1402151-90-9Relevant academic research and scientific papers
Luminescent Quadrupolar Borazine Oligomers: Synthesis, Photophysics, and Two-Photon Absorption Properties
Chen, Pangkuan,Marshall, Ariel S.,Chi, San-Hui,Yin, Xiaodong,Perry, Joseph W.,J?kle, Frieder
, p. 18237 - 18247 (2015/12/24)
A set of monodisperse bent donor-acceptor-donor-type conjugated borazine oligomers, BnNn+1 (n=1-4), incorporating electron-rich triarylamine donor and electron-deficient triarylborane acceptor units has been prepared through an iterative synthetic approach that takes advantage of highly selective silicon-boron and tin-boron exchange reactions. The effect of chain elongation on the electrochemical, one- and two-photon properties and excited-state photodynamics has been investigated. Strong intramolecular charge transfer (ICT) from the arylamine donors to boryl-centered acceptor sites results in emissions with high quantum yields (Φfl>0.5) in the range of 400-500nm. Solvatochromic effects lead to solvent shifts as large as ?70nm for the shortest member (n=1) and gradually decrease with chain elongation. The oligomers exhibit strong two-photon absorption (2PA) in the visible spectral region with 2PA cross sections as large as 1410GM (n=4), and broadband excited-state absorption (ESA) attributed to long-lived singlet-singlet and radical cation/anion absorption. The excited-state dynamics also show sensitivity to the solvent environment. Electrochemical observations and DFT calculations (B3LYP/6-31G) reveal spatially separated HOMO and LUMO levels resulting in highly fluorescent oligomers with strong ICT character. The BnNn+1 oligomers have been used to demonstrate the detection of cyanide anions with association constants of log K>7.
π-Expanded borazine: An ambipolar conjugated B-π-N macrocycle
Chen, Pangkuan,Lalancette, Roger A.,Jaekle, Frieder
, p. 7994 - 7998 (2012/10/08)
Staying at a B 'N' B: A highly symmetric cyclic structure in which N donor and B acceptor sites are alternating (see picture) is found for the first ambipolar π-conjugated B-N macrocycle. The donor-π-acceptor arrangement results in mutual interactions between B and N and a pronounced solvatochromic effect on the emission. The strong luminescence in solution also lends itself to use in anion recognition. Copyright
