Naslov
Computer Aided Design of Organic Superbases - The Role of Intramolecular Hydrogen Bonding

Autori
Kovačević, Borislav ; Maksić, Zvonimir B. ; Vianello, Robert ; Primorac, Miljenko

Izvornik
New Journal of Chemistry (1144-0546) 26 (2002); 1329-1334

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
organic superbase; hydrogen bond; proton affinity

Sažetak
The role of intramolecular hydrogen bonding (IMHB) in determining the proton affinities and basicities of some bis(tetramethylguanidine) systems is examined. For this purpose a series of molecular backbone moieties serving as carriers of the bis(tetramethylguanidine) crowns are explored. It was found that the best backbones are provided by phenanthrene and 9, 10–dihidrophenanthrene giving rise to the proton affinity as large as 268.2 and 266.8 kcal/mol, respectively. The corresponding pKa values in acetonitrile are 29.0 and 28.8 implying that these two compounds (6(bs) and 5(bs)) are candidates for powerful superbases. Their intramolecular hydrogen bond strengths are = 19 kcal/mol, which result inter alia from the partial protonation of the vis–?–vis guanidine group.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA