Ito M,
Mera A,
Mashimo T,
Seki T,
Karanjit S,
Ohashi E,
Nakayama A,
Kitamura K,
Hamura T,
Ito H,
Namba K.
* Tokushima University, Tokushima, Hokkaido University, and Kwansei Gakuin University,
Hyogo, Japan
Synthesis and Evaluation of a 1,3a,6a-Triazapentalene (TAP)-Bonded System.
Chem. Eur. J. 2018;
24: 17727-17733
Key words
nitrogen heterocycles - click chemistry - mechanochromism
Significance
Designing linearly bonded aromatic systems with a planar form introduces new materials
with highly conductive properties for potential applications in molecular wires. A
recently developed 1,3a,6a-triazapentalene (TAP) has been developed as a novel fluorescent
chromophore with a 10π-electron system in a compact bicyclo[3.3.0]octane skeleton
(highlighted core of 5). The dimer and trimer (8 and 10, respectively) were synthesized sequentially and characterized by a linear connection
in planar form with alternating charges between the linked monomers.
Comment
Tap units were synthesized by click reactions of alkynes (1) with azidotriflate (2), which could be extended by sequential reactions repeating the same procedure. The
alternating charge led to unique fluorescence properties derived from changes in the
aggregation state under concentrated conditions. Extension of the bonded systems also
resulted in increased fluorescence in the solid state and fluorescence change upon
mechanical grinding.
