Molecular ice

This cluster structure is the smallest unit of the 3D hydrogen-bonded network of naturally occurring fc-type ice. If the ice structure is defined by the 3D network of water molecules, the (H2O)10 cluster in our cavity is regarded as molecular ice . The 

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Four years of study led to the discovery of glycine in the millimetre wavelength range in the hot molecular clouds of Sagittarius (around 81,500 light years away), Orion KL and W51. We can only conjecture as to the mechanism of its formation. Ion-molecule reactions in the gas phase, as well as UV photolytic processes in molecular ice, have been discussed. 

While many of these new species sublime when the irradiated ice is warmed from 200K to room temperature under vacuum, a thick oily residue of nonvolatile material remains. Among many other things, this residue is rich in the cage molecule hexamethylenetetramine (HMT, C6H12N4) 38). This contrasts with the organic residues produced by irradiating mixed molecular ices which do not contain methanol (e.g. refs. 14, 38, 39) and those produced in thermally promoted polymerization-type reactions in non-irradiated realistic ice mixtures... 

M. Yoshizawa, T. Kusukawa, M. Kawano, T. Ohhara, I. Tanaka, K. Kurihara, N. Niimura, M. Fujita, Endohedral clusterization of ten water molecules into a molecular ice within the hydrophobic pocket of a self-assembled cage, J. Am. Chem. Soc., 2005, 127, 2798-2799. 

One of the recent examples to underscore the unique water properties is the endohedral clusterization of water molecules into a molecular ice within a hydrophobic self-assembled cage. It was known earlier that the hydrogen-bond network of water can spontaneously grow not only on the surface of hydrophobic solute, affording stable hydrate... 

The presence of mantles on silicate grains is revealed by absorption bands of water ice, superimposed with features from carbon monoxide, carbon dioxide, methanol and other less abundant constituents. As for the silicate bands, the spectral features associated with molecular ices are most prominent in the infrared spectral region, between 3 and 40 pm mainly. Because water ice is the main constituent of ice mantles, the spectral features due to water ice are the strongest, especially the 3.1 pm feature due to the stretching mode of the 0-H bound in solid water. This band can be fully saturated for deeply embedded young stellar objects. 

Das MC, Bharadwaj PK (2007) Molecular ice with hybrid water-bromide network around a cryptand with a bromide ion included in the cavity to form a host-within-a-host-Uke structure. Eur J Inorg Chem 2007 1229-1232... 

Scheme 4.8 - 649, thus forming an adamantanoid cluster (H20)io (so-called molecular ice ) within its cavity. Such molecular ice does not melt even at room temperature and is not sustained by any metal cation or anion coordination [10] it flUs the void of the cavity of 488 forming OH...% and H2O... K interactions. A single-crystal neutron diffraction smdy of [10] showed that the cluster (H20)io donated the electrons of a lone pair of the bridgehead water molecule. 

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