Syntheses, Structures, and Properties of Two Coordination Polymers Based on 2-Pyrimidineamidoxime

Abstract

Two coordination polymers, {[Cd(L¹)₂(L₂)] · 0.25H₂O}_n (I) and {[Cd(L¹)(L₃)H₂O] · 2H₂O}_n (II) (L¹ = 2-pyrimidineamidoxime, L² = 4-sulfobenzoate dianion and L³ = 5-sulfosalicylate dianion), has been synthesized and structurally characterized by single-crystal X-ray diffraction (CIF files CCDC nos. 1565646 (I) and 1565728 (II)). Complex I crystallizes in monoclinic space group P2₁/n with a = 10.1462(3), b = 16.0152(5), c = 14.0349(5) Å, β = 93.267(3)°, V = 2276.87(13) ų, C₆₈H₆₆N₃₂O₂₉S₄Cd₄, M = 2373.36, ρ_calcd = 1.731 g/cm³, μ(MoK_α) = 1.109 mm⁻¹, F(000) = 1186, GOOF = 0.806, Z = 1, the final R¹ = 0.0287 and wR² = 0.0733 for I > 2σ(I). Complex II crystallizes in monoclinic space group P2₁ with a = 6.882(2), b = 17.138(2), c = 7.883(2) Å, β = 103.83(3)°, V = 902.8(4) ų, C₁₂H₁₆N₄O₁₀SCd, M = 520.75, ρ_calcd = 1.916 g/cm³, μ(MoK_α) = 1.388 mm⁻¹, F(000) = 520, GOOF = 1.047, Z = 2, the final R¹ = 0.0739 and wR² = 0.2041 for I > 2σ(I). Crystal structural analysis reveals that complex I possesses the corrugated 1D chain structure extending along the \([\bar 101]\) direction. However, complex II displays a 2D coordination network lying on the ab crystal plane, which can be simplified as a binodal 3-connected 6³ topological network by considering Cd²⁺ ions and L³ ligands as 3-connected nodes. Their photoluminescent and thermal properties were also investigated.