A New 2D Double-layer Network Constructed from a 2D Single Layer

摘要

Two Zn(II) coordination polymers, namely [Zn_2(bpy)(aobtc)(H_2O)_2]·2H_2O(1) and [Zn_2(bpy)(aobtc)(H_2O)]·4H_2O(2)(bpy = 4,4?-bipyridine, H4 aobtc = 3,3?,5,5?-azoxybenzenetetracarboxylic acid) have been hydrothermally synthesized through tuning the p H value of the reaction system(1, C_(26)H_(22)N_(4)O_(13)Zn_2, Mr = 729.21; 2, C_(26)H_(24)N_4O_(14)Zn_2, Mr = 747.23), and their structures have been determined by single-crystal X-ray diffraction analyses. Compound 2 has been further characterized by infrared spectra(IR), elemental analyses, thermal analyses and powder X-ray diffraction(PXRD) analyses. Additionally, the photoluminescence of 2 is also discussed. The structure demonstrates that the crystal of 2 belongs to the triclinic system, space group P1 with a = 8.41494(18), b = 9.59838(19), c = 17.6477(3) ?, α = 91.5098(16), β = 98.1439(17), γ = 90.4323(17)°, V = 1410.44(5) ?3, Z = 2, ρcalc = 1.759 g/cm^3, μ = 2.819 mm-1, F(000) = 760.0, R = 0.0311 and w R = 0.0839(I > 2σ(I)). Compound 1 shows a two-dimensional monolayer while compound 2 displays a novel 2D double-layered network constructed from monolayer motifs, which is similar to the single layer in 1. Further, each bilayer motif in 2 is interdigitated by two others in a parallel fashion to yield an unusual 2D → 3D interdigitated framework.