Imidazole and Triazole Coordination Chemistry for Antifouling Coatings
Figure 9
Coordination geometries [38]. (a) Tetrahedral [Zn(Me-Im)2Cl2], (b) octahedral [ZnIm6]2+, and (c) tetragonal [CuIm4Cl2] and [Cu(Me-Im)4Cl2]. R1 and R2 are defined as in Scheme 1. The coordination geometry for Cu2+ complexes is tetragonal D4āh symmetry for the methylated imidazoles, equivalent to unsubstituted imidazole. The imidazole ligands are almost perpendicular to the coordination axis and the chlorides are weakly bound axially [38, 154ā156]. However, regarding Zn2+ complexes, unsubstituted imidazole forms octahedral complexes [38, 155] [Zn(Im)6]2+, whereas the methylated imidazoles form tetrahedral C2v complexes [38, 156, 157] [Zn(Me-Im)2Cl2] despite the large excess of imidazole ligand.