Synthesis of new heteroleptic strontium complexes stabilized by β-ketoiminato ligands

Heteroleptic strontium complexes stabilized by amine functionalized tridentate beta-ketoiminato ligands in combination with bis(trimethylsilyl) amide [Sr(btsa)(L-1)](2) (1) and [Sr(btsa)(L-2)](2) (2) and stabilized by beta-ketoiminato and aminoalkoxy ligands [Sr(dmamp)(L-1)](2) (3) were synthesized and characterized. All the complexes formed as dimers where the strontium metal centers were connected by a pair of mu(2)-O bridging. In 1 and 2 the beta-ketoiminato oxygen bridges the metal centers, leaving the complex in a highly strained state bearing a penta-coordinate strontium. The introduction of aminoalkoxy ligand (dmamp) to 1 gave complex 3, where the aminoalkoxy oxygen assumed the bridging role and allowed beta-ketoiminato ligands to attain a more relaxed planar state for its ketoimine backbone and a stable hexa-coordinate metal center. All the complexes were characterized using FT-IR, FT-NMR, elemental analyses, and single crystal X-ray crystallography. (C) 2015 Elsevier B.V. All rights reserved.