Preparation, Characterisation, and Structure ofN-Methylated Derivatives of 1,3,5-Triamino-1,3,5-trideoxy-cis-inositol: Polyalcohols with Unusual Acidity
nositol (TTCI) were prepared by methylation of 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (TACI). The ability of TDCI to form both intermolecular and intramolecular H-bonds, as demonstrated by X-ray diffraction, is probably responsible for the good solubility of TDCI in almost every common solvent. TTCI was found to be a polyol of unusual high acidity (pK1 = 8.14 ± 0.02, pK2 = 13.0 ± 0.2). This phenomenon
1,3,5-三甲氧基-1,3,5-三(二甲基氨基)-顺式肌醇(TDCI)和1,3,5-三甲氧基-1,3,5-三(三甲基铵)-顺式肌醇(TTCI)通过1,3,5-三氨基-1,3,5-三苯氧基-顺-肌醇(TACI)的甲基化制备。X射线衍射表明,TDCI形成分子间和分子内H键的能力可能是TDCI在几乎所有常见溶剂中的良好溶解性的原因。发现TTCI是具有异常高酸度的多元醇(p K 1 = 8.14±0.02,p K 2 = 13.0±0.2)。该现象可以通过环己烷残基的带电取代基之间的静电相互作用来解释。
Quadbeck; Roehm, Chemische Berichte, 1956, vol. 89, p. 1645,1648
作者:Quadbeck、Roehm
DOI:——
日期:——
Lanthanide(<scp>iii</scp>) complexation by the ligand 1,3,5-triamino-1,3,5-trideoxy-cis-inositol: an unusual thermodynamic behaviour across the rare-earth series
1,3,5-Triamino-1,3,5-trideoxy-cis-inositol (taci) gives trinuclear sandwich-type complexes of trivalent lanthanide cations [Ln3(taciH−3)2]3+ in aqueous solution, whose stability constants experience a very great increase across the rare-earth series. To have a better insight into factors controlling lanthanide recognition, the enthalpy changes of the complexation reaction were measured by microcalorimetry. This thermodynamic analysis demonstrates that the discrimination is mainly due to enthalpic effects; the entropic contribution shows little variation. The X-ray structure of the lutetium complex [Lu3(taciH−3)2(H2O)6](SO4)1.5 is also presented and gives crucial structural information for the smallest lanthanide cations.