Extending framework based on the linear coordination polymers: Alternative chains containing lanthanum ion and acrylic acid ligand

One-dimensional alternative chains of two lanthanum complexes: [La(L¹)₃(CH₃OH)(H₂O)₂]·5H₂O (L¹=anion of α-cyano-4-hydroxycinnamic acid ) 1 and [La(L²)₃(H₂O)₂]·3H₂O (L²=anion of trans-3-(4-methyl-benzoyl)-acrylic acid) 2 were synthesized and structurally characterized by single-crystal X-ray diffraction, element analysis, IR and thermogravimetric analysis. The crystal structure data are as follows for 1: C₃₁H₃₆LaN₃O₁₇, triclinic, P-1, a = 9.8279 (4) Å, b = 11.8278 (5) Å, c = 17.8730 (7) Å, α = 72.7960 (10) °, β = 83.3820 (10) °, γ = 67.1650 (10) ^o, Z = 2, R₁ = 0.0377, w R₂ = 0.0746; for 2: C₃₃H₃₇LaO₁₄, triclinic, P-1, a = 8.7174 (5) Å, b = 9.9377 (5) Å, c = 21.153 (2) Å, α = 81.145 (2) °, β = 87.591 (2) °, γ = 67.345 (5) °, Z = 2, R₁ = 0.0869, w R₂ = 0.220. 1 is a rare example of the alternative chain constructed by syn-syn and anti-syn coordination mode of carboxylato ligand arranged along the chain alternatively. La(III) ions in 2 are linked by two η³-O bridges and four bridges (two η²-O and two η³-O) alternatively. Both of the linear coordination polymers grow into two- and three-dimensional networks by packing through extending hydrogen-bond network directed by ligands.