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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 10 (1996), S. 779-790 
    ISSN: 0268-2605
    Keywords: organotin ; N-acetyltriglycine ; N-benzoyltriglycine ; Mössbauer ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Di- and tri-organotin(IV) derivatives of N-acetyltriglycine and N-benzoyltriglycine (HA) were obtained by refluxing equimolar mixtures of the ligand and the organotin(IV) oxide or hydroxide in methanol or acetone. According to the spectroscopic data, triorganotin(IV) derivatives adopt a trigonal-bipyramidal structure in which the planar R3SnIV unit is bonded by a monodentate carboxylate group and a donor group, presumably the amide C=O. The reaction of HA with the appropriate diorganotin(IV) compounds gave both dicarboxylates R2SnA2, with six-coordinated tin, and dimeric tetraorganodistannoxanes {[R2SnA]2O}2, in which the tin atoms are essentially five-coordinated.
    Additional Material: 3 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 8 (1994), S. 113-117 
    ISSN: 0268-2605
    Keywords: Organotin ; stannacycloalkyl compounds ; dipeptides ; Mössbauer ; NMR ; IR ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 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 Mössbauer 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.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0268-2605
    Keywords: Diorganotin dipeptides ; X-ray structure determination ; 13C ; 119Sn NMR ; IR ; Mössbauer ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 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 and amino nitrogen atoms, into a monomeric unit. Bond lengths and angles are reported. Infrared spectroscopic data show the occurrence of monodentate carboxyl in all solid compounds, as well as in methanol solutions of some representative complexes. 119Sn Mössbauer spectroscopic data, and their rationalization through point-charge model (literal version) calculations of the parameter nuclear quadrupole splitting (ΔE) confirm the general occurrence of trigonal bipyramidal structures of the Et2SnGlyTyr type, in the solid state, and give evidence of variations of the C—Sn—C angle in the individual Et2SnL species. Monomers occur in CH3OH solution as suggested by osmometric measurements. 13C and 119Sn NMR spectroscopic data in CD3OD show the persistence of the solid-state structures also in the solution phase, where the order of magnitude of the C—Sn—C angles, as estimated from the coupling constants |1J(119Sn,13C)|, corresponds to that shown by Et2SnGlyTyr in the solid state. 119Sn Mössbauer parameters of Et2SnGlyGly in frozen CH3OH solution are consistent with the assumptions from the NMR studies.
    Additional Material: 2 Ill.
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  • 4
    ISSN: 0268-2605
    Keywords: organotin ; amino-acid ; cysteine ; penicillamine ; Mössbauer ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 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 Mössbauer-Zeeman spectra of Ph2Sn(cysH)2 and Ph2Sn(penH)2 in the solid state, and through conventional Mössbauer 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 coordinate tin in Me2Sn(cysH)2 and Me2Sn(penH)2, with formation of trigonal bipyramidal tin environments. The latter solutions undergo slow decomposition reactions at room temperature. From (Me2SnS)3 occurs, as well as formation of soluble complex species in the presence of glycylglycine; Me2Sn(penH)2 appears to undergo a slow desulfuration reaction.
    Additional Material: 2 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 7 (1993), S. 243-252 
    ISSN: 0268-2605
    Keywords: Organotin ; biocidal ; biological ; Mössbauer ; NMR ; IR ; peptide ; protein ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Triorganotin(IV) derivatives of N-acetyldipeptides R3SnAcDip; R=Me, Et, n-Bu, n-Oct, Cy or Ph (HAcDip=N-acetylglycylglycine and N-acetylglycylvaline; R=Me, n-Bu, Cy, HAcDip=N-acetylglycylalanine) were obtained by neutralization of R3SnOH and HAcDip. The complexes were studied by means of 119Sn Mössbauer, IR and 1H, 13C and 119Sn NMR spectroscopy. The C—Sn—C bond angles have been inferred by rationalization of Mössbauer nuclear quadrupole splittings as well as from NMR coupling constants. Correlations of Mössbauer 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 C=O amide donor groups are inferred for all the compounds in the solid state, except for Cy3SnAcGlyVal for which a tetrahedral structure is proposed. In solution the complexes are monomeric; in methanol a solvent molecule is coordinated to tin which then is still in a trigonal bipyramidal environment.
