basis set, was applied. Hydration energies were computed by various methods, as well as dissociation energies of some L₂M complexes. L₂Ca complexes result as more stable against dissociation than L₂Mg complexes. Hydration energy calculation results, for some of the methods, here used, seem rather reliable as compared to experimental results.     

Halocarbon and arene coordination of lithium(I) in (1‐anilino‐3‐phenyl­imino­propenyl)chloro(methyl)­aluminium bis{[tetrakis(pentafluoro­phenyl)­borato]­lithium} benzene solvate

The crystal structure of the title compound, [AlCl(CH₃)‐(C₁₅H₁₃N₂)]­[Li(C₂₄BF₂₀)]₂­·C₆H₆, is reported. The unusual coordination features of the lithium(I) cation, including Li‐atom coordination to six organohalogen atoms and the shortest Li—F(C) distances so far observed, are discussed.