Core IRC projects involving NMR
Conformational assignment of novel fully and partially substituted calix[4]-, calix[5]-, and calix[6]arenes.
Lead Researchers: Drs. M. Deasy & B. Creaven
Postgraduate Student: C. McKenna, graduated with PhD 2004
This project has enabled the Lead Researchers to identify the principal conformation of new calixarenes more rapidly and reliably. Exploiting in particular the NMR technique of nuclear Overhauser enhancement (nOe) to identify atoms close in 3-D space, the precise shape of the molecules has been determined, a critical parameter in determining their binding properties to guest species. It is hoped to extend this work further to calixarene-guest complexes, using intermolecular nOe measurements to identify the relative positions and binding modes of the guest inside the calixarene. The new work in Molecular Modelling, supports this research by computing likely stable conformations of both the calixarene and the calixarene-guest complex.
Characterisation of Differentially Substituted “ABAB” Calixarenes
Lead Researchers: Drs. B. Murray & B. Creaven
Postdoctoral Fellow: Dr. J. McGinley (now at NUI Maynooth and an IRC member)
This project involved the design and synthesis of new calixarenes for sensor application and is another area in which nOe NMR experiments have helped to pin down the shape of new calixarenes, and allow full assignment of their 1H- and 13C-NMR spectra. It formed the basis of an NCSR project back in 1999, with a Postdoctoral Fellow based here at the Institute. The patterns established then have been exploited in a wide range of postgraduate projects since, at both MSc and PhD level. They have underpinned projects designed to make ‘super-receptors’, in which two host molecules are joined together to give an entity which can bind two guest molecules simultaneously: examples include Calixarenes with Molecular Clips and Calixarenes with Tetrazoles (see below).
Towards Intelligent Molecular Recognition Devices: Calix-Clips
Lead Researchers: Drs. B. Creaven, M. Deasy & B. Murray
Postgraduate Student: P. Flood, recommended to graduate with PhD in 2006
This project involved design and synthesis of new macromolecules with potential to act as more efficient molecular recognition devices for small cationic guests and neutral molecules. The system proposed involved the combination of two well-characterised receptor molecules, calixarenes and glycoluril-based molecular clips. It also involved using NMR to study the mechanism of the host-guest interaction to control the level of binding to the highest level.
