2,3,3 ',4 '-tetramethylbiphenyl

2,3,3',4'-Tetramethylbiphenyl, C<sub>16</sub>H<sub>18</sub>, was synthesized in a palladium-catalysed boronic acid cross-coupling reaction. In the solid state, these weakly interacting unsymmetrical molecules show an apparent dimerization of the ortho-dimethylphenyl groups, a packing motif that is seen in a significant number of other ortho-dimethylphenyl-containing compounds

Dipotassium [N,N '-(propane-1,3-diyl)dioxamato-kappa O-4,N,N ',O ']copper(II) trihydrate: redetermination at 100 K

Redetermination of the structure of the title compound, K-2[Cu(C7H6N2O6)]center dot 3H(2)O,at 100 K reveals conformational disorder in the almost planar copper-containing molecular dianions and clarifies the complex hydrogen-bonded network involving the water molecules. The asymmetric unit contains two independent formula units. In one of the [Cu(C7H6N2O6)](2-) dianions, the propyl chain is disordered over two orientiations, with site-occupancy factors of 0.852 (5) and 0.148 (5)

Copper(II) complexes with a flexible oxamato ligand

We report on a convenient synthesis of the ligand precursor, diethylethylene-1,2-bis(oxamate), (Et2H2oeo, 1), and show how a partial and preferential hydrolysis of the ester group can give rise to the dianionic ligand, (H2oeo)2−. Reaction of this ligand with Cu(II) affords the neutral dimeric species, [Cu2(H2oeo)2], which has a low aqueous solubility. We describe the crystal structure of the hydrate Cu2(H2oeo)2(H2O)4 (2) and report magnetic studies that show a weak exchange interaction in the solid. Under more basic conditions and in the presence of Cu(II) ions, we are able to avoid amide cleavage and yet deprotonate the amide group, resulting in the formation of the highly soluble [Cu(Hoeo)2]4− complex anion. The structure of (NBu4)4[Cu(Hoeo)2](H2O)4 (3) is described and compared with the recently reported anhydrous phase

Tetra-n-butylamine(carbonato-kappa O-2,O')cobalt(III)n-butylcarbamate dihydrate

The title compound, [Co(CO3)(C4H11N)4](C5H10NO2)·2H2O, is a coordination complex with an N4O2 coordination sphere around the central CoIII ion. The small bite angle of the chelating carbonate causes a distortion of the octahedral geometry to an approximately C2v local symmetry. Hydrogen-bonding between the carbonate, carbamate and amine groups, and the water of crystallization, results in a complex two-dimensional network

Possible strong symmetric hydrogen bonding in disodium trihydrogen bis(2,2'-oxydiacetate) nitrate

In the title compound, 2Na+·C8H11O10-·NO3-, the NaI atom is heptacoordinate with an approximately pentagonal-bipyramidal geometry. A possible strong symmetric hydrogen bond, with the H atom located at an inversion centre and an OO distance of 2.450 (2) Å, is observed in the crystal structure

Idler-resonant femtosecond optical parametric oscillator with high mid-infra-red beam quality

We report an idler-resonant femtosecond optical parametric oscillator (OPO) with average output power of 520 mW, repetition-rate of 80 MHz, pulse duration of 90 fs and nearly diffraction-limited beam quality at ~2.4 µm

Suppression of the accretion rate in thin discs around binary black holes

We present three-dimensional Smoothed Particle Hydrodynamics (SPH) simulations investigating the dependence of the accretion rate on the disc thickness around an equal-mass, circular black hole binary system. We find that for thick/hot discs, with H/R 73 0.1, the binary torque does not prevent the gas from penetrating the cavity formed in the disc by the binary (in line with previous investigations). The situation drastically changes for thinner discs; in this case the mass accretion rate is suppressed, such that only a fraction (linearly dependent on H/R) of the available gas is able to flow within the cavity and accrete on to the binary. Extrapolating this result to the cold and thin accretion discs expected around supermassive black hole binary systems implies that this kind of system accretes less material than predicted so far, with consequences not only for the electromagnetic and gravitational waves emissions during the late inspiral phase but also for the recoil speed of the black hole formed after binary coalescence, thus influencing also the evolutionary path both of the binary and of the host galaxy. Our results, being scale-free, are also applicable to equal-mass, circular binaries of stellar mass black holes, such as the progenitor of the recently discovered gravitational wave source GW150914

Transient simulations of the last 22,000 years, with a fully dynamic atmosphere in the GENIE earth-system framework

This paper presents and discusses an ensemble of transient model simulations from the Last Glacial Maximum to present-day. The model includes a fully dynamic, primitive equation atmosphere (the Reading IGCM), computed vegetation (TRIFFID), and a slab-ocean and seaice. The atmospheric model is more akin to a low-resolution GCM than traditional EMICS, and yet is fast enough for long ensemble simulations to be carried out. The model is tuned in a purely objective manner, using a genetic algorithm, which perturbs 30 tunable paramters in the model to find the best fit to a prescribed pre-industrial climate.The control deglaciation experiment has good agreement with data at the Last glacial Maximum and mid-Holocene. The deglaciation ensembles are over initial conditions, physical processes, and tunable model parameters. The ice-sheets are prescribed, and changes in oceanic heat transport are neglected, and yet the model exhibits rapid transitions in many of the ensemble members. These are attributable to the interaction of the dynamic atmosphere with the sea-ice, and are not observed when the ocean and sea-ice surface temperatures are prescribed. The timing of these transitions is sensitive to the initial conditions, pointing to the chaotic nature of the climate system.The simulations have been carried out making use of GRID technologies, developed as part of the GENIE project

Sheet SK 00 SW and SK 00 SE ALDRIDGE - BROWNHILLS : part of 1:50 000 Sheet 154 (Lichfield)

This report embodies some of the results of a study commissioned by the Department of the Environment in 1983 to provide a geological information base, to enable informed consideration to be given to development proposals for the Aldridge - Brownhills area. It is mainly concerned with hydrogeology, subsidence and bulk minerals resources.There is a substantial introductory section on general geology, to give the geological context of these planning-related aspects