- Preparation and characterization of osmium-stannyl polyhydrides: d4-d2 oxidative addition of neutral molecules in a late transition metal
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Complex OsH2Cl2 (PiPr3)2 (1) reacts with 2.0 equiv of HSnPh3 to give the tetrahydridestannyl derivative OsH4Cl(SnPh3)(PiPr3)2 (2) and ClSnPh3. The structure of 2 has been determined by X-ray diffraction analysis. In the solid state and in solution at temperatures lower than 298 K, the coordination geometry around the osmium atom can be rationalized as derived from a distorted dodecahedron. In the presence of diphenylacetylene, complex 2 gives OsH3(SnClPh2){η2- CH2=C(CH3)PiPr2}(Pi Pr3) (3), cis-stilbene, and benzene. In the solid state, the structure of 3 determined by X-ray diffraction analysis can be described as a very distorted pentagonal bipyramid, with the phosphorus atom of the triisopropylphosphine ligand and the midpoint of the olefinic bond of the isopropenyl group of the dehydrogenated phosphine occupying axial positions. In solution, at temperatures higher than 233 K, the coordinated olefin is released. Complex 3 reacts with molecular hydrogen to afford the pentahydride OsH5(SnClPh2)(PiPr3)2 (4), as a result of the hydrogenation of the coordinated olefinic bond and the d4-d2 oxidative addition of hydrogen. The structure of 4 in the solid state also has been determined by X-ray diffraction. The coordination geometry around the osmium atom can be rationalized as a distorted dodecahedron. In solution, complex 4 does not have a rigid structure even at 193 K. DFT calculations in model systems of 2, 3, and 4, in which the bulky ligands have been replaced by small models, followed by QM/MM optimizations with the real ligands have allowed the complete determination of the hydride positions and of the role played by steric effects in the experimental structures.
- Esteruelas, Miguel A.,Lledos, Agusti,Maseras, Feliu,Olivan, Montserrat,Onate, Enrique,Tajada, Maria A.,Tomas, Jaume
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- Synthesis and reactivity of β-stannylated phenylalanines
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The free radical hydrostannation of a series of N-benzoyl and N-acetyl dehydrophenylalanine esters 2a-h yields β-stannylated phenylalanine derivatives 3 and 4. This addition of tin hydride to such unsaturated compounds simultaneously creates two new chiral centers leading to mixtures of two diastereomeric pairs of enantiomers. The reaction of 3-stannylated phenylalanine 3 with methanolic HCl yields chlorostannyl-substituted compounds 5 and 6 and, with one equivalent of bromine, the bromostannylated compounds 7 and 8 are formed. The bromostannylated phenylalanine derivative 7 reacts with one further equivalent of bromine to produce the dibromostannylated compound 9. Even the chlorostannylated phenylalanine derivative 5 reacts with one further equivalent of HCl to give the dichlorostannylated compound 10. The products were characterized by elemental analysis, infrared (IR), and multinuclear (1H, 13C, 119Sn) nuclear magnetic resonance (NMR) spectroscopy. Attempts were made to assign the preferred conformation of the stannylated phenylalanine derivatives using Karplus-type relationship of coupling constants 3J(H,H), 3J(Sn,H), and 3J(Sn,C=O). The results of these analyses have been confirmed by three crystal structure determinations.
- D?lling, Karin
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- A utility for organoleads: Selective alkyl and aryl group transfer to tin
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Me4Pb and Ph4Pb readily transfer methyl or phenyl groups to an equivalent molar ratio of tin(iv) chlorides in the order SnCl4 > MeSnCl3 > Me2SnCl2 > Me3SnCl, often in a selective manner. Me3PbCl and Ph3PbCl specifically transfer a single methyl/phenyl group under the same reaction conditions to produce recovered yields in >75%. Specific transfer of 2 methyl groups from PbMe4 can be achieved at elevated temperatures and/or a 2:1 molar ratio Pb:Sn.
- Arias-Ugarte, Renzo N.,Pannell, Keith H.
