通过在环境和高压(4 kbar)下对各种同位素化合物的非弹性和准弹性中子散射研究了乙酰丙酮甲基的隧穿和释放动力学。通过淬火液体制备的样品显示由分子的酮和烯醇形式的混合物组成。这一事实解释了以前研究的数据分析中的困难。在目前的工作中,可以通过制备纯烯醇样品和富含酮的样品来分离两种形式的贡献。对于烯醇形式,确定了两个不等价的甲基,其势垒高度在 220-800 K 范围内。这些势垒对非甲基质子的氘化和晶体中的无序相当敏感。相比之下,对于酮形式,电位对这些因素不敏感。这些差异反映了氢键质子对烯醇分子中甲基动力学的影响。
Structure and dynamics of the keto and enol forms of acetylacetone in the solid state
作者:M. R. Johnson、N. H. Jones、A. Geis、A. J. Horsewill、H. P. Trommsdorff
DOI:10.1063/1.1456032
日期:2002.4
of the two forms could be separated, by preparing pure enol samples as well as keto-enriched samples. Two inequivalent methyl groups are identified for the enolform with barrier heights of the hindering potential in the range of 220–800 K. These potential barriers are fairly sensitive to deuteration of the nonmethyl protons and to disorder in the crystal. In contrast, for the ketoform the potential
通过在环境和高压(4 kbar)下对各种同位素化合物的非弹性和准弹性中子散射研究了乙酰丙酮甲基的隧穿和释放动力学。通过淬火液体制备的样品显示由分子的酮和烯醇形式的混合物组成。这一事实解释了以前研究的数据分析中的困难。在目前的工作中,可以通过制备纯烯醇样品和富含酮的样品来分离两种形式的贡献。对于烯醇形式,确定了两个不等价的甲基,其势垒高度在 220-800 K 范围内。这些势垒对非甲基质子的氘化和晶体中的无序相当敏感。相比之下,对于酮形式,电位对这些因素不敏感。这些差异反映了氢键质子对烯醇分子中甲基动力学的影响。
Kinetics and Mechanisms of Ligand Exchange Reactions of Tris(acetylacetonato)-chromium(III), -cobalt(III), -ruthenium(III), and -rhodium(III) in Acetylacetone
作者:Hiroaki Kido
DOI:10.1246/bcsj.53.82
日期:1980.1
Tris(acetylacetonato[2-14C])-cobalt(III), -chromium(III), -ruthenium(III), and -rhodium(III) undergo ligandexchange in acetylacetone (Hacac) at 85–190 °C without decomposition of the complexes. The exchange rate is proportional to the complex concentration, and the first-order rate constant k0 decreases in the sequence Co(III)>Cr(III)>Ru(III)>Rh(III), k0⁄10−5 s−1 being 2.4 (93 °C), 5.6 (117 °C), 9
hydroperoxorhodium complex, (Ph3P)2(acac)ClRhOOH, has been prepared by treatment of the peroxorhodium complex (Ph3P)3ClRh(O)2 with acetylacetone (acacH) in benzene. The stretching vibration of the OO bond is proven to appear at 813 cm−1 by comparison with that of the 18O2-labeled complex. The hydroperoxorhodium complex decomposes in chloroform in the presence of triphenylphosphine to (Ph3P)2(acac)RhCl2
通过在苯中用乙酰丙酮(acacH)处理过氧铑络合物(Ph 3 P)3 ClRh(O)2,已经制备了新型的氢过氧铑络合物(Ph 3 P)2(acac)ClRhOOH 。与18 O 2标记的络合物相比,OO键的拉伸振动被证明在813 cm -1处出现。氢过氧铑络合物在三苯膦的存在下在氯仿中分解,通过相应的羟基络合物分解为(Ph 3 P)2(acac)RhCl 2,同时配位的三苯膦被氧化。
Kinetics of nucleophilic attack on co-ordinated organic moeities. Part 3. Effect of solvent on addition of pentane-2,4-dione to complexes of cyclic dienyls
作者:C. A. Mansfield、L. A. P. Kane-Maguire
DOI:10.1039/dt9760002187
日期:——
The kinetics of addition of pantane-2.4-dione (Hpd) to [Fe(C6H7)(CO)1][BF4] and related dienyl salts have been studied in the solvents nitromethane. acetone.and dichloromethane. Comparison with previous data in acetonitrile shows that the reactions are not sensitive to solvent changes, and indicate the general rate law –d[R]/dt=k[R][ Hpd](R = dienyl cation). These solvent effects. together with the
已经研究了在溶剂硝基甲烷中向[Fe(C 6 H 7)(CO)1 ] [BF 4 ]和相关的二烯基盐中添加潘丹-2.4-二酮(Hpd)的动力学。丙酮和二氯甲烷。与乙腈中先前数据的比较表明,反应对溶剂的变化不敏感,并表明一般的速率定律– d [R] / d t = k [R] [Hpd](R =二烯基阳离子)。这些溶剂的作用。以及添加的酸,添加的碱和Hpd的氘代作用。在涉及HPD的快速预平衡解离,得到PD的共同机制的术语解释-碳负离子,然后直接添加到二烯基环。[Ru(C具有Hpd的6 H 7)(CO) 3 ] [BF 4 ]相当慢。
NMR and magnetic-relaxation study of the structure of the products of the reaction of aluminum tris(acetylacetonate) with aluminum chloride in a chloroform solution
作者:A. G. Stepanov、V. M. Nekipelov
DOI:10.1007/bf00752013
日期:——
It has been shown with the aid of NMR that the reaction of aluminum acetylacetonate [Al(acac)3] with AlCl3 and CHCl3 results in the formation of Al(acac)2Cl and Al(acac)Cl2. The dimensions of the complexes formed have been determined, and it has been concluded on their basis that the complexes are monomeric. The structures of the compounds formed have been proposed. The data obtained attest to the fact that Al(acac)Cl2 has a tetrahedral configuration of ligands.