Synthesis and structure of organometallic coordination polymer based on lanthanum(III) and brominated terphenyl dicarboxylic acid

Abstract

A new organometallic coordination polymer {La2(6BrTerPDC)3DMSO3} (2) was obtained by a solvothermal synthesis (in DMSO/1,4-dioxane solution) between lanthanum(III) nitrate and brominated terphenyl dicarboxylic acid derivative 6BrTerPDC (1). The structure of compound 2 was solved for the first time by direct methods using the X-ray diffraction analysis data. Crystallogra¬phic data: C36H30Br9LaO9S3, М 1560.88; space group P ; cell parameters: a = b = 26.822(4) Å, c = 8.6710(17) Å, α = β = 90°, γ = 120°, V = 5402.3(19) Å3, F (000) = 1476.0, absorption coefficient μ = 4.399 мм–1, crystal size 0.2 × 0.02 × 0.02 mm, reflection index intervals –21 ≤ h ≤ 32, –32 ≤ k ≤ 32, –10 ≤ l ≤ 9, total reflections 17717, independent reflections 6459, Rint 0.1072, residual electron density 1.31/–0.62 e/Å3. The unit cell consists of two structurally independent La3+ cations. Relatively high factor R1 = 0.1942 is associated with disorder in the arrangement and degree of occupancy of the bromine atoms. This is a consequence of the fact that in the process of bromination of dimethyl ester of terphenyl dicarboxylic acid, bromine is attached both to the central and peripheral aromatic rings of the acid, forming many homologs, presumably mono-, di-, tri-, tetra-, penta-, and hexabromo derivatives, inclu¬ding position isomers.