Conjugates of calixarenes emerging as molecular entities of nanoscience

Calixarenes, along with cyclodextrins (viz. beta-CD) and crown ethers, are the most commonly studied macrocyclic compounds. These bucket shaped molecules have gained tremendous importance for having both hydrophilic and hydrophobic compartments together in the same species. The primary target of this review is to give the readers of various disciplines an updated overview of the recent advancements of the conjugates of calixarenes with respect to their nano chemistry in understanding the nanoscience of these supramolecular systems. Calixarenes now compete with cyclodextrins and calixresorcinols. Thus it is important to look into the current advancement in the literature to draw appropriate comparisons and to provide appropriate designs for their nano science aspects. This review is expected to provide all this. The review covers over 113 conjugates of calixarenes published in 106 references that include contributions from our research group. All the conjugates and their nanoscience aspects were depicted through 63 figures and two schemes. The characterization of these nano systems has been carried out by a variety of techniques that includes spectroscopy and microscopy. The advancement of the conjugates of calixarenes in the nanoworld can be considered as one of the most recent encroachment in the calixarene chemistry and is expected to come out as a major thrust research area in near future. (C) 2012 Elsevier B.V. All rights reserved.