Synthetic Diversity and Luminescence Properties of ArN(PPh 2 ) 2 ‐Based Copper(I) Complexes

The dinuclear copper(I) complexes 1 and 2 were prepared by reacting PNP ligands ArN(PPh 2 ) 2 , (Ar = 2,6‐Me 2 C 6 H 3 ; L1 ) with CuCl and CuBr. By altering the position of the methyl substituents from ortho to meta (Ar = 3,5‐Me 2 C 6 H 3 ; L2 ), trinuclear copper(I) complexes 3 and 4 were obtained, while the methyl substituent at the para position (Ar = 4‐MeC 6 H 4 ; L3 ) led to the tetranuclear copper(I) complexes 5 and 6 . Single crystal X‐ray studies show the different Cu ··· Cu interactions in complexes 1 – 6 ranging from 2.650 to 2.935 Å. The copper(I) complexes 3 – 6 were found to exhibit mechanochromic as well as thermochromic luminescent behavior presumably stemming from a decrease in their Cu ··· Cu distances.