Bond Dissociation Energies of Tungsten Molecules: WC, WSi, WS, WSe, and WCl
Bond Dissociation Energies of Tungsten Molecules: WC, WSi, WS, WSe, and WCl
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钨分子的键解离能：WC、WSi、WS、WSe 和 WCl
DOI：
10.1021/acs.jpca.7b09704
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Morse, Michael D.
中科院分区：
文献类型：
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作者：
Sevy, Andrew;Huffaker, Robert F.;Morse, Michael D.
用共振双光子电离光谱确定了WC、WSI、WS、WSE和WCL的预解离阈值，从而测量了这些物种的键离解能。由于在观察到的光谱中存在高度的振动拥塞，人们认为一旦超过最低分离原子极限，分子就会解离。根据观察到的预解离阈值，D0(WC)=5.289(8)eV，D0(WSi)=3.103(10)eV，D0(WS)=4.935(3)eV，D0(Wse)=4.333(6)eV，D0(WCL)=3.818(6)eV。结合其他数据，得到电离能IE(WC)=8.39(9)eV，阴离子键离解能D0(W-C-)=6.181(17)eV，D0(W-C)=7.363(19)eV，D0(W-Si-)≤3.44(4)eV，D0(W-Si)≤4.01(4)eV。D0(Wx)值与原子生成热焓的组合也提供了气态Wx分子的ΔfH0K°值。计算结果也为这些分子的电子结构提供了一些线索。
Resonant two-photon ionization spectroscopy was used to locate predissociation thresholds in WC, WSi, WS, WSe, and WCl, allowing bond dissociation energies to be measured for these species. Because of the high degree of vibronic congestion in the observed spectra, it is thought that the molecules dissociate as soon as the lowest separated atom limit is exceeded. From the observed predissociation thresholds, dissociation energies are assigned asD0(WC) = 5.289(8) eV,D0(WSi) = 3.103(10) eV,D0(WS) = 4.935(3) eV,D0(WSe) = 4.333(6) eV, andD0(WCl) = 3.818(6) eV. These results are combined with other data to obtain the ionization energy IE(WC) = 8.39(9) eV and the anionic bond dissociation energies ofD0(W–C–) = 6.181(17) eV,D0(W––C) = 7.363(19) eV,D0(W–Si–) ≤ 3.44(4) eV, andD0(W––Si) ≤ 4.01(4) eV. Combination of theD0(WX) values with atomic enthalpies of formation also provides ΔfH0K° values for the gaseous WX molecules. Computational results are also provided, which shed some light on the electronic structure of these molecules.