Synthesis and Thermochromic Luminescence of Ag(I) Complexes Based on 4,6-Bis(diphenylphosphino)-Pyrimidine
oleh: Alexander V. Artem’ev, Maria P. Davydova, Alexey S. Berezin, Denis G. Samsonenko
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2020-08-01 |
Deskripsi
Two Ag(I)-based metal-organic compounds have been synthesized exploiting 4,6-bis(diphenylphosphino)pyrimidine (L). The reaction of this ligand with AgNO<sub>3</sub> and AgBF<sub>4</sub> in acetonitrile produces dinuclear complex, [Ag<sub>2</sub>L<sub>2</sub>(MeCN)<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>] (<b>1</b>) and 1D coordination polymer, [Ag<sub>2</sub>L(MeCN)<sub>3</sub>]<i><sub>n</sub></i>(BF<sub>4</sub>)<sub>2<i>n</i></sub> (<b>2</b>), respectively. In complex <b>1</b>, µ<sub>2</sub>-P,P′-bridging coordination pattern of the ligand L is observed, whereas its µ<sub>4</sub>-P,N,N′,P′-coordination mode appears in <b>2</b>. Both compounds exhibit pronounced thermochromic luminescence expressed by reversible changing of the emission chromaticity from a yellow at 300 K to an orange at 77 K. At room temperature, the emission lifetimes of <b>1</b> and <b>2</b> are 15.5 and 9.4 µs, the quantum efficiency being 18 and 56%, respectively. On account of temperature-dependent experimental data, the phenomenon was tentatively ascribed to alteration of the emission nature from thermally activated delayed fluorescence at 300 K to phosphoresce at 77 K.