2-(3,5-Dimethylbenzene)-1-ferrocenylmethyl-1H-1,3-benzimidazole

In the title molecule, [Fe(C5H5)(C21H19N2)], the five-membered imidazole ring forms dihedral angles of 88.61 (8) and 42.15 (6)° with the substituted cyclopentadienyl and dimethyl-substituted benzene rings, respectively. In the crystal structure, there is an Nsp2...H contact and a modest C-H...[pi](arene) interaction involving the benzene ring of the benzimidizole system

N-Ferrocenylmethyl-2-(3-methylstyryl)-N’-methylbenzimidazolium hexafluorophosphate

In the title compound, [Fe(C5H5)(C23H22N2)]PF6, the F atoms of the [PF6]- anion are disordered over four different orientations with equal occupancies. In the cation, the five-membered imidazolium ring forms dihedral angles of 71.48 (10) and 19.83 (10)° with the substituted C5H4 ring and the benzene ring of the styryl group, respectively. In the crystal structure, there is a significant C-H...[pi]([eta]5-C5H4) interaction

Apparatus to Determine Static and Dynamic Elastic Moduli

Conclusions 1. The apparatus makes it possible to concurrently measure ES and ED of cylindrical rock specimens under triaxial conditions in the NX Hoek cell. 2. Accuracy of the apparatus is comparable to usual dynamic modulus testing. 3. Preliminary test results for one particular rock type, show that under triaxial conditions the differences between E D and E S are smaller at high confining pressures than at low confining pressures. Circumstantial evidence suggests that microcracks and microfissures are responsible for this phenomenon. Further work needs to be undertaken in other rock types to substantiate these preliminary findings

A detailed X-ray investigation of zeta Puppis IV. Further characterization of the variability

Previously, the X-ray emission of zeta Puppis was found to be variable with light curves harbouring "trends" with a typical timescale longer than the exposure length. The origin of these changes was proposed to be linked to large-scale structures in the wind, but further characterization of the variability at high energies was needed. Since then, a number of new X-ray observations have become available. Furthermore, a cyclic behaviour with a 1.78d period was identified in long optical photometric runs, which is thought to be associated with the launching mechanism of large-scale wind structures. We analysed these new X-ray data, revisited the old data, and compared X-ray with optical data, including when simultaneous. We found that the behaviour in X-rays cannot be explained in terms of a perfect clock because the amplitude and shape of its variations change with time. For example, zeta Puppis was much more strongly variable between 2007 and 2011 than before and after this interval. Comparing the X-ray spectra of the star at maximum and minimum brightness yields no compelling difference beyond the overall flux change: the temperatures, absorptions, and line shapes seem to remain constant, well within errors. The only common feature between X-ray datasets is that the variation amplitudes appear maximum in the medium (0.6-1.2keV) energy band. Finally, no clear and coherent correlation can be found between simultaneous X-ray and optical data. Only a subgroup of observations may be combined coherently with the optical period of 1.78d, although the simultaneous optical behaviour is unknown. The currently available data do not reveal any obvious, permanent, and direct correlation between X-ray and optical variations. The origin of the X-ray variability therefore still needs to be ascertained, highlighting the need for long-term monitoring in multiwavelengths, i.e. X-ray, UV, and optical.Comment: accepted for publication by A&

FUSE Observations of a Full Orbit of Hercules X-1: Signatures of Disk, Star, and Wind

We observed an entire 1.7 day orbit of the X-ray binary Hercules X-1 with the Far Ultraviolet Spectroscopic Explorer (FUSE). Changes in the O VI 1032,1037 line profiles through eclipse ingress and egress indicate a Keplerian accretion disk spinning prograde with the orbit. These observations may show the first double-peaked accretion disk line profile to be seen in the Hercules X-1 system. Doppler tomograms of the emission lines show a bright spot offset from the Roche lobe of the companion star HZ Her, but no obvious signs of the accretion disk. Simulations show that the bright spot is too far offset from the Roche lobe to result from uneven X-ray heating of its surface. The absence of disk signatures in the tomogram can be reproduced in simulations which include absorption from a stellar wind. We attempt to diagnose the state of the emitting gas from the C III 977, C III 1175, and N III 991 emission lines. The latter may be enhanced through Bowen fluorescence.Comment: Accepted for publication in The Astrophysical Journa

