Synthesis and characterization of monomeric and dimeric structures of calix[4]arenes containing amidoferrocene

Abstract

The reaction of 1,1′-bis(chlorocarbonyl)ferrocene with bis-aminobenzylcalix[4]arene gave amidoferrocene calix[4]arene monomer 1. Compound 1 crystallized in the monoclinic system P21/c with a = 11.196(6) Å, b = 14.971(11) Å, c = 32.007(2) Å, β = 96.413(4)° and V = 5330.9(6) Å3. X-ray diffraction analyses of 1 showed that the calix[4]arene scaffold was in cone conformation in which the intramolecular hydrogen bonding were formed through OH groups at the lower rim to stabilize the structure. Moreover, the intramolecular hydrogen bond between the amide groups of the amidoferrocene unit also presented in the crystal structure. On the other hand, the condensation of 1,1′-bis(chlorocarbonyl) ferrocene with p-tert-bis-aminobenzylcalix[4]arene resulted in the monomeric 2 and [2 + 2] dimeric compounds 3.1H-NMR studies signified that the calix[4]arene building block in compounds 2 and 3 adopted the cone conformation. Synthesis and Characterization of Monomeric and Dimeric Structures of Calix[4]arenes Containing Amidoferrocene Chomchai Suksai*, Pannee Leeladee, Colin Jennings, Thawatchai Tuntulani*, Palangpon Kongsaeree The condensation of 1,1′-bis(chlorocarbonyl)ferrocene with p-tert-bis-aminobenzylcalix[4]arene resulted in the monomeric and [2 + 2] dimeric compounds. [Figure not available: see fulltext.] © 2007 Springer Science+Business Media, LLC.