Riesen H, Wallace L, Krausz E
School of Chemistry, University College, The University of New South Wales, Australian Defence Force Academy, Canberra, ACT.
Inorg Chem. 2000 Oct 30;39(22):5044-52. doi: 10.1021/ic0005386.
Transient spectral hole-burning (THB), a powerful technique for probing the electronic structures of coordination compounds, is applied to the lowest excited 3MLCT states of specifically deuterated [Ru(bpy)3]2+ complexes doped into crystals of racemic Zn(bpy)32. Results are consistent with and complementary to conclusions reached from excitation-line-narrowing experiments. Two sets of 3MLCT transitions are observed in conventional spectroscopy of [Ru(bpy-d(n))(3-x)(bpy-d(m))x]2+ (x = 1, 2; n = 0, 2; m = 2, 8; n not = m) complexes doped into Zn(bpy)32. The two sets coincide with the 3MLCT transitions observed for the homoleptic [Ru(bpy-d(m))3]2+ and [Ru(bpy-d(n))3]2+ complexes and can thus be assigned to localized 3MLCT transitions to the bpy-d(m) and bpy-d(n) ligands. The THB experiments presented in this paper exclude a two-site hypothesis. When spectral holes are burnt at 1.8 K into 3MLCT transitions associated with the bpy and bpy-d2 ligands in [Ru(bpy)(bpy-d8)2]2+, [Ru(bpy)2(bpy-d8)]2+, and [Ru(bpy-d2)2(bpy-d8)]2+, side holes appear in the 3MLCT transitions associated with the bpy-d8 ligands approximately 40 and approximately 30 cm(-1) higher in energy. Since energy transfer to sites 40 or 30 cm(-1) higher in energy cannot occur at 1.8 K, the experiments unequivocally establish that the two sets of 3MLCT transitions observed for [Ru(bpy-d(n))(3-x)(bpy-d(m))x]2+ (x = 1, 2) complexes in Zn(bpy)32 occur on one molecular cation.
瞬态光谱烧孔（THB）是一种用于探测配位化合物电子结构的强大技术，已被应用于掺杂到外消旋Zn(bpy)₃₂晶体中的特定氘代[Ru(bpy)₃]²⁺配合物的最低激发³MLCT态。实验结果与通过激发线变窄实验得出的结论一致且相互补充。在掺杂到Zn(bpy)₃₂中的[Ru(bpy-d(n))(3-x)(bpy-d(m))x]²⁺（x = 1, 2；n = 0, 2；m = 2, 8；n ≠ m）配合物的常规光谱中观察到两组³MLCT跃迁。这两组跃迁与在纯配体[Ru(bpy-d(m))₃]²⁺和[Ru(bpy-d(n))₃]²⁺配合物中观察到的³MLCT跃迁一致，因此可以归因于向bpy-d(m)和bpy-d(n)配体的局域³MLCT跃迁。本文所展示的THB实验排除了双位点假设。当在1.8 K下对[Ru(bpy)(bpy-d8)₂]²⁺、[Ru(bpy)₂(bpy-d8)]²⁺和[Ru(bpy-d2)₂(bpy-d8)]²⁺中与bpy和bpy-d2配体相关的³MLCT跃迁进行光谱烧孔时，在与bpy-d8配体相关的³MLCT跃迁中会出现能量高约40和约30 cm⁻¹的边孔。由于在1.8 K时不可能发生向能量高40或30 cm⁻¹的位点的能量转移，这些实验明确证实，在Zn(bpy)₃₂中[Ru(bpy-d(n))(3-x)(bpy-d(m))x]²⁺（x = 1, 2）配合物中观察到的两组³MLCT跃迁发生在一个分子阳离子上。