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p. 1703 - 1708
(2018/02/09)
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- Tri- and diorganostannates containing 2-(N,N-dimethylaminomethyl)phenyl ligand
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The C,N-chelated tri and diorganotin(IV) chlorides react with both protic mineral acids and carboxylic acids. The nitrogen atom of the LCN ligand (where LCN is 2-(dimethylaminomethyl)phenyl) is thus quarternized - protonated and new Sn-X bond (X = Cl, Br, I or the remainder of the starting acid used) is simultaneously formed. The set of zwitterionic tri and diorganostannates containing protonated 2-(dimethylaminomethyl)phenyl-moiety was prepared and structurally characterized by multinuclear NMR spectroscopy and XRD techniques. In all these cases, the intramolecular N-H?X bond is present in the molecule. Despite the central tin atom remains five-coordinated (except for the [HLCNH]+[(n-Bu)2SnCl(NO 3)2]-) and reveals a distorted trigonal bipyramidal geometry, the 119Sn NMR chemical shift values of these zwitterionic stannates are somewhat shifted to the higher field than corresponding starting C,N-chelated tri and diorganotin(IV) halides. Reactions of C,N-chelated organotin(IV) halides with various Lewis acids are also discussed.
- ?vec, Petr,?erno?ková, Eva,Padělková, Zdeňka,R??i?ka, Ale,Hole?ek, Jaroslav
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p. 2475 - 2485
(2010/11/16)
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- Synthesis and characterization of some organotin(IV) adducts containing a related series of pyridines: Crystal structure of [SnMe2Cl2(bu2bpy)]
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Organotin(IV) complexes of [SnR(4-n)Cln] (n = 2, R = Me, nBu; n = 1, R = Ph) react with the bidentate pyridyl ligand 4,4′-di-tert-butyl-2,2′-bipyridine (bu2bpy) to give hexa-coordinated adducts with the general formula [SnR(4-n)Cln(bu2b py)]. However, the reaction of these organotin(IV) complexes with the corresponding monodentate ligand 4-tert-butylpyridine (bupy) resulted in the formation of the hexa-coordinated complex [SnMe2Cl2(bupy)2] and the penta-coordinated complexes [SnR(4-n)Cln(bupy)] (n = 2, R = nBu; n = 1, R = Ph). Moreover, the reaction of the above organotin(IV) complexes with 4,4′-trimethylenedipyridine (tmdp) yields hexa-coordinated adducts with the general formula [SnR2Cl2(tmdp)] (R = Me, nBu) and the penta-coordinated complex [ClPh3Sn-μ-(tmdp)SnPh3Cl] in the solid state. The resulting complexes have been characterized by multinuclear NMR (1H, 13C, 119Sn) spectroscopy and elemental analysis. NMR data shows that the triphenyltin(IV) adducts are not stable in solution and dissociate to give tetra-coordinated tin(IV) complexes. The X-ray crystal structure determination of [SnMe2Cl2(bu2bpy)] reveals that the tin atom is hexa-coordinated in an octahedral geometry with a trans-[SnMe2] configuration.
- Momeni, Badri Z.,Shahbazi, Soheila,Khavasi, Hamid Reza
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p. 1393 - 1398
(2010/05/01)
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- Platinum-catalyzed phenyl and methyl group transfer from tin to iridium: Evidence for an autocatalytic reaction pathway with an unusual preference for methyl transfer
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Platinum complexes have been found to catalyze the transfer of σ-bound ligands to the Ir center in Cp*(PMe3)IrCl2 (Cp* = η5-C5Me5) from Bu3SnPh and PhxSnMe
- Smith, Stuart E.,Sasaki, Jennifer M.,Bergman, Robert G.,Mondloch, Joseph E.,Finke, Richard G.
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p. 1839 - 1841
(2008/09/17)
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- Alkali-metal sandwich complexes of a 1,2-diaza-3,5-diborolyl ligand featuring η1, η2, η3, and η4 coordination modes
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The ring closure of 1,2-diisopropylhydrazine and 1,1-bis(phenylchloroboryl) ethane produced a heterocyclic compound with a CB2N2 framework. Deprotonation of this precursor yielded 1,2-diisopropyl-4-methyl-3,5- diphenyl-1,2-diaza-3,5-diborolyl, a cyclopentadienyl analogue containing only one carbon atom in the ring skeleton. Lithium, sodium, and potassium salts of the new ligand have been prepared and characterized. The structures of both monomeric and polymeric sodium metallocenes, as well as the structures of polymeric potassium metallocenes incorporating the new heterocycle, have been determined by single-crystal X-ray diffractometry. These structures reveal not only many similarities but also significant differences in the coordination behavior of the new ligand compared with that of the carbon-based analogue.
