title: Exploring intertrimer Cu...Cu interactions and further phosphorescent properties of aryl trimer copper(I) Pyrazolates via substituent changing and external pressure.
abstract: To explore the effect of intertrimer Cu...Cu interactions on the phosphorescent properties of trimeric copper(I) pyrazolates, three new complexes with identical core cluster structures and different substituents, {[3,5-(Me)(2)-4-(Ph)Pz]Cu}(3) (MPC-P), {[3,5-(Me)(2)-4-(1-Naph)Pz]Cu}(3) (MPC-N), and {[3,5-(Me)(2)-4-(9-Anthr)Pz]Cu}(3) (MPC-A), were synthesized. The intertrimer Cu...Cu distances of the three complexes were obtained from X-ray crystallographic data or molecular dynamics simulations. The phosphorescent properties of the three complexes were investigated at various pressures. At ambient pressure, the emissions of the three complexes were dramatically different from each other. For MPC-P, the main emission band was identified as phosphorescence and MPC-N gave a predominant emission of fluorescence and a weak emission of phosphorescence. When the substitutent was replaced by an anthryl group in MPC-A, no phosphorescence was observed, except for a strong fluorescence band. The phosphorescence of the trimer copper(I) pyrazolates was assigned to the excited-state dimer/polymer *[Cu(3)](n) with LMCT characteristics. Under higher external pressures, only phosphorescent intensities of MPC-P showed considerable enhancement at pressures up to 2 GPa. External pressure reduced the intertrimer Cu...Cu distances of MPC-P and enhanced the phosphorescence intensities, providing a direct evidence to support the assignment of phosphorescence.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Fangbin
authors.initials: F
authors.lastname: Gong
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Zhipei
authors.initials: Z
authors.lastname: Yang
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Shayu
authors.initials: S
authors.lastname: Li
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Yang
authors.forename: Ligang
authors.initials: L
authors.lastname: Bai
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Dong