Harvest L. Collier

A simple helix based on 2,2′-biimidazole. Crystal and molecular structure of [Ag(NO3)(H2biim)]n

Abstract Silver(I) nitrate and 2,2′-biimidazole (H2biim) crystallize from an aqueous solution to afford a single-strand helix, as evidenced by X-ray crystallography. This assemblage is based on an approximate cis conformation of H2biim acting in concert with the preferred linear two-coordinate nature of the ligated silver(I) atom.

Polymeric octahedral and monomeric tetrahedral Group 12 pseudohalogeno (NCX−: X=O, S, Se) complexes of 4-(N,N-dimethylamino)pyridine

Abstract 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.

Synthesis and characterization of polymeric [(CdBr2(H2biim)]n

The reaction of CdBr2 with (H2biim = 2,2′-biimidazole) in an aqueous solution affords the linear coordination polymer [CdBr2(H2biim)]n. An X-ray crystallographic study of this complex reveals a 1-dimensional chain in which adjacent pseudooctahedrally coordinated Cd atoms are bridged in a bis(μ-bromo) fashion. Published by Elsevier Science Ltd

Synthesis and Crystal Structure of 1,1′-di(ethylpropionato)-2,2′-biimidazole, a Macromolecular Precursor

Abstract1,1,′-Di(ethylpropionato)-2,2′-biimidazole, C16H22N4O4, crystallizes from ice-cold ethanol in the space group P

Crystal structures of 1,1'-di(methylacetato)- and 1,1'-di(chloroethoxyethyl)-2,2'-biimidazole

\bar 1

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

, with a = 4.6742(9), b = 9.1119(13), c = 10.175(2) Å, α = 96.22(1), β = 96.29(2), γ = 97.53(1)°, and Z = 1. The molecule crystallizes with coplanar rings and the substituents assume a trans conformation with a center of inversion between the bridging carbon atoms.

Bis[2-(1H-imidazol-2-yl-κN 3 )-1H-imidazol-3-ium]silver(I) Trinitrate

Copolymerisation en masse et en solution, avec ou et sans chlorure stannique. Polymeres obtenus amorphes peu solubles dans le TMF, la NMP ou le DMF. Tg variant de 373 a 391°C. Perte de masse de 25% sous 330°C et 75% au-dessus de 400°C

1-Hydroxyethyl-2,2'-biimidazole

Abstract1,1′-Di(methylacetato)-2,2′-biimidazole, C12H14N4O4, crystallizes from methanol in the space groupP21/c, wherea=9.535(2),b=13.385(2),c=5.1208(8) Å,V=652.2(2) Å3, andZ=4.1,1′-Di(chloroethoxyethyl)-2,2′-biimidazole, C14H20Cl2N4O2, crystallizes from cyclohexane in the space groupPbca, wherea=12.372(2),b=8.959(2),c=14.840(2) Å,V=1644.9(5) Å3, andZ=8. The structures were refined toR=0.041 (1380 observed reflections) andR=0.043 (3243 observed reflections), respectively. Both molecules crystallize with coplanar rings and the substituents assume atrans configuration with a center of inversion between the bridging carbon atoms.