Structures and thermal properties of silver(i) β-diketonates with bulky terminal substituents

Silver β-diketonates [Ag(RC(O)CHC(O)R′)]_∞ with bulky terminal substituents are synthesized and characterized: R = C(OCH₃)(CH₃)₂, R′ = CF₃ (1), R = R′ = C(CH₃)₃ (2). Complex 1 is obtained for the first time. Structures of compounds are determined by single crystal X-ray diffraction. For complex 1 the crystallographic data are: space group P1, a = 5.8012(6) Å, b = 9.1717(10) Å, c = 9.9251(11) Å, α = 73.722(4)°, β = 78.377(4)°, γ = 87.336(4)°, V = 496.49(9) Å³, Z = 2, d_calc = 2.134 g/cm³, μ = 2.059 mm^–1; for complex 2: space group C2, a = 22.1700(6) Å, b = 5.84530(10) Å, c = 9.3249(2) Å, β = 104.9670(10)°, V = 1167.42(5) Å³, Z = 4, d_calc = 1.656 g/cm³, μ = 1.701 mm^–1. Both compounds are chain coordination polymers. Anions are coordinated in a bidentate-cyclic fashion. One of carbonyl oxygen atoms and the carbon atom in the CH-group perform the bridging function. In complex 2, the coordination environment of silver is a distorted vacant trigonal bipyramid (CN = 4). In complex 1, it is a tetragonal pyramid due to the additional coordination of the methoxy oxygen atom of the neighboring anion (CN = 5). The structure and thermal stability of the synthesized complexes are compared with those of the closest analogue (R = C(CH₃)₃, R′ = CF₃), which allowed us to reveal the effect of terminal substituents in the β-diketonate ligand.