Heteroleptic copper(I) photosensitizers of dibenzo[b,j]-1,10-phenanthroline derivatives driven hydrogen generation from water reduction

A series of dibenzo[b,j]-1,10-phenanthroline derivatives as N ligands was synthesized and their heteroleptic copper complexes were applied as photosensitizer in photocatalytic Cu-Fe water reduction system. The highest turnover number of copper was up to 441 and the system achieved a stability of 15 h. Noteworthy, for the first time it could be detected and explained why a C-C single bond at 6,7 positions of phenanthroline could significantly increase the light conversion efficiency.