Synthesis and structural study of 1-(N,N-diethylamino)-2,2-bis(2-nitrophenylthio)ethene

J. J. Aupers, Janet Mabel Scott Skakle, J. L. Wardell, S. M. S. V. Wardell

Research output: Contribution to journalArticle

Abstract

The synthesis, variable temperature NMR spectra, and crystal structures of two crystalline forms, 2a and 2b, of the enamine 1-(N,N-diethylamino)-2,2-bis(2-nitrophenylthio)ethene have been obtained. Both forms crystallize in the monoclinic space group P2(1)/a. The two phases have similar molecular structures but possess different intermolecular C-H... O hydrogen bonding interactions. Both forms exhibit disorder within the NEt2 fragment at 298 K: sufficient disorder persisted with 2a (orange needles) down to 100 K to make the geometric parameters pertaining to the enamine fragment unreliable. The disorder was effectively eliminated on cooling 2b down (red colored blocks) to 150 K. Cell dimensions for the 2a-phase are at 100 K: a = 11.1030(4) Angstrom, b = 15.1325(7) Angstrom, c = 12.4504(7) Angstrom, beta = 114.606(3)degrees, while for the 2b-phase at 150 K, a = 15.5206(4) Angstrom, b = 7.6958(2) Angstrom, c = 15.7137(3) Angstrom, beta = 92.580(7)degrees. The C-N bond length in the beta-form at 150 K of 1.335(3) Angstrom indicates considerable double bond character: the rotational barrier of the C-N bond in CDCl3 was calculated to be 52.4 kJ mol(-1).

Original languageEnglish
Pages (from-to)435-443
Number of pages8
JournalJournal of Chemical Crystallography
Volume31
Issue number9
DOIs
Publication statusPublished - 2001

Keywords

  • enamine
  • ketene dithioacetals
  • rotational barrier
  • push-pull compounds
  • PUSH-PULL
  • CONFORMATIONAL PREFERENCES
  • X-RAY
  • BOND
  • ETHYLENES
  • CRYSTALS
  • NMR

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