This distinct involvement of the sulfur atoms must be linked to their respective relative location to the boron and nitrogen atoms that are central to the SRCT emissive state. For tDPABT1B and tCzBT1B, the electron-donating strength of the sulfur atoms is counteracted by the inductively electron-accepting effect from the para-positioned boron atom, whereas for tDPABT2B and tCzBT2B, the ortho positioned nitrogen atoms enhance the electron-donating character of the sulfur atoms. Notably, although all four emitters possess much larger SOCME values between S1/T1 (𝐻 ,-. #/0/ > 0.10 cm -1 ) compared to DtBuCzB (𝐻 ,-. #/0/ = 0.02 cm -1 calculated at the wB97XD/def2-SVP level), or DABNA-1 (𝐻 ,-. #/0/ = 0.06 cm -1 calculated at the RHF/6-31 G level level), tCzBT2B and tDPABT2B in particular have two times higher 𝐻 ,-. #/0/ of 0.60 and 0.24 cm -1 compared to those of 0.27 and 0.11 cm -1 for tCzBT1B and tDPABT1B, respectively.