Investigations on organoantimony compounds

Abstract Trichlorodiorganoantimony(V) compounds, R2SbCl3, in which the antimony atom is part of a heterocyclic ring have been synthesized. They have been converted into the corresponding tetramethylammonium tetrachlorodiorganoantimonates, [R2SbCl4]− [Me4N]+, which are hexacoordinate diorganoantimony(V) species in which the antimony-carbon bonds are forced into a cis-position. 5,5,5-Trichlorodibenzostibole, 10,10,10-trichlorophenoxantimonin, 5,5,5-trichloro-5,10-dihydrodibenz[b, e]antimonin and 5,5,5-trichloro-10,11-dihydro-5H-dibenzo[b, f]stibepin have been prepared by chlorination of the corresponding heterocyclic chlorodiarylstibines. Heterocyclic trichlorodialkylantimony(V) compounds hav…

The dynamics of (57)Fe nuclei in Fe(III)-DNA condensates.

Abstract The dynamics of iron nuclei in the condensates obtained by interaction of Fe III with DNA, Fe III (DNA monomer) 2 , have been investigated by variable temperature 57 Fe Mossbauer spectroscopy. Studies were effected on gel and freeze-dried samples, obtaining nearly coincident values of the parameters isomer shift and nuclear quadrupole splitting in T ranges 20–260 K. Functions ln( A T / A 77.3 ) vs. T , here employed to investigate the dynamics of Fe nuclei, showed linear trends in the T ranges 20–150 and 150–260 K, respectively, the latter with larger slopes. Data coincided for gelled and freeze-dried specimens. No variation of δ or Δ E parameters occurred at the two T intervals, w…

Coordination properties of adenosine-5'-monophosphate and related ligands towards Me2Sn(IV)2+ in aqueous solution.

Abstract The coordination of Me 2 Sn(IV) 2+ to adenosine-5′-monophosphate (AMP) and the related compounds d -ribose-5-phosphate (R5P), d -glucose-1-phosphate (G1P) and d -glucose-6-phosphate (G6P) in aqueous solution was investigated by means of potentiometric titration, and 1 H-, 31 P-NMR and Mossbauer spectroscopic methods in the pH range 2–11 ( I =0.1 M NaClO 4 , 298 K). The complex of AMP and Me 2 Sn(IV) 2+ precipitated at low pH was characterised by elemental analysis, FT-IR and Mossbauer spectroscopic methods. From a comparison of the p K values obtained in the presence and absence of metal ion and the stability constants for the different systems, the coordination of {N} is excluded,…

Synthesis and spectroscopic characterization of diethyltin (IV) derivatives of dipeptides: Crystal and molecular structure of diethyltin glycyltrosinate

Dipeptide complexes of the diethyltin(IV) moiety, Et2SnL, have been synthesized, H2L being glycylglycine (H2GlyGly), glycylalanine (H2GlyAla), alanylalanine (H2AlaAla), glycylvaline (H2GlyVal), valylvaline (H2ValVal), glycylmethionine (H2GlyMet), glycyltyrosine (H2GlyTyr). The crystal and molecular structure of the complex Et2SnGlyTyr has been determined by singlecrystal X-ray diffraction. It consists of monomeric units, with the tin atom having a considerably distorted trigonal bipyramidal environment. The dipeptide acts as a tridentate ligand bonding the tin of the C2Sn fragment (equatorial carbon atoms) with the peptide nitrogen atom (equatorial) and axial (monodentate) carboxyl oxygen a…

Synthesis of polymeric alkoxides from dialkyltin(IV) oxides and chloral, and their characterization by mössbauer and infrared spectroscopy

Abstract The reaction of (Alk2SnO)n with OCH·CCl3 gives compounds of elemental formula Alk2SnOCH- (CCI3)O (Alk = Bun, Octn), probably by addition of the Sn-O bond to the carbonyl group. Mossbauer parameters suggest the occurrence of five-coordinated Sn, and polymeric structures with bridging three- coordinating oxygens are proposed. The assumption that C2SnO3 units with trigonal bipyramidal type structures are present is consistent with point-charge model rationalization of the quadrupole splitting. Infrared spectra are in keeping with the proposed structures, suggesting, inter alia, bent C Sn C skeletons, but the analysis of possible ν(Sn-O) modes does not provide conclusive evidence for t…

Mössbauer spectroscopic studies of clusters Mn2(CO)8[μ-Sn(hal)Mn(CO)5]2 (hal = Cl, Br) and related Mn and Re compounds

Abstract In order to be acquainted with the nature of bonds at Sn involved in the title compounds, as well as to get information on the configuration of the strictly related derivatives I2Sn2Mn4(CO)18 and Cl2Sn2Re4(CO)18, the Mossbauer spectroscopic investigation reported in this paper has been carried out. The experimental parameters (isomer shifts, δ; nuclear quadrupole splittings, ΔE; for the bromide derivative only, the asymmetry parameter η and the sign of the nuclear quadrupole coupling constant e2qQ) have been discussed in connection with data concerning compounds with tin-transition metal bonds, mainly hal2Sn[Mn(CO)5]2 (hal = Cl, Br) and ClSn[Mn(CO)5]3. Rationalizations of ΔE and η …

Complexes of Tin(IV) with Tridentate Ligands M�SSBAUER, Infrared, and Solution Phase Studies