- Ly, Hanh V.,Forster, Taryn D.,Corrente, Andrea M.,Eisler, Dana J.,Konu, Jari,Parvez, Masood,Roesler, Roland
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p. 1750 - 1756
(2008/10/09)
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- Mercapto derivatives of triorganotin Y,C,Y-pincer complexes: Role of Y,C,Y-chelating ligands in a new coordination mode of organotin compounds
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We report the use of triorganotin fragments R2L1-2Sn containing N,C,N and O,C,O-ligands L1-2(L1 = C6H3(Me2NCH2)2-2,6-, L2 = C6H3(tBuOCH2)2-2,6-) on stabilization of both thiol-form in R2L1-2Sn-2-SPy (2-SPy = pyridine-2-thiolate) and thione-form in R2L1-2Sn(mimt) (mimt = 1-methylimidazole-2-thiolate) of the polar groups. Treatment of ionic organotin compounds [Me2L1Sn]+[Cl]- (1) and [Ph2L2Sn]+[OTf]- (2) with appropriate sodium salts Na-2-SPy and Na(mimt) resulted in the isolation of Me2L1Sn-2-SPy (3), Ph2L2Sn-2-SPy (4), Me2L1Sn(mimt) (5), Ph2L2Sn(mimt) (6). While polar group 2-SPy exists in its thiol-tautomeric form in compounds 3 and 4, the second polar group (mimt) has been stabilized as the thione-tautomeric form by triorganotin fragments R2L1-2Sn in compounds 5 and 6. The products were characterized by 1H, 13C and 119Sn NMR and IR spectroscopy, ESI/MS, elemental analyses and structures of 3, 6 were determined by X-ray diffraction study. The reactivity of compound 4 containing non-coordinated nitrogen atom of 2-SPy polar group towards CuCl and AgNO3 is also reported. The reactions led to isolation of organotin compounds Ph2L2SnCl (7) and Ph2L2SnNO3 (8) as the result of polar group transfer. The mechanism of this reaction has been investigated and compounds Ph3Sn-2-SPy (9) and Ph2L2Sn-4-SPy (10) (4-SPy = pyridine-4-thiolate) have been prepared for this purpose.
- Martincová, Jana,Dostál, Libor,Taraba, Jan,R??i?ka, Ale?,Jambor, Roman
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p. 3415 - 3423
(2008/02/12)
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- Novel triphenyltin substituted derivatives of heavier alkaline earth metals
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The synthesis and characterization of a family of novel alkaline earth metal stannides, in addition to tri- and pentastannanes are described. [Ba(18-crown-6)(HMPA)2][SnPh3]2 (4), [Ca(18-crown-6)(HMPA)2][Sn(SnPh3)3]2 (5), and [Sr(18-crown-6)(HMPA)2][Sn(SnPh3)3]2 (6) were synthesized by insertion of the corresponding alkaline earth metals into the tin-tin bond of hexaphenyldistannane. Ph3SnSnPh2SnPh3 (7), and Sn(SnPh3)4 (8) became available by treating 4 with diphenyldichlorostannane. All compounds were studied by NMR spectroscopy, and X-ray crystallography. The stannanes 7 and 8 were also characterized by elemental analysis.
- Englich, Ulrich,Ruhlandt-Senge, Karin,Uhlig, Frank
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p. 139 - 147
(2007/10/03)
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- Synthesis and reactivity of stannyloligosilanes, I. Stannyloligosilane chains containing SiMe2 moieties
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Stannyloligosilanes 1 and 2 with terminal organotin groups are available by reacting alkali metal tri-or diorganostannides with α,ω-dichloro-or difluorosilanes, or by treatment of organochlorostannanes with α,ω-difluorosilanes in the presence of magnesium. Attempts to functionalize the triorganotin derivatives 2 by halogenation reagents did not result in the halogen compounds 5; instead cleavage of silicon-tin bonds is observed. In contrast, reactions of the hydridotin derivatives 1 with CHX3 (X = Cl, Br) lead to the quantitative formation of the bis(chloro-or bromostannyl)oligosilanes 5. All compounds were characterized by NMR, IR, MS and elemental analysis. In addition, the triorganotin compound 2i and the hydridotin species 1b have been characterized by X-ray crystallography.
