【摘要】 本文报道一个新的三核钼原子簇化合物在室温和77K固态和液态的EPR谱,这些谱均呈现出a,b两套谱线的叠加。分析谱线的强度比、线宽和谱参数,认为g值较大的a谱归属于三核钼原子簇化合物,而b谱归属于单核钼杂质。从由X射线晶体结构方法确定的空间结构出发,三核钼原子簇化合物可能有两种分子形式: Mo₃（μ₃-S）（μ₂-S）₃Cl[S₂P（OEt）₂]₄ 1 Mo₃（μ₃-S）（μ₂-S）（μ₂-Cl）₂Cl[S₂P（OEt）₂]₄ 2分别用简单量子化学理论和EHMO法计算出未配对电子所处的分子轨道,求出g_∥和g_⊥,并与EPR实验值相比较,认为该化合物的分子式应为2,簇骼{Mo₃}属七电子体系。在77K温度下,其未配对电子主要局域在三个钼原子所组成的近似等腰三角形簇骼的顶点钼原子周围。更多还原

【Abstract】 The EPR spectra of a new trinuclear molybdenum cluster in solid and solution at room temperature and 77 K have been investigated. These spectra exhibit two-overlap spectra a and b respectively. Analysis of the intensity ratio （I_a/I_b）, line-width and parameters of spectra a and b suggests that spectrum a with larger g-factor is attributed to trinuclear molybdenum, whereas spectrum b with smaller g-factor should be due to impurity of a mononuclear molybdenum complex.The molecular orbitals in which unpair electron localizes are obtained by calculating two plausible molecular formulas 1 and 2 using both the simple quantum chemical theory and EHMO method.Mo₃（μ₃-S）（μ₂-S）₃Cl[S₂P（OEt）₂]₄, 1Mo₃（μ₃-S）（μ₂-S）（μ₂-Cl）₂Cl[S₂P（OEt）₂]₄ 2A comparison of g （cal.）, g （cal.） and g （exp.）, g （exp.） indicates that the molecular formula for thin cluster is 2 having seven electrons localize in the {Mo₃}-skeleton. At 77 K, the unpair electron localizes mainly in the apex molybdenum of the isosceles triangle constituted by {Mo₃}-skeleton.更多还原