The configuration in the solid state and in solution phase of complexes of SuIV wit,li tridentate “planar” ligands, Sn(trid)2 and HNEt3Cl3 Sntrid, have been investigated by infrared and MOSSBAUER spectroscopy, as well as by osmometry, conductivity, and electronic and PMR spectroscopy. The presence of monomeric Sn(trid)2 and ionic [HNEt] [Cl3Sn trid−] species has been inferred. Octahedral type configurations are advanced for both classes of compounds. Komplexe des Zinn (IV) mit dreizahigen Liganden. Mossbauer- und IR-Spektren sowie Untersuchungen von Losungen Die Struktur von SnIV-Komplexen mit dreizahnigen “planaren” Liganden, Sn(trid)2 und HNEt3Cl2Sntrid, wurde in fester Phase und in Losun…

Synthesis and spectroscopic characterization of R3SnIV derivatives ofN-acetyldipeptides

Triorganotin(IV) derivatives of N-acetyldipeptides R3SnAcDip; RMe, Et, n-Bu, n-Oct, Cy or Ph (HAcDipN-acetylglycylglycine and N-acetylglycylvaline; RMe, n-Bu, Cy, HAcDipN-acetylglycylalanine) were obtained by neutralization of R3SnOH and HAcDip. The complexes were studied by means of 119Sn Mossbauer, IR and 1H, 13C and 119Sn NMR spectroscopy. The CSnC bond angles have been inferred by rationalization of Mossbauer nuclear quadrupole splittings as well as from NMR coupling constants. Correlations of Mossbauer isomer shifts with partial atomic charges on tin atoms have been determined: Polymeric trigonal bipyramidal structures, with near-planar R3Sn units and axial carboxylate (unidentate) and…

Infrared and M�SSBAUER spectroscopic studies on complexes of Hal2SnIV moieties with tridentate ligands

Novel complexes hal2Sntrid, where hal Cl, Br, and trid2− are dianions of „planar” tridentate ligands with ONO and SNO donor basic atoms, were synthesized and structurally investigated in the solid state mainly by far infrared and MOSSBAUER spectroscopy. Possible configurations were advanced and discussed, and it was concluded that the most probable is a monomeric trigonal bipyramidal structure for all compounds, although polymers, or dimers with O or Cl bridges, were not a priori excluded, in a special way for Br2Sntrid. Infrarot- und MOSSBAUER-spektroskopische Untersuchungen an Komplexen von Hal2SnIV mit dreizahnigen Liganden Neue Komplexverbindungen von Typ hal2Sntrid werden dargestellt (…

Complexes of organometallic compounds

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.

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 th…

Semiempirical calculations on the interaction between dimethyltin(IV) and DNA model system

Abstract The interaction between a dinucleotide triphosphate duplex (DD), mimicking the DNA molecule, and the dimethyltin(IV) cation is studied by the semiempirical PM3 method. The results show that the interaction can occur involving the tin atom and the electron-donor centres of DD, requiring in some cases the presence of water molecules. In particular, the binding of the dimethyltin(IV) moiety with two adjacent phosphate oxygen atoms is allowed by the presence of water molecules coordinating to the tin atom. In this case the tin environment shows a geometry in agreement with 119 Sn Mossbauer and X-ray data.

Complexes of organometallic compounds. XLVII. Synthesis of dimethyltin(IV) adenosinate and its characterization by Mössbauer and infrared spectroscopy

Organotin(IV) azido and mixed azidothiocyanato complex anions; A Mössbauer and vibrational spectroscopic study

Abstract Tetraphenylarsonium and tetramethylammonium salts of the complex anions Ph 3 Sn(N 3 ) − 2 , Ph 3 Sn(N 3 )(NCS) − , Me 2 Sn(N 3 ) 2− 4 and Ph 2 Sn(N 3 ) 2 (NCS) 2− 2 have been synthesized, and the solid state configuration of the complex anions has been studied by Mossbauer and vibrational spectroscopies. Trigonal bipyramidal structures are advanced for the Ph 3 Sn IV derivatives, with equatorial SnC 3 and apical pseudohalide ligands, while the R 2 Sn IV compounds are assumed to be trans -octahedral species. The NCS − ligands are observed to be N-bonded to Sn IV . Conductance and PMR (for the Me 2 Sn IV compound) data suggest the presence of the complex anions also in solution phase…

Synthesis and spectroscopic characterization of dimethyl-, di-n-butyl-, di-t-butyl-and diphenyl-tin(iv) derivatives of dipeptides: Crystal and molecular structure of di-n-butyltin(iv) glycylvalinate

The dipeptide complexes R2SnL listed below have been synthesized: (a) Me2SnL; H2L = glycylalanine (H2GlyAla), glycylvaline (H2GlyVal), glycylmethionine (H2GlyMet), glycyltryptophan (H2GlyTrp), glycyltyrosine (H2GlyTyr); (b) nBu2SnL; H2L = H2GlyAla, H2GlyVal; (c) nBu2SnL.H2O; H2L = glycylglycine (H2GlyGly), H2GlyAla; (d) tBu2SnL; H2L = H2GlyAla, H2GlyVal; (e) tBu2SnGlyGly. H2O; (f) Ph2SnL; H2L = H2GlyAla, H2GlyVal, H2GlyTyr, H2GlyTrp; (g) Ph2Sn(HGlyVal)2. The crystal and molecular structures of nBu2SnGl Val have been determined by single-crystal X-ray diffraction. The polyhedron around tin is a distorted trigonal bipyramid, analogous to that of Et2SnGlyTyr (see Vornefeld et al., Appl. Organo…

