Complexes of alkaline-earth metal β-diketonates with 15-crown-5: Synthesis, structures, and properties

Metal–Organic Derivatives with Fluorinated Ligands as Precursors for Inorganic Nanomaterials

“…In contrast, the metal center in [M(η 2 -ptac) 2 (η 6 -15-crown-5)] (M = Ca, Ba) is outside the crown-ether cavity and coordinated by five O atoms of 15-crown-5 and four O atoms of two chelating fluorinated β-dikenonate ligands arranged in cis position. 332 The 9-coordinated metal center has a distorted tricapped trigonal prismatic geometry. The 10-coordinated Ba center in [Ba(η 2 -ptac) 2 (η 6 -18-dibenzocrown-6)], which crystallizes with either dichloromethane or toluene as a solvated molecule, also has two β-diketonate ligands in the cis position relative to the plane of the macrocycle.…”

“…Structural aspects of group 2 metal β-diketonates were reviewed by Otway and Rees in the year 2000 . Since then, a number of fluorinated β-diketonate complexes of group 2 metals with neutral ancillary ligands have appeared in the literature. ,,,− The structure of [Ba­(dfhd) 2 (tetraglyme)] (Hdfhd = 1,1,1,2,2,6,6,7,7,7-decafluoro-heptane-3,5-dione) is similar to that of [Ba­(hfac) 2 (tetraglyme)], where 9-coordinated barium centers have distorted antiprismatic geometry comprised of five tetraglyme oxygen atoms in equatorial positions and four β-diketonate oxygen atoms arranged in nearly orthogonal fashions. The hydrated complex [Mg­(hfac) 2 (H 2 O) 2 ]·2diglyme has two water molecules bonded in the trans position .…”

“…In the structures of [Sr­(η 2 -hfac) 2 (η 6 -18-crown-6)] and [Ba­(η 2 -ptac) 2 (η 6 -18-crown-6)­(THF)], the M 2+ ion resides in the center position of the 18-crown-6 cavity and is coordinated by 10 oxygens, including four from the two β-diketonate ligands. , The β-diketonate ligands are in a trans arrangement with respect to the nearly planar macrocycle. In contrast, the metal center in [M­(η 2 -ptac) 2 (η 6 -15-crown-5)] (M = Ca, Ba) is outside the crown-ether cavity and coordinated by five O atoms of 15-crown-5 and four O atoms of two chelating fluorinated β-dikenonate ligands arranged in cis position . The 9-coordinated metal center has a distorted tricapped trigonal prismatic geometry.…”