A structural, spectroscopic and theoretical study of the triphenylphosphine chalcogenide complexes of tungsten carbonyl, [W(XPPh3)(CO)5], X=O, S, Se

The series [W(XPPh3)(CO)5], X=O, S, Se has been structurally determined by X-ray crystallography and fully characterised spectroscopically to provide data for comparing the bonding of the Ph3PX ligands to the metal. The P-X-W angles are 134.3°, 113.2° and 109.2°, respectively, for X=O, S, Se. The bonding has been analysed using EHMO calculations which suggest that lower P-X-W angles depend on the relative importance of σ-bonding, which in turn depends on the chalcogen in the order X=Se > S > O. The effect is enhanced by lower energies of the metal σ and π orbital energies

Lattice study of trapped fermions at unitarity

We present a lattice study of up to N=20 unitary fermions confined to a harmonic trap. Our preliminary results show better than 1% agreement with high precision solutions to the many-body Schrodinger equation for up to N=6. We are able to make predictions for larger N which were inaccessible by the Hamiltonian approach due to computational limitations. Harmonic traps are used experimentally to study cold atoms tuned to a Feshbach resonance. We show that they also provide certain benefits to numerical studies of many-body correlators on the lattice. In particular, we anticipate that the methods described here could be used for studying nuclear physics.Comment: 7 pages, 5 figures, presented at the XXVIII International Symposium on Lattice Field Theory (Lattice 2010), Villasimius, Italy, June 14-19 201

Elucidating the sign problem through noise distributions

Due to the presence of light pions in the theory, lattice QCD at finite densities suffers from issues with noise in both grand canonical and canonical formulations. We study two different formulations of the Nambu-Jona-Lasinio model reduced to 2+1 dimensions at large N, where N is the number of flavors. At finite chemical potential one formulation has a severe sign problem and a fermion correlator which displays a broad probability distribution with small mean. In the other we find no sign problem and a distribution amenable to the cumulant expansion techniques developed in earlier work.Comment: 6 pages, proceedings for the "Extreme QCD" workshop, Washington DC, August 201

Synthesis and alkyne-coupling chemistry of cyclomanganated 1- and 3-acetylindoles, 3-formylindole and analogues

The syntheses are reported of new cyclomanganated indole derivatives (1-acetyl-κO-indolyl-κC2)dicarbonylbis(trimethylphosphite)manganese (2), (1-methyl-3-acetyl-κO-indolyl-κC2)tetracarbonylmanganese (4), (3-formyl-κO-indolyl-κC2)tetracarbonylmanganese (5a) and (1-methyl-3-formyl-κO-indolyl-κC2)tetracarbonylmanganese (5b). The unusually complicated crystal structure of 5b has been determined, the first for a cyclomanganated aryl aldehyde. The preparations of a mitomycin-related pyrrolo-indole and related products by thermally promoted and oxidatively (Me3NO) initiated alkyne-coupling reactions of the previously known complex (1-acetyl-κO-indolyl-κC2)tetracarbonylmanganese (1) are reported for different alkynes and solvents. X-ray crystal structures are reported for the dimethyl acetylenedicarboxylate coupling product of 1 (dimethyl 1-methyl-l-hydroxypyrrolo[1,2a]-indole-2,3-dicarboxylate; 6a), and an unusually-cyclised triple insertion product 8 from the coupling of acetylene with 4, in which a cyclopentadiene moiety is η3-allyl-coordinated to Mn through only one double bond and an exocyclic carbon, but which rearranges on heating to an η5-cyclopentadienyl complex

Holman v. Commissioner: A Death Knell for the Tax Value of Transfer Restrictions in Family Limited Partnerships?

This Article examines a recent United States court of appeals case concerning section 2703, Holman v. Commissioner,7 and some earlier cases, including a few under the 1958 regulation, that are relevant to Holman. The purpose of this Article is to explain the current state of the law with respect to buy-sell type agreements and their influence on setting the transfer tax value. The Article begins with a discussion of the relevant Code and Regulations, focusing on section 2703 and its legislative history. The Article then follows with a look at some of the relevant case law and an in-depth look at Holman and ends with an analysis of the Holman decision