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

Abstract The compounds (C2H5)2PbCl2, (C2H5)3PbCl and PbCl2 were studied by paper electrophoresis in aqueous LiCl solutions of various molarities. Determination was made of the formation of chloride complexes in which the electric charge was a function of ligand concentration in the solution. From the results of these experiments, and from a comparative examination of anion exchange data obtained in previous researches, useful information is obtained for determining the ligand concentrations relative to the preponderance of cationic, neutral and anionic complexes in the aqueous solutions. From this information it is possible to assume (C2H5)2PbCl42− and (C2H5)3PbCl32− as the fully coordinate…

Bis(triorganometal) and diorganometal 1,3-dithiolates (R3M)2(C6H3XS2) and R2M(C6H3XS2) (M = Sn, Pb; X= H, Cl)

Abstract Bis(triorganometal) and diorganometal 1,3-dithiolates (R3M)2(C6H3XS2) (C6H5XS2 1,3-dithiobenzene (for X = H) or 1,3-dithio-4-chlorobenzene (for X = Cl); M = Sn, X = Cl, R = CH3, C6H5; M = Pb, X = H, Cl, R = CH3, C2H5) and R2M(C6H3XS2) (R = CH3, C2H5, C6H5; M = Sn, X = Cl; M = Pb, X = H, Cl) have been prepared as the first organometal IVB derivatives of 1,3-dithiols, and investigated by vibrational, 1H NMR, and (in the case of organotin compounds) Mossbauer spectroscopy. The triorganometal derivatives are monomeric and the diorganometal derivatives dimeric in solution (37° C). For the latter a twelve-membered ring structure is proposed for both solution and the solid state.

Complexes of organometallic compounds. XLVI. Synthesis of adducts formed by organotin(IV) trichlorides with 1,2-bis(diphenylphosphino)ethane, and their characterization by mössbauer and infrared spectroscopy

Abstract Adducts between RSnCl 3 (R = Me, Bu n , Oct n , Ph) and 1,2-bisz(diphenylphosphino)ethane, DPE, have 1:1 composition. In Mossbauer spectroscopic experiences at variable absorber temperature the area under the resonant peaks, A, has been measured for RSnCl 3 ·DPE, R = Me, Ph; slopes plots of in A vs. T suggest strong coupling between Mossbauer atoms, which has been interpreted in terms of solid state polymeric structures, due to DPE acting as a bridging bis-monodentate ligand. Infrared data indicate the covalency of SnCl bonds. Three possible structural isomers of octahedral type are then proposed, one having trans -P 2 and two cis -P 2 atoms. A choice between these structures has …

Complexes of organometallic compounds. LI. The correlation between 119Sn Mössbauer isomer shifts and partial atomic charges on tin in R3SnL compounds

Abstract The 119Sn Mossbauer isomer shift parameters, δ, of compounds R3SnL (R = AlK, Ph; L = F, Cl, OH, OR′, CN, NCS, NCO, N3) have been correlated to partial atomic charges on tin QSn, calculated according to a valence state electronegativity equalization procedure carried out by the CHELEQ program. A unique δ/QSn correlation has been obtained for all the five-coordinated R3SnL species by using average δ parameters for the AlK3IV derivatives.

The structure and dynamics of Cl-substituted tetraphenyl- and tetrabenzyl-tin(IV)

Abstract The crystal and molecular structure of (o-ClC6H4CH2)4Sn has been determined by X-ray crystallography. Tin is in a slightly distorted environment. The molecular dynamics of (p-ClC6H4)4Sn, (o-ClC6H4)4Sn and (o-ClC6H4CH2)4Sn have been investigated by variable temperature 119Sn Mossbauer spectroscopy (VTMS). A Debye-solid behaviour has been detected for (p-ClC6H4)4Sn, where, on the other hand, no influence by hydrogen–chlorine interaction on the magnitude of the dynamics data and functions seems to occur. For the o-Cl-substituted derivatives, a non-Debye-solid character could be advanced.

Complexes of Organometallic Compounds. XXIV. Spectroscopic Studies on Complexes of Diorganotin(IV) Moieties with SNO and ONO Tridentate Ligands

Komplexverbindungen vom Typ R2SnL (R = CH3, C6H5; L ist ein dreizahniger ONO- oder SNO-Ligand) werden dargestellt und ihre IR-, KMR- und elektronischen Spektren untersucht, um die Strukturen zu klaren. Als Liganden (LH2) werden benutzt: 4-(2-Benzothiazolinyl)-pentan-2-on, (hier zum ersten Mal dargestellt); 3-(o-Hydroxyphenylamino)crotonophenon; 2-(o-Hydroxyphenyl)-benzothiazolin; und N-o-Hydroxybenzyliden-o′-hydroxyanilin. Im festem Zustand umgeben die organischen Liganden L2− das Zinn(IV)-Atom als ebene dreizahnige Liganden. Die R2SnIV-Reste sind wahrscheinlich nicht linear. Eine mogliche Anordnung der Liganden ist eine trigonale Bipyramide, in der die zwei R-Reste und das Stickstoffatom i…

Tin(IV), Monomethyltin(IV), and Dimethyltin(IV) Complexes with thiol sulfur and heterocyclic nitrogen donors: Molecular dynamics and structure by119Sn m�ssbauer spectroscopy

