Synthetic precursors for TCNQF4(2-) compounds: synthesis, characterization, and electrochemical studies of (Pr4N)2TCNQF4 and Li2TCNQF4

J Org Chem. 2012 Dec 7;77(23):10568-74. doi: 10.1021/jo301403v. Epub 2012 Nov 15.

Abstract

Careful control of the reaction stoichiometry and conditions enables the synthesis of both LiTCNQF(4) and Li(2)TCNQF(4) to be achieved. Reaction of LiI with TCNQF(4), in a 4:1 molar ratio, in boiling acetonitrile yields Li(2)TCNQF(4). However, deviation from this ratio or the reaction temperature gives either LiTCNQF(4) or a mixture of Li(2)TCNQF(4) and LiTCNQF(4). This is the first report of the large-scale chemical synthesis of Li(2)TCNQF(4). Attempts to prepare a single crystal of Li(2)TCNQF(4) have been unsuccessful, although air-stable (Pr(4)N)(2)TCNQF(4) was obtained by mixing Pr(4)NBr with Li(2)TCNQF(4) in aqueous solution. Pr(4)NTCNQF(4) was also obtained by reaction of LiTCNQF(4) with Pr(4)NBr in water. Li(2)TCNQF(4), (Pr(4)N)(2)TCNQF(4), and Pr(4)NTCNQF(4) have been characterized by UV-vis, FT-IR, Raman, and NMR spectroscopy, high resolution electrospray ionization mass spectrometry, and electrochemistry. The structures of single crystals of (Pr(4)N)(2)TCNQF(4) and Pr(4)NTCNQF(4) have been determined by X-ray crystallography. These TCNQF(4)(2-) salts will provide useful precursors for the synthesis of derivatives of the dianions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallography, X-Ray
  • Electrochemistry
  • Lithium Compounds / chemical synthesis*
  • Lithium Compounds / chemistry
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Quaternary Ammonium Compounds / chemical synthesis*
  • Quaternary Ammonium Compounds / chemistry
  • Technetium Compounds / chemical synthesis*
  • Technetium Compounds / chemistry

Substances

  • Lithium Compounds
  • Quaternary Ammonium Compounds
  • Technetium Compounds
  • tetrapropylammonium