Neutral intramolecular hydrogen-bonded bases

Zhixin Tian, Alireza Fattahi, Lev Lis, Steven R. Kass

Research output: Contribution to journalArticle

22 Scopus citations

Abstract

B3LYP/aug-cc-pVDZ computations were carried out on polyamines with up to seven amino groups. The gas-phase proton affinities of these compounds are 219.6 (1-BuNH2), 238.6 (H2NCH2CH2CH 2CH2NH2), 252.8 [(H2NCH 2CH2CH2)2CHNH2], 261.3 [(H2NCH2CH2CH2) 3CNH 2 (1)], and 288.5 kcal mol-1 [(H2NCH 2CH2CH(NH2)CH2CH2) 3CNH2]. These results indicate that the tetraamine is near the top of the basicity scale and the heptaamine is more basic than any neutral organic compound which has been measured to date. A gas-phase equilibrium acidity determination between 1 and DBU also was carried out, and PA(1) = 256.2 ± 2.1 kcal mol-1 was obtained. This demonstrates that multiple intramolecular hydrogen bonds can greatly increase basicities, and represents a new motif for designing super bases.

Original languageEnglish (US)
Pages (from-to)41-45
Number of pages5
JournalCroatica Chemica Acta
Volume82
Issue number1
StatePublished - Jun 1 2009

Keywords

  • Computations
  • Gas-phase basicity
  • Hydrogen-bonding
  • Super bases

Fingerprint Dive into the research topics of 'Neutral intramolecular hydrogen-bonded bases'. Together they form a unique fingerprint.

  • Cite this

    Tian, Z., Fattahi, A., Lis, L., & Kass, S. R. (2009). Neutral intramolecular hydrogen-bonded bases. Croatica Chemica Acta, 82(1), 41-45.