The molecular dynamics of the complexes Sn(SPyN)4 (1), SnCl2(SPyN)2 (2), MeSn(SPy)3 (3), MeSnCl(SPyN)2 (4), Me2Sn(TCy)2 (5), Me2SnCl(TOx) (6), and Me2Sn(TUr) (7) [HSPy = 2-mercaptopyridine; HSPyN = 2-mercaptopyrimidine; HTCy = 2-thiocytosine; HTOx = 8-thioquinoline; H2TUr = 2-thiouracil] has been investigated by variable temperature 119Sn Mossbauer spectroscopy. The area under the resonant peaks has been determined as function of temperature, from which Debye temperatures and cut-off frequencies, as well as recoil-free fractions (Lamb Mossbauer factor) and mean square displacements of 119Sn, have been calculated. By fingerprint procedures on the basis of literature data, monomeric structure…

119Sn Mössbauer spectroscopic studies of the products of the reaction of triorganotin(IV) derivatives with 6-thiopurine

Abstract A structural study of the products of the reaction of R 3 Sn IV derivatives (R = Me, Bu n , Ph) with 6-thiopurine, 6-TPH 2 , and its sodium salt, 6-TPHNa, has been undertaken using Mossbauer spectroscopy and the point-charge model rationalization of the Mossbauer parameter nuclear quadrupole splitting. The synthetic reactions have been carried out at ca . 0 °C, 20 °C and 50 °C. The Mossbauer spectra of the complexes AlK 3 Sn(6-TPH) are consistent with the occurrence of two distinct tin(IV) sites in samples prepared at the lower temperature, while one only site appears by increasing the temperature of the reaction. Two tin sites constantly occur in the products of the reactions invo…

The interaction of organotins with native DNA

The compounds R2SnCl2 and R3SnCl (RMe, Et, nBu, nOct, Ph, in ethanol solution) as well as the aqueous species [Me2Sn(OH2)n]2+ and [Me3Sn(OH2)2]+, react with aqueous native DNA, yielding solid phases. According to the pointcharge model treatment of the 119Sn Mossbauer parameter nuclear quadrupole splitting, trans-octahedral R2Sn(O2PXY)2, and trigonalbipyramidal R3Sn(O2PXY), (RMe, Et, nBu), would occur in the pellets, the tin atoms being coordinated by phosphodiester groups of the nucleic acid. The precipitates from Ph2SnIV would consist of the DNA complex as well as of the Ph2SnIV distannoxane obtained by hydrolysis of the reactant, whilst nOct2SnCl2, nOct3SnCl and Ph3SnCl would mainly yield…

(2-Chlorobenzyl)tris(2-pyridinethiolato)tin(IV).

In the title compound, (2-chlorobenzyl)tris(pyridine-2-thiolato)-kappa(2)N,S;kappa2N,S;kappaS-tin(IV), [Sn(C7H6Cl)(C5H4NS)3], two of the three pyridine-2-thiolato ligands (SPy) are bidentate and one is monodentate. The bonding C atom of the 2-chlorobenzyl group, the S atom of the monodentate SPy and the S and N atoms of the two bidentate SPy ligands form a distorted octahedron around the Sn atom. The three S atoms and the N atom of one of the bidentate SPy ligands occupy the equatorial positions, while the N atom of the second bidentate SPy ligand and the C(CH2) atom are axial. The axial N-Sn-C angle of 157.9 (1) degree demonstrates the heavy distortion of the octahedron.

Stannacycloalkyl and stannepinyl derivatives of dipeptides

Stannacyclohexyl and stannacycloheptyl derivatives of dipeptides (CH2)nSnAA · xH2O (H2AA = H2GlyGly, with n = 5, x = 2 or n = 6, x = 1; H2AA = H2GlyAla, H2GlyVal, H2GlyMet, with n = 5, 6, x = 1) and stannepinyl glycylglycinate monohydrate have been obtained by the reaction of (CH2)nSnCl2 or stannepinyl dichloride with Na2AA. According to infrared and 119Sn Mossbauer data of the solid compounds, AA acts as a tridentate ONN ligand and tin has a trigonalbipyramidal environment. An analogous structure has been inferred from 1H, 13C, and 119Sn NMR data for the undissociated molecules in methanol solution.

Relationship between XPS core binding energies and atomic charge in adducts of SnIV derivatives with pyrazine, and comparison with mössbauer isomer shift data

Abstract Adducts Snhal·pyz (hal = Cl, Br, I; pyz = pyrazine), RnSnCl 4−n ·pyz (n = 1, R = Me, Bu n , Oct n , Ph; n = 2, R = Ph) and SnCl 4 ·(pyz) 2 have been investigated by X-ray photoelectron spectroscopy. Binding energy (b.e.) values are discussed in the light of structural characteristics of the adducts as well as of valence state electronegativities of atoms and groups bound to tin. Sn 3d 5 2 b.e.s, corrected for the Madelung potential at the metal atom, linearly correlate with both partial atomic charges on tin, accounting for relaxation upon ionization, and 119 Sn Mossbauer isomer shifts. The results are interpreted in terms of six-coordinated, octahedral type, configurations of the …

Complexes of organometallic compounds.XXIII. Aryllead(IV)—thiocyanate complex systems

