TY - JOUR
T1 - Selective Binding of Imidazolium Cations in Building Multi-Component Layers
AU - Ling, Irene
AU - Alias, Yatimah
AU - Sobolev, Alexandre
AU - Byrne, Lindsay
AU - Raston, Colin
PY - 2010/6/18
Y1 - 2010/6/18
N2 - Addition of l-alkyl-3-methyl-imidazolium (Cn-mim) cations 3-5 to a mixture of bis-phosphonium cation 2 and sodium p-sulfonatocalix[4]arene (1) in the presence of lanthanide ions results in the selective binding of an imidazolium cation into the cavity of the calixarene. The result is a multi-layered solid material with an inherently flexible interplay of the components. Incorporating ethyl-, n-butyl- or nhexyl-mim cations into the multi-layers results in significant perturbation of the structure, the most striking effect is the tilting of the plane of the bowl-shaped calixarene relative to the plane of the multi-layer, with tilt angles of 7.2, 28.9 and 65.5°, respectively. The lanthanide ions facilitate complexation, but are not incorporated into the structures and, in all cases, the calixarene takes on a 5- charge, with one of the lower-rim phenolic groups deprotonated. ROESY NMR experiments and other 1H NMR spectroscopy studies establish the formation of 1:1 supermolecules of Cn-mim and calixarene, regardless of the ratio of the two components, and indicate that the supermolecules undergo rapid exchange on the NMR spectroscopy timescale.
AB - Addition of l-alkyl-3-methyl-imidazolium (Cn-mim) cations 3-5 to a mixture of bis-phosphonium cation 2 and sodium p-sulfonatocalix[4]arene (1) in the presence of lanthanide ions results in the selective binding of an imidazolium cation into the cavity of the calixarene. The result is a multi-layered solid material with an inherently flexible interplay of the components. Incorporating ethyl-, n-butyl- or nhexyl-mim cations into the multi-layers results in significant perturbation of the structure, the most striking effect is the tilting of the plane of the bowl-shaped calixarene relative to the plane of the multi-layer, with tilt angles of 7.2, 28.9 and 65.5°, respectively. The lanthanide ions facilitate complexation, but are not incorporated into the structures and, in all cases, the calixarene takes on a 5- charge, with one of the lower-rim phenolic groups deprotonated. ROESY NMR experiments and other 1H NMR spectroscopy studies establish the formation of 1:1 supermolecules of Cn-mim and calixarene, regardless of the ratio of the two components, and indicate that the supermolecules undergo rapid exchange on the NMR spectroscopy timescale.
KW - Bis-phosphonium cations
KW - Calixarenes
KW - Host-guest systems
KW - Imidazolium cations
UR - http://www.scopus.com/inward/record.url?scp=77953598033&partnerID=8YFLogxK
U2 - 10.1002/chem.200903320
DO - 10.1002/chem.200903320
M3 - Article
VL - 16
SP - 6973
EP - 6982
JO - Chemistry-A European Journal
JF - Chemistry-A European Journal
SN - 0947-6539
IS - 23
ER -