化合物(CO)2Co(C5H4-COCl)(4)與(COha 反應得化合物(CO^Coh5 -(C5H4CONHCH3) (5). 5的結構已由X-ray繞射法解析出.晶體參數如下: Space group, P21/c; monoclinic; a = 10.767(3), b = 9.869(2), c = 9.555(3)A, P = 105.58 (2)。; Z = 4.五環上羰取代基的碳位向與Cr原子的位向相反,0角為-0.54。.經由二維異核相對應NMR光譜儀，化合物(CO)2Co(< - C5H4CONHCH3) C(2)-C(5)的 13C 化學位移得以確認.文中論述以B3LYP correlation- exchange理論計算法得出的電子密度分佈，呼應於由C13 NMR化學位移所得之Cp(Co)的電子密度分佈.

Dicarbonyl(^5-N-methylcarbamoylcyclopentadienyl)cobalt (5) was prepared by the reaction of the corresponding acid chloride with methylamine. The structure of 5 has been determined by X-ray diffraction studies: space group, P21/c; monoclinic; a = 10.767(3), b = 9.869(2), c = 9.555(3) A, P = 105.58(2)° ; Z = 4. The exocyclic carbon is bent away from the cobalt atom with an angle 0 of -0.54°. The chemical shifts of C(2,5) and C(3,4) on the Cp ring were assigned using two-dimensional HetCOR NMR spectroscopy. The electron density distribution in the cyclopentadienyl ring of the Cp(Co) was discussed on the basis of 13C NMR data and compared with calculations via the density functional B3LYP exchange-correlation method.