A new polyimidazole tripod N,N-bis((1-methyl-4-pivalamidoimidazol-2-yl)methyl)-N'-((1-methylimidazol-2-yl)methyl)amine (L2) has been synthesized and shown to form intramolecular hydrogen bonds with different axial ligands bonded to Cu(II) in the solid state. The same hydrogen-bonding property of L2 appears responsible for the stabilization of a Cu(II)-OOH species in solution. The crystal structures of L2 and three of its Cu(II) complexes are reported. The [Cu(L2)X]ClO4 complexes, 4-6 (X- = Cl-, OH-, or N3-) have distorted trigonal bipyramidal geometries in the solid state and have been characterized further by UV-vis absorption, electron paramagnetic resonance (EPR) spectroscopy, and cyclic voltammetry. The reaction of [Cu(L2)OH](ClO4) (5) with H2O2 and tert-butyl hydroperoxide in methanol generates [Cu(L2)OOH](ClO4) (7) and [Cu(L2)OO(t)Bu](ClO4) (8) which have been characterized by different spectroscopic methods. The compound [Cu(L2)OO(t)Bu]+ displays a band at 395 nm (epsilon = 950 M(-1) cm(-1)) assigned to an alkylperoxo pi*(sigma) --> Cu ligand-to-metal charge transfer (LMCT) transition, while [Cu(L2)OOH]+ displays a peroxo pi*(sigma) --> Cu charge-transfer transition at 365 nm with epsilon = 1300 M(-1) cm(-1), a mass ion at m/z 593.4, and nu(O-O) stretch (resonance Raman) at 854 cm(-1) that shifts to lower energy by 46 cm(-1) upon 18O substitution.

The self assembly of (bis(1-methyl-imidazol-2-yl)methyl)(1-methyl-4-nitroimidazol-2-yl)methyl)amine and boric acid results in a supramolecular structure containing bundled antiparallel imidazole-boric acid helices and boric acid filled one-dimensional channels.

Crystallization of the title compound, C8H8N4O2, results in the formation of one-dimensional chains of imidazole (im) molecules linked together by strong hydrogen bonds. The O...N(im) separation and O-H(...N) distance are 2.6906 (17) and 1.74 (2) A, respectively, and the O-H...N angle is 173 (2) degrees. The one-dimensional chains are weakly pi stacked along the b axis, with centroid-to-centroid separations of 3.678 (2) A between five- and six-membered rings and 3.963 (2) A between six-membered rings. Each molecule is arranged around an inversion center.

Protonenleiter: Ketten aus Wassermolekülen spielen eine wichtige Rolle bei der Permeation von Protonen durch Transmembranproteine. Berichtet wird über die Kristallstrukturen, 2H- und 17O-Festkörper-NMR-Spektren und kalorimetrische Untersuchungen zweier Imidazolhydrate, die endlose eindimensionale Ketten aus Wassermolekülen stabilisieren (siehe Bild; N blau, O rot, H weiß). Die 2H-NMR-Spektren weisen auf eine unterschiedliche Umorientierungsdynamik der Wassermoleküle in beiden Verbindungen hin. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2001/2003/z52157_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.