Ali R. Salimi

C–H⋯π synthon repetitivity in coordination compounds, established from single-crystal and powder diffraction

Three Hg(II) complexes, [HgCl2(L)2], 1, [HgBr2(L)2], 2, and [Hg2I4(L)2], 3, containing the flexible N-(2-pyrazine)-thiophene-3-acetamide ligand (L) have been prepared and crystal structures of these compounds have been elucidated by single crystal (L, 1 and 3) and powder (2) X-ray diffraction. The crystal structures are determined mostly by N–H⋯N/O classical hydrogen bonding interactions, but in all compounds, the hydrogen atoms of thiophene ring and/or of connecting CH2 are pointed toward the adjacent thiophene rings to generate C–H⋯π synthons that participate in additional stabilization of the crystal structures.

Acridinium 2-hy-droxy-benzoate.

In the title compound, C13H10N+·C7H5O3 − or (acrH)+(Hsal)−, the asymmetric unit contains one acridinium cation and one salicylate anion. The acridinium N atom is protonated and the carboxylic acid group of salicylic acid is deprotonated. Both moieties are planar, with an r.m.s. deviation of 0.0127 Å for the acr cation and 0.0235 ° for the sal anion. They are aligned with a dihedral angle of 71.68 (3)° between them. The crystal structure is stabilized by a network of intermolecular N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds. C—H⋯π interactions are also present.

Synthesis, molecular structure, and characterization of a new 3D-layered inorganic-organic hybrid material: [D/L-C{sub 6}H{sub 13}O{sub 2}N-H]{sub 3}[(PO{sub 4})W{sub 12}O{sub 36}].4.5H{sub 2}O

Abstract A new 3D-layered inorganic–organic hybrid [ d / l -C 6 H 13 O 2 N–H] 3 [(PO 4 )W 12 O 36 ]·4.5H 2 O ( 1 ), as racemic material in the solid phase, has been synthesized and fully characterized by elemental microanalysis, single crystal X-ray diffraction, and infrared, Raman, and proton nuclear magnetic resonance spectroscopes. The most unique structural feature of 1 is its three-dimensional inorganic infinite tunnel-like framework that results in weak van der Waals interactions along the a -axis. A weak interlayer interaction between the titled layers provides a desirable condition to explore its potential as a host in a host–guest complex. The racemization has been observed in the crystal structure with the centric space group ( P 2 1 / c ). The latter consists of α-[(PO 4 )W 12 O 36 ] 3− and [ d / l -C 6 H 13 O 2 N–H] + moieties with water molecules linked together by a complex network of hydrogen bond interactions.