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1.
A set of C,N-chelated organotin(IV) ferrocenecarboxylates, [LCN(n-Bu)Sn(O2CFc)2] (1), [(LCN)2Sn(O2CFc)2] (2), [LCN(n-Bu)Sn(O2CCH2Fc)2] (3), [LCN(n-Bu)Sn(O2CCH2CH2Fc)2] (4), [LCN(n-Bu)Sn(O2CCHCHFc)2] (5), [LCN(n-Bu)Sn(O2CfcPPh2)2] (6), [(LCN)2Sn(O2CfcPPh2)2] (7), and [LCN(n-Bu)2Sn(O2CFc)] (8) (LCN = 2-(N,N-dimethylaminomethyl)phenyl, Fc = ferrocenyl and fc = ferrocene-1,1′-diyl) has been synthesized by metathesis of the respective organotin(IV) halides and carboxylate potassium salts and characterized by multinuclear NMR and IR spectroscopy. The spectral data indicated that the tin atoms in diorganotin(IV) dicarboxylates bearing one C,N-chelating ligand (1 and 3-6) are seven-coordinated with a distorted pentagonal bipyramidal environment around the tin constituted by the n-butyl group, the chelating LCN ligand and bidentate carboxylate. Compounds 2 and 7 possessing two chelating LCN ligands comprise octahedrally coordinated tin atoms and monodentate carboxylate donors, whereas compound 8 assumes a distorted trigonal bipyramidal geometry around tin with the carboxylate binding in unidentate fashion. The solid state structures determined for 1⋅C6D6 and 2 by single-crystal X-ray diffraction analysis are in agreement with spectroscopic data. Compounds 1, 3-5, and 8 were further studied by electrochemical methods. Whereas the oxidations of ferrocene units in bis(carboxylate) 2 and monocarboxylate 8 proceed in single steps, compound 1 undergoes two closely spaced one-electron redox waves due to two independently oxidized ferrocenyl groups. The spaced analogues of 2, compounds 3-5, again display only single waves corresponding to two-electron exchanged.  相似文献   

2.
The C,N-chelated tri-, di- and monoorganotin(IV) halides react with equimolar amounts of CF3COOAg to give corresponding C,N-chelated organotin(IV) trifluoroacetates. The set of prepared tri-, di- and monoorganotin(IV) trifluoroacetates bearing the LCN ligand (where LCN is 2-(N,N-dimethylaminomethyl)phenyl-) was structurally characterized by X-ray diffraction analyses, multinuclear NMR and IR spectroscopy. In the case of triorganotin(IV) trifluoroacetates and (LCN)2Sn(OC(O)CF3)2, no tendency to form hydrolytic products, or instability towards the moisture was observed. LCNRSn(OC(O)CF3)2 (where R is n-Bu or Ph) and LCNSn(OC(O)CF3)3 forms upon crystallization from THF in the air mainly dinuclear complexes in which the two tin atoms are interconnected either by hydroxo-bridges or by an oxo-bridge and/or by a bridging trifluoroacetate(s). In the case of hydrolysis of LCN(n-Bu)Sn(OC(O)CF3)2, a zwitterionic stannate of formula LCN(n-Bu)Sn(OC(O)CF3)2·CF3COOH was isolated from the mother liquor, too. Products of hydrolysis of LCN(n-Bu)Sn(OC(O)CF3)2 and LCNSn(OC(O)CF3)3, and some other oxygen bridged organotin(IV) compounds containing the same ligand, were tested as possible catalysts of some transesterification reactions as well as in direct dimethyl carbonate (DMC) synthesis from CO2 and methanol.  相似文献   

3.
Triorganotin(IV) chlorides containing one LCN chelating ligand were hydrolyzed with an excess of sodium hydroxide. The composition of the products is strongly dependent on the nature of the organic groups bound to the tin atom. Di(n-butyl)tin, dimethyltin as well as the diphenyl derivative exhibits an equilibrium between hydroxide and stannoxane forms (oxide), whereas alkyltin species react spontaneously and reversibly with carbon dioxide present in the air to form carbonate species. On the other hand, diphenyl derivatives display virtually no reaction with CO2 towards carbonates, while the di-t-butyl-substituted tin derivative is stable under the same experimental condition and remains as a tin hydroxide. In the case of the dimethyltin derivative, a methyl group migration was observed with displacement of one LCN chelating ligand during the reaction on the air. The coordination geometry of the tin central atom(s) of all studied compounds can be described as trigonal bipyramidal with a dative bonded dimethylamino group occupying one coordination site. The catalytic activity of these compounds in transesterification reactions is generally lower compared to the systems reported in the literature, with the exception of the transesterification of ethyl acetate by cyclohexanol which displays a remarkable activity.  相似文献   

4.
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(NO3)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.  相似文献   

