Fig. 2: Synthesis of 5, 7 and 10.

a Synthesis of 5 and its mixed BF₂–Cu(III) complex 7. Conditions: (i) 1 equiv. DDQ and trifluoromethanesulfonic acid in dichloromethane (DCM) with stirring at 0 °C for 0.5 h, then room temperature for 12 h, 30%; (ii) n-BuLi in THF, −78 °C, 1 h, then mesitaldehyde, −78 °C, 1 h, 71%; (iii) pyrrole and BF₃·OEt₂, reflux, 20 h, 75%; (iv) pentafluorobenzaldehyde and BF₃·OEt₂ in dry DCM, room temperature, 2.5 h, followed by DDQ, room temperature, 0.5 h, 6%; (v), BF₃·OEt₂ and N,N-diisopropylethylamine (DIPEA) in toluene, with stirring at 80 °C for 12 h, 70%; (vi) Cu(OAc)₂ in CHCl₃/CH₃CN (v/v 3:2), reflux, 48 h, 24%. Mes and C₆F₅ denote mesityl and pentafluorophenyl groups, respectively; (b) Synthesis of bis-BODIPY complex 10. Conditions: (vii), BF₃·OEt₂ and N,N-diisopropylethylamine (DIPEA) in toluene, with stirring at 80 °C for 12 h, 59%.