Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China.
J Phys Chem A. 2012 Mar 15;116(10):2484-9. doi: 10.1021/jp211936b. Epub 2012 Mar 6.
The infrared photodissociation spectroscopy of mass-selected mononuclear iron carbonyl anions Fe(CO)(n)(-) (n = 2-8) were studied in the carbonyl stretching frequency region. The FeCO(-) anion does not fragment when excited with infrared light. Only a single IR active band was observed for the Fe(CO)(2)(-) and Fe(CO)(3)(-) anions, consistent with theoretical predictions that these complexes have linear D(∞h) and planar D(3h) symmetry, respectively. The Fe(CO)(4)(-) anion is the most intense peak in the mass spectra and was characterized to have a completed coordination sphere with high stability. Anion clusters larger than n = 4 were determined to involve a Fe(CO)(4)(-) core anion that is progressively solvated by external CO molecules. Three CO stretching vibrational fundamentals were observed for the Fe(CO)(4)(-) core anion, indicating that the Fe(CO)(4)(-) anion has a C(3v) structure. All the carbonyl stretching frequencies of the Fe(CO)(n)(-) anion complexes are red-shifted with respect to those of the corresponding neutrals.
采用红外光解离光谱法研究了质量选择的单核铁羰基阴离子 Fe(CO)(n)(-)（n=2-8）在羰基伸缩频率区域的性质。FeCO(-)阴离子在红外光激发下不会发生碎片反应。只有 Fe(CO)(2)(-)和 Fe(CO)(3)(-)阴离子观察到单个 IR 活性带，这与理论预测一致，即这些配合物分别具有线性 D(∞h)和平面 D(3h)对称性。Fe(CO)(4)(-)阴离子是质谱中最强的峰，其特征是具有完整的配位球和高稳定性。大于 n=4 的阴离子团簇被确定为涉及 Fe(CO)(4)(-)核心阴离子，该核心阴离子被外部 CO 分子逐渐溶剂化。Fe(CO)(4)(-)核心阴离子观察到三个 CO 伸缩振动基频，表明 Fe(CO)(4)(-)阴离子具有 C(3v)结构。所有 Fe(CO)(n)(-)阴离子配合物的羰基伸缩频率都相对于相应的中性体发生红移。
