[00.5] JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 (7) 1315-1321 2000

Cation coordination by calix[4]arenes bearing amide and/or phosphine oxide pendant groups: how many arms are needed to bind Li+ vs. Na+? A combined NMR and molecular dynamics study

Marc Baaden, Georges Wipff^1,* Mohammad Reza Yaftian ², Michel Burgard ², Dominique Matt ³

Abstract

Combined spectroscopic and theoretical studies have been performed on two recently developed calix[4]arenes in the cone conformation, L1 (bearing two -CH2C(O)NEt2 and two -CH2P(O)Ph-2 substituents occupying respectively distal phenolic positions) and L2 (with four -CH2P(O)Ph-2 substituents), in order to compare the Li+ vs. Na+ cation binding mode. Molecular dynamics simulations indicate that coordination of the Li+ cation involves three of the four substituents (the two phosphoryl groups and one of the two amide functions of L1; three phosphoryl arms of L2). A variable temperature NMR study carried out with L1 . Li+ confirms this fourfold coordination and reveals that in solution the lithium cation moves between the two adjacent OPOPOamide units. The weaker binding of the Na+ cation results in a more symmetrical coordination of the four phenolic oxygen atoms and two carbonyls of L1 or four phosphoryls of L2.

Errata

Two typographic errors concerning atomic charges were made.

1. In the amide fragment, the alpha amide carbon is not charged -0.323 but +0.323.
2. In the phosphine-oxide, the bottom HA is indicated as 0.0122 but should read 0.122

Online Access

Article 2000.5 (Perkin Trans 2, 1315)

Addresses

Correspondence should be addressed to Prof. G. Wipff.

1. Univ Strasbourg 1, CNRS, UMR 7551, Inst Chim, 4 Rue B Pascal, F-67000 Strasbourg, France.
2. Univ Strasbourg 1, Lab Chim Minerale & Chim Phys Ind, ECPM, UMR CNRS 7512, F-67087 Strasbourg, France.
3. Univ Strasbourg 1, Grp Chim Inorgan Mol, UMR CNRS 7513, F-67008 Strasbourg, France.

Impact

7 times cited on 2/2/2005 (Ref. ISI Web Of Science)