A flexible supramolecular host with a crowned chair octameric water cluster and highly selective adsorption properties

作者：Hazra Arpan; Kanoo Prakash; Mohapatra Sudip; Mostafa Golam; Maji Tapas Kumar^*

来源：CrystEngComm, 2010, 12(10): 2775-2780.

DOI：10.1039/b924511a

A novel supramolecular host {[Fe(CN)(6)]center dot(H-bipy)(3)center dot 8H(2)O} (1) was obtained by the reaction of K-3[Fe(CN)(6)] and 4,4'-bipyridyl (bipy) under an acidic medium (pH approximate to 3). The supramolecular structure of 1 is made up of non-covalent forces viz. hydrogen bonding and pi-pi interactions. The host houses a discrete octameric water cluster with the conformation of a 1,4-substituted cyclohexane molecule where six water molecules are positioned on the vertices of the cyclohexane ring and the seventh and eighth occupy the 1,4-equatorial positions of the ring. DFT calculations suggest that this conformation is more stable (-73.08 kcal mol(-1)) when compared to the a,a conformation. Upon removal of the water molecules, the host network of 1 undergoes a structural transformation and the dehydrated phase exhibits a stepwise uptake of H2O vapour and completely excludes CO2 and other organic solvent molecules (CH3OH, CH3CN and EtOH).

• 出版日期2010