Interplay between intramolecular resonance-assisted hydrogen bonding and aromaticity in o-hydroxyaryl aldehydes.
In this work, we analyze a series of o-hydroxyaryl aldehydes to discuss the interrelation between the resonance-assisted hydrogen bond (RAHB) formation and the aromaticity of the adjacent aromatic rings. As compared to the nonaromatic reference species (malonaldehyde), the studied compounds can be separated into two groups: first, the set of systems that have a stronger RAHB than that of the reference species, for which there is a Kekulé structure with a localized double CC bond linking substituted carbon atoms; and second, the systems having a weaker RAHB than that of the reference species, for which only pi-electrons coming from a localized Clar pi-sextet can be involved in the RAHB. As to aromaticity, there is a clear reduction of aromaticity in the substituted ipso ring for the former group of systems due to the formation of the RAHB, while for the latter group of species only a slight change of local aromaticity is observed in the substituted ipso ring.
Palusiak
Marcin
M
Institut de Química Computacional and Departament de Química, Universitat de Girona, Campus de Montilivi, 17071 Girona, Catalonia, Spain.
Simon
Sílvia
S
Solà
Miquel
M
D000447:Aldehydes / Q000737:chemistry*; D000873:Anthracenes / Q000737:chemistry; D006860:Hydrogen Bonding; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry; D010616:Phenanthrenes / Q000737:chemistry
D000447:Aldehydes; D000873:Anthracenes; D009281:Naphthalenes; D010616:Phenanthrenes