Solid-State Structure, Quantum Calculations and Spectroscopic Characterization of the Hydrogen-Bonded Complex [Os(bpy)2(CO)(EtO···H-DMAP)][PF6]2

✍ Scribed by Claudio Garino; Roberto Gobetto; Carlo Nervi; Luca Salassa; Gianluca Croce; Marco Milanesio; Edward Rosenberg; J. B. Alexander Ross

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 170 KB
• Volume: 2005
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200400631

✦ Synopsis

Abstract

The new H‐bonded complex [Os(bpy)~2~(CO)(EtO···H‐DMAP)][PF~6~]~2~, where DMAP = 4‐(dimethylamino)pyridine and bpy = 2,2′‐bipyridine, has been synthesized and characterized by X‐ray diffraction, IR, solution and solid‐state NMR spectroscopy. The complex shows a strong hydrogen bond between the protonated DMAP moiety and the deprotonated ethanolic group directly bonded to the Os atom. High‐speed (28 KHz) solid‐state ^1^H MAS NMR spectroscopy and quantum‐mechanical calculations were used to assess the location of the hydrogen atom involved in the H‐bond. Both confirmed a proton characteristic of an N−H···O−Y hydrogen bond. A molecular orbital analysis was performed to elucidate the IR CO stretching frequency red shift of the H‐bonded complex with respect to [Os(bpy)~2~(CO)O(H)Et][OTf]~2~. Absorption spectra indicate that the H‐bond is present both in water and dichloromethane solutions. However, no direct evidence of the H‐bond interaction in solution is observed from the ^1^H NMR spectrum (CD~2~Cl~2~) between 298 and 193 K. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)