Lanthanide-organic complexes based on polyoxometalates: Solvent effect on the luminescence properties

作者：Tang, Qun; Liu, Shu-Xia^*; Liang, Da-Dong; Ma, Feng-Ji; Ren, Guo-Jian; Wei, Feng; Yang, Yuan; Li, Cong-Cong

来源：Journal of Solid State Chemistry, 2012, 190: 85-91.

DOI：10.1016/j.jssc.2012.02.006

• Polyoxometalate
• Lanthanide
• Luminescence property
• Solvent effect

A series of lanthanide-organic complexes based on polyoxometalates (POMs) [Ln(2)(DNBA)(4)(DMF)(8)] [W6O19] (Ln=La(1), Ce(2), Sm(3), Eu(4), Gd(5); DNBA=3,5-dinitrobenzoate; DMF=N,N-dimethylformamide) has been synthesized. These complexes consist of [W6O19](2-) and dimeric [Ln(2)(DNBA)(4) (DMF)(8)](2+) cations. The luminescence properties of 4 are measured in solid state and different solutions, respectively. Notably, the emission intensity increases gradually with the increase of solvent permittivity, and this solvent effect can be directly observed by electrospray mass spectrometry (ESI-MS). The analyses of ESI-MS show that the eight coordinated solvent DMF units of dimeric cation are active. They can move away from dimeric cations and exchange with solvent molecules. Although the POM anions escape from 3D supramolecular network, the dimeric state structure of [Ln2(DNBA)4]2+ remains unchanged in solution. The conservation of red luminescence is attributed to the maintenance of the aggregated state structures of dimeric cations.

• 出版日期2012-6
• 单位东北师范大学