2,2′,4,4′,6,6′-Hexamethyl­biphenyl-3,3′,5,5′-tetra­yltetra­methyl­ene tetra­acetate

The title compound, C30H38O8, possess Ci symmetry, with the inversion center situated at the center of the bridging C—C bond. In the crystal structure, mol­ecules are held together by C—H⋯O inter­actions

Bicyclo­[2.2.2]oct-7-ene-2,3,5,6-tetra­carboxylic dianhydride

In the title compound, C12H8O6, mol­ecules are linked by weak C—H⋯O inter­actions involving all the potential donors, generating a three-dimensional network

2,2′-[2,3,5,6-Tetra­methyl-p-phenyl­enebis­(methyl­eneoxy)]dibenzoic acid

The asymmetric unit of the title compound, C26H26O6, contains only a half-mol­ecule, the other half being generated by an inversion center. The two carboxy­phenoxy­methyl units occupy the 1,4-positions of the central aromatic ring. The central ring and the six linked C atoms are almost planar, with a maximum deviation of 0.0286 (17) Å, and the plane makes a dihedral angle of 75.50 (6)° with the benzene ring. In the crystal, strong O—H⋯O hydrogen bonds between the carboxyl groups of adjacent mol­ecules and C—H⋯π inter­actions link the mol­ecules into zigzag chains along (220) and (10); the two types of chain are arranged alternately, forming a three-dimensional framework

Tetra­aqua­bis{5-[2-(1H-tetrazol-5-yl)ethenyl]pyrazolato-κN 2}manganese(II) dihydrate

The title compound, [Mn(C4H3N8)2(H2O)4]·2H2O, represents the first structurally characterized transition metal complex of the 1,2-bis­(tetra­zol-5-yl)ethene ligand. The complex mol­ecule occupies a special position on an inversion centre and the Mn atom has a tetra­gonally distorted octa­hedral coordination. The bis­(tetra­zolyl)ethene ligand is planar within 0.0366 (7) Å. All ‘active’ H atoms participate in hydrogen bonds, which link mol­ecules of the complex and the uncoordinated water mol­ecules into an infinite three-dimensional framework

1,1′-Dimethyl-4,4′-bipyridinium bis(triiodide)

In the title compound, C12H14N22+·2I3−, the 1,1′-dimethyl-4,4′-bipyridinium (DMBP) dication is charge balanced by two triiodide ions. The DMBP dication is planar within 0.010 (5) Å. The asymmetric unit contains only half of the dication, the other half being generated by an inversion center. Weak C—H...I interactions link the ions into sheets parallel to (121)