Interactions of organotins with biological systems

The bonding and structure in the environments of tin atoms in organotin-biological molecules has been investigated by 119Sn Mossbauer spectroscopy, mainly through the rationalization of the nuclear quadrupole splitting parameter by pointcharge model approaches. Organotin moieties R2SnIV and R3SnIV (R = Me, nBu, Ph) generally assume trigonal-bipyramidal type configurations in membranes of human erythrocytes, when incubated with whole erythrocytes and erythrocyte ghosts at the level of micromolar (μmol dm−3) organotin per mg of membrane protein. Corresponding structures are assumed by Me2SnIV and Me3SnIV in the cytoplasm. Ethanolic Me2SnCl2 yielded distorted trans-octahedral species when reac…

Complexes of organometallic compounds. XLIX. A Mössbauer-zeeman spectroscopic study of glycylglycinato-O,N,N(2−) diphenyltin(IV), and the point-charge model rationalization of the quadrupole splittings of some glycylglycinato-O,N,N(2−) diorganotin(IV) complexes

Mössbauer study of the solid state configuration of triorganotin derivatives with intramolecular coordination

Triorganotin bromides with intramolecular nitrogen-to-tin coordination (I-VIII, Fig. 1) have been structurally investigated by Mossbauer and infrared spectroscopy. Mossbauer-Zeeman spectra have been measured for I and VIII in order to obtain the sign of the nuclear quadrupole splitting ΔE and the value of the asymmetry parameter η. Point-charge model values of ΔE and η have been calculated for environments of tin atoms in I-VIII which are plausible in view of the results of previous investigations. From trends of experimental ΔE in the series, and from the agreement between experimental and calculated Mossbauer parameters it is concluded that the compounds I-VIII all have trigonal bipyramid…

Organozin- und organobleiderivate von N-(2,4-dinitrophenyl)glycin

Abstract Organotin and organolead derivatives of N -(2,4-dinitrophenyl)glycine (HDNG), R 3 MDNG (M = Sn, Pb; R = CH 3 , C 6 H 5 ) and (C 6 H 5 ) 2 Pb(DNG) 2 , have been prepared from R 3 MOH or [(C 6 H 5 ) 2 PbO] n and HDNG, respectively. (CH 3 ) 3 PbDNG was also obtained from (CH 3 ) 3 PbBr and TlDNG. According to spectroscopic data R 3 M groups in R 3 MDNG are essentially planar and are bridged by bidentate carboxylate groups of DNG. NH does not coordinate to M. Penta-coordination is also indicated by Mossbauer data of R 3 SnDNG. Also for (C 6 H 5 ) 2 Pb(DNG) 2 a chain structure but with hexacoordination of Pb is proposed. The compounds are monomeric in solution.

Complexes of Organometallic Compounds. XXVII. Studies on Diorganolead (IV) Moieties Six-coordinated by ONNO Tetradentate Ligands

New complexes R2PbL, where L2− are the dianions in the “planar” SCHIFF base form, of the tetradentate ONNO ligands α, α′ (ethylenedinitrilo)dicresol and 2,2′ bis-benzoxazoline, were synthesized. Their configuration was investigated at the solid state by infrared spectroscopy, and in solution phase mainly by electronic and PMR spectroscopy. An octahedral type structure with linear CPbC moieties, and the ONNO ligand atoms chelating PbIV in a square plane, was advanced. Darstellung neuer Komplexverbindungen: R2PbL (R = CH3, C2H5, C6H5; L−2 sind zweiwertige Anionen, in der „planaren” SCHIFFSCHEN Basen-Konfiguration, der vierzahnigen ONNO-Liganden Disalicylal-athylendiamin und Glyoxal-bis-[2-hyd…

Infrared, Mössbauer and lattice dynamics studies of (3-mercaptopropionato)bis(trimethyltin(IV))

Complexes of organometallic compounds. XLVIII. Mössbauer and other studies on pyrazine derivatives of tin(IV) compounds. A relationship between isomer shift and charge on tin

Abstract Adducts RSnCl 3 ·pyz (R = Me, Bu n , Oct n , Ph; pyz = pyrazine) have been synthesized and characterized in the solid state. It has been determined that RSnCl 3 ·pyz are polymeric compounds, where the ligand acts as bridging bis-monodentate and the tin atoms attain the coordination number six. This has been duduced from: i) temperature dependent Mossbauer spectroscopy; ii) the correlation between Mossbauer isomer shift, δ, and electrical charge on tin, Q Sn , concerning pyrazine adducts of RSnCl 3 and others; iii) an infrared study of the coordinated ligand in RSnCl 3 ·pyz. Other implications of the Mossbauer T dependent study ( e.g. , the decrease of the Debye temperature in RSnCl…

Investigations on organotin, organolead, lead(IV), and lead(II) dithiolates

Abstract Bis(triorganometal) 1,2-dithiolates (R3M)2S2R′ [(HS)2R′ = C7H8S2 for toluene-dithiol-3,4 (H2TDT); M = Sn, Pb; R = Ph; or (HS)2R′ = C10H14S2 for 1,2-dimethyl-4,5-bis(mercaptomethyl)benzene (H2DBB); M = Sn, R = CH3, C6H5; M = Pb, R = C6H5], diorganometal 1,2-dithiolates R2MS2R′ [(HS)2R′ = C6H6S2 for 1,2-dimercaptobenzene (H2DMB); M = Pb, R = CH3, C2H5, C6H5; or (HS)2R′ = H2TDT; M = Sn, R = CH3, C6H5; M = Pb, R = C6H5; or (HS)2R′ = H2DBB; M = Sn, R = CH3, C6H5; M = Pb, R = CH3, C2H2, C6H5; or (HS)2R′ = C8H6N2S2 for 2,3-dimercaptoquinoxaline (H2QDT); M = Pb, R = C6H5] and some lead(IV) and lead(II) dithiolates Pb(S2R′)n [(HS)2R′ = H2DMB, n = 2; (HS)2R′ = H2TDT, n = 2; (HS)2R′ = H2DBB, …

