Widely Differing Photochemical Behavior in Related Octahedral {Ru-NO}6 Compounds: Intramolecular Redox Isomerism of the Excited State Controlling the Photodelivery of NO
Widely Differing Photochemical Behavior in Related Octahedral {Ru-NO}6 Compounds: Intramolecular Redox Isomerism of the Excited State Controlling the Photodelivery of NO
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DOI：
10.1021/ic100491g
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发表时间：
2010-08-02
影响因子：
4.6
通讯作者：
Slep, Leonardo D.
中科院分区：
文献类型：
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作者：
De Candia, Ariel G.;Marcolongo, Juan P.;Slep, Leonardo D.
Trans-[(NC)Ru(py)(4)(mu-CN)Ru(py)(4)(NO)](3(sic))(Py=吡啶)在水溶液中是一个稳定的物种。该化合物在可见光区有很强的吸收(最大吸收波长为518 nm，最大吸收波长为6100M-1 cm(-1))，是一种很有前途的光传递NO的试剂。实验发现，在455 nm可见光照射下，光传输过程的量子产率为(0.06+/-0.01)×10(-3)摩尔·爱因斯坦(-1)，比密切相关的顺式[RuL(NH3)(4)(Mu-Pz)Ru(Bpy)(2)(NO)](5+)物种(L=NH3或吡啶，Pz=吡嗪，bpy=2，2‘-联吡啶)的量子产率小近3个数量级；Phi(NO)=0.02-0.04molEinstein(-1)，取决于L)，也远小于单核化合物Trans-[Ciru(Py)(4)(NO)](2+)(Phi(NO)=(1.63+/-0.04)×10(-3)molEinstein(-1))。密度泛函理论计算提供了光活性激发态的电子结构图，这有助于理解这种明显的反常行为。
trans-[(NC)Ru(py)(4)(mu-CN)Ru(py)(4)(NO)](3(sic)) (py = pyridine) is a stable species in aqueous solution. It displays an intense absorption in the visible region of the spectrum (lambda(max) = 518 nm; epsilon(max) = 6100 M-1 cm(-1)), which turns this compound into a promising agent for the photodelivery of NO. The quantum yield for the photodelivery process resulting from irradiation with 455 nm visible light was found experimentally to be (0.06 +/- 0.01) x 10(-3) mol einstein(-1), almost 3 orders of magnitude smaller than that in the closely related cis-[RuL(NH3)(4)(mu-pz)Ru(bpy)(2)(NO)](5+) species (L = NH3 or pyridine, pz = pyrazine, bpy = 2,2'-bipyridine; phi(NO) = 0.02-0.04 mol einstein(-1) depending on L) and also much smaller than the one in the mononuclear compound trans-[CIRu(py)(4)(NO)](2+) (phi(NO) = (1.63 +/- 0.04) x 10(-3) mol einstein(-1)). DFT computations provide an electronic structure picture of the photoactive excited states that helps to understand this apparently abnormal behavior.