Cui Jieming, Zhou Xiaojie, Wang Guanjun, Chi Chaoxian, Li Zhen Hua, Zhou Mingfei
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University , Shanghai 200433, China.
J Phys Chem A. 2014 Apr 17;118(15):2719-27. doi: 10.1021/jp411237p. Epub 2014 Apr 4.
Infrared spectra of mass-selected homoleptic cobalt carbonyl cluster cations including dinuclear Co2(CO)8(+) and Co2(CO)9(+), trinuclear Co3(CO)10(+) and Co3(CO)11(+), as well as tetranuclear Co4(CO)12(+) are measured via infrared photodissociation spectroscopy in the carbonyl stretching frequency region. The geometric structures of these complexes are determined by comparison of the experimental spectra with those calculated by density functional theory. The Co2(CO)8(+) cation is characterized to have a Co-Co bonded structure with Cs symmetry involving a bridging CO ligand. The Co2(CO)9(+) cation is determined to be a mixture of the CO-tagged Co2(CO)8(+)-CO complex and the Co(CO)5(+)-Co(CO)4 ion-molecular complex. The Co3(CO)10(+) cation is the coordination-saturated trinuclear cluster, which is characterized to have a triangle Co3 core with C2 symmetry involving two edge-bridging and eight terminal CO ligands. The Co3(CO)11(+) cation is a weakly bound complex involving a Co3(CO)10(+) core ion. The Co4(CO)12(+) cluster cation is deduced to have a tetrahedral Co4(+) core structure with three edge-bridging and nine terminal carbonyls.
通过红外光解离光谱法在羰基伸缩频率区域测量了质量选择的同核钴羰基簇阳离子的红外光谱，这些阳离子包括双核Co2(CO)8(+)和Co2(CO)9(+)、三核Co3(CO)10(+)和Co3(CO)11(+)以及四核Co4(CO)12(+)。通过将实验光谱与密度泛函理论计算的光谱进行比较，确定了这些配合物的几何结构。Co2(CO)8(+)阳离子的特征是具有Cs对称性的Co-Co键合结构，涉及一个桥连CO配体。Co2(CO)9(+)阳离子被确定为CO标记的Co2(CO)8(+)-CO配合物和Co(CO)5(+)-Co(CO)4离子-分子配合物的混合物。Co3(CO)10(+)阳离子是配位饱和的三核簇，其特征是具有C2对称性的三角形Co3核心，涉及两个边桥连和八个端基CO配体。Co3(CO)11(+)阳离子是一种弱结合配合物，涉及Co3(CO)10(+)核心离子。Co4(CO)12(+)簇阳离子被推断具有四面体Co4(+)核心结构，带有三个边桥连和九个端基羰基。
