Rosalba Cefalù

Studies on adducts of organotin(IV) halides with bis(acetylacetone)ethylenediimine

The solid state configuration of 1/1 adducts, formed by mono-, di- and tri-organotin(IV) halides with the potentially tetradentate ligand bis(acetylacetone)ethylenediimine, has been investigated. The infrared spectra suggest that the neutral ligand coordinates SnIV through N (or O) atoms of the H-bonded acetylacetoneimine moieties. The skeletal vibrations associated to Sn-C and Sn-Cl bonds are consistent with square planar configurations of the organotin(IV) halide moieties, where SnCl3 and C3Sn groups would be T-shaped, and Alk2SnCl2 would have trans-dialkyl, trans-dichloro arrangements. The latter configuration is supported by the magnitude of the quadrupole splittings. Measurements of the temperature dependence of the Debye-Waller factor, as obtained by Mossbauer spectroscopy for the (CH3)3SnCl adduct, indicate a polymeric structure. An octahedral type configuration is then proposed, in which the planar organotin(IV) halide moieties are bridged by the ligand, axially coordinating tin(IV).

Complexes of organometallic compounds XXVIII. The solution chemistry of bis(acetylacetone)ethylenediimine adducts of organotin(IV) halides

Abstract The nature of methanol solutions of a series of bis(acetylacetone)ethylenediimine adducts of organotin(IV) halides has been studied by electronic and PMR spectroscopy and by osmometry and conductivity. Effectively complete dissociation to the free ligand and solvated organotin(IV) halide moieties is inferred.

Complexes of organometallic compounds : XXXIX. synthesis, infrared and mössbauer studies on monoorganotin(IV) complexes with tridentate ligands

Abstract Novel complexes RClSntrid, where R is Me, Ph, n-Oct, and trid 2− are dianions of tridentate “planar” ligands with ONO and SNO donor atoms, were synthesized and investigated in the solid state by infrared and Mossbauer spectroscopy. Possible configurations are discussed; polymeric trigonal bipyramidal structures seem to occur, although five-coordinated monomers as well as octahedral dimers (via oxygen or sulfur bridges) are not excluded.

Complexes of organometallic compounds : XXV. Studies on five-coordinated diorganolead(IV)

Abstract A number of novel compounds of dimethyllead(IV) and diphenyllead(IV) moieties with ligands having a rigid geometry when coordinating, have been prepared and characterized. The goal of the work was the building of model molecules for five-coordinated R 2 Pb IV , with known configuration of the CPbC skeleton. From spectroscopic data it is inferred that the complexes under investigation have a distorted bipyramidal trigonal structure, with the CPbC moiety allocated in the trigonal plane.

Complexes of organometallic compounds : XXXVII. Mössbauer and other studies on adducts of organotin(IV) chlorides with N,N′-ethylenebis(salicylideneiminato)-nickel(II)

Abstract Novel 1/1 adducts have been obtained from the complex N , N ′-ethylenebis(salicylideneiminato)nickel(II) (NiSalen) with di- and mono-organotin(IV) chlorides, and their solid state configuration investigated by Mossbauer , IR and electronic spectroscopy and magnetic measurements. In coordinated NiSalen the square planar structure is maintained around Ni II , and the coordination to tin involves three-coordinate phenolic oxygens. The environment of Sn IV is judged to be octahedral in both types of compounds. A trans -R 2 , cis -Cl 2 configuration is advanced for R 2 SnCl 2 NiSalen.

Complexes of organometallic compounds : XXXII. The coordination chemistry of monophenylthallium(III) with tri- and tetradentate ligands

Abstract Several new complexes formed by PhTlCl 2 with tridentate ligands (with ONO and SNO donor atoms) and a tetradentate ligand (with ONNO donor atoms), have been prepared. The complexes show 1/1 organothallium(lll)/Ligand ( = L 2− ) stoichiometry. Their nature and configuration are investigated in the solid state by vibrational spectroscopy, and in solution by electronic spectroscopy. The existence of chelation by the dianionic ligands on Tl III is inferred, and suggestions are made concerning the Tl III coordination number and the stereochemistry of the complexes.

Adducts of organolead(IV) and organothallium(III) chlorides with N,N′-ethylenebis(salicylideneiminato)nickel(II) and bis(β-mercaptoethylamine)nickel(II)

Abstract Novel 1/1 adducts of organolead(IV) and organothallium(III) chlorides with the complexes N,N′-ethylenebis(salicylideneiminato)nickel(II) and bis(β-mercaptoethylamine)nickel(II) have been synthesized. Their configurations have been investigated in the solid state by IR and electronic spectroscopy and by magnetic measurements.