Marcela López-Cardoso

Influence of the steric effect on the conformation of stannocanes. The synthesis and X-ray structure of X(CH2CH2S)2Sn(n-Bu)Cl (X=S, O)

Abstract 5-Chloro-5- n -butyl-1-oxa-4,6-dithia-5-stannocane ( 1 ) and 2-chloro-2- n -butyl-1,3,6-trithia-2-stannocane ( 2 ) have been prepared by reacting n -butyltin trichloride with 2-mercaptoethyl ether and 2-mercaptoethyl sulphide, respectively. Complexes 1 and 2 were characterised by elemental analyses, IR, EI MS, and multinuclear NMR ( 1 H, 13 C, 119 Sn). The molecular structures of 1 and 2 were determined by X-ray analyses. The eight-membered rings in both compounds are in the boat–chair conformation with a 1,5 transannular Sn⋯O (2.409(7) A) or Sn⋯S (2.7855(16) A) interaction. The coordination around the Sn atoms can be described as trigonal bipyramidal with Cl and X in the apical positions.

1-Oxa-4,6-Dithia-5-Arsocane and 1,3,6-Trithia-2-Arsocane Dithiocarbamates Competition Between Transannular and Exocyclic Secondary Bonding to Arsenic

1-oxa-4,6-dithia-5-arsocane morpholinyldithiocarbamate (1) and 1,3,6-trithia-2-arsocane 2-diethyldithiocarbamate (2) have been prepared by reacting the corresponding sodium dithiocarbamates with 1-oxa-4,6-dithia-5-arsocane or 1,3,6-trithia-2-arsocane. (1) and (2) were characterized by elemental analyses, IR, MS, 1H and 13CNMR. The X-ray single-crystal molecular structures of (1) [monoclinic, a = 9.931(5), b = 18.253(5), c = 8.076(3) A; β = 92.56(2)°; V = 1462.5(7) A3; space group P21/c; Z = 4; R = 4.33%] and (2) [monoclinic, a = 7.830(2), b = 10.465(2), c = 19.025(6) A; β = 95.82(2)°; V = 1550.8(10) A3; space group P21/c; Z = 4; R = 3.41%], show that the compounds are monomeric and contain an asymetric monometallic biconnective dithiocarbamate ligand with a large distortion in the geometry around the As and a weak heterocyclic arsocane transannular secondary interaction.

On the easy oxidation of (R)-2-[N-(1-phenylethyl)amino]-1-cyclopentenedithiocarboxylic acid to its disulfide dimer

Abstract The physical and spectroscopic data of (R)-2-[N-(1-phenylethyl)amino]-1-cyclopentenedithiocarboxylic acid are reviewed and the synthesis of (R)-di-[2-(N-(1-phenylethyl)amino]-1-cyclopentenedithiocarboxylic acid disulfide is described. The product resulting from the conjugate addition of the dithioacid to 2(5H)-furanone is also characterised.

Structural diversity of four-co-ordinate metal(II) compounds with the bidentate bis(diphenylselenophosphoryl)amide ligand, [M{N(PPh(2)Se)(2)-Se,Se'}(2)] (M=Sn, Pb, Zn, Cd or Hg)

The [N(PPh 2 Se) 2 ] - ion formed stable bis-chelates with M II (M = Sn, Pb, Zn, Cd or Hg), [M{N(PPh 2 Se) 2 -Se,Se′ } 2 ], which exhibit a large diversity of structural arrangements around the metal, as shown by X-ray crystallography. The tin(II) complex crystallises dimorphically, as yellow triclinic prisms (1) and red tetragonal octahedrons (1′). The yellow isomer is square planar, representing the first example of a true square-planar tin(II) spiro-compound. The red isomer and the lead(II) compound (2) exhibit a distorted ψ-trigonal-bipyramidal co-ordination geometry with a vacant equatorial position, which suggests the presence of a stereoactive electron lone pair. The cadmium(II) and mercury(II) complexes (3 and 4) are tetrahedral.

Organometallic tin(IV) derivatives of the ambidentate O-cholesteryl-O-phenyl phosphorothioate ligand

Abstract Organotin(IV) compounds of the potentially ambidentate O-cholesteryl-O-phenyl phosphorothioate ligand formulated as Me3SnOSPR′R′′ (1), Ph3SnOSPR′R′′ (2), O(CH2CH2S)2Sn(n-Bu)OSPR′R′′ (3), S(CH2CH2S)2Sn(n-Bu)OSPR′R′′ (4), (R′=O-Ph; R′′=O-cholesteryl) were obtained and characterized by elemental analyses, IR, MS and multinuclear NMR (1H, 13C, 31P and 119Sn) spectroscopy. The spectroscopic data are consistent with bonding of the phosphorothioate ligand through both sulfur and oxygen atoms to the Sn(IV) center.

