(E)-(2,4-Dichloro­benzyl­idene)amino cyclo­propane­carboxyl­ate

In the title compound C11H9Cl2NO2, the dihedral angle between the benzene and cyclo­propane ring planes is 89.95 (13)°. The carbon­yl–oxime grouping is almost coplanar with the benzene ring [dihedral angle = 4.08 (6)°]. In the crystal, mol­ecules are linked by C—H⋯O inter­actions into [100] chains

Scalable quantum information processing with atomic ensembles and flying photons

We present a scheme for scalable quantum information processing (QIP) with atomic ensembles and flying photons. Using the Rydberg blockade, we encode the qubits in the collective atomic states, which could be manipulated fast and easily due to the enhanced interaction, in comparison to the single-atom case. We demonstrate that our proposed gating could be applied to generation of two-dimensional cluster states for measurement-based quantum computation. Moreover, the atomic ensembles also function as quantum repeaters useful for long distance quantum state transfer. We show the possibility of our scheme to work in bad cavity or in weak coupling regime, which could much relax the experimental requirement. The efficient coherent operations on the ensemble qubits enable our scheme to be switchable between quantum computation and quantum communication using atomic ensembles.Comment: 8 pages, 7 figure

Treatment of Hydrogen Bonds in Protein Simulations

The hydrogen bond plays an essential role in maintaining the secondary structures of protein, and an accurate description of hydrogen bond interaction is critical in protein folding simulation. Modern classical force fields treat hydrogen bonding as nonbonded interaction, which is dominated by electrostatic interaction. However, in the widely used nonpolarizable force fields, atomic charges are fixed and are determined in a mean-field fashion. Applying nonpolarizable AMBER force field in the folding simulations of some short peptides, the native structure cannot be well populated. When polarization effect is introduced into the simulation by utilizing either the on-the-fly charge fitting or the polarizable hydrogen bond model, the native structure becomes prominent in the free energy landscape. These studies highlight the necessity of electrostatic polarization effect in protein simulation

Poly[diethyl­enetriammonium [aquadi-μ2-sulfato-sulfatocerium(III)]]

A new organically templated open-framework cerium sulfate, {(C4H16N3)[Ce(SO4)3(H2O)]}n, was hydro­thermally synthesized. The CeIII cation is nine-coordinated by nine O atoms, including one water mol­ecule. Two of the SO4 groups afford one monodentate and bidentate linkages as the bridge to connect adjacent CeIII cations, while the third SO4 group attaches the CeIII cation in a bidentate mode. The crystal structure consists of layers composed of eight-membered-ring networks formed by four CeO9 polyhedra and four SO4 tetra­hedra. The triply protonated diethyl­enetriamine cations are located between adjacent layers and connect the layers via hydrogen bonds

Di-μ-aqua-bis­{diaqua­[μ-4-({4-[bis­(2-hy­droxy­eth­yl)amino]-6-chloro-1,3,5-triazin-2-yl}amino)­benzene­sulfonato]­sodium(I)}

In the dinuclear title compound, [Na2(C13H15ClN5O5S)2(H2O)6]n, two Na+ cations, disposed about a centre of inversion, are linked by two bridging water mol­ecules. The coordination geometry is based on an O5 donor set defined by four water mol­ecules and a 4-amino­benzene­sulfonate O atom in a distorted trigonal–bipyramidal geometry. In the crystal, significant O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds lead to the formation of a three-dimensional architecture

3,3,3′,3′-Tetra­methyl-6,6′-bis­[(pyridin-4-yl)meth­oxy]-1,1′-spiro­biindane ­monohydrate

The asymmetric unit in the title compound, C33H34N2O2·H2O, consists of a V-shaped mol­ecule and a water mol­ecule to which it is hydrogen bonded. The angle between the mean planes of the two spiro-connected indane groups is 77.06 (5)°. The two five-membered rings of the indane groups have envelope conformations with the methyl­ene atoms adjacent to the spiro C atom forming the flaps. They have deviations from the mean plane of the other four atoms in the rings of 0.374 (4) and 0.362 (4) Å. In the crystal, molecules are linked to form inversion dimers via O—H⋯N hydrogen bonds involving the pyridine N atoms and the solvent water mol­ecule. The dimers are linked into a chain along the b axis by π–π stacking inter­actions between a pyridine ring and its centrosymmetrically related ring in an adjacent dimer. The centroid–centroid distance between the planes is 3.7756 (17) Å, the perpendicular distance is 3.4478 (11) Å and the offset is 1.539 Å