Synthesis, crystal structures, linear and nonlinear optical properties, and theoretical studies of (p-R-phenyl)-, (p-R-phenylethynyl)-, and (E)-[2-(p-Rphenyl)ethenyl]dimesitylboranes and related compounds

Zheng Yuan, Christopher D. Entwistle, Jonathan C. Collings, David Albesa-Jové, Andrei S. Batsanov, Judith A.K. Howard, Nicholas J. Taylor, Hanns Martin Kaiser, Dieter E. Kaufmann, Suk Yue Poon, Wai Yeung Wong, Christophe Jardin, Sofiane Fathallah, Abdou Boucekkine, Jean François Halet, Todd B. Marder

Research output: Journal article publicationJournal articleAcademic researchpeer-review

195 Citations (Scopus)

Abstract

The (p-R-phenyl)dimesitylboranes (R = Me2N, MeO, MeS, Br, I), (p-R-phenylethynyl)dimesitylboranes (R = Me2N, MeO, MeS, H), (E)-[2-(pR-phenyl)ethenyl]dimesitylboranes (R = Me2N, H2N, MeO, MeS, H, CN, NO2), (E)-[2-(2-thienyl)ethenyl]dimesitylborane, and (E)-[2-(o-carboranyl)ethenyl]dimesitylborane have been prepared through the reaction of the appropriate p-R-phenyl- and p-R-phenylethynyllithium reagents with dimesitylboron fluoride and by hydroboration of the appropriate p-R-phenylacetylene, 2-ethynylthiophene, and o-ethynylcarborane with dimesitylborane. Their UV/Vis absorption and emission spectra have been recorded in a range of solvents with the fluorescence maxima of the donor-substituted compounds in particular exhibiting large bathochromic shifts in highly polar solvents, indicative of charge transfer leading to large dipole moments in the excited state. The molecular structures of the (p-R-phenyl)dimesitylboranes (R = Me2N, MeO, MeS, Br, I), the (E)-[2-(pR-phenyl)ethenyl] dimesitylboranes (R = Me2N, H2N MeO, MeS, H), (p-Rphenylethynyl)dimesitylborane (R = Me2N), and (E)-[2-(2-thienyl)ethenyl]dimesitylborane, which have been determined from single-crystal X-ray diffraction measurements, offer evidence of increased conjugation in the ground state with increased donor strength of the R substituent. Their first- and second-order molecular hyperpolarizabilities have been obtained from EFISH and THG measurements, the first-order hyperpolarizabilities being largest for the strongest R-substituent donors. AMI calculations have been performed on these compounds, showing reasonable agreement with the experimentally obtained bond lengths and hyperpolarizabilities, as well as on several related hypothetical compounds containing multiple C=C bonds, most of which are proposed to have even larger hyperpolarizabilities. KGaA.
Original languageEnglish
Pages (from-to)2758-2771
Number of pages14
JournalChemistry - A European Journal
Volume12
Issue number10
DOIs
Publication statusPublished - 20 Mar 2006
Externally publishedYes

Keywords

  • Boranes
  • Nonlinear optics
  • Semiempirical calculations
  • Synthetic methods
  • X-ray diffraction

ASJC Scopus subject areas

  • Chemistry(all)

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