- Uhlig, Frank,Kayser, Christian,Klassen, Ralph,Hermann, Uwe,Brecker, Lothar,Schürmann, Markus,Ruhland-Senge, Karin,Englich, Ulrich
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p. 278 - 287
(2007/10/03)
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- Intramolecular donor-assisted cyclization of organotin compounds
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New intramolecularly coordinated organotin compounds containing the monoanionic O,C,O-coordinating ligand {4-tert-Bu-2,6- [P(O)(OEt)2]2C6H2}- have been synthesized by substitution reactions starting from organotin halides. In view of the enhanced reactivity of the intramolecularly coordinated compounds [4-tert-Bu-2,6- [P(O)(OEt)2]2C6H2}SnR2R' (2, R = Ph, R' = CH2SiMe3; 3, R = R' = Ph; 6, R = R' = Cl), cationic tin species are suggested to occur as intermediates in the formation of the heterocyclic compounds [1(Sn),3(P)Ph2SnOP(O)(OEt)-5- tert-Bu-7-P(O)(OEt)2]C6H2 (8), [l(Sn), 3(P)-Ph(Me3SiCH2)SnOP(O)(OEt)-5- tert-Bu-7-P(O) (OEt)2]C6H2 (15), and {[1(Sn),3(P)-Cl2SnOP(O)(OEt)-5- tert-Bu-7P(O)(OEt)]C6H2}'2 (16). The latter compounds are formed by intramolecular cyclizations of pentacoordinate cationic tin species under elimination of ethyl halide. Furthermore, the synthesis of [1(Sn),3(P)- Ph2SnOP(O)(OH)-5-tert-Bu-7-P(O)(OH)2]C6H2 (13) is described. Reaction of 8 with an excess of MesSiBr leads to the unexpected formation of {2[P(O)(OEt)(OSiMe3)]-4-tert-Bu-6-[P(O)(OEt)2]C6H2}SnPhBr2 (9) as a result of an O-Sn bond cleavage initiated by Me3SiBr and subsequent reaction of the intermediate with further Me3SiBr under Sn-C bond cleavage. The high donor capacity and the rigidity of the new ligand [4-tert-Bu- 2,6[P(O)(OEt)2]2C6H2}- are demonstrated by X-ray diffraction analyses of the tetraorganotin compound 2 and the monoorganotin trichloride 6. Furthermore, the molecular structures of the 2,3,1-oxaphosphastannoles 8 and 16 are discussed.
- Mehring, Michael,L?w, Christian,Schürmann, Markus,Jurkschat, Klaus
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p. 887 - 898
(2007/10/03)
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- Easy general method for interhalide conversions in organotin compounds
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The halides in organotin halides are easily interconverted in excellent yields using aqueous ammonium halide solutions and various organic solvents.
- Zobel, Bernhard,Lim, Allan E. K.,Dunn, Kerri,Dakternieks, Dainis
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p. 4889 - 4890
(2008/10/08)
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- Photochemical 1,3-stannyl rearrangement of allylic stannanes
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The photochemical 1,3-stannyl rearrangement of allylic stannanes has been investigated. The photorearrangement of (E)-cinnamyl(triphenyl)stannane is not observed in benzene under anaerobic conditions, while the photoinduced 1,3-stannyl migration takes place in the same solvent under aerobic conditions, or in the presence of organic halides or a radical-trapping agent to give a photoequllibrium mixture of the cinnamylstannane and its branched regioisomer, 1-phenylprop-2-enyl(triphenyl)stannane, with the latter predominating. Cinnamyl(trialkyl)stannanes and their homologues also afford the corresponding branched allylstannanes under similar photochemical conditions. These 1,3-stannyl migrations proceed intramolecularly via cinnamyl π-π* excitation in competition with homolytic (cinnamyl)C-Sn bond fission. In contrast, the 1,3-stannyl migration of crotyl- and prenyl-(tributyl)-stannanes is not efficient, but their triphenyl or dibutylphenyl derivatives undergo the 1,3-rearrangement via excitation of the phenyl group(s) on the tin atom to give a regioisomeric mixture of the starting linear tin compounds and the branched ones with the former predominating.
