Ultrafast photodissociation of a metalloporphyrin in the condensed phase
Ultrafast photodissociation of a metalloporphyrin in the condensed phase
复制标题
金属卟啉在凝聚相中的超快光解离
DOI：
10.1063/1.458364
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发表时间：
1990
影响因子：
4.4
通讯作者：
D. Holten
中科院分区：
文献类型：
--
作者：
J. Rodríguez;D. Holten
用亚皮秒分辨率的瞬态吸收光谱研究了六配位镍卟啉轴向配体在溶液中的光解。我们的观察表明，deligation过程发生在前几个皮秒的大环的光激发后，作为最初观察到的3（π，π*）状态松弛到解离配位场激发态。没有证据表明两个弹射配体与四坐标光产物的成对重组。一小部分的配合物似乎只有一个松散的配体。最初观察到的激发态和脱配位物质的吸收带也被发现在前10 ps内经历光谱演化，类似于最近在非配位溶剂中四配位镍（II）卟啉的光动力学中发现的光谱演化[J. Rodriguez和D. Holten，J.Chem.Phys.91，3525（1989）]。我们考虑了这些随时间变化的光谱位移的几种可能性，包括振动动力学。我们用亚皮秒分辨率的瞬态吸收光谱研究了六配位镍卟啉溶液中轴向配体的光解。我们的观察表明，deligation过程发生在前几个皮秒的大环的光激发后，作为最初观察到的3（π，π*）状态松弛到解离配位场激发态。没有证据表明两个弹射配体与四坐标光产物的成对重组。一小部分的配合物似乎只有一个松散的配体。最初观察到的激发态和脱配位物质的吸收带也被发现在前10 ps内经历光谱演化，类似于最近在非配位溶剂中四配位镍（II）卟啉的光动力学中发现的光谱演化[J. Rodriguez和D. Holten，J.Chem.Phys.91，3525（1989）]。几种可能性被认为是这些随时间变化的光谱.
The photodissociation of axial ligands from six‐coordinate nickel(II) porphyrins in solution has been studied by transient absorption spectroscopy with subpicosecond resolution. Our observations indicate that the deligation process takes place during the first several picoseconds following optical excitation of the macrocycle as the initially observed 3(π,π*) state relaxes to a dissociative ligand field excited state. No evidence is found for geminate recombination of the two ejected ligands with the four‐coordinate photoproduct. A small fraction of the complexes appear to loose only one ligand. The absorption bands of the initially observed excited state and of the deligated species are also found to undergo a spectral evolution within the first 10 ps similar to that uncovered recently in the photodynamics of four‐coordinate nickel(II) porphyrins in noncoordinating solvents [J. Rodriguez and D. Holten, J. Chem. Phys. 91, 3525 (1989)]. Several possibilities are considered for these time‐dependent spectral shifts, including vibrational dynamics.The photodissociation of axial ligands from six‐coordinate nickel(II) porphyrins in solution has been studied by transient absorption spectroscopy with subpicosecond resolution. Our observations indicate that the deligation process takes place during the first several picoseconds following optical excitation of the macrocycle as the initially observed 3(π,π*) state relaxes to a dissociative ligand field excited state. No evidence is found for geminate recombination of the two ejected ligands with the four‐coordinate photoproduct. A small fraction of the complexes appear to loose only one ligand. The absorption bands of the initially observed excited state and of the deligated species are also found to undergo a spectral evolution within the first 10 ps similar to that uncovered recently in the photodynamics of four‐coordinate nickel(II) porphyrins in noncoordinating solvents [J. Rodriguez and D. Holten, J. Chem. Phys. 91, 3525 (1989)]. Several possibilities are considered for these time‐dependent spectral...