Tapes of water hexamer clusters in the interlayer space of a 2D MOF:
Structural, spectroscopic and computational insight of the confined
water
POLYHEDRON, 31 (1):
729-737 (2012)DOI: 10.1016/j.poly.2011.10.030
Abstract
The synthesis, crystal structure and characterization of
Er-2(C4H4O4)(3)(H2O)(4)center dot 6H(2)O, with particular emphasis
on the structural details and the vibrational behavior of the highly
organized sub-net of water are reported. X-ray structural analysis
reveals that the hybrid framework, which can be classified as belonging
to the (IO2)-O-0 type, acts as a host of an infinite tape of
six-membered water rings with distorted chair conformation. The water
network extends between the hybrid layers helping the close packing and
the stabilization of the structure through H-bond interactions, with
further development of the supramolecular tridimensional structure. The
self-assembly of the hydration water molecules is conditioned by the
hybrid host, forcing them to adopt a less stable conformation when
compared with hexagonal ice. The vibrational spectra of partially and
completely dehydrated samples as well as of partially isotopic diluted
ones have been obtained and analyzed. In order to guide the assignment
of the vibrational spectra a theoretical calculation was performed at
the B3LYP/6-31G** level for a model consisting of three water
clusters. (C) 2011 Elsevier Ltd. All rights reserved.