Crystal structure of lead(ii) acetylacetonate and the structure of the acetylacetone solvated lead(ii) ion in solution studied by large-angle X-ray scattering

Abstract

The crystal structure of bis(acetylacetonato)lead(II) and the structure of the acetylacetone solvated lead(II) ion in solution have been determined by single-crystal X-ray diffraction and large-angle X-ray scattering (LAXS), respectively. The acetylacetone is deprotonated and acts as a bidentate anionic ligand (acac-) in the solid Pb(acac)2 compound. The lead(II) ion binds four oxygen atoms strongly in a nearly flat pyramidal configuration with Pb-O bond lengths in the range 2.32-2.37 A, and additionally three oxygens from neighboring complexes at 3.01-3.26 A. Acetylacetone acts as a solvent (Hacac) at dissolution of lead(II) trifluoromethanesulfonate forming a pentasolvate with a mean Pb-O bond distance of 2.724(5) A. The 6s2 lone electron pair on the lead(II) ion becomes stereochemically active in the crystalline acetylacetonate complex, while it is inactive in the solvate in solution. The solution was also analysed using IR and 1H NMR spectroscopy.

New Insights into the Complexation of Lead(II) by 1,4,7,10‐Tetrakis(carbamoylmethyl)‐1,4,7,10‐tetraazacyclododecane (DOTAM): Structural, Thermodynamic, and Kinetic Studies

“…[62] This holds also for the bis(acetylacetonate) (acac) complex. [63] However, a completely different situation is encountered when Pb 2+ is bound to 18-crown-6. [64] In the latter compound, the metal center is octacoordinated in the equatorial plane by the six oxygen atoms belonging to the macrocycle and by two thiocyanate anions on the axial positions.…”

“…[44] Hemidirected geometries (i.e., stereoactive lone pair) were sought to produce plots evidencing large scattering and an increase in bond lengths when the L-Pb-Lp angle tends to zero. 2+ ( ), [62] [Pb(acac) 2 ] (᭡), [63] [Pb(18-crown-6)(SCN) 2 ] (o), [64] and [Pb(DOTAM)] 2+ complexes (᭹, nitrate salt, this work; ᭺, perchlorate salt; the dashed line is drawn as an eye guide and is supposed to differentiate holodirected from hemidirected structures according to ref. [44] ).…”

Stereochemistry of lead(II) complexes with oxygen donor ligands

“…In the crystal structure of bis(acetylacetonate)lead(II), Pb(acac) 2 , each Pb atom is also chelated by four O atoms of two acac − anions [51]. According to the VSEPR model, the coordination polyhedron of the Pb atom in the structure of Pb(acac) 2 is expected to be a -trigonal bipyramid (II) (Fig.…”

“…The crystal structures of bis(acetylacetonate)lead(II) complexes were investigated in a number of publications [49][50][51][52][53][54] and were characterized in detail because of their possible use in the metal-organic chemical vapour decomposition (MOCVD) technique for the production of new materials.…”

catena-Poly[(μ3-2-hydroxy-4-isopropylcyclohepta-2,4,6-trien-1-onato)(μ2-2-hydroxy-4-isopropylcyclohepta-2,4,6-trien-1-onato)lead(II)]

“…For related structures, see: Malik et al (1999); Harrowfield et al (2004); Lyczko et al (2006Lyczko et al ( , 2007. For hemi-and holodirected geometries of lead(II) complexes, see: Shimoni-Livny et al (1998).…”