Mono-aryltin(IV) and mono-benzyltin(IV) complexes with pyridine-2-carboxylic acid and 8-hydroxyquinoline. X-ray structure of p-chloro-phenyl-tris(8-quinolinato)tin(IV)·2CHCl3

Abstract Complexes RSn(O2CPy)3·2H2O and RSn(Ox)3, (PyCOOH=pyridine-2-carboxylic acid, HOx=8-hydroxyquinoline, R=o- and p-Tolyl, o- and p-ClC6H4=o- and p-ClPh, o-ClC6H4CH2=o-ClBenzyl; besides, R=Ph in RSn(Ox)3) have been synthesized and characterized by elemental analysis and determination of molecular weights in CHCl3 solutions. The structure of p-ClPhSn(Ox)3·2CHCl3 has been determined by X-ray diffractometry. The 7-coordinated tin atom of the monomeric compound is in the center of a pentagonal bipyramid formed by (p-ClPh)C and O and N atoms of the chelating Ox− ligands. The latter type of structure would hold for all complexes according to 119Sn Mossbauer (including the determination of th…

Mössbauer spectroscopic studies on compounds containing tin-cadmium and tin-zinc bonds

The Mossbauer parameters of compounds Ph3Sn MCl · TMED (M = Cd, Zn; TMED = N,N,N′,N′-tetramethylethylenediamine), (Ph3Sn)2CdL2 (L2 = TMED, 2,2′-bipyridine and o-phenanthroline) and (Ph3Sn)2 Zn · TMED have been determined and are discussed in connection with Mossbauer data concerning Ph3SnIV derivatives with other Sn-metal bonds. The isomer shift values suggest a high s character in SnCd and SnZn bonds resulting in deviations from regular tetrahedral environments around tin. Experimental quadrupole splittings and calculated partial quadrupole splitting values indicate reduced donor abilities towards the tin atom of an individual Ph3SnIV moiety by Cd-and Zn(Ph3Sn)1−nClnL2 (i.e., the remaini…

Mossbauer spectroscopic studies on the molecular dynamics of organotin(IV) polymers

Abstract Linear organotin(IV) polymers with tin appended to the polymer chain or inserted into the polymer backbone have been characterized by Mossbauer spectroscopy. The lattice dynamics of three representative examples of these classes, as well as of a cross-linked organotin(IV) polymer, have been investigated by temperature-dependent Mossbauer spectroscopy. It has been shown that parameters associated with polymers having low interchain interactions practically correspond to those of molecular, non-coupled, solids.

Synthesis and characterization of diorganotin(IV) derivatives of 2-mercaptopyridine and crystal structure of diphenyl pyridine-2-thiolatochlorotin(IV)

Diorganotin(IV) derivatives of 2-mercaptopyridine (HSPy), R2Sn(SPy)2, R2SnCl(SPy) (R = Me, iPr, nBu, tBu, Cy, Ph) and Cy2SnBr(SPy), were obtained from R2SnX2 (X = Cl, Br) and NaSPy. Ph2SnCl(SPy) crystals, as determined by singlecrystal X–ray diffraction, are monoclinic in the space group P21/n. Tin forms with the bidentate SPy ligand a four–membered chelate ring with a short NSnS bite angle of 64.8(1)° leading to a heavily distorted trigonal–bipyramidal environment about tin. Apical Cl–Sn–N angle = 156.1(1)° equatorial C–Sn–C angle = 121.9(2)°. From 119Sn Mossbauer and IR data, analogous structures are inferred for the other solid compounds R2SnX(SPy), and distorted octahedral molecular str…

ChemInform Abstract: Synthesis and Characterization of Diorganotin(IV) Derivatives of 2- Mercaptopyridine and Crystal Structure of Diphenyl Pyridine-2- thiolatochlorotin(IV).

Diorganotin(IV) derivatives of 2-mercaptopyridine (HSPy), R2Sn(SPy)2, R2SnCl(SPy) (R = Me, iPr, nBu, tBu, Cy, Ph) and Cy2SnBr(SPy), were obtained from R2SnX2 (X = Cl, Br) and NaSPy. Ph2SnCl(SPy) crystals, as determined by singlecrystal X–ray diffraction, are monoclinic in the space group P21/n. Tin forms with the bidentate SPy ligand a four–membered chelate ring with a short NSnS bite angle of 64.8(1)° leading to a heavily distorted trigonal–bipyramidal environment about tin. Apical Cl–Sn–N angle = 156.1(1)° equatorial C–Sn–C angle = 121.9(2)°. From 119Sn Mossbauer and IR data, analogous structures are inferred for the other solid compounds R2SnX(SPy), and distorted octahedral molecular str…

A119Sn Mössbauer spectroscopic study on complexes of di-and tri-organotin(IV) moieties with 2-mercaptoethanesulfonates, in the solid state and in aqueous solution

