Bis(1H-imidazole-κN 3)bis­(2-methyl­benzoato-κO)bis­(2-methyl­benzoic acid-κO)copper(II)

The structure of the title compound, [Cu(C8H7O2)2(C3H4N2)2(C8H8O2)2], consists of centrosymmetric monomeric units, in which the CuII atom has a tetra­gonally distorted octa­hedral coordination involving two imidazole N atoms and two carboxyl­ate O atoms in the square plane [Cu—N = 1.964 (3) and Cu—O = 1.960 (2) Å] and 2-methyl­benzoic acid O atoms in axial sites [Cu—O = 2.753 (3) Å]. Within the complex, the carb­oxy­lic acid forms intra­molecular O—H⋯O hydrogen bonds, while the mol­ecules are assembled through N—H⋯O(carbox­yl) hydrogen bonds into chains extending along the a-axis direction. These chains are further linked by weak π–π inter­actions [centroid–centroid separation = 3.930 (2) Å]

ηQ\eta_{Q} meson photoproduction in ultrarelativistic heavy ion collisions

The transverse momentum distributions for inclusive $\eta_{c,b}$ meson described by gluon-gluon interactions from photoproduction processes in relativistic heavy ion collisions are calculated. We considered the color singlet (CS) and color octet (CO) components with the framework of non-relativistic Quantum Chromodynamics (NRQCD) into the production of heavy quarkonium. The phenomenological values of the matrix elements for the color-singlet and color-octet components give the main contribution to the production of heavy quarkonium from the gluon-gluon interaction caused by the emission of additional gluon in the initial state. The numerical results indicate that the contribution of photoproduction processes cannot be negligible for mid-rapidity in p-p and Pb-Pb collisions at the Large Hadron Collider (LHC) energies.Comment: 11 pages, 2 figure