Transition metal complexes with bidentate ligands spanning trans-positions. XII. The preparation and properties of complexes trans-[MX2 (1)] and trans-[PtHCl (1)] (M = Ni,Pd and Pt; X = Cl and NCS; 1 = ditertiary phosphine)

Complexes [MX₂(1)] (M = Ni, Pd and Pt; X=Cl and NCS; 1 = 2,11-bis(dialkyl-[or diaryl]phosphinomethyl)benzo[c]phenanthrene; alkyl = cyclohexyl t-butyl; aryl = m-tolyl, p-anisyl and m-CF₃ C₆H₄) have been synthesized. An NMR. study of the t-butyl complexes provides evidence for a “fan-like” motion of the benzo[c]phenanthrene moiety over the plane of the complex.     

Reactions of trapped electrons in methanol-isopropanol glasses irradiated at 77 K

Trapped electron (e _T ^– ) reactivity in methanol-isopropanol glasses irradiated at 77 K has been studied as a function of trap-depth, the variation in the trap depth being achieved by varying the methanol:isopropanol ratio. Benzyl chloride and carbon disulfide have been used as scavengers. In the case of the glasses containing benzyl chloride, the observed yield of the benzyl radical has been correlated with the trapping efficiency of the matrix. The data has been interpreted with the aim of assessing the relative importance of tunnelling in the scavenging of electrons in low temperature glassy matrices.     

Preparation,X-ray crystallography,and thermolysis of phenylenediammonium dibromide salts

Phenylenediammonium dibromide (PDADBr) salts have been prepared and characterized by X-ray crystallography. The thermal decomposition of PDADBr has been studied by thermogravimetry (TG) and differential thermal analysis (DTA). Kinetic parameters have been evaluated using model fitting and isoconversional methods. The thermolytic pathways have also been suggested which involve proton transfer as a primary step to regenerate parent amine and HBr. Interaction between amine and HBr at higher temperature yields gaseous products.     

Oleic acid-assisted phase transfer of nanosized silver colloids

In this study, it is demonstrated that silver nanoparticles can be transferred from formamide to chloroform using oleic acid as a phase transfer agent with a transfer efficiency of 90–95%. The silver nanoparticles are initially formed as an organosol by the reduction of silver ions with formamide. On aging the complex, the particles self-assemble to form an ordered close-packed two-dimensional array of silver nanocrystals when dissolved in CHCl₃. The size distribution of the colloidal silver particles after transfer in different solvents remains almost the same. On the basis of IR spectroscopy, we discuss the adsorption of oleic acid over the silver particles.     

Reactions of dichlorobis(cyclopentadienyl)titanium (IV) with multidentate Schiff bases

Summary Dichlorobis(cyclopentadienyl)titanium(IV), Cp₂TiCI₂, reacts with bidentate Schiff bases such as salicylideneaniline, salicylidene-o-toluidine, salicylidene-m-toluidine, salicylidene-p-toluidine and 2-hydroxy-l-naphthylReprints of this paper are not available.To whom all correspondence should be addressed.     

The transition from bulk to nano as a phase transition

It is demonstrated that the chemical potential of bosons trapped in a harmonic potential shows a discontinuity as a function of the number of particles in the system. In the model used, it is shown that if the number of particles is of the order of 10⁶ or greater, bulk-like behaviour is exhibited by the system. This translates to a ratio of V/V_c>10⁶ for bulk behaviour, where V is the crystallite volume of the experimental sample and V_c is the volume of the unit cell. Several experimental results covering a wide range of physical phenomena that corroborate the fact that such a number-induced phase transition indeed exists are presented.     

Degradation process in organic thin film devices fabricated using P3HT

The stability of regioregular poly(3-hexylthiophene 2,5-diyl) (P3HT) thin films sandwiched between indium tin oxide (ITO) and aluminium (Al) electrodes have been investigated under normal environmental conditions (25°C and RH∼45–50%). Electrical and optical properties of ITO/P3HT/Al devices have been studied over a period of 30 days. Mobility μ of the order of 10⁻⁴ cm²/V-s has been obtained from the V ² law in the as-deposited P3HT films. Scanning electron microscopy (SEM) investigations show blistering of Al contacts in devices with a poly(3,4-ethylenedioxythiophene) (PEDOT) interlayer on application of voltage whereas no blistering is seen in devices without PEDOT. The results have been explained in terms of trap generation and propagation and the moisture-absorbing nature of PEDOT.      

Single Crystal X-ray Study of 6-Phenyl-4-(p-tolyl)pyridin-2(1H)-one

Crystallography Reports - The title compound 6-phenyl-4-(p-tolyl)pyridin-2(1H)-one was synthesized via one-pot, three component reaction of (E)-1-phenyl-3-(p-tolyl)-2-propen-1-one, ethyl...     

Particle multiplicities in the fission-like reactions of 340 MeV Si on Th

Pre-scission and post-scission multiplicities of neutrons and alpha particles have been simultaneously measured for the fission-like reactions of 340 MeV ²⁸Si on ²³²Th. Dynamical model calculations using HICOL code predict that about 90% of the observed events are of quasi-fission type while the remaining 10% are from compound nucleus fission decay. Moving source fits were carried out to the observed neutron and alpha particle spectra, measured at different angles with respect to the fragment directions. The pre-scission and post-scission neutron multiplicities are deduced to be 8.7±2.0 and 9.4±2.0, respectively. The corresponding multiplicity values for alpha particles are found to be 0.22±0.08 and 0.1±0.03. From the measured post-scission neutron multiplicity, it is inferred that about 65±20 MeV of the initial excitation energy remains at scission. This may be compared to the value of 85±30 MeV estimated from PACE2 statistical model calculations, adjusted to reproduce the measured pre-scission neutron multiplicity. From a comparison of the Statistical Model predictions with the measured pre-scission neutron multiplicity, the fission delay is estimated to be of 5⁺⁷₋₃×10⁻²⁰ s which overlaps with the average duration of fission-like process from the contact to the scission point (2×10⁻²⁰ s) as determined from HICOL-based dynamical calculations. For the delay time deduced as above, the pre-scission alpha particle multiplicity calculated by the PACE2 code is about a factor two larger than the experimental one, demonstrating the difficulties in modelling the alpha particle emission from highly elongated shapes that characterize the fissioning system from the contact point to scission.