Collins and co-workers in 2018 examined the series of heteroleptic diamine diphosphine copper (I) complexes for synthesis of pyrroles from vinyl azides via their sensitization through energy transfer (Figure ), 100 a transformation initially reported by the Yoon group in 2013 using ruthenium (II) photocatalysis. Notably, [Cu(dmp)(BINAP)]BF4 was found to be highly effective and provided the desired pyrrole product 22.3, in quantitative yields. It was observed while screening the catalysts that Cu(I)-BINAP based complexes had the most comparable triplet state energies to the vinyl azide 22.1 (1.9 eV); 142 however, [Cu(dmp)(BINAP)]BF4 exhibited the longest excited state lifetime which correlated with the highest yields.