5.
《Polyhedron》1986,5(11):1771-1776
Variable-temperature 119Sn Mössbauer spectroscopic (VTMS) data for six tin phthalocyanine (pc) derivatives have been collected in order to ascertain the restrictions imposed by the macrocyclic ring on the vibrational motion of the tin atom. Thermal condensation of [(t-Bu)4pc]Sn(OH)2 yields the co-facially stacked polymer {[(t-Bu)4pc]SnO}n which can be distinguished in the VTMS experiment by the enhanced rigidity of its structure.  相似文献   

6.
The potential catalytic activity of selected C,N‐chelated organotin(IV) compounds (e.g. halides and trifluoroacetates) for derivatization of both dimethyl carbonate (DMC) and diethyl carbonate (DEC) was investigated. Some tri‐, di‐ and monoorganotin(IV) species (LCN(n‐Bu)2SnCl (1), LCN(n‐Bu)2SnCl.HCl (1a), LCN(n‐Bu)2SnI (2), LCNPh2SnCl (3), LCNPh2SnI (4), LCN(n‐Bu)SnCl2 (5), LCNSnBr3 (6) and [LCNSn(OC(O)CF3)]2(μ‐O)(μ‐OC(O)CF3)2 (7)) bearing the LCN moiety (LCN = 2‐(N,N‐dimethylaminomethyl)phenyl‐) were assessed as catalysts for reactions of both DMC and DEC with various substituted anilines. The catalytic activities of 4 and 7 for derivatization of DMC with p‐substituted phenols were studied for comparison with the standard base K2CO3/Silcarbon K835 catalyst (catalyst 8). The composition of resulting reaction mixtures was monitored by multinuclear NMR spectroscopy, GC and GC‐MS techniques. In general, catalysts 1, 3 and 7 exhibited the highest catalytic activity for all reactions studied, while some of them yielded selectively carbonates, carbamates, lactam or substituted urea. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

7.
The modification of bis(pyrazol-1-yl)methanes by organotin halide on the methine carbon atom has been successfully carried out, and their related reactions have also been studied. Bis(3,5-dimethylpyrazol-1-yl)(iododiphenylstannyl)methane [Ph2ISnCH(3,5-Me2Pz)2] can be obtained by the selective cleavage of the Sn-Csp2 bond in bis(3,5-dimethylpyrazol-1-yl)triphenylstannylmethane with I2 in a 1:1 molar ratio, while {di(tert-butyl)chlorostannyl}bis(3,5-dimethylpyrazol-1-yl)methane [(t-Bu)2ClSnCH(3,5-Me2Pz)2] and {di(tert-butyl)chlorostannyl}bis(3,4,5-trimethylpyrazol-1-yl)methane [(t-Bu)2ClSnCH(3,4,5-Me3Pz)2] are easily prepared by the reaction of the bis(3,5-dimethylpyrazol-1-yl)methide or bis(3,4,5-trimethylpyrazol-1-yl)methide anion with di(tert-butyl)tin dichloride. The molecular structure of [(t-Bu)2ClSnCH(3,5-Me2Pz)2] determined by X-ray structure analysis indicates that bis(3,5-dimethylpyrazol-1-yl)methide acts as a bidentate monoanionic κ2-[C,N] chelating ligand. Reaction of these bis(pyrazol-1-yl)methanes functionalized by organotin halide with W(CO)5THF results in the oxidative addition of the relative electrophilic Sn-X (X = Cl or I) bond instead of the Sn-Csp3 bond to the tungsten(0) atom, yielding new metal-metal bonded complexes R2SnCHPz2W(CO)3X (R = Ph or t-Bu, Pz represents substituted pyrazol-1-yl). Furthermore, treatment of the oxidative addition product (t-Bu)2SnCH(3,5-Me2Pz)2W(CO)3Cl with n-BuLi results in known complex CH2(3,5-Me2Pz)2W(CO)4 with the loss of the organotin fragment. In addition, reaction of Ph2ISnCH(3,5-Me2Pz)2 with 2-PySNa (Py = pyridyl) leads to the replacement of iodide by 2-PyS anion to give Ph2(2-PyS)SnCH(3,5-Me2Pz)2, which subsequently reacts with W(CO)5THF to result in the decomposition of this ligand, also yielding the known bis(3,5-dimethylpyrazol-1-yl)methane derivative of CH2(3,5-Me2Pz)2W(CO)4.  相似文献   

8.
The reaction of tert-butyl 4-oxopiperidine-1-carboxylate dimethylhydrazone with BuLi and further with iodides of protected alcohols ICH2(CH2) n OSiMe2(t-Bu) (n = 1–4) led to the formation of the corresponding tert-butyl 3-{[tert-butyl(dimethyl)silyl]alkyl}-4-oxopiperidine-1-carboxylates that under the treatment with triethylsilane in the presence of anhydrous BiBr3 underwent cyclization with a high stereoselectivity into cis-isomers of N-Boc piperidine derivatives [3,2-c]-fused with oxygen heterocycles. The latter at the treatment with anhydrous HCl eliminate the Boc group affording hydrochlorides of stereochemically homogeneous N-unsubstituted fused bicyclic systems.  相似文献   

