R. H. P. Francisco

Organotin(IV) Derivatives of 2-Acetylpyridine-N(4)-Phenylthiosemicarbazone, HAP4P, and 2-Hydroxyacetophenone-N(4)-Phenylthiosemicarbazone, H2DAP4P: Crystal and Molecular Structure of [SnMe2(DAP4P)] and [SnBu2(DAP4P)]

The reactions of 2-acetylpyridine-N(4)-phenylthiosemicarbazone, HAP4P, and 2-hydroxyacetophenone-N(4)-phenylthiosemicarbazone, H2DAP4P, with R4-mSnXm (m = 2, 3; R = Me, nBu, Ph and X = Cl, Br) led to the formation of hexa- and penta-coordinated organotin(IV) complexes, which were studied by microanalysis, IR, 1H-NMR and Mossbauer spectroscopies. The molecular structures of [SnMe2(DAP4P)] and [SnnBu2(DAP4P)] were determined by single-crystal X-ray diffraction studies. In the compounds [SnClMe2(AP4P)] and [SnBrMe2(AP4P)], the deprotonated ligand AP4P- is N,N,S-bonded to the Sn(IV) atoms, which exhibit strongly distorted octahedral coordination. The structures of [SnMe2(DAP4P)] and [SnnBu2(DAP4P)] revealed that the DAP4P2- anion acts as a O,N,S-tridentate ligand. In these cases, the Sn(IV) atoms adopt a strongly distorted trigonal bipyramidal configuration where the azomethine N and the two C atoms are on the equatorial plane while the O and the S atoms occupy the axial positions.

New Heptacoordinated Organotin(IV) Complexes Derivatives of 2,6-diacetylpyridinebis(2-furanoylhydrazone), H2dapf, and 2,6-diacetylpyridinebis(2-thenoylhydrazone), H2dapt: Crystal and Molecular Structure of [Me2Sn(Hdapt]Br.H2O

The reaction of the ligands H2dapf and H2dapt, with R4-mSnXm (m = 2, 3; R = Me, Ph and X = Cl, Br) led to the formation of eight new heptacoordinated organotin(IV) complexes, which were studied by microanalysis, IR, NMR and Mossbauer spectroscopy to investigate their structural properties. The methyl derivative [Me2Sn(Hdapt)]Br.H2O was also studied by single crystal X-ray diffraction. It crystallizes in the monoclinic system, space group P21/c, with a = 21.920(3), b = 7.4470(5), c = 16.805(2) A, b = 110.18(1)o, Z = 4. The structure determination revealed a monocationic complex of Sn(IV) in a distorted bipyramidal geometry [Me2Sn(Hdapf)]+, with Br- as counter ion and one molecule of water helping the crystal packing. Mossbauer parameters of the complex [Me2Sn(Hdapf)]2[Me2SnCl4] have evidenced two Sn(IV) sites, as observed in the crystal structure determination. Also a correlation between Mossbauer and X-ray data based on the point-charge model is discussed.

trans-[2,6-Diacetylpyridine bis(thiosemicarbazone)(1–)]diphenyltin(IV) Chloride

The chelating properties of the pentadentate ligand 2,6-diacetylpyridine bis(thiosemicarbazone) hydrochloride, H2daptsc.HCl, have been investigated in a new organotin complex, [PhSnPh(Hdaptsc)]Cl {or [Sn(C 6 H 5 ) 2 (C 11 H 14 N 7 S 2 )]Cl}. The structure determination revealed a monocationic complex consisting of a heptacoordinated Sn IV in a distorted pentagonal-bipyramidal geometry, with the thiosemicarbazone derivative acting as a pentadentate species at the equatorial plane and two phenyl groups at trans positions. The chloride acts as a counterion. 119 Sn Mossbauer measurements showed that the isomer shift and the quadrupole splitting are consistent with structural interpretation.

A crystallographic study of (2-acetylpyridine-κN 4-phenylthyosemicarbazonate-κ2N1,S) methyl-trans-dichlorotin(IV)

AbstractThe preparation and characterization of [Sn(C14H13N4S)(CH3)Cl2], an organotin(IV) complex containing 2-acetylpyridine(4)-phenylthiosemicarbazone, is described. The molecular structure was studied by single crystal X-ray diffraction, and IR and Mössbauer spectroscopies. The title compound crystallizes in the centric triclinic space group, P

Pyridine N-oxide and 4-nitrophenol (1:1 complex)

\overline 1

Study of Ca2Fe2−xNbxO5+x phases by X-ray diffraction, IR and EPR spectroscopy

, as discrete neutral complexes, with the Sn(IV) ion in a distorted octahedral coordination geometry, with the thiosemicarbazone derivative in a meridional configuration and the chlorides in trans positions.

Bis{[2,6-diacetylpyridine bis(2-furoylhydrazone)(1–)]dimethyltin(IV)}trans-Tetrachlorodi-methylstannate(IV)

Abstract The petrol extract from leaves of Neoraputia alba yielded two flavones, in addition to sitosterol. The two new flavones were identified as: 7,8,3′,4′-tetramethoxy-6,5-(2″,2″-dimethylpyran)flavone and 7,8,3′,4′,5′-pentamethoxy-6,5-(2″,2″-dimethylpyran)flavone. The compounds were identified by spectroscopic analysis. The structure of the first compound was confirmed by X-ray diffraction.

[μ-N,N'-Bis(2-pyridylethyl)oxamide]bis[acetatocopper(II)]

In the title hydrogen-bonded complex, C 5 H 5 NO.C 6 H 5 -NO 3 , the two components are linked by an O-H...O hydrogen bond between the phenol hydroxyl group and the N-oxide O atom [O...O 2.553(2) A]. The interplanar angle between the aromatic rings in the two components is 41.29 (6)°.