Intramolecular short hydrogen bonding. Synthesis and spectroscopic studies of pyridine N-oxide diadducts: X-ray structure of [(2,6-(CH 3) 2pyNO) 2−H][AuCl 4

Abstract

The [AuCl 4] − stabilized pyridine N-oxide (pyNO) diadducts [(pyNO)—H—(OBpy)] + were synthesized and their FT-IR, 1H NMR and X-ray structures were studied. The FT-IR exhibited a broad absorption centred around 800 cm −1. The 1H NMR revealed a resonance at 10.3 ppm typical of a short intramolecular hydrogen bond in these diadducts. The X-ray structure analysis of the title complex revealed a short intramolecular O---H---O hydrogen bond. The structure consists of discrete, [(2,6-(CH 3) 2pyNO) 2—H] + cations and [AuCl 4] − anions. The cation has a symmetry restricted intramolecular hydrogen bond with R(O---O)=2.426(4) A ̊ . The [AuCl 4] − ion is planar with an average AuCl distance of 2.283(5) Å and ClAuCl angle of 90.1°.