Diverse Ag(i) complexes constructed from methyl-4-(5-halopyrimidin-2-ylcarbamoyl)benzoate ligands: roles of the halogen atom and anion

Abstract

The synthesis and structures of eight new silver(I) complexes [Ag(L¹111)(NO₃)]_∞ (L¹111 = methyl-4-(pyrimidin-2-ylcarbamoyl)benzoate), 1, [Ag₂(L²22)(NO₃)₂]_∞ (L²22 = methyl-4-(5-chloropyrimidin-2-ylcarbamoyl)benzoate), 2, [Ag₂(L³3)(NO₃)₂]_∞ (L³3 = methyl-4-(5-bromopyrimidin-2-ylcarbamoyl)benzoate), 3, [Ag(L⁴4)(NO₃)]_∞ (L⁴4 = methyl-4-(5-iodopyrimidin-2-ylcarbamoyl)benzoate), 4, {[Ag(L³3)](BF₄)·0.5THF}_∞, 5, [Ag₂(L⁴4)₄](BF₄)₂·2CH₃OH, 6, and [Ag₂(L⁴4)₄](X)₂ (X = PF₆⁻, 7; SbF₆⁻, 8) are reported. In complexes 1–3, the L¹1–L³3 ligands adopt the tridentate mode, featuring chelation and bridge through two pyrimidyl nitrogen atoms and one amidecarbonyl oxygen atom and resulting in a 1D chain for 1 and 2D nets for 2 and 3 with the topology of {4·6·8}{4·6²·8³}{6²·8}, while in 4, the L⁴4 ligand coordinates to the silver(I) metal center through one of the two pyrimidyl nitrogen atoms, the amide oxygen atom and the iodine atom to afford a 1D chain. The L³3 ligands in 5 coordinate to the silver(I) metal centers in a tetradentate bonding mode through two nitrogen and two oxygen donor atoms, resulting in a 2D net with the topology of {4·6²}₂{4²·6²·8²}. In complexes 6–8, the L⁴4 ligands show both bidentate and tridentate fashions, showing dinuclear structures with ten-membered metallocycles. While the halogen atoms of 2 and 3 are involved in the X⋯O (X = Cl for 2 and Br for 3) interactions, short Ag–I bond distances of 2.7700(5) Å in 4 and 2.8925(10), 2.8353(9) and 2.8520(8) Å in 6–8 are found, which appear to be due to the high polarizability of the iodine atom.