摘要
Nanoclusters of dicyanocuprate (1) ions doped in potassium chloride crystals have been studied. Several emission bands are observed in this system and each emission band can be tuned by site-selective spectroscopy. These bands are assigned to different [Cu(CN)(2)](-) luminescent nanoclusters in the host lattice. The Cu( ) ions substitute for K( ) ions in the lattice and the CN(-) ions substitute for Cl(-) ions in the host with dimer and trimer nanoclusters bonded together by CN(-) bridges. This is unlike KAg(CN)(2) or KAu(CN)(2) substituted in a KCl lattice, in which Ag-Ag or Au-Au bonding directly occurs. Ab initio calculations show that the LUMO is a bonding MO while the HOMO is antibonding. Extended Huckel calculations indicate the formation of the LUMO excited-state well is deeper than the ground-state HOMO potential well and with a shorter internuclear separation characteristic of exciplex behavior. Time-resolved luminescence measuremence at room temperature and 78 K demonstrate that, upon pulsed excitation, energy transfer occurs between the dimer and trimer nanoclusters. We conclude that the presence of different luminescent Cu(CN)(2)(-) nanoclusters in different environments results in tunability over a wide wavelength range.
- 出版日期2009-4-16
- 单位吉林大学