Fujisawa Seiichiro, Kadoma Yoshinori
Meikai University School of Dentistry, Sakado, Saitama 350-0283, Japan.
Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
Int J Mol Sci. 2012;13(5):5789-5800. doi: 10.3390/ijms13055789. Epub 2012 Mar 13.
The NMR chemical shift, i.e., the π-electron density of the double bond, of acrylates and methacrylates is related to the reactivity of their monomers. We investigated quantitative structure-property relationships (QSPRs) between the base-catalyzed hydrolysis rate constants (k1) or the rate constant with glutathione (GSH) (log k(GSH)) for acrylates and methacrylates and the (13)C NMR chemical shifts of their α,β-unsaturated carbonyl groups (δC(α) and δC(β)) or heat of formation (Hf) calculated by the semi-empirical MO method. Reported data for the independent variables were employed. A significant linear relationship between k1 and δC(β), but not δC(α), was obtained for methacrylates (r(2) = 0.93), but not for acrylates. Also, a significant relationship between k1 and Hf was obtained for both acrylates and methacrylates (r(2) = 0.89). By contrast, log k(GSH) for acrylates and methacrylates was linearly related to their δC(β) (r(2) = 0.99), but not to Hf. These findings indicate that the (13)C NMR chemical shifts and calculated Hf values for acrylates and methacrylates could be valuable for estimating the hydrolysis rate constants and GSH reactivity of these compounds. Also, these data for monomers may be an important tool for examining mechanisms of reactivity.
丙烯酸酯类和甲基丙烯酸酯类的核磁共振化学位移，即双键的π电子密度，与其单体的反应活性相关。我们研究了丙烯酸酯类和甲基丙烯酸酯类在碱催化水解速率常数（k1）或与谷胱甘肽（GSH）反应的速率常数（log k(GSH)）与它们α,β-不饱和羰基的(13)C核磁共振化学位移（δC(α)和δC(β)）或通过半经验分子轨道方法计算的生成热（Hf）之间的定量结构-性质关系（QSPRs）。采用了已报道的自变量数据。对于甲基丙烯酸酯类，得到了k1与δC(β)之间的显著线性关系，但与δC(α)无关（r(2)=0.93），而对于丙烯酸酯类则未得到此关系。此外，对于丙烯酸酯类和甲基丙烯酸酯类，k1与Hf之间均得到了显著关系（r(2)=0.89）。相比之下，丙烯酸酯类和甲基丙烯酸酯类的log k(GSH)与它们的δC(β)呈线性相关（r(2)=0.99），但与Hf无关。这些发现表明，丙烯酸酯类和甲基丙烯酸酯类的(13)C核磁共振化学位移和计算得到的Hf值对于估算这些化合物的水解速率常数和GSH反应活性可能具有重要价值。此外，这些单体的数据可能是研究反应机理的重要工具。
