Cascade C-H Halogenation of Tetraazapyrene with Iodine Halides.

Iodine halide as an efficient and selective halogenation reagent is presented for the cascade halogenation of an electron-deficient tetraazapyrene (TAP), yielding both chlorinated and heterohalogenated derivatives. This approach enables precise control over the LUMO energy levels of the resulting TAPs by varying the type and extent of halogenation, offering a powerful strategy for fine-tuning their electronic properties. These findings open new avenues for the rational design of TAP-based materials in organic molecular electronics.