| Autor: |
Zafar M; Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem 9190401, Israel., Subramaniyan V; Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem 9190401, Israel., Ansari KU; Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem 9190401, Israel., Yakir H; Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem 9190401, Israel., Danovich D; Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem 9190401, Israel., Tulchinsky Y; Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem 9190401, Israel. |
| Abstrakt: |
Thioxanthone (TX) molecules and their derivatives are well-known photoactive compounds. Yet, there exist only a handful of luminescent systems combining TX with transition metals. Recently, we reported a TX-based PSP pincer ligand ( L1 ) that appears as a promising platform for filling this niche. Herein, we demonstrate that with Cu(I) this ligand exclusively assembles into dimeric structures with either di- or polynuclear Cu(I) cores. With cationic Cu(I) precursors, complexes featuring solvent-bridged bis-cationic cores were obtained. These coordinatively unsaturated bimetallic systems showed surprisingly facile activation of the chloroform C-Cl bonds, suggesting a possible metal-metal cooperation. The reaction of L1 with binary Cu(I) halides afforded dimeric complexes with polynuclear [CuX] n ( n = 3 or 4) cores. With X = Br or I, emissive complexes containing stairstep [CuX] 4 clusters were obtained. Emission lifetimes in the microsecond range measured for these complexes were indicative of a triplet emission (phosphorescence), which according to our time-dependent density functional theory study originates from a halide-metal-to-ligand charge transfer between the [CuX] 4 cluster and the TX backbone of L1 . Finally, the distinctive polynucleating behavior of L1 toward Cu(I) was also showcased by a comparison to another PSP ligand with a diaryl thioether backbone ( L2 ), which formed only mononuclear pincer-type complexes, lacking any unusual reactivity or photoluminescence. |
