Naslov
Solvent-free synthesis and crystal structures of s-cis and s-trans N, N’-bis(2- hydroxycyclohexyl)ethane-1, 2-diamine

Autori
Hakimi, Mohammad ; Kukovec, Boris-Marko ; Raissi, Heidar ; Pouyanmehr, Leila ; Mohr, Fabian ; Schuh, Esther

Izvornik
Structural chemistry (1040-0400) 24 (2013), 1; 81-88

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

Ključne riječi
microwave synthesis; amino alcohol isomers; crystal structure; DFT calculations; pH-potentiometry

Sažetak
The symmetrical amino alcohol synthesis via ring opening of cyclohexene oxide with ethylendiamine is illustrated by synthesis and characterization of ß-amino alcohols s-cis- (SSSS)-cy2en (1) and s-trans-(SSRR)-cy2en (2) (cy2en = N, N’-bis(2- hydroxycyclohexyl)ethane-1, 2-diamine) in one step and with high yield. The reaction was carried out in a microwave reactor under solvent-free conditions. These products were characterized by IR and Raman spectroscopy, elemental analysis, thermal methods (TGA, DTG, DTA), mass spectrometry, and 1H and 13C NMR spectroscopy. The crystal structures of 1 and 2 were determined by single crystal X-ray structural analysis, followed by DFT calculations. Intramolecular hydrogen bond was observed in 1 with C2 symmetry, but not in 2 with Ci symmetry. The nature of intramolecular hydrogen bond in 1 has been investigated by AIM and NBO analyses. The molecules in 1 are linked into an infinite chain along the [001] direction, giving rise to R4 4(8) graph-set motif, while the molecules in 2 are linked into a 2D network in the bc plane, giving rise to R2 2(10) and R3 3(12) motifs. The protonation equilibria of 1 and 2 have been studied by pH-potentiometry, with pK1 9.01, pK2 5.50 determined for 1 and pK1 8.58, pK2 5.26 for 2.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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