The interface of gravity and quantum mechanics illuminated by Wigner phase space

We provide an introduction into the formulation of non-relativistic quantum mechanics using the Wigner phase-space distribution function and apply this concept to two physical situations at the interface of quantum theory and general relativity: (i) the motion of an ensemble of cold atoms relevant to tests of the weak equivalence principle, and (ii) the Kasevich-Chu interferometer. In order to lay the foundations for this analysis we first present a representation-free description of the Kasevich-Chu interferometer based on unitary operators.Comment: 69 pages, 6 figures, minor changes to match the published version. The original publication is available at http://en.sif.it/books/series/proceedings_fermi or http://ebooks.iospress.nl/volumearticle/3809

Palladium(II) complexes of a bridging amine bis(phenolate) ligand featuring κ² and κ³ coordination modes

Bidentate and tridentate coordination of a 2,4-di-tert-butyl-substituted bridging amine bis­(phenolate) ligand to a palladium(II) center are observed within the same crystal structure, namely di­chlorido­({6,6′-[(ethane-1,2-diylbis(methyl­aza­nedi­yl)]bis­(methyl­ene)}bis­(2,4-di-tert-butyl­phenol))palladium(II) chlorido­(2,4-di-tert-butyl-6-{[(2-{[(3,5-di-tert-butyl-2-hy­droxy­phen­yl)meth­yl](meth­yl)amino}­eth­yl)(meth­yl)amino]­meth­yl}phenolato)palladium(II) methanol 1.685-solvate 0.315-hydrate, [PdCl2(C34H56N2O2)][PdCl(C34H55N2O2)]·1.685CH3OH·0.315H2O. Both complexes exhibit a square-planar geometry, with unbound phenol moieties participating in inter­molecular hydrogen bonding with co-crystallized water and methanol. The presence of both κ2 and κ3 coordination modes arising from the same solution suggest a dynamic process in which phenol donors may coordinate or dissociate from the metal center, and offers insight into catalyst speciation throughout Pd-mediated processes. The unit cell contains di­chlorido­({6,6′-[(ethane-1,2-diylbis(methyl­aza­nedi­yl)]bis­(methyl­ene)}bis­(2,4-di-tert-butyl­phenol))palladium(II), {(L2)PdCl2}, and chlorido­(2,4-di-tert-butyl-6-{[(2-{[(3,5-di-tert-butyl-2-hy­droxy­phen­yl)meth­yl](methyl)amino}eth­yl)(meth­yl)amino]­meth­yl}phenolato)palladium(II), {(L2X)PdCl}, mol­ecules as well as fractional water and methanol solvent mol­ecules

Synthesis of an Ortho-Triazacyclophane: N,N\u27,N\u27\u27-Trimethyltribenzo-1,4,7-triazacyclononatriene

N,N\u27,N\u27\u27-Trimethyltribenzo-1,4,7-triazacyclononatriene has been synthesized via sequential palladium-catalyzed Buchwald-Hartwig N-arylation reactions affording the 9-membered triaza o-cyclophane in 35% overall yield. An X-ray crystal structure shows the new cyclophane to have a C(2)-symmetric saddle conformation, as compared to the crown conformation exhibited by the related carbocyclic cyclotriveratrylene (CTV)

Di-μ-acetato-bis­(dimethyl­formamide)­penta­kis­(μ-N,2-dioxidobenzene-1-car­boximidato)tetra­kis­(1-ethyl­imidazole)­penta­manganese(III)­manganese(II)–diethyl ether–dimethyl­foramide–methanol–water (1/1/1/1/0.12)

The title compound [Mn6(C7H4NO3)5(CH3CO2)2(C5H8N2)4(C3H7NO)2]·(C2H5)2O·C3H7NO·CH3OH·0.12H2O, abbreviated as MnII(OAc)2[15-MCMnIII(N)shi-5](EtIm)4(DMF)2·diethyl ether·DMF·MeOH·0.12H2O (where −OAc is acetate, MC is metallacrown, shi3− is salicylhydroximate, EtIM is n-ethylimidazole, DMF is N,N-dimethylformamide, and MeOH is methanol) contains five MnIII ions as members of the metallacrown ring and an MnII ion bound in the central cavity. The central MnII ion is seven-coordinate with a distorted face-capped trigonal–prismatic geometry. The five MnIII ions of the metallacrown ring are six-coordinate with distorted octa­hedral geometries. The configuration of the MnIII ions about the metallacrown ring follow a ΔΛΔPP pattern, with P representing planar. The four 1-ethyl­imidazole ligands are bound to four different MnIII ions. A diethyl ether solvent mol­ecule was found to be disordered over two mutually exclusive sites with an occupancy ratio of 0.568 (7):0.432 (7). A methanol solvent mol­ecule was found to be disordered over two mutually exclusive sites by being hydrogen bonded either to a dimethyl­formamide solvent mol­ecule (major occupancy component) or to an O atom of the main mol­ecule (minor occupancy component). The occupancy ratio refined to 0.678 (11):0.322 (11). Associated with the minor component is a partially occupied water mol­ecule [total occupancy 0.124 (15)]