- Takuwa, Akio,Kanaue, Takashi,Yamashita, Koichi,Nishigaichi, Yutaka
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p. 1309 - 1314
(2007/10/03)
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- Cleavage Reactions of some Phenyltin Compounds with Iodine Halides, -Pseudohalides and -Carboxylates
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Cleavage reactions of iodinehalides, -pseudohalides IX (X = Cl, Br, NCO, NCS, N3 and CN) with Ph3SnCp yield triphenyltinhalides, -pseudohalides (Ph3SnX) indicating cleavage of Cp-Sn bond in preference to Ph-Sn bond, and cleavage reactions of iodine carboxylates IX′ (X′ = CH3OCO, C5H5OCO, C6H5CH2OCO, o-NH2C6H4OCO, o-CIC6H4OCO, p-NO2C6H4OCO, p-NH2C6H4OCO, C6H5CH =CHOCO) (in situ) with Ph3SnCl give hitherto unknown diphenylchlorotin carboxylates (Ph2SnX′Cl) indicating cleavage of Ph-Sn bond in preference to Cl-Sn bond. On the basis of the results, it is predicated that these diphenylchlorotin carboxylates possess bridging carboxylate groups (inter-molecularly chelated structure) in the solid state, whereas in solution they contain chelated carboxylate groups (intra-molecularly chelated structures).
- Srivastava,Singh,Tangri,Sinha,Bajpai
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p. 443 - 445
(2007/10/03)
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- Synthesis and characterization of allylic dihaloboranes
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Volatile allylic dihaloboranes have been prepared and characterized by 1H, 11B, 13C, and 19F NMR spectroscopy and mass spectrometry. The stability (τ1/2) of such compounds in dilute CDCl3 solutions depends on the substituents and the halides and ranges from a few minutes (allylic dibromoboranes) to several days (allylic difluoroboranes). Allyldihaloborane etherates were obtained by addition of diethyl ether to the corresponding free allyldihaloborane.
- Le Serre, Stéphanie,Guillemin, Jean-Claude
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p. 5844 - 5848
(2008/10/08)
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- Photochemical bond homolysis in a novel series of metal-metal bonded complexes Ru(E)(E′)(CO)2(iPr-DAB)
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Photochemistry of the complexes trans,cis-Ru(E)(E′)(CO)2(iPr-DAB) (E = Cl, SnPh3, PbPh3, Mn(CO)5, Re(CO)5, Me; E′ (depending on E) = SnPh3, PbPh3, GePh3, Mn(CO)5, Re(CO)5) was found to be strongly dependent on the combination and characters of the axial ligands E and E′. Except for Ru(Cl)(SnPh3)(CO)2(iPr-DAB) and Ru(Cl)(PbPh3)(CO)2(iPr-DAB) which are nearly unreactive, one of the Ru-E/E′ bonds is split homolytically upon irradiation into the lowest-energy absorption band of the complex. For Ru(SnPh3)2(CO)2(iPr-DAB), this reaction occurs from a thermally equilibrated 3σπ* excited state with a rate constant of 2.3 × 105 s-1 and a temperature-dependent quantum yield (Ea = 1450 cm-1). The unselective Ru-Ge (60%) and Ru-Sn (40%) bond homolysis of Ru(SnPh3)(GePh3)(CO)2-(iPr-DAB) follows the same mechanism. On the other hand, bond homolysis is much faster (?108 s-1) for complexes which contain Ru-Me, Ru-Mn or Ru-Re bonds. Bond homolysis in these species is highly selective, since only Ru-Me, Ru-Mn and Ru-Re bond splitting was observed for Ru(Me)(SnPh3)(CO)2(iPr-DAB), Ru(SnPh3)(Mn(CO)5)(CO)2(iPr-DAB) and Ru(SnPh3)(Re(CO)5)(CO)2(iPr-DAB), respectively. The photoproduced [Ru(E)(CO)2(iPr-DAB)]· radicals were detected by time resolved UV-Vis spectroscopy on a timescale 10 ns-100 μs. The [Ru(SnPh3)(CO)2(iPr-DAB)]· radical was also characterised by EPR in the form of its adduct with PPh3. Depending on the solvent used, they either dimerise or abstract a chlorine atom from the solvent to produce Ru(Cl)(E)(CO)2(iPr-DAB).
