1,1′-Diketone and 1,1′-dinitrile Derivatives of 2,2′-biimidazole

The crystal structures of 2,2′-biimidazole-1,1′-diacetone, C12H14N4O2, and 2,2′-biimidazole-1,1′-diacetonitrile, C10H8N6, have been determined. Both molecules crystallize with coplanar rings having substituents in a trans disposition with a center of inversion located midway between the bridging C atoms

1,1′-diacetyl-2,2′-biimidazole

A crystallographic twofold rotation axis passes through the C-C bond joining the imidazole rings of the title compound, C10H10N4O2. the molecule crystallizes in a cis disposition. the planar acetyl group is twisted by 5.0 (3)° with respect to the imidazole ring and the two imidazole rings are tilted by 60.53 (5)° in relation to one another

Crystal Structures of 1,1′-di(2-propanone)-2,2′-biimidazole Dihydrazone and 2,6-diacetylpyridine Dihydrazone

The nucleophilic addition reactions between 1,1′-di(2-propanone)-2,2′-biimidazole or 2,6-diacetylpyridine and hydrazine hydrate afford 1,1′-di(2-propanone)-2,2′-biimidazole dihydrazone (1) and 2,6-diacetylpyridine dihydrazone (2), respectively. Compound 1 crystallizes in the orthorhombic space group P212121, with a = 9.042(2), b = 9.731(3), c = 15.683(4)Å, V = 1379.9(6)Å3 and Z = 4. Compound 2 crystallizes in the orthorhombic space group Pnma, with a = 10.948(2), b = 19.742(6), c = 4.566(1)Å, V = 986.9(4)Å

Polymeric Octahedral and Monomeric Tetrahedral Group 12 Pseudohalogeno (NCXˉ: X = O, S, Se) Complexes of 4-(N,N-dimethylamino)pyridine

A series of new pseudohalogeno complexes of Zn(II), Cd(II) and Hg(II) with 4-(N,N-dimethylamino)pyridine (4-dmap) has been prepared. The compounds Zn(NCS)2L2 (1), Cd(NCS)2L2 (2a), Hg1.5(NCS)3L2 (3), Zn(NCO)2L2 (4), Cd(NCO)2L2 (5), Hg(NCO)2L (6), Zn(NCSe)2L2 (7) and Cd(NCSe)2L2 (8a) (L = 4-dmap) were characterized by elemental analyses, mid and far IR, 1H and 13C NMR spectroscopy, and differential scanning calorimetry. The structures of 1, 2a, 4 and 8a have been confirmed by X-ray crystallography. In addition, molecular geometries of Cd(NCS)2L2·2DMSO (2b) and Cd(NCSe)2L2·2DMSO (8b) have been determined by X-ray crystallography. Compounds 1 and 4 consist of monomeric units in which the Zn(II) atoms are tetrahedrally surrounded by two N-donating pseudohalide ions and two 4-dmap moities, coordinating at the endocyclic nitrogen atom. Complexes 2a and 8a are isostructural polymers comprised of chains of the monomeric unit MX2N2, where X is NCS- or NCSe-. Within each monomeric unit one pseudohalide ligand is bound through the chalcogen atom; the other through the nitrogen atom. The polymer chain is a distorted octahedron sharing common edges through nearly linear bridging pseudohalide groups displaced trans to each other; the two 4-dmap ligands are also displaced trans to each other. Complexes 2b and 8b are isostructural monomeric units, in which the central Cd(II) atom exhibits an N4O2 octahedral geometry