Strontium beta-diketonate complexes with polyamine donor ligands: the synthesis and structural characterization of [Sr(thd)(2)(L)](n) (n=2; L = diethylenetriamine, n=1; L = triethylenetetramine, tetraethylenepentamine and tris(2-aminoethyl)amine) complex

Four novel [Sr(thd)(2)(L)](n) (n = 2; L = diethylenetriamine CI), n = 1; L = triethylenetetramine (IT), tetraethylenepentamine (III), and tris(2-amino ethyl)amine (IV) complexes were synthesized by the reaction of Sr(thd)(2) w ith corresponding polyamines in THF and characterized by FTIR,H-1 NMR and s ingle-crystal X-ray crystallography. Complex I exists as a dimmer in the so lid state in which two strontium atoms are bridged by two thd ligands. Comp lexes II and III exist as monomers in the solid state and in both complexes , the polyamine ligands are coordinated to the central strontium atom in a meridional fashion, with the two thd ligands on opposite sides of the neutr al ligand plane. Complex IV also exist as a monomer in the solid slate. In this molecule, strontium atom is eight-coordinate with all of the nitrogens of the amine ligand and all oxygens of the thd ligand binding to the metal atom. The amine ligand is coordinated to one side of the metal atom and re sulting in a cis-relationship, Thermogravimetric analysis shows that comple xes I, II, III and IV are sufficiently volatile and sublimed without residu e. (C) 2000 Elsevier Science B.V. All rights reserved.