2-(3-Chlorophenyl)-1-ferrocenylmethyl-1H-1,3-benzimidazole: an electroactive agent for anion sensor and malarial parasite studies

The title compound, [Fe(C₅H₅)(C₁₉H₁₄ClN₂)], a model electroactive agent for anion sensor and malarial parasite studies, has Fe-C bond lengths in the range 2.020 (3)-2.0543 (18) Å. The Fe...Cg distances (Cg indicates a ring centroid) are essentially similar, with values of 1.6467 (10) and 1.6487 (11) Å for the substituted and unsubstituted cyclopentadienyl rings, respectively, with a linear Cg...Fe...Cg angle of 179.12 (7)°. The Fe-CCp-Csp³ angle is 128.43 (13)° and the Fe1-CCp-Csp³-NBz torsion angle 110.27 (17)° (Cp is cyclopentadienyl and Bz is benzimidazole). Weak C-H...Cl contacts form the only intermolecular interactions of significance

Amplitude variability in satellite photometry of the non-radially pulsating O9.5V star zeta Oph

We report a time-series analysis of satellite photometry of the non-radially pulsating Oe star zeta Oph, principally using data from SMEI obtained 2003--2008, but augmented with MOST and WIRE results. Amplitudes of the strongest photometric signals, at 5.18, 2.96, and 2.67/d, each vary independently over the 6-year monitoring period (from ca. 30 to <2 mmag at 5.18/d), on timescales of hundreds of days. Signals at 7.19/d and 5.18/d have persisted (or recurred) for around two decades. Supplementary spectroscopic observations show an H-alpha emission episode in 2006; this coincided with small increases in amplitudes of the three strongest photometric signals.Comment: MNRAS, in pres

Of?p stars: a class of slowly rotating magnetic massive stars

Only 5 Of?p stars have been identified in the Galaxy. Of these, 3 have been studied in detail, and within the past 5 years magnetic fields have been detected in each of them. The observed magnetic and spectral characteristics are indicative of organised magnetic fields, likely of fossil origin, confining their supersonic stellar winds into dense, structured magnetospheres. The systematic detection of magnetic fields in these stars strongly suggests that the Of?p stars represent a general class of magnetic O-type stars.Comment: Proceedings of IAUS 272: Active OB star

Intermolecular interactions in two (ferrocenylmethyl)benzimidazoles incorporating the 4-MeOC6H4 and 3,4-(MeO)2C6H3 groups: analysis of MeO--C--C distortions from ideal 120 degrees geometry.

The title compounds, 1-ferrocenylmethyl-2-(4-methoxyphenyl)-1H-benzimidazole,[Fe(C5H5)(C20H17N2O)], (I), and 2-(3,4-dimethoxyphenyl)-1-ferrocenylmethyl-1H-benzimidazole, [Fe(C5H5)(C21H19N2O2)], (II), are model electroactive compounds for anion sensor and antimalarial applications. Distortions from the ideal 120 angle about the MeO--C--C groups are evident, with angles of 115.1(2) and 125.0(2) in (I), and 115.9(2) and 124.6(2), and 115.7(2) and 125.1(2) in (II). The main intermolecular hydrogen bonds in (I) comprise C--H...N and C--H...pi(C5H5) interactions, while in (II), only weak C--H...(imidazole) and C--H...pi(arene) interactions are present

Development of a flameproof elastic elastomeric fiber

Various flexible polyurethane structures containing halogen were synthesized from polyesters derived from aliphatic or aromatic polyols and dibasic acids. Aliphatic halide structures could not be used because they are unstable at the required reaction temperatures, giving of hydrogen halide which hydrolyzes the ester linkages. In contract, halogen-containing aromatic polyols were stable and satisfactory products were made. The most promising composition, a brominated neopentyl glycol capped with toluene disocyanate, was used as a conventional diisocyanate, in conjunction with hydroxy-terminated polyethers or polyesters to form elastomeric urethanes containing about 10% bromine with weight. Products made in this manner will not burn in air, have an oxygen index value of about 25, and have tensile strength values of about 5,000 psi at 450% elongation. The most efficient additives for imparting flame retardancy to Spandex urethanes are aromatic halides and the most effective of these are the bromide compounds. Various levels of flame retardancy have been achieved depending on the levels of additives used