<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>R.C. Burruss</dc:contributor>
  <dc:contributor>E.D. Sloan Jr.</dc:contributor>
  <dc:creator>A. K. Sum</dc:creator>
  <dc:date>1997</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Raman spectra of clathrate hydrate guest molecules are presented for three known structures (&lt;/span&gt;&lt;strong&gt;I&lt;/strong&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sI&lt;/strong&gt;&lt;span&gt;),&amp;nbsp;&lt;/span&gt;&lt;strong&gt;II&lt;/strong&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sII&lt;/strong&gt;&lt;span&gt;), and&amp;nbsp;&lt;/span&gt;&lt;strong&gt;H&lt;/strong&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sH&lt;/strong&gt;&lt;span&gt;)) in the following systems:  CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sI&lt;/strong&gt;&lt;span&gt;), CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sI&lt;/strong&gt;&lt;span&gt;), C&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;H&lt;/span&gt;&lt;sub&gt;8&lt;/sub&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sII&lt;/strong&gt;&lt;span&gt;), CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;+ CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sI&lt;/strong&gt;&lt;span&gt;), CD&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;+ C&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;H&lt;/span&gt;&lt;sub&gt;8&lt;/sub&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sII&lt;/strong&gt;&lt;span&gt;), CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;+ N&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sI&lt;/strong&gt;&lt;span&gt;), CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;+ THF-&lt;/span&gt;&lt;i&gt;d&lt;/i&gt;&lt;sub&gt;8&lt;/sub&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sII&lt;/strong&gt;&lt;span&gt;), and CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;+ C&lt;/span&gt;&lt;sub&gt;7&lt;/sub&gt;&lt;span&gt;D&lt;/span&gt;&lt;sub&gt;14&lt;/sub&gt;&lt;span&gt;&amp;nbsp;(&lt;/span&gt;&lt;strong&gt;sH&lt;/strong&gt;&lt;span&gt;). Relative occupancy of CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;in the large and small cavities of&amp;nbsp;&lt;/span&gt;&lt;strong&gt;sI&lt;/strong&gt;&lt;span&gt;&amp;nbsp;were determined by deconvoluting the ν&lt;/span&gt;&lt;sub&gt;1&lt;/sub&gt;&lt;span&gt;&amp;nbsp;symmetric bands, resulting in hydration numbers of 6.04 ± 0.03. The frequency of the ν&lt;/span&gt;&lt;sub&gt;1&lt;/sub&gt;&lt;span&gt;&amp;nbsp;bands for CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;in structures I, II, and H differ statistically, so that Raman spectroscopy is a potential tool to identify hydrate crystal structure. Hydrate guest compositions were also measured for two vapor compositions of the CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;+ CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;system, and they compared favorably with predictions. The large cavities were measured to be almost fully occupied by CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;, whereas only a small fraction of the small cavities are occupied by CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;. No CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;was found in the small cavities. Hydration numbers from 7.27 to 7.45 were calculated for the mixed hydrate.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1021/jp970768e</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>ACS Publications</dc:publisher>
  <dc:title>Measurement of clathrate hydrates via Raman spectroscopy</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>