Synthesis and characterization of the new ambidentate O-cholesteryl-O-phenyl phosphorothioate ligand and its organoarsenic derivatives of phenoxarsin-10-yl and phenothiarsin-10-yl phosphorothioate

A new anionic phosphorothioate ligand that incorporates the bioactive cholesteryl group was obtained (2), Na(RR′P(S)O; R, O-phenyl; R′, O-cholesteryl) from the phenylphosphoramidate (1) and NaH in dioxane. In order to test the coordination ability of 2, two organoarsenic derivatives were prepared, O(C6H4)2AsS(O)PRR′ (3) and S(C6H4)2AsS(O)PRR′ (4) by reacting 2 with 10-chlorophenoxarsine or 10-chlorophenothiarsine. Compounds 2, 3, and 4 were characterized by elemental microanalysis, IR, multi-element NMR (1H, 13C, and 31P), and mass spectrometry. The spectroscopic data suggest that the ligand is bonded to the arsenic only through the sulfur donor atom in both organoarsenic derivatives.

Synthesis and Structural Characterizationof the Two Epimeric O-Cholesteryl-O-phenyl- N -phenylphosphoramidates

Summary. O-Cholesteryl-O-phenyl-N-phenylphosphoramidate was synthesized as intermediate for the stereoselective synthesis of organophosphates and phosphorothioates. Single crystal X-ray diffraction discerned four independent P-epimeric phosphoramidates cocrystallizing in the triclinic P1 space group. They were found to be selectively paired in the crystal forming pseudo-centrosymmetric dimers via hydrogen bonds between the amide group of one epimer and the phosphinoyl group of the other.Zusammenfassung. O-Cholesteryl-O-phenyl-N-phosphoramidat wurde als Zwischenprodukt für die stereoselektive Synthese von Organophosphaten und Phosphorthioaten dargestellt. Die Einkristallröntgenstrukturanalyse ergab vier unabhängige P-epimere Phosphoramidate, die in der triklinen Raumgruppe P1 kristrallisieren. Sie liegen im Kristall selektiv gepaart in From von pseudo-zentrosymmetrischen Dimeren vor, die über Wasserstoffbrücken zwischen der Amidgruppe des einen Epimers und der Phosphinoylgruppe des zweiten aneinander gebunden sind.

Structural Diversity of [M{N(SePPh2)2/Se,Se'}2,3] [M(II)=Sn,Pb, Cd, Hg, Se; M(III)=In, Sb, Bi].

The anion [N(SePPh2)(2)](-) forms stable complexes with cations M(II, III); [M(II) = Sn, Se, Cd, Hg; M(III) = In, Sb, Bi], they exhibit a large diversity of structural arrangements around the metal centre. Tin(II) complex crystallizes dimorphically, as square planar and distorted tetragonal pyramidal, Pb(II) is also distorted tetragonal pyramidal, Cd(II) and Hg(II) are tetrahedral, but the Se(II) is square planar. The coordination geometry in the M(III) complexes can be described as a distorted octahedron. The structural situation around the Sb(III) and Bi(III) suggests a stereochemically non-active electron lone pair.

Synthesis, spectroscopic characterization and crystal structures of diorganotin (IV) complexes of 2-N-propyl and 2-N-benzyl-amino-1-cyclopentene-1-carbodithioates

Abstract Six new diorganotin (IV) complexes, [Ph2Sn(Pr-ACDA)2] 1, [Bu2Sn(Pr-ACDA)2] 2, [Ph2Sn(Bz-ACDA)2] 3, [Bu2Sn(Bz-ACDA)2] 4, [Me2Sn(Bz-ACDA)2] 5, [t-Bu2Sn(Bz-ACDA)2] 6 are reported (where ACDA is the 2-amino-1-cyclopentene-1-carbodithioic anion). The diorganotin complexes were prepared from reactions between sodium N-propyl and N-benzyl-2-amino-1-cyclopentene-1-carbodithioate with R2SnCl2 (R=Ph, Bu, Me, tBu) in a 2:1 ratio. All complexes were characterized by elemental analysis, IR, multinuclear NMR (1H, 13C, and 119Sn), FAB+ mass spectrometry and in the case of 2, 3 and 5 by single-crystal X-ray diffraction. Both solution and solid state studies show that dithioacid ligands are coordinated to tin in an aniso-bidentate manner. In all complexes coordination takes place only through the carbodithioate moieties. 119Sn NMR data indicate pentacoordination of tin in solution. The tin coordination geometry, in all three structures is a highly distorted octahedral geometry, where tin is bonded to the four sulfur atoms of the two aniso-bidentate carbodithioate ligands in the equatorial plane and the organic substituents on tin atom in trans-positions. In addition, the crystal structures show the presence of N-H…S hydrogen bonding contacts.

Synthesis and characterization of stannacyclododecane-yl-dithiocarbamates

Thirteen new stannacyclododecane dithiocarbamate complexes have been prepared by reacting 12-chloro-12-n-butyl-1,11-dioxa-4,8-dithia-12-stannacyclododecane (1) and 12-chloro-12-n-butyl-1,4,8,11-tetrathia-12-stannacyclododecane (2) with pyrrolidine-, morpholine-, thiomorpholine-, piperidine-, piperazinebis-, and 3-pyrroline-carbodithioates, respectively, as well as with diethyl-dithiocarbamate. All complexes were characterized by elemental analyses, IR, EI-MS, and NMR (1H, 13C, and 119Sn) studies. The spectroscopic data suggest the replacement of the chlorides by the corresponding dithiocarbamates with monodentate coordination, leading to six-coordinate tin atoms in all the cases.