The configuration of the bonding environment of tin in the complexes [R2Sn(SCH2CH2SO3)2]2− (R = Me, Ph) and [Me3Sn(SCH2CH2SO3)]− has been determined to be tetrahedral both in the solid state and in aqueous solution (for the methyl derivatives). The coordination number of tin increases to five in aqueous solutions for the Me2Sn(IV) complexes in Hepes buffer (N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid; at least in fivefold excess, at pH 7.4) due to coordination by the tertiary amino nitrogen atom. No effect is detected due to the surfactant 2-hydroxypropylcellulose concerning both coordination to tin and influence on the Mossbauer parameters. The stoichiometry of mixed complex format…

The interaction of S,N-coordinated dimethyltin(IV) derivatives with deoxyribonucleic acid: structure and dynamics by119Sn Mössbauer spectroscopy

Complexes Me2SnCl(SPy) and Me2SnCl(SPym) (HSPy = 2-mercaptopyridine; HSPym = 2-mercaptopyrimidine), from ethanol solutions, interact with aqueous calf-thymus DNA yielding condensed phases with probable Me2Sn(SPy,SPym) (DNA monomer) stoichiometries of 1:1; the condensation of DNA is inferred originated from electrostatic bonding between complex cations Me2Sn(SPy,SPym)+ and the phosphate oxygen of the phosphodiester groups. Octahedral-or trigonal-bipyramidal tin environments are inferred from the point-charge model treatment of the 119Sn Mossbauer parameter nuclear quadrupole splitting, considering the bonding by S and N, or only S donor atoms from the ligand, as well as possible coordination…

Complexes of organometallic compounds. L. The correlation between 119Sn mössbauer isomer shifts and calculated partial charges on tin in adducts of tin(IV) and organotin(IV) halides with phosphorus and oxygen donors

Abstract The relationship between Mossbauer isomer shifts, δ, and atomic charges on tin, QSn has been studied for homologous series RnSnhal4−n· L2 [ n = 0−3; L2 = donor atoms of 1, 2-bis(dipheylphosphino)ethane, N, N′-ethylenebes(salicylideneimine) and N, N′-ethylenbes(acetylacetoneimine)] and Snhal4· 2PR3. Semiempirical values of QSn have been calculated by two methods based on the concept of orbital electronegativity equalization upon bond formation. Linear correlations δ/QSn are obtained, which can be function of the coordination number of the metal atom, for terms of the series characterized by different orbital electronegativities of atoms directly bound to tin. Deviations occur for ad…

Studies on the antitumor activity of complexes of R2Sn(IV) with penicillamine enantiomers and with 3-thio-propanoic acid, and correlation with structural aspects

Abstract The activity of diorganotin(IV) derivatives, with SnS bonds, against murine leukemia P-388, has been investigated. The water-soluble penicillamine (PenH2) complexes, Me2Sn(D-Pen), Me2Sn(L-Pen), Me2Sn(D-PenH)2 and Me2Sn(L-PenH)2, are essentially inactive, and do not show any dependence of the antitumor activity from the configuration about the chiral centre. The complexes with 3-thiopropanoic acid (H2Tpr), R2Sn(Tpr), are active for REt and Ph, in line with the general behaviour of R2Sn(IV) derivatives. The nature of the organotins in the vehicle of administration is investigated by 119Sn Mossbauer spectroscopy. The structures of solid state polymers, occurring in suspensions, are …

Investigations on organoantimony compounds

Abstract Diorganoantimony(V) complexes of the type R 2 SbClTrid (R = Me, Ph) containing dianionic, potentially tridentate Schiff-base ligands with ONO donor atoms (Trid 2− ) have been prepared and characterized. IR and NMR data suggest an octahedral coordination environment for the antimony atom with meridional arrangement of the ONO ligand atoms and a linear CSbC skeleton.

The hydrolysis of Me2SnIV and Me3SnIV moieties monitored through 119Sn Mössbauer spectroscopy

Abstract The 119 Sn Mossbauer parameters δ, isomer shift, and Δ E , nuclear quadrupole splitting, have been determined in frozen aqueous solutions of Me 2 Sn IV and Me 3 Sn IV moieties at varying pH. The resulting functions n versus pH (where n is the average number of protons released per mole of the organotin aquocation) agree satisfactorily with functions from potentiometry. The structures of the aquocations, as well as of the hydroxides, and of the mono-hydroxo complex [Me 2 Sn(OH)(OH 2 ) n ] + , are correlated to the Δ E exp data by point-charge model calculations.

Complexes of organometallic compounds

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.

Semi-empirical MNDO study of the structure of some diorganotin (IV) glycylglycinates

The geometrical structures of some diorganotin glycylglycinates have been obtained using the MNDO semi-empirical method. A good agreement with the experimental diffractometric data was found.