Bis[μ-pentane-2,4-dionato(1−)]bis­{aqua­[1,1,1,5,5,5-hexa­fluoro­pentane-2,4-dionato(1−)]cobalt(II)}

The title complex, [Co2(C5HF6O2)2(C5H7O2)2(H2O)2], is centrosymmetric with a crystallographic inversion center in the middle of the mol­ecule. The octa­hedrally coordinated CoII atoms are bridged by two chelating acetyl­acetonate (acac) ligands and two more electron-poor 1,1,1,5,5,5-hexa­fluoro­pentane-2,4-dionato (hfac) ligands are bonded terminally in a solely chelating manner. The coordinated water mol­ecules form inter­molecular O—H⋯O hydrogen bonds with electron-rich acac O atoms of neighboring mol­ecules, leading to strings of mol­ecules along the a axis

Beckmann Rearrangement of Cyclotriveratrylene (CTV) Oxime: Tandem Beckmann-Electrophilic Aromatic Addition

The Beckmann rearrangement has been performed on the oxime of cyclotriveratrylene (CTV) with thionyl chloride affording the ring-expanded 10-membered ring amide exclusively in high yield. Modified conditions afford a helical pentacycle derived from an unusual tandem Beckmann rearrangement and electrophilic aromatic addition followed by demethylation and tautomerization

4,4′-Bipyridine–terephthalic acid (1/1)

The asymmetric unit of the title compound, C10H8N2·C8H6O4, consists of one half-mol­ecule of each moiety, 4,4′-bipyridine (bpy) and terephthalic acid (bdc), both being located on crystallographic inversion centers. They are linked together via strong inter­molecular O—H⋯N hydrogen bonds, forming infinite chains propagating along [1-21]. The chains are further connected through C—H⋯O inter­actions giving sheets in (012). The sheets are linked via π–π inter­actions between the bpy rings and the bdc–bpy rings [centroid–centroid distances = 3.690 (2) and 3.869 (2) Å], resulting in the formation of a three-dimensional supra­molecular layer-like structure

First international diagnostic accuracy study for the serological detection of West Nile virus infection

<p>Abstract</p> <p>Background</p> <p>The diagnosis of an acute or convalescent West Nile (WN) virus infection can be confirmed by various serological assays such as enzyme immunoassay (EIA), immunofluorescence assay (IFA), or neutralisation test (NT) which are conducted by a growing number of laboratories. However, as the degree of proficiency may vary between laboratories, quality control measures for laboratory diagnostics are essential.</p> <p>Methods</p> <p>We have performed an external quality assurance (EQA) programme for the serological detection of WN virus infection to assess the diagnostic quality of laboratories. The participating laboratories received a proficiency panel of 10 coded lyophilised test samples comprising four antisera positive for WN antibodies as positive controls, three antisera positive for antibodies against other heterologous flaviviruses plus one multireactive unspecific serum as specificity controls, and two negative serum samples.</p> <p>Results</p> <p>Twenty-seven laboratories from 20 different countries in Europe, the Middle East, the Americas and Africa participated in this EQA programme. Applying the proficiency criteria of this study, only eight laboratories correctly analysed all samples with their respective EIA, IFA or NT methods. Eighteen laboratories correctly identified between 77.8 and 90% of the samples, and one laboratory identified only 70% correctly with a clear need to eliminate cross-reactivity with other antisera, particularly those elicited by yellow fever virus. Differentiation between the results for IgM and IgG was considered separately and revealed that IgM-antibodies were detected less frequently than IgG-antibodies (p < 0.001). However, the assay used was not a significant technical factor influencing laboratory performance.</p> <p>Conclusion</p> <p>The EQA programme provides information on the quality of different serological assays used by the participating laboratories and indicates that most need to improve their assays, in particular to avoid cross-reactions with antibodies to heterologous flaviviruses.</p

Tetra­kis[(3-hydroxy­prop­yl)dimethyl­ammonium] tetra-μ-acetato-κ8 O:O′-bis­[chloridocuprate(II)](Cu—Cu) dichloride

The title compound (C5H14NO)4[Cu2(CH3COO)4Cl2]Cl2, consists of a pair of CuII ions bridged by four acetate groups, resulting in a Cu2(CH3COO)4 unit, four (3-hydroxy­prop­yl)dimethyl­ammonium cations (two crystallographically independent pairs) and two chloride anions. The Cu atoms at both termini are bonded to chloride anions. The latter are hydrogen bonded to one of the two pairs of crystallographically independent (3-hydroxy­prop­yl)dimethyl­ammonium cations. The Cu2(CH3COO)4 unit is located on a crystallographic inversion center, and the geometry around each metal center is close to octa­hedral. The Cl—Cu—Cu angles are nearly linear [177.48 (2)°] and the Cu—O bond lengths are in the range 1.9712 (18)–1.9809 (19) Å. The Cu⋯Cu separation between the two acetate-bridged CuII centers is 2.6793 (8) Å. The packing of the crystal structure is dominated by N—H⋯Cl hydrogen bonding between the ammonium groups and the chloride anions, as well as by O—H⋯O and O—H⋯Cl hydrogen bonds. One of the 3-hydroxypropyldimethylammonium cations shows orientational disorder with an occupancy ratio of 0.812 (4): 0.188 (4)