4,4′-(Propane-1,3-di­yl)dipyridinium tetra­chloridonickelate(II)

The title compound, (C13H16N2)[NiCl4] or (H2bpp)·NiCl4 [bpp is 1,3-bis­(4-pyrid­yl)propane], is isostructural with its already reported Cu, Zn and Hg analogues. The structure consists of a doubly charged (H2bpp)2+ cation and a tetra­hedral [NiCl4]2− dianion. Both pyridyl N atoms are protonated and form a (H2bpp)2+ cation which adopts an anti–anti conformation with a dihedral angle of 6.287 (7)° between the pyridyl rings. The two pyridyl N atoms are both involved in strong N—H⋯Cl hydrogen bonds, which link both units into a dimer

Poly[bis­[μ2-2-(2-pyridylmethyl­amino)ethanesulfonato]cadmium(II)]

The title compound [Cd(C8H11N2O3S)2]n, is a two-dimensional coordination polymer based on a Cd2+ atom and deprotonated 2-(2-pyridylmethyl­amino)ethanesulfonic acid (Hpmt). The complex has mol­ecular symmetry C i as a consequence of the CdII being located on an inversion centre. Two N atoms of each pmt− ligand coordinate to the Cd2+ ion and its sulfonate O atom bonds to an adjacent Cd2+ ion. 24-membered (–Cd—N—C—C—S—O–)4 rings are formed between neighbouring Cd2+ ions; these are inter­connected, forming a two-dimensional layer structure. In respect to stereogenic amino N atom and the inversion symmetry of the complex, the compound is a 1:1 racemate. The crystal packing is stabilized by inter­molecular N—H⋯O hydrogen bonds and further connected by π–π stacking inter­actions between the pyridyl rings [average inter­planar distance and centroid–centroid separation = 3.582 (1) and 3.634 (1)Å, respectively], forming a three-dimensional supra­molecular architecture

catena-Poly[[diaqua­nickel(II)]-bis­(μ-pyridine-4-sulfinato)-κ2 N,O;κ2 O,N]

In the title coordination polymer, [Ni(C5H4NO2S)2(H2O)2]n, the NiII ion is located on an inversion centre and is octa­hedrally coordinated by two N and two O atoms of four symmetry-related and deprotonated pyridine-4-sulfinate (ps) ligands together with two water mol­ecules in axial positions. The ps− anions, acting as μ2-bridging ligands, link neighbouring NiII ions into a chain structure along the c axis. These polymeric chains are extended into a three-dimensional framework via inter­molecular O—H⋯O hydrogen bonds with participation of the water mol­ecules

3,3′-Di-tert-butyl-5,5′-dimethoxy­biphenyl-2,2′-diol

The title compound, C22H30O4, displays twofold rotational symmetry. The two benzene rings are almost perpendicular to each other, forming a dihedral angle of 89.8 (6)°. In the crystal, mol­ecules are linked into an extended one-dimensional chain structure via inter­molecular O—H⋯O hydrogen bonds

Bis[2-(2-pyridylmethyl­amino)ethane­sulfonato-κ3 N,N′,O]zinc(II)

The title mononuclear complex, [Zn(C8H11N2O3S)2], is a zinc salt of 2-(2-pyridylmethyl­amino)ethane­sulfonic acid (Hpmt). The ZnII ion is located on an inversion centre and is octahedrally surrounded by four N and two O atoms. The deprotonated pmt− anion coordinates in a facial arrangement through its two N atoms and one of the sulfonate O atoms. The crystal packing is determined by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds

4-(4-Carb­oxy-1,3-thia­zol-2-yl)pyridinium 3-carb­oxy-4-hydroxy­benzene­sulfonate dihydrate

In the crystal structure of the title compound, C9H7N2O2S+·C7H5O6S−·2H2O, an H atom from the 5-sulfosalicylic acid is transferred to the pyridyl N atom, forming a salt. The dihedral angle between the thiazole and pyridinium rings is 5.909 (5)°. The crystal packing is determined by O—H⋯O and N—H⋯O hydrogen bonds involving water mol­ecules

Di-μ-chlorido-bis­{[2-(2-pyridylmethyl­amino)ethanesulfonato-κ3 N,N′,O]copper(II)}

In the title compound, [Cu2(C8H11N2O3S)2Cl2], the Cu atoms are five-coordinated in a distorted square-pyramidal geometry by three donor atoms of the deprotonated anionic 2-(2-pyridylmethyl­amino)ethanesulfonate (pmt) ligand and two Cl atoms. The Cl atoms bridge two Cu atoms, giving a binuclear structure; the centroid of the Cu2Cl2 ring lies on a crystallographic center of inversion. The complex is stabilized by hydrogen bonds and π–π stacking inter­actions [average inter­planar distance = 3.4969 (1) Å and ring-centroid separation distance = 4.1068 (4) Å]

Poly[[diaqua(μ2-4,4′-dipyridyl sulfide-κ2 N:N′)(4,4′-dipyridyl sulfide-κN)(2-hydroxy-5-sulfonatobenzoato-κO 1)nickel(II)] dihydrate]

The asymmetric unit of the title helical coordination polymer, {[Ni(C7H4O6S)(C10H8N2S)2(H2O)2]·2H2O}n, is comprised of an NiII ion, one 5-sulfosalicylic acid dianion (HSSA), two 4,4′-dipyridylsulfide (4,4′-dps) ligands, and two coordinated and two uncoordinated water mol­ecules. The NiII ion is coordinated by two water mol­ecules, one carboxyl­ate O atom of the HSSA dianion and three N atoms from three 4,4′-dps ligands in a distorted octa­hedral environment. Half of the 4,4′-dps ligands are μ2-bridging ligands which link adjacent NiII centers, forming a one-dimensional helical structure along the b axis. This helical structure is further stabilized by O—H⋯O intra- and inter­molecular hydrogen bonds

Radiative transitions in charmonium from Nf=2N_f=2 twisted mass lattice QCD

We present a study for charmonium radiative transitions: $J/\psi\rightarrow\eta_c\gamma$, $\chi_{c0}\rightarrow J/\Psi\gamma$ and $h_c\rightarrow\eta_c\gamma$ using $N_f=2$ twisted mass lattice QCD gauge configurations. The single-quark vector form factors for $\eta_c$ and $\chi_{c0}$ are also determined. The simulation is performed at a lattice spacing of $a= 0.06666$ fm and the lattice size is $32^3\times 64$. After extrapolation of lattice data at nonzero $Q^2$ to 0, we compare our results with previous quenched lattice results and the available experimental values.Comment: typeset with revtex, 15 pages, 11 figures, 4 table