Bidentate phosphorus baskets by intramolecular phosphinidene addition

Intramolecular phosphinidene addition to the C==C bond of Mo-complexed, seven-membered phosphorus heterocycles affords three novel [(diphos)Mo(CO)(4)] complexes (18-20). The three bidentate phosphorus baskets differ in the composition of the seven-membered ring: one of the phosphorus atoms is flanked by CH(2), NCH(3), or O. The unsaturated tetrahydrophosphepine precursors are synthesized by either ring-closing metathesis (C and N derivatives) or by a cyclization sequence (O derivative). The crystal structures of the nitrogen- (19) and oxygen-containing (20) baskets have relatively small P-Mo-P angles of 76.240(13) degrees and 77.626(12) degrees , respectively, and complex 20 has slightly shortened Mo--P bond lengths.     

Alkynide and acetonitrile activation by strained AlPC(2) heterocycles

Bicyclic compounds with annulated four- (AlPC(2)) and five-membered (P(2)C(3)) rings activate and capture Al-alkynides and acetonitrile at room temperature to afford bicyclic compounds with unique six-membered Al(2)PC(3) and AlNPC(3) heterocycles.     

Hybrid coordinate approach for the modelling and simulation of multibody systems

The main goal of the present work is to provide an add-on scheme for the formulation of multibody dynamics, based on natural coordinates, in regard to ideally balanced rigid bodies with high rotational spin, e.g. gyroscopes. The underlying aim of this approach is to achieve higher numerical accuracy whenever the preferred axis of rotation coincides with the balanced main axis of the body. This will be achieved by seperating the spin of the balanced rigid body along the denoted axis as an additional angular coordinate, whereas the other rotations will be covered by a carried frame, parameterized via natural coordinates. At the same time the carried frame provides a link to the existing modelling framework in terms of natural coordinates, enabling a straightforward implementation into existing multibody systems (e.g. rotary crane [2]). (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Polonium 210Po activities in human blood of patients with ischaemic heart disease from Gdańsk in Poland

The determination of polonium ²¹⁰Po in human blood samples is presented and discussed in this paper. The human blood samples were collected from patients of Medical University of Gdańsk with ischaemic heart disease (morbus ischaemicus cordis, MIC). The polonium concentrations in analyzed human blood samples are very differentiated. ²¹⁰Po is of particular interest in public health and although is present in the environment in extremely low amounts, it is easily bioaccumulated to the human body. The study shows that the amount of ²¹⁰Po that is incorporated into the human body depends on the food habits and some difference in its levels could be observed between smokers and non-smokers.     

Thermal and acid labile polyurethanes as a new class of responsive materials in polymeric nanoparticles and nanocapsules

A new class of polyurethanes has been designed, containing tertiary carbamate groups in the main chain of the polymer, which enable the resulting polymer to degrade completely under acid and thermal treatment. The decomposition temperatures of the polymers were determined by measuring the evolution of carbon dioxide and other decomposition products using TGA‐MS. Until decomposition of the polymer, no glass transition was found. The polymers exhibit excellent solubility in common organic solvents like chloroform and tetrahydrofuran, making them to suitable materials for film formation. From the obtained polymers, nanoparticles were synthesized by the solvent evaporation method combined with the miniemulsion technique. The resulting nanoparticles can be used as intelligent fillers in films and sensors, since they degrade at temperatures of above 180 °C, which can be detected by a color change reaction with ninhydrin. Polymeric nanocapsules were prepared by an interfacial polyaddition reaction from 2,4‐toluene diisocyanate and tertiary diols performed at the droplet's interface in inverse (water‐in‐oil) miniemulsions. These nanocapsules with an encapsulated photoacid generator can act as a release system, whereby an acidic release through irradiation with ultraviolet light can be triggered. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012