Intramolecular Spodium Bonds in Zn(II) Complexes: Insights from Theory and Experiment

Abstract

Two new dinuclear zinc(II) complexes, [Zn2(µ1,3-OAc)(L1)2]I·MeOH (1) and [Zn2(µ1,3-OAc)(L2)(NCS)] (2), (where HL1 = 2-(((3-(dimethylamino)propyl)amino)methyl)-6-methoxy-phenol and H2L2 = 2,2′-[(1-Methyl-1,2-ethanediyl)bis(iminomethylene)]bis[6-ethoxyphenol]) have been synthesized and characterized by elemental and spectral analysis. Their X-ray solid state structures have been determined, revealing the existence of intramolecular Zn···O spodium bonds in both complexes due to the presence of methoxy (1) or ethoxy (2) substituents adjacent to the coordinated phenolic O-atom. These noncovalent interactions have been studied using density functional theory (DFT) calculations, the quantum theory of “atoms-in-molecules” and the noncovalent interaction plot. Moreover, a search in the Cambridge structure database (CSD) has been conducted in order to investigate the prevalence of intramolecular spodium bonds in Zn complexes. To our knowledge this is the first investigation dealing with intramolecular spodium bonds.

Spodium bonding and other non-covalent interactions assisted supramolecular aggregation in a new mercury(II) complex of a nicotinohydrazide derivative

“…Therefore, the total contribution of the hydrogen bonds to the formation of DIMER-II is -1.20 kcal/mol, which is insignificant compared to the spodium bonding energy, which is -12.9 kcal/ mol (-6.5 kcal/mol each spodium bond). These values agree well with the recently reported energetic features of spodium bonds [80].…”

Group 12 Carbonates and their Binary Complexes with Nitrogen Bases and FH2Z Molecules (Z=P, As, Sb): Synergism in Forming Ternary Complexes

“…[22][23][24][25] Since last year, the related experimental and theoretical studies have been reported for spodium bonds rapidly. [26][27][28][29][30][31][32][33] For the planar structures such as MCl 3 À (M=Zn, Cd, Hg), a π-hole lies directly above each M atom, [26] while a σ-hole is found for it in the nonplanar molecules. [21] The spodium bond is usually present between different or same molecules [27] although intramolecular spodium bond is also described.…”

“…[21] The spodium bond is usually present between different or same molecules [27] although intramolecular spodium bond is also described. [28,29] Other than molecules with lone pairs, carbenes are also evidenced to be used as the electron donors in the spodium bonds. [30] Through the regulation of the group 12 atom and the electron donor, the spodium bond varies with strength from weak to strong.…”

“…This concept was proposed last year, but the role of Lewis acid for the group 12 atoms has been recognized before [22–25] . Since last year, the related experimental and theoretical studies have been reported for spodium bonds rapidly [26–33] . For the planar structures such as MCl 3 − (M=Zn, Cd, Hg), a π‐hole lies directly above each M atom, [26] while a σ‐hole is found for it in the non‐planar molecules [21] .…”

“…For the planar structures such as MCl 3 − (M=Zn, Cd, Hg), a π‐hole lies directly above each M atom, [26] while a σ‐hole is found for it in the non‐planar molecules [21] . The spodium bond is usually present between different or same molecules [27] although intramolecular spodium bond is also described [28,29] . Other than molecules with lone pairs, carbenes are also evidenced to be used as the electron donors in the spodium bonds [30] .…”