Citir Murat, Altinay Gokhan, Metz Ricardo B
Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA.
J Phys Chem A. 2006 Apr 20;110(15):5051-7. doi: 10.1021/jp060375s.
Electronic spectra of gas-phase V+(OCO) are measured in the near-infrared from 6050 to 7420 cm(-1) and in the visible from 15,500 to 16,560 cm(-1), using photofragment spectroscopy. The near-IR band is complex, with a 107 cm(-1) progression in the metal-ligand stretch. The visible band shows clearly resolved vibrational progressions in the metal-ligand stretch and rock, and in the OCO bend, as observed by Brucat and co-workers. A vibrational hot band gives the metal-ligand stretch frequency in the ground electronic state nu3'' = 210 cm(-1). The OCO antisymmetric stretch frequency in the ground electronic state (nu1'') is measured by using vibrationally mediated photodissociation. An IR laser vibrationally excites ions to nu1'' = 1. Vibrationally excited ions selectively dissociate following absorption of a second, visible photon at the nu1' = 1 <-- nu1'' = 1 transition. Rotational structure in the resulting vibrational action spectrum confirms that V+(OCO) is linear and gives nu1'' = 2392.0 cm(-1). The OCO antisymmetric stretch frequency in the excited electronic state is nu1' = 2368 cm(-1). Both show a blue shift from the value in free CO2, due to interaction with the metal. Larger blue shifts observed for complexes with fewer ligands agree with trends seen for larger V+(OCO)n clusters.
利用光碎片光谱法，在6050至7420厘米⁻¹的近红外区域以及15500至16560厘米⁻¹的可见光区域测量了气相V⁺(OCO)的电子光谱。近红外波段很复杂，在金属 - 配体伸缩振动方面有107厘米⁻¹的进展。如Brucat及其同事所观察到的，可见波段在金属 - 配体伸缩振动和摇摆以及OCO弯曲振动方面显示出清晰分辨的振动进展。一个振动热带来自基电子态下金属 - 配体伸缩振动频率ν₃'' = 210厘米⁻¹。通过振动介导的光解离测量了基电子态下OCO反对称伸缩振动频率(ν₁'')。红外激光将离子振动激发至ν₁'' = 1。振动激发的离子在ν₁' = 1 ← ν₁'' = 1跃迁处吸收第二个可见光子后选择性解离。所得振动作用光谱中的转动结构证实V⁺(OCO)是线性的，并给出ν₁'' = 2392.0厘米⁻¹。激发电子态下OCO反对称伸缩振动频率为ν₁' = 2368厘米⁻¹。由于与金属的相互作用，两者都相对于游离CO₂中的值出现蓝移。对于配体较少的配合物观察到的较大蓝移与较大的V⁺(OCO)ₙ簇的趋势一致。