Investigations with ion-exchange papers

Mono-organotin(IV) and tin(IV) derivatives of 2-mercaptopyridine and 2-mercaptopyrimidine: X-ray structures of methyl-tris(2-pyridinethiolato)tin(IV) and phenyl-tris(2-pyridinethiolato)tin(IV)�1.5CHCl3

Mono-organotin(IV) and tin(IV) derivatives of 2-mercaptopyridine (HSPy) and 2-mercaptopyrimidine (HSPym), RSnL 3 (R=Me, n-Bu, Ph; L=SPy, SPym; R=Bz=benzyl, o-CIBz, oClC 6 H 4 , p-ClC 6 H 4 , o-tolyl, p-tolyl; L=SPy), RSnCIL 2 (R=Me, n-Bu, Ph; L=SPy, SPym), RSnCI 2 L (R=Me, n-Bu; L=SPy, SPym) and SnCI 4-n L n (L=SPy, SPym; n=2,4) were obtained from RSnCI 3 or SnCI 4 and NaL or by neutralization (R=Ph,p-tolyl; L=SPy, SPym). RSnCIL 2 and RSnCI 2 L were better prepared by comproportionation of RSnCI 3 and RSnL 3 . MeSn(Spy) 3 and PhSn(SPy) 3 .1.5CHCI 3 crystals, as determined by single-crystal X-ray diffraction, are monoclinic. In the discrete monomeric RSn(SPy) 3 units, three bidentate SPy lig…

Mössbauer spectroscopy of mono-organotin(IV) derivatives

Abstract The Mossbauer parameters isomer shift, δ, and quadrupole splitting, ΔE, of mono-organotin compounds insofar investigated have been collected and tabulated. It is demonstrated that isomer shifts consistently depend on ligand electronegativities and coordination numbers, from which it is deduced that RSn IV behave much more as Sn IV rather than R 2 Sn IV and R 3 Sn IV derivatives. The changes of δ for RSn IV are then interpreted by hypotheses analogous to those advanced for Sn IV and its adducts and complexes. It is also inferred that in RSn IV compounds there is a consistent s-character in all tin-ligand atom bonds.

Synthesis and structural studies by infrared and Mössbauer spectroscopy of adducts of tin(IV) and organotin(IV) derivatives with 2,2′-azopyridine

Abstract A number of complexes have been prepared by the reaction between 2,2′-azopyridine(AZP) and tin(IV) halides and organotin(IV) halides, and characterized by elemental analysis and infrared and variable temperature 119Sn Mossbauer spectroscopies. All of the new compounds have 1:1 stoichiometry, with the AZP ligand occupying two coordination sites by bonding through one of the ring and one of the azo group nitrogen atoms, to give rise to distorted octahedral structures. In the diorganotin complexes the two organic groups occupy trans positions. The infrared and Mossbauer spectroscopic data suggest that these compounds are monomeric in the solid state.

119Sn M�ssbauer studies of bis[cysteinato(1?)-S]- and bis[penicillaminato(1?)-S]-diorganotin(IV) species in the crystalline state and in frozen aqueous solution

The bonding and the configuration of the tin environment in the title compounds {R2Sn[SCH2CH(NH3+)COO−]2 and R2Sn[SC(CH3)2CH(NH3+)COO−]2, indicated in the following as R2Sn(cysH)2 and R2Sn(penH)2 respectively} has been investigated through the determination of the Mossbauer-Zeeman spectra of Ph2Sn(cysH)2 and Ph2Sn(penH)2 in the solid state, and through conventional Mossbauer spectroscopy of Me2Sn(penH)2 in the solid state as well as of Me2Sn(cysH)2 and Me2Sn(penH)2 in aqueous solution (frozen). The treatment of the data by the pointcharge model approach suggested the general occurrence of a tetrahedral C2SnS2 core. In aqueous Hepes buffer, a tertiary amino nitrogen atom has been observed to…

Diorganotin(IV)-2-mercaptopyrimidine complexes

The complexes formed between the diorganotin(IV) moieties, R 2 Sn(IV), and the ligand 2-mercaptopyrimidine, (H)SPym, were investigated. Complexes R 2 SnHal(SPym) and R 2 Sn(SPym) 2 [R = Me, i Pr, n Bu, i Bu, t Bu, cyclohexyl(Cy), Ph] were synthesized, and characterized by elemental analysis. In the solid state, chelation of SPym through S and N donors was established by IR spectroscopy, and the nature of the environment of tin centers was investigated by 119 Sn Mossbauer spectroscopy. From the dynamics of 119 Sn nuclei determined by variable-temperature measurements on representative compounds [Me 2 SnCl(SPym) and Cy 2- SnBr(SPym)], as well as by point-charge model treatment of nuclear quad…

Crystal structure of the molecular adduct of dimethyltin(IV) chloride with N,N′-ethylenebis(salicylideneiminato) nickel(II)

Abstract N,N′-Ethylenebis(salicylideneiminato)nickel(II) behaves as a neutral bidentate ligand through its oxygen atoms forming binuclear complexes with organotin(IV) chlorides. The crystal structure of the dimethyl derivative is reported.

The interaction of deoxyribonucleic acid with methyltin(IV) moieties in solution studied by small-angle X-ray scattering, circular dichroism and UV spectroscopy

The nature of calf thymus DNA in aqueous solution, in the presence of the organotin(IV) species Sn IV Me 3 , Sn IV Me 2 and Sn IV Me, possibly partly hydrolysed and/or hydrated, was investigated by small-angle X-ray scattering (SAXS), ultraviolet spectroscopy (UV) at different temperatures and circular dichroism (CD). The results are compared with those of previous 119 Sn Mossbauer studies on condensed DNA phases. The effects of tin-phosphate oxygen bonding on the DNA melting profile in DNA-Sn IV Me systems are in agreement with previous reports on DNA-Main Group metal ion interactions. The structure and conformation of the DNA double helix are not influenced by Sn IV Me n species, even in …