Borylated Pyrenes and Terrylenes as blue and green emitters

Pyrene, a classical polycyclic aromatic hydrocarbon and promising chromophore, has been frequently employed as a building block to develop novel π-extended systems. It can be readily functionalized at the most of the postions, only the 2- and 7-positions are less reactive and modifications at these positions are thus very difficult.

Prof. Klaus Müllen an co-workers at the Max-Planck-Institute for Polymer Research developed a straightforward C-H borylation at the 2- and 2,7-positions of pyrene derivatives, generating a new type of non-K-region heteroannelated pyrene-based chromophores, i.e. 2-(tert-butyl)-10,11-dioxa-10a-boratribenzo[a,f,lm]perylene (1) and 11,12,23,24-tetraoxa-11a,23a-diboratetrabenzo[a,f,n,s]terrylene (2).

Compound 1 exhibits strong blue fluorescence (λ_max: 442 nm) with a quantum yield of 70%, whereas compound 2 with alkyl substituents displays bright green fluorescence (λ_max: 525 nm) with a quantum yield of 84%.

• neutral organic molecules with a relative molare mass (RMM) < 1000
• high photoluminiscense quantum yield (PLQY)
• fluorescence spectrum sharp emission peeks between 400-550 nm

MI 0903-5692-LC: "Novel fluorescent pyrene derivatives, methods for preparing the same, and uses thereo", EP priority application filed in September 2018, PCT application WO2020058203A1 filed in September 2019.

Substance, Method, Use and Device claims - only A citations in the ISR.

Xuelin Yao, Ke Zhang, Klaus Müllen, Xiao-Ye Wang: "Direct C-H Borylation at the 2- and 2,7-Positions of Pyrene Leading to Brightly Blue- and Green-Emitting Chromophores"; Asian J. Org. Chem. 2018, 7, 2233 – 2238