A Novel Acetylenic Complex of Tungsten(0) Carbonyl
A Novel Acetylenic Complex of Tungsten(0) Carbonyl
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新型钨(0)羰基乙炔配合物
DOI：
10.1021/ja00897a036
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发表时间：
1963
影响因子：
15
通讯作者：
J. Augl
中科院分区：
文献类型：
--
作者：
D. P. Tate;J. Augl
从存在的酸物质的平均羟基共振维持了100万。即使溶剂含有少至0.2重量%的水，也会导致酸的非常大的假“稀释偏移”。制备不含这种微量水的溶剂常常需要相当复杂的程序。然而，在参考文献2中使用了“分析级或试剂级”溶剂，并且已经证实6 Baker Cp丙酮（例如）含有0.39重量%的水。那么参考文献2和3的结果之间的差异可能是由于所用溶剂的干燥度不同。此外，有一定的可能性，这两项研究都没有用足够无水的溶剂进行，以揭示真实的AcOH稀释位移，从中可以得出关于二聚平衡的可靠结论。为了确定严格无水样品的稀释位移，我们检查了AcOH在乙酸酐（Ac20）中的溶液的NMR光谱。我们纯化的Ac20含有0.8±0.1摩尔%的AcOH，通过比较AcOH的甲基NMR峰与Ac20的C13边带的强度发现。通过向Ac20中加入已知量的水，按体积制备一系列样品。反应
million upheld from the averaged hydroxyl resonances of the acid species present. A very large spurious “dilution shift” for the acid will result even if the solvent contains as little as 0.2 weight% water. Quite elaborate procedures are often necessary to prepare solvents free of suchtraces of water. However, in ref. 2 “analytical or reagent grade” solvents were used, and it has been reported6 that Baker Cp acetone, for example, con-tained 0.39 weight% water. Then perhaps the dis-crepancy between the results of ref. 2 and 3 is due to a difference in dryness of the solvents used. Moreover, there is some likelihood that neither study was made with solvent sufficiently anhydrous to reveal the true AcOH dilution shift from which reliable conclusions about the dimerization equilibrium might be drawn. In order to determine the dilution shift in rigorously anhydrous samples we examined nmr spectra of solu-tions of AcOH in acetic anhydride (Ac20). Our puri-fied Ac20 contained 0.8±0.1 mole% of AcOH, found by comparing the intensity of the methyl nmr peak of the AcOH with that of the C13 side band from Ac20. A series of samples was prepared volumetrically by adding known amounts of waterto Ac20. The reaction