Light-Induced Metastable States in Oxalatenitrosylruthenium(II) and Terpyridinenitrosylruthenium(II) Complexes

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• 作者：Sylvie Ferlay ; Helmut W. Schmalle ; Giancarlo Francese ; Helen Stoeckli-Evans ; Mirco Imlau ; Dominik Schaniel ; and Theo Woike
• 刊名：Inorganic Chemistry
• 出版年：2004
• 出版时间：May 31, 2004
• 年：2004
• 卷：43
• 期：11
• 页码：3500 - 3506
• 全文大小：127K
• 年卷期：v.43,no.11(May 31, 2004)
• ISSN：1520-510X

文摘

Two extremely long lived metastable states (SI and SII) can be accessed by irradiation with light in the blue-greenspectral range at temperatures below 200 K in Cs₂[Ru(ox)(NO)Cl₃], [Ni(cyclam)][Ru(ox)(NO)Cl₃]·3H₂O, and[Ru(terpy)(NO)(OH)Cl][PF₆]. The crystal structures of the ground states of the oxalate-containing compounds arepresented, and the influence of the atomic distances of the cations/anions is discussed with respect to the decaytemperatures. The radiationless thermal decay of the metastable states is detected by differential scanning calorimetry(DSC) for the three compounds. Both metastable states decay exponentially in time under isothermal conditions.The excited states are energetically separated from the ground state by potential barriers given by the activationenergy of the Arrhenius law. In [Ni(cyclam)][Ru(ox)(NO)Cl₃]·3H₂O the enthalpy maximum of the thermal decay ofSII appears at 182 K, which is a relatively high decay temperature for SII. The reason for this strong temperatureshift compared to those of the other compounds could be due to the polarization effect of Ni²⁺ on the electrondensity at the Ru site via the Cl atom.