- Aarnts, Maxim P.,Stufkens, Derk J.,Vlcek Jr., Antonin
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- Properties and dynamics of the σ(M′-Re) π* excited state of photoreactive dinuclear LnM′-Re(CO) 3 (α-diimine) (LnM′ = Ph3Sn, (CO)5Mn, (CO)5Re; α-diimine = bpy′, iPr-PyCa, iPr-DAB) complexes studied by time-resolved emission and absorption spectroscopies
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The photophysics and photochemistry of the metal-metal bonded complexes LnM′Re(CO)3(α-diimine) (LnM′ = Ph3Sn, (CO)5Re, (CO)5Mn; α-diimine = bpy′, iPr-PyCa, iPr-DAB) have been studied. According to the time-resolved emission (80 K) and absorption (room temperature) spectra, the lowest excited state has a 3σ (M′-Re) π* character. It is a bound state, which can only be populated by surface crossing from optically excited MLCT states. Homolysis of the metal-metal bond from the σπ* state is promoted by nucleophilic and chlorinated solvents. Exceptional in this respect is the complex Ph3SnRe(CO)3(bpy′), which is nearly photostable in non-chlorinated solvents. The lifetime of the 3σπ* state decreases in the order α-diimine = bpy′ > iPr-PyCa > iPr-DAB > pAn-DAB. This trend is mainly determined by the energy gap law. The LnM′ dependence is more complicated because of an additional deactivating effect of an excited state distortion which depends on LnM′. At 80 K, the lifetime is determined by the weak coupling to the ground state; at room temperature by dissociation of M′-Re (with the exception of Sn-Re).
- Rossenaar, Brenda D.,Lindsay, Elspeth,Stufkens, Derk J.,Vl?ek Jr., Antonín
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- Synthesis, Structures and Properties of CF3S-Substituted Tellurium Compounds
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New preparations for the following compounds are described: Te(SCF3)2, Te(NSO)2, and Cl2Te(NSO)2.The catalytic or thermal SO2 elimination from Cl2Te(NSO)2 affords a coordinated or non-coordinated thiachalcogenadiazole.Conversions of these compounds are reported.Evidence for the proposed mechanism for the reaction between Te(NSO)2 and SbCl5 is provided.Cl4Te2N2(SCF3)2, prepared from TeCl4 and CF3SN(SiMe3)2, reacts with LiN(SiMe3)2 to form 4Te2N2(SCF3)2.An X-ray structural analysis of Cl4Te2N2(SCF3)2 is presented. - Key Words: Tellurium, bis(sulfinylamido)-, bis(trifluoromethylthio)- / Thiachalcogenadiazole / Ditelluradiazetidine
- Boese, Roland,Dworak, Juergen,Haas, Alois,Pryka, Michael
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p. 477 - 480
(2007/10/02)
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- Vinylidene Transition-Metal Complexes, XXXI Stannylalkynes as Starting Materials for the Synthesis of Vinylidene Rhodium Complexes and of Heterodimetallic Compounds Containing a Rh-Hg or Rh-Sn Bond
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Reaction of n (1) with stannylalkynes RCCSnPh3 gives the vinylidenerhodium(I) complexes trans- (2a-j) in good to excellent yields.These compounds react with protic acid to give trans- and, for R = CH(Ph)OH, to give the allenylidene complex trans- (5).On treatment of 2b-j with PhHgCl, the heterodimetallic compounds CR)(HgPh)Cl(PiPr3)2> (6a-i) are formed.The bis(alkynyl)rhodium(III) complexes C SiMe3)(CCSnPh3)(py)(PiPr3)2> (9) and CSiMe3)(CCCH2OMe)(SnPh3)(PiPr3)2> (10) are prepared from trans-CSiMe3)(L)(PiPr3)2> (7, 8, L = py, C2H4) and HCCSnPh3 or Ph3SnCCCH2OMe, respectively.The crystal and molecular structures of trans- (2e) and CCH2OMe)(HgPh)Cl(PiPr3)2> (6d) have been determined. - Key Words: Alkynes, (triphenylstannyl)- / Rhodium(I) complexes, vinylidene / Rhodium(III) complexes, alkynyl(hydrido)- and bis(alkynyl)hydrido- / Dimetallic rhodium compounds, with Rh-Hg and Rh-Sn bonds
- Baum, Matthias,Mahr, Norbert,Werner, Helmut
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p. 1877 - 1886
(2007/10/02)
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- Simple procedure for conversion of a trialkyltin fluoride into the corresponding chloride or bromide
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Trialkyltin fluorides are converted into the chlorides or bromides on treatment with an excess of the corresponding sodium halide in tetrahydrofuran.
