Synthesis and crystal structure of a one-dimensional chain-like strontium(II) coordination polymer built of N-methyldiethanolamine and isobutyrate ligands

Abstract

The one-dimensional coordination polymer (I) [Sr(ib)2(H2mda)]n (Hib = isobutyric acid, C4H8O2, and H2mda = N-methyldiethanolamine, C5H13NO2), namely, catena-poly[[(N-methyldiethanolamine-κ3O,N,O′)strontium(II)]-di-μ2-isobutyrato-κ3O,O′:O;κ3O:O,O′], was prepared by the one-pot aerobic reaction of [Zr6O4(OH)4(ib)12(H2O)]·3Hib with Sr(NO3)2 and H2mda in the presence of MnCl2 and Et3N in acetonitrile. The use of MnCl2 is key to the isolation of I as high-quality colorless crystals in good yield. The molecular solid-state structure of I was determined by single-crystal X-ray diffraction. Compound I crystallizes in the monoclinic space group P21/c and shows a one-dimensional polymeric chain structure. Each monomeric unit of this coordination polymer consists of a central SrII ion in the NO8 coordination environment of two deprotonated ib− ligands and one fully protonated H2mda ligand. The C and O atoms of the H2mda ligand were refined as disordered over two sets of sites with site occupancies of 0.619 (3) and 0.381 (3). Compound I shows thermal stability up to 130°C in air.

Keywords

• crystal structure
• strontium
• carboxylates
• n-methyldiethanolamine
• coordination polymer
• zirconium