<?xml version="1.0" encoding="utf-8"?>
<export-example>
  <doc>
    <id>2465</id>
    <completedYear/>
    <publishedYear>2003</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>219</pageFirst>
    <pageLast>230</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>649</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace>Amsterdam</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Characterization of a new non-centrosymmetric polymorph of diphenyl-1,3,4-oxadiazole</title>
    <abstract language="eng">Diphenyl-1,3,4-oxadiazole (DPO) crystallization experiments from solutions clearly reveal the polymorphism of the substance. Besides the formerly known centrosymmetric monoclinic structure with space group P21/c (DPO I) a new monoclinic structure with the non-centrosymmetric space group Cc is found (DPO II): a=2.4134(4) nm, b=2.4099(3)  nm, c=1.2879(2) nm,?=110.048(3)°, and V=7.0363(17) nm3. The asymmetric unit contains six independent molecules in a complex packing motif. A re-determination of the crystal structure of DPO I at room temperature gives lattice parameters a=0.51885(6) nm, b=1.8078(2) nm, c=1.21435(14) nm, ?=93.193(3)°, and V=1.1373(2) nm3. X-ray measurements at 363 K show a significant increase of the unit cell volume by 1.6%. Differences between both structures concerning morphology and characteristic Raman bands are outlined in detail. DSC investigations show an irreversible transition from DPO I to DPO II at 97 °C. DPO II does not show any transition in the temperature range up to the melting point at 141 °C. The non-centrosymmetric DPO II structure shows triboluminescence.</abstract>
    <parentTitle language="eng">Journal of molecular structure</parentTitle>
    <identifier type="old">2424</identifier>
    <identifier type="doi">10.1016/S0022-2860(02)00569-0</identifier>
    <identifier type="issn">0022-2860</identifier>
    <identifier type="issn">1872-8014</identifier>
    <identifier type="issn">0377-046X</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="date_peer_review">24.04.2003</enrichment>
    <author>O. Franco</author>
    <author>Günter Reck</author>
    <author>I. Orgzall</author>
    <author>Burkhard Schulz</author>
    <author>B. Schulz</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Diphenyl-1,3,4-oxadiazole</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>X-ray structure</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Polymorphism</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Non-centrosymmetric structure</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
</export-example>