- Mitchell, Terence N.,Kwetkat, Klaus,Godry, Bernd
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p. 1633 - 1634
(2008/10/08)
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- Transition-Metal Silyl Complexes. 37.1 Reaction of Anionic Silyl, Germyl, and Stannyl Complexes [(η5-C5H4Me)(CO)2MnER 3]- (E = Si, Ge, Sn) with Geminal Organic Dihalides: A Novel Route for the Preparation of Carbene Complexes
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The anionic complexes Na[MeCp(CO)2MnER3] (E = Si, Ge, Sn) (MeCp = η5-C5H4Me), obtained by deprotonation of the corresponding hydrido complexes MeCp(CO)2Mn(H)ER3, react with 3,3-dichlorocyclopropenes to give the cyclopropenylidene complexes MeCp(CO)2Mn=C-CR=CR (2) by NaCl and R3ECl elimination. Aminocarbene complexes MeCp(CO)2Mn=C(NR2)R′ (5), including the N-methylpyridinylidene complex MeCp(CO)2Mn=CN(Me)CHCHCHCH (5h) and a thiazolinylidene derivative, MeCp(CO)2Mn=CN(Me)C(Me)CHS (5i), were alalogously prepared from [MeCp(CO)2MnSiMePh2]- and [R2N=C(R′)Cl]+. In these reactions, the anionic complexes Na[MeCp(CO)2MnER3] act as preparative equivalents to the dianionic complex MeCp(CO)2Mn2-. The X-ray structure analysis of 5i is reported (Mn-C(carbene) 197.0 (3) pm): monoclinic, space group P21/c (Z = 4), a = 736.4 (1) pm, b = 1418.4 (3) pm, c = 1304.6 (1) pm, β = 95.58 (1)°.
- Kirchg?ssner, Uwe,Piana, Hermann,Schubert, Ulrich
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p. 2228 - 2232
(2007/10/02)
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- Haloalkylation process
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A process for the haloalkylation of certain tin, phosphorus and germanium halides is disclosed. The process is carried out typically in a halocarbon solvent at temperatures of less than 0° C. using as the haloalkylating reagent an admixture of a haloalkyl halide and tris(lower alkylamino)phosphine.
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- REACTION OF TRIPHENYLSTANNYL ISOCYANATE WITH 1-CHLORO-5,5-DIMETHYL-2-HEXENE
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The reaction of triphenylstannyl isocyanate with 1-chloro-5,5-dimethyl-2-hexene at 180 deg C takes place with substitution of the chlorine atom in the halogenoalkene by the NCO group of the isocyanate and simultaneous allylic rearrangement in the reaction complex.The reaction was used as a model to explain the deactivation of the labile chlorine atoms at the end of the growing polyene, which leads to inhibition of the thermal dehydrochlorination of polyvinyl chloride in the presence of organotin isocyanates.
- Sedel'nikova, V. N.,Terman, L. M.,Sykhranova, M. I.,Khorshev, S. Ya.
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p. 685 - 687
(2007/10/02)
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- HALOGEN AND PEUDOHALOGEN SUBSTITUTION OF SOME ADAMANTANOID CHALCOGENATE CLUSTERS (2-) USING METHYLMERCURY AND TRIPHENYLTIN DERIVATIVES. A MULTINUCLEAR NUCLEAR MAGNETIC RESONANCE STUDY
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Multinuclear nmr (1H, 77Se, 111/113Cd, 119Sn, 199Hg, as appropriate) has been used to study Y(1-) - EPh(1-) exchange in Me2CO or MeCN between (RnM'Y (RnM' = Ph3Sn or MeHg; Y = Cl, Br, I, NCO, or NCS) and the adamantane-like anions (2-) (E = S, M = Zn, Cd, or Co; E = Se, M = Zn or Cd), as their tetraalkylammonium salts.Quantitative terminal substitution of the clusters occurs in most cases, giving 4-x(MY)x>(2-) (x = 1-4).However, reaction is incomplete for M = Cd, E = S or Se, RnM'Y = Ph3SnNCO or Ph3SnNCS and for M = Zn or Co, E = S, RnM'Y = MeHgI.Differences in the extents of reaction for Ph3SnY and MeHgY are consistent with the position of equilibrium in MeHgY:Ph3SnEPh mixtures.Group interchange provides a convenient alternative synthesis of the known halogen-substituted clusters (2-) (M = Zn or Cd, Y = Cl, Br, or I; M = Co, Y = Cl), and the first syntheses of (2-) (Y = Br or I) and various pseudohalogen-substituted adamantanoid anions.The nuclei used for full direct nmr characterization of the new clusters in solution were: 77Se and 113Cd for 4-x(CdY)x>(2-) (x = 1-4; Y = NCO or NCS); 77Se for 4-x(ZnY)x>(2-) (x = 1-4, Y = NCO or NCS); 113Cd for 4-x(CdY)x>(2-) (x = 1-4; Y = NCO or NCS); 1H for (2-) (Y = Br, I, NCO, or NCS).The first solution 1H nmr spectrum of (2-) is also reported.
