Kerr Stephen, Naumkin Fedor Y
Faculty of Science, Ontario Tech University/UOIT, Oshawa, ON L1G 0C5, Canada.
Molecules. 2024 Sep 18;29(18):4429. doi: 10.3390/molecules29184429.
Carbon-based molecules are of universal importance for a huge variety of chemical and biological processes. The complication of the structure of such molecules proceeds via the bonding of carbon atoms. An efficient mechanism for such reactions proceeds via cross-coupling, related to the association of bond-terminating counter-ions. Here, an uncommon version of such a process is investigated, with at least some ions bound in the system noncovalently and/or switching the bonding mode in due course. The analyzed sample reactions involve a single C-C bond formation in environmentally relevant halocarbon species and involve alkali-halide ion-pair components. A consistent ab initio computational study predicts the related energy barriers to alter significantly in the presence of the ion pair. Different channels are checked, with the carbon-halogen bond cleavage preceding or following the actual C-C bonding and with the counter-ions located closely or farther apart. The relative heights of the corresponding energy barriers are found to be switched by the ion pair. The above results suggest a possibility of facilitating such reactions without expensive catalysts.
碳基分子对于各种各样的化学和生物过程具有普遍重要性。此类分子结构的复杂性通过碳原子的键合来实现。这种反应的有效机制是通过交叉偶联进行的，这与键终止反离子的缔合有关。在此，研究了这种过程的一种不常见形式，其中至少有一些离子以非共价方式结合在系统中，并且/或者在适当的时候改变键合模式。所分析的样本反应涉及在与环境相关的卤代烃物种中形成单个碳 - 碳键，并涉及碱金属卤化物离子对成分。一项一致的从头算计算研究预测，在离子对存在的情况下，相关的能量障碍会发生显著变化。检查了不同的通道，包括碳 - 卤键的断裂是在实际碳 - 碳键形成之前还是之后，以及反离子是紧密还是相距较远。发现离子对会改变相应能量障碍的相对高度。上述结果表明，有可能在不使用昂贵催化剂的情况下促进此类反应。