    Additional Material: 2 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 12 (1998), S. 861-871 
    ISSN: 0268-2605
    Keywords: diorganotin ; Pyrimidine ; complex ; Mössbauer ; IR ; NMR ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The complexes formed between the diorganotin(IV) moieties, R2Sn(IV), and the ligand 2-mercaptopyrimidine, (H)SPym, were investigated. Complexes R2SnHal(SPym) and R2Sn(SPym)2 [R = Me, iPr, nBu, iBu, tBu, 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 119Sn Mössbauer spectroscopy. From the dynamics of 119Sn nuclei determined by variable-temperature measurements on representative compounds [Me2SnCl(SPym) and Cy2SnBr(SPym)], as well as by point-charge model treatment of nuclear quadrupole splitting parameters, it was inferred that Me2SnCl-­(SPym) may assume a trans-Me2 octahedral coordination geometry around tin in a monodimensional polymer, or a monomeric trigonal-bipyramidal structure (distorted). The latter type of structure was assigned to the other R2SnHal(SPym) species, while R2Sn(SPym)2 complexes assume a trans-octahedral, or skew trapezoidal, tin environment. In CHCl3-CDCl3 solutions, monomeric species occur (according to vapor-pressure osmometry), where 1H and 13C NMR spectroscopic parameters of SPym indicate the persistence of Sn chelation by S and N donor atoms. The Me2SnCl(SPym) species assume trigonal-bipyramidal structures with a chelating SPym ligand, in CDCl3 and C2H5OH solutions, according to the coupling constants 1J(119Sn,13C), as well as IR and 119Sn Mössbauer spectroscopic data. 119Sn NMR parameters fully correspond with data for the homologous complexes with 2-mercaptopyridine. Copyright © 1998 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
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  • 7
    ISSN: 0268-2605
    Keywords: Organotin ; 2-mercaptopyridine ; pyridine-2-thiolato complexes ; Mössbauer ; IR ; NMR ; crystal structure ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 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 Mössbauer and IR data, analogous structures are inferred for the other solid compounds R2SnX(SPy), and distorted octahedral molecular structures for the solid compounds R2Sn(SPy)2 with R in the trans position, and sulfur atoms and nitrogen-donor atoms each in cis positions. According to IR and 1H, 13C and 119Sn NMR data, the solid-state molecular structures are retained in chloroform solution.
    Additional Material: 3 Ill.
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  • 8
    ISSN: 0268-2605
    Keywords: Organotin ; dipeptides ; structures ; X-ray diffraction ; NMR ; Mössbauer ; infrared ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 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. Organomet. Chem., 1992, 6: 75). According to infrared and 119Sn (ΔE parameters) Mössbauer spectroscopic data the R2SnL derivatives can be classified by their solid-state structure into two types which are distinguished by the nature of the axial carboxylate [(i) monodentate, as in nBu2SnGlyVal; (ii) bidentate]. Bonding in R2SnL.H2O and Ph2Sn(HGlyVal)2 has been discussed on the basis of vibrational data. Rationalization of the 119Sn Mössbauer parameters has been attempted by ‘literal’ point-charge model, calculations of ΔE in the structural context described above. According to 13C NMR spectra, compounds Me2SnL are undissociated in methanol solutions, whilst dissociation is inferred for aqueous solutions, probably concerning the carboxyl and amino groups only. Five-coordination in methanol and aqueous solutions has been assumed for Me2Snl from 119Sn NMR chemical shifts. Values of coupling constants |2J(119Sn, 1H)|, determined from 1H NMR spectra, gave estimates of C—Sn—C angles in Me2SnL in the range 128-136° in methanol and aqueous solutions, which correspond to values from 119Sn Mössbauer ΔE parameters (129.6-133.8°). The structural relationship of R2SnL molecules in the solid state and in solution phase has been discussed.
    Additional Material: 2 Ill.
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  • 9
    ISSN: 0268-2605
    Keywords: organotin ; pyridine-2-thiolate complexes ; pyrimidine-2-thiolate complexes ; crystal structure ; Mössbauer ; IR ; NMR ; Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mono-organotin(IV) and tin(IV) derivatives of 2-mercaptopyridine (HSPy) and 2-mercaptopyrimidine (HSPym), RSnL3 (R=Me, n-Bu, Ph; L=SPy, SPym; R=Bz=benzyl, o-ClBz, o-ClC6H4, p-ClC6H4, o-tolyl, p-tolyl; L=SPy), RSnClL2 (R=Me, n-Bu, Ph; L=SPy, SPym), RSnCl2L (R=Me, n-Bu; L=SPy, SPym) and SnCl4-nLn (L=SPy, SPym; n=2, 4) were obtained from RSnCl3 or SnCl4 and NaL or by neutralization (R=Ph, p-tolyl; L=SPy, SPym). RSnClL2 and RSnCl2L were better prepared by comproportionation of RSnCl3 and RSnL3.MeSn(SPy)3 and PhSn(SPy)3·1.5CHCl3 crystals, as determined by single-crystal X-ray diffraction, are monoclinic. In the discrete monomeric RSn(SPy)3 units, three bidentate SPy ligands together with R form a distorted pentagonal bipyramid around tin. One S and the C(R) atom are in the axial positions. Two S atoms and three N atoms form the pentagonal plane.From 119Sn Mössbauer and IR data, analogous structures are inferred for the other solid RSnL3 compounds, except for R=Bz, o-ClBz, o-ClC6H4 and o-tolyl, in which tin would be hexacoordinated. In the compounds RSnClL2 and RSnCl2L, tin is at the center of an octahedron or a trigonal bipyramid, respectively. For Sn(SPym)4 and SnCl2(SPym)2, the same type of octahedral structure as was previously found for Sn(SPy)4·HSPy and SnCl2(SPy)2 is proposed.According to IR and 1H, 13C and 119Sn NMR data, the solid-state molecular structures are retained in chloroform and dimethyl sulfoxide solution. © 1997 John Wiley & Sons, Ltd.
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