- Dean, Philip A. W.,Vittal, Jagadese J.
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p. 2443 - 2451
(2007/10/02)
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- Synthesis and some reactions of tris (pentafluorophenyl) antimony compounds
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(C6F5)3Sb has been found to react with interhalogens and halo-pseudohalogens, IX(X = Cl, Br, N3 and NCO), pseudohalogen (SCN), and elemental sulphur to give oxidative addition products (I-VI). (C6F5)3SbS(VI) may also be prepared by the reaction of (C6F5)3SbCl2 with H2S. Metathetical reactions of (C6F5)3SbCl2 with appropriate metallic salts yield covalent pentacoordinate disubstituted products (V, VII-XII) of the general formula, (C6F5)3SbY2 (Y = NCS, NCO, -ONCMe2, -ONCMePh -NCO(CH2)2CO and p-NO2C6H4OCO). Treatment of (C6F5)3SbCl2 with aqueous NaN3 gives the binuclear oxo-bridge compound, [(C6F5)3SbOSb(C6F5)3](N3)2·(III) and (IV) are also accessible by displacement reaction of (I) or (II) with the corresponding metallic salt. Molecular weight, conductance measurements, and IR spectra on the new organoantimony(V) derivatives have been obtained. Reductive cleavage reactions of (C6F5)3SbS with hexaaryldileads, Ar6Pb2(Ar = Phenyl, p-tolyl) produce (C6F5)3Sb and the corresponding bis(triaryllead) sulphide but treatment of (C6F5)3SbX2(X = NCO, Cl) with Ar6Pb2 gave Ar4Pb and Ar2PbX2 together with (C6F5)3Sb. (C6F5)3SbCl2 and bis(triorganotin)sulphides undergo exchange of anionic groups.
- Raj, Prem,Saxena,Singhal, Kiran,Ranjan, Ashok
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p. 251 - 258
(2008/10/08)
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- Coupurs par transfert d'electrons de la liaison Sn-CH2 dans les composes R3SnCH2X
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In the presence of nucleophiles , the Sn-CH2 bond in organotin iodides R3SnCH2I with R=Me, Et and Ph is cleaved by an ionic mechanism or by an electron-transfer involving R3SnCh2., R3SnCH2CN(1). and R3Sn. radicals which can be induced electrochemically.Dimerisation, reoxydation of reduction of the R3Sn. radical occur depending on the potential, the solvent and the substituent.A complete description of the mechanism led us to study the electrochemical behaviour of R3SnCH2I iodides and resulted in a simple preparation of bis mercury compounds.
- Devaud, Marguerite,Lecat, Jean-Luc
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p. 1187 - 1190
(2007/10/02)
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- METAL-HALOGEN BONDING STUDIES WITH GROUP IV A TRIALKYLMETAL HALIDES
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Halogen redistribution reactions have been found to take place between benzyl bromide or benzyl iodide and the Group IV A silicon, germanium, tin, and lead containing trialkylmetal chlorides.However, for the reactions of the Si, Ge and Sn compounds, a quaternary ammonium halide catalyst was necessary to enable the equilibria to be established at reasonably rapid rates.The equilibrium constants at 50 deg C have been measured for each of these halogen redistributions.They have been found to increase gradually on going down in Group IV A from silicon to lead, being conside rably less than unity in the case of silicon and somewhat greater than unity in the case of lead for both the R3MCl + BzBr and R3MCl + BzI reactions.The ΔG0 values for these equilibria have been calculated, and it is suggested that their differences may be explained in terms of the relative importance of p?-d? contributions to the halogen-metal bonding in the various Group IV A trialkylmetal halide systems.
- Friedrich, Edwin C.,Abma, Charles B.,Vartanian, Paul F.
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p. 203 - 212
(2007/10/02)
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Solutions of triphenyl tin hydroxide (resp. hexaphenyl distannoxane) in benzene can be used for the extraction of numerous inorganic and organic anions out of slightly acid aqueous solutions. Several separations will be possible.
- Bock, Rudolf,Niederauer, Heinz-Theo,Behrends, Karl
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