Tunable Radiationless Energy Transfer in Eu[Au(CN)2]3·3H2O by High Pressure
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- 作者：Hartmut Yersin ; Dietrich Trü ; mbach ; Johann Strasser ; Howard H. Patterson ; and Zerihun Assefa
- 刊名：Inorganic Chemistry
- 出版年：1998
- 出版时间：June 29, 1998
- 年：1998
- 卷：37
- 期：13
- 页码：3209 - 3216
- 全文大小：138K
- 年卷期：v.37,no.13(June 29, 1998)
- ISSN：1520-510X
文摘
The title compound consists of two-dimensional layers of[Au(CN)2]- complexes alternating withlayers of Eu3+ions. Due to this structure type, the lowest electronictransitions of the dicyanoaurates(I) exhibit an extremeredshift of 
max/p = -130 ± 10cm-1/kbar under high-pressure application atleast up to 
60 kbar (T = 20 K),while the shifts of the different Eu3+ transitions liebetween -0.70 and -0.94 cm-1/kbar.At ambient pressure,the usually very intense emission of the dicyanoaurates(I) iscompletely quenched due to radiationless energytransfer to the Eu3+ acceptors. As a consequence,one observes a strong emission from Eu3+, which isassignedto stem mainly from 5D0 but also weakly from5D1. At T = 20 K,5D3 seems to be the dominant acceptorterm.It is a highlight of this investigation that, with increasingpressure, the emission from the dicyanoaurate(I)donorstates can continuously be tuned in by tuning off the resonancecondition (spectral overlap) for radiationlessenergy transfer to 5D3. With furtherincrease of pressure, successively, 5D2 and5D1 become acceptor terms,however, being less efficient. Interestingly,5D0 does not act as an acceptor term even withmaximum spectraloverlap. Between 30 and 60 kbar, when only the7F0 
5D1 acceptorabsorption overlaps with the donor emission,one finds a linear dependence of the (integrated)5D0 emission intensity on the spectral overlapintegral, as isexpected for resonance energy transfer. As the dominant transfermechanism, the Dexter exchange mechanismis proposed. Besides the high-pressure studies of theEu3+ line structure at T = 20 K, theEu3+ emission is alsoinvestigated at T = 1.2 K (p = 0 kbar) bytime-resolved emission spectroscopy, which strongly facilitatestheassignments of the emitting terms.
max/p = -130 ± 10cm-1/kbar under high-pressure application atleast up to 60 kbar (T = 20 K),while the shifts of the different Eu3+ transitions liebetween -0.70 and -0.94 cm-1/kbar.At ambient pressure,the usually very intense emission of the dicyanoaurates(I) iscompletely quenched due to radiationless energytransfer to the Eu3+ acceptors. As a consequence,one observes a strong emission from Eu3+, which isassignedto stem mainly from 5D0 but also weakly from5D1. At T = 20 K,5D3 seems to be the dominant acceptorterm.It is a highlight of this investigation that, with increasingpressure, the emission from the dicyanoaurate(I)donorstates can continuously be tuned in by tuning off the resonancecondition (spectral overlap) for radiationlessenergy transfer to 5D3. With furtherincrease of pressure, successively, 5D2 and5D1 become acceptor terms,however, being less efficient. Interestingly,5D0 does not act as an acceptor term even withmaximum spectraloverlap. Between 30 and 60 kbar, when only the7F0 5D1 acceptorabsorption overlaps with the donor emission,one finds a linear dependence of the (integrated)5D0 emission intensity on the spectral overlapintegral, as isexpected for resonance energy transfer. As the dominant transfermechanism, the Dexter exchange mechanismis proposed. Besides the high-pressure studies of theEu3+ line structure at T = 20 K, theEu3+ emission is alsoinvestigated at T = 1.2 K (p = 0 kbar) bytime-resolved emission spectroscopy, which strongly facilitatestheassignments of the emitting terms.