Diazadibora[1.1.1.1]m,p,m,p-cyclophanes: Ambipolar Conjugated Macrocycles with Different B-π-N Embedded Patterns.

Are different B(boron)-π-N(nitrogen) embedded patterns to bring about significant different (opto)electronic properties for the same macrocyclic molecular backbone? A series of B-π-N-embedded alternate-meta-para-linked cyclophanes 1-3 have been prepared and characterized as a new class of ambipolar π-conjugated B-π-N macrocycles. The answer to the opening question is yes. These macrocycles revealed the intramolecular charge transfer in the oxidized states and the intriguing photophysical proprerties in accordance with the embedded patterns, suggesting the electronic structures are tunable by introducing multiple B-π-N moieties.