KINETIC AND THERMODYNAMIC ACIDITY OF HYDRIDO TRANSITION-METAL COMPLEXES .3. THERMODYNAMIC ACIDITY OF COMMON MONONUCLEAR CARBONYL HYDRIDES
KINETIC AND THERMODYNAMIC ACIDITY OF HYDRIDO TRANSITION-METAL COMPLEXES .3. THERMODYNAMIC ACIDITY OF COMMON MONONUCLEAR CARBONYL HYDRIDES
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DOI：
10.1021/ja00269a022
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发表时间：
1986-04-30
影响因子：
15
通讯作者：
NORTON, JR
中科院分区：
文献类型：
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作者：
MOORE, EJ;SULLIVAN, JM;NORTON, JR
用红外光谱法测定了常用单核羰基氢化物在乙腈中与各种氮碱和酚酸钾脱质子平衡的位置，测定了它们的pAa值。结果值约为20个pATa单位，从HCo (CO) 4的8.3到CpW (CO) 2 (PMe3) h的26.6，ij5-C5Me5配体的氢化物明显弱于t/5-C5H5配体的氢化物(例如，（775-C5Me5） Fe （CO) 2H的paa为26.3，而（7/5-C5H5） Fe (CO) 2H的paa为19.4）。8族羰基氢化物H2M (CO) 4的酸度依次为Fe b> Ru b> Os。尽管1971年有这样的评论1：“确实需要在受控的、相同的条件下测量一系列系统的金属氢化物的酸度函数”，但直到最近才进行了这样的测量。早期的德国工人仔细地测定了几种羰基氢化物在水中的pAa，但这种方法的范围受到过渡金属氢化物在该溶剂中的溶解度低的限制
The pAa values of the common mononuclearcarbonyl hydrides have been determinedin acetonitrile by IR measurement of the position of deprotonation equilibria with various nitrogen bases and potassium phenolate. The resulting values cover a range of about 20 pATa units, from 8.3 for HCo (CO) 4 to 26.6 for CpW (CO) 2 (PMe3) H. Hydrides with ij5-C5Me5 ligands are appreciably weaker acids than the corresponding hydrides with t/5-C5H5 ligands (eg, the pAfa of (775-C5Me5) Fe (CO) 2H is 26.3, while that of (7/5-C5H5) Fe (CO) 2H is 19.4). The acidities of the group 8 carbonyl hydrides H2M (CO) 4 decrease in the order Fe> Ru> Os.Despite the 1971 comment1 that “there is a definite need for the measurement of the acidity functions of a systematic series of metal hydrides under controlled, identical conditions”, few such measurements have been made until recently. Early German workers carefully determined the pAa of a few carbonyl hydrides in H20, 2 but the scope of thisapproach is limited by the low solubility of transition-metal hydridesin that solvent (and