Supramolecular assembled of hexameric water clusters into a 1D chain containing (H2O)6 and [(H2O)4O2] stabilized by hydrogen bonding in a copper complex

{[Cu(pydc)(amp)].3H2O}n has been hydrothermally synthesized and characterized by elemental analysis and by IR spectroscopy. A wide range of hydrogen bonds (of the O-H...O, N-H...O and N-H...N type) are present in the crystal structure. Hydrogen bond interactions between the co-crystallized water molecules led to formation of six-membered rings with chair conformation.In {[Cu(pydc)(amp)].3H2O}n, there are three uncoordinated water molecules. Thermal methods confirm number of co-crystallized water molecules in polymer. Hydrogen bond interactions between the co-crystallized water molecules led to the formation of a six-membered ring with the chair conformation. These rings are part of a 1D chain containing six-membered O6 rings, which are alternately made from (H2O)6 and [(H2O)4O2] rings. [(H2O)4O2] rings are also in chair conformation.Water is nature's solvent and plays a fundamental role in biological and chemical processes. It is the most abundant and cheapest solvent available for the development of new reagents and the study of chemical processes [1]. Understanding of the behavior of water clusters are important and structural information of small water clusters is the first step towards the understanding of the behavior of bulk water [2]. An extensive investigation of small and medium sized water cluster (H2O)n (n = 2-100) structures have been reported in recent years [3,4]. Various water clusters including pentamers [5,6], hexamers [6-8], heptamers [9-11], octamers [6,8,12,13], decamers [6,14-16] and 1D or 2D infinite water chains [2,17,18] in a number of organic and inorganic-organic hybrid hosts, have been structurally characterized. Recently, we also reported a tetrameric water cluster rings in the crystal structure of a new proton transfer system derived from pyridine-2,6-dicarboxylic acid and 2-amino-4-methylpyridine [19]. Several different conformations for the water hexamer, such as all-boat [20], all chairs or an intermediate between chair and boat [3,21