Single-electron spodium bonds: Substituent effects

This study performed a theoretical exploration to predict and characterize the single-electron spodium bond in the complexes of SpX(2) (Sp = Zn, Cd, and Hg; X = H, F, Cl, Br, and CH3) with the H3C radical, in which the H3C radical serves as the Lewis base and the pi-hole on the Sp atom in SpX(2) plays an acid role. The interaction energy varies in the range 7-30 kJ/mol, indicating that the Sp atom in SpX(2) has a good affinity for the H3C radical. The spodium bond strength is not only dependent on the size of the Sp atom of SpX(2) but is also affected by the substituent X in the Lewis acid. For most complexes, the spodium bond is stronger in the rank of Hg < Cd < Zn. The halogen substitution in SpX(2) strengthens the spodium bond, whereas a weakening effect is found for the CH3 groups of Sp (CH3)(2). Regardless of the interaction intensity, the single-electron spodium bond exhibits the characteristics of a partially covalent interaction.

Automated summary

This study predicted and characterized the single-electron spodium bond in the complexes of SpX(2) (Sp = Zn, Cd, and Hg; X = H, F, Cl, Br, and CH3) with the H3C radical. The interaction energy range was 7-30 kJ/mol, indicating a strong affinity between the Sp atom in SpX(2) and the H3C radical. The strength of the spodium bond depended on the size of the Sp atom and the substituent X in the Lewis acid, with the strongest bond observed in Hg < Cd < Zn complexes. Halogen substitution strengthened the spodium bond, while CH3 groups weakened it. Regardless of the intensity, the single-electron spodium bond exhibited partially covalent characteristics.