Naslov
Calix[4]arene amino acid derivatives. Intra- and intermolecular hydrogen-bonded organisation in solution and the solid state

Autori
Frkanec, Leo ; Višnjevac, Aleksandar ; Kojić-Prodić, Biserka ; Žinić, Mladen

Izvornik
Chemistry : a European journal (0947-6539) 6 (2000), 3; 442-453

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

Ključne riječi
calixarenes; hydrogen bonds; X-ray structure; supramolecular chemistry

Sažetak
Chiral calix[4]arene derivatives bearing four O-(N-acetyl-PhgOMe), (1), (Phg denotes (R)-phenylglycine) or O-(N-acetyl-LeuOMe) (2) strands have been synthesised. Both compounds in chloroform exist in stable cone conformations with non-covalently organised cavity at lower rim formed by circular interstrand amidic hydrogen bonds. Such organisation affects considerably both, the selectivity and extraction/transport properties of 1 and 2 toward metal cations. Also, the calix[4]arene derivatives with one (3) and two (5) OCH2COPhgOMe strands and the one with 1,3-OMe-2,4-(O-CH2COPhgOMe) (4) type of the substitution at lower rim have been prepared. In chloroform, derivatives 3 - 5 exist in stable conformation possessing more or less distorted calix[4]arene cone as the consequence of organisation at lower rim. For 3, NH-OH-OH-OH-OCH2, circular hydrogen bonding, for 4, two NH-OCH3 and for 5 two OH-O=CNH hydrogen bonds were found responsible for organisation at lower rim. The X-ray crystal analysis of 1, 2 and 5 showed completely different conformations and organisation than those found in solution. However, solid state and solution structures of (1, Na+) complex were identical.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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