9.
Complexation between 5,10,15,20-tetraphenylporphine H2TPP and tetra(tert-butyl)phthalocyanine H2(t-Bu)4Pc with copper(II) ethylenediaminetetraacetate in DMSO was studied by spectrophotometry. The kinetic parameters of the reaction were calculated and the mechanism of ligand exchange in the complexone-porphyrin macrocycle system was proposed. The reactivities of H2TPP and H2(t-Bu)4Pc in reactions with copper ethylenediaminetetraacetate and some other copper chelate complexes were compared.  相似文献   

10.
A series of tri‐ and diorganotin(IV) compounds containing potentially chelating S,N‐ligand(s) (LSN, where LSN is 6‐phenylpyridazine‐3‐thiolate) were prepared and structurally characterized by multinuclear NMR spectroscopy. X‐ray diffraction techniques were used for determination of the structure of compounds containing one [(LSN)Ph2SnCl], two [(n‐Bu)2Sn(LSN)2] and the combination of two LSN and one LCN [(LCN)(n‐Bu)Sn(LSN)2] (where LCN is {2‐[(CH3)2NCH2]C6H4}‐) ligands. The coordination number of the tin atom varies from five to seven and is dependent on the number of chelating ligands present. The formation of the five‐membered azastanna heterocycle is favored over the formation of four‐membered azastannathia heterocycle in compounds containing both types of ligands. The di‐n‐butyl‐substituted compounds are the most efficient ones in inhibition of growth of yeasts, molds and G+ bacteria strains. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

11.
The solid state structures of products of fluorination of LCNnBuSnCl2 (where LCN is 2-[(CH3)2NCH2]C6H4-) by different methods are reported. The reaction of 3 equiv. of [NH4]+[LCNnBuSnF3] and Pr(OTf)3 led to dimeric arrangement [LCNnBuSnF(μ-F)2SnLCNnBuF] · 2HOTf. Two different polymorphs of polymeric [LCNnBuSnF2]n have been obtained by crystallization. Prepared compounds were studied by X-ray crystallographic methods, DSC and theoretical calculations at the B3LYP/LANL2DZ level.  相似文献   

12.
Diorganotin(IV) dichlorides of formula LCNRSnCl2 (where R is nBu or Ph) containing one LCN chelating ligand were hydrolyzed with aqueous sodium hydroxide in benzene. The composition of the products is strongly dependent on the amount of hydroxide. The partially hydrolyzed compounds of composition (LCNRSnCl)2(µ‐O) were isolated as crystalline products. A hydrolysis where more than one molar equivalent of NaOH is employed gave only a mixture of unidentifiable products. The structure of (LCNPhSnCl)2(µ‐O) was determined by X‐ray diffraction techniques in the solid state. In solution there was a mixture of diastereoisomers found, where the tin atoms serve as a stereogenic centers. The catalytic activity of starting dichlorides as well as (LCNPhSnCl)2(µ‐O) in various transesterification processes was investigated. The activity is very low in the case of starting dichlorides. When two molar equivalents of NaH are added or (LCNPhSnCl)2(µ‐O) is employed in the catalytic experiments, the activity is comparable to the literature data. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

13.
Various primary amides and ketoamides have been obtained in good yields in a two-step reaction sequence. The first step involves the synthesis of aryl/alkenyl N-tert-butyl amides and aryl N-tert-butyl ketoamides from the corresponding iodides via palladium-catalysed carbonylation in the presence of t-BuNH2 as the nucleophile. Carbonylation was followed by selective cleavage of the t-Bu group using TBDMSOTf as the reagent.  相似文献   

14.
Hydrocarbon solutions of Mo2(O—t-Bu)6 and PF3 (2 equiv) yield Mo4F4(O—t-Bu)8, I, and PF2(O—t-Bu). Compound I contains a bisphenoid of molybdenum atoms with two short MoMo distances, 2.26 Å, and four long MoMo distances, 3.75 Å, corresponding to localized MoMo triple bonding and non-bonding distances, respectively. The tetranuclear compound may be viewed as a dimer, [Mo22-F)2(O-t-Bu)4]2, and addition of PMe3 to hydrocarbon solutions of I yields Mo2F2(O—t-Bu)4(PMe3)2, II, which contains an unbridged MoMo triple bond of distance 2.27 Å. Each molybdenum atom is coordinated to two oxygen atoms, one fluorine atom and the phosphorus atom of the PMe3 ligand in a roughly square planar manner. The overall central Mo2O4F2P2 skeleton has C2 symmetry and NMR studies (1H, 19F and 31P) are consistent with the maintenance of this type of structure in solution. Infrared and electronic absorption spectral data are reported. These are the first compounds containing fluorine ligands attached to the (MoMo)6+ unit.  相似文献   

15.
New (O−Sn)-bischelate bis(lactamomethyl)dibromo- and-diiodostannanes [L(n)]2SnX2 (L is the bidentate lactamomethyl C,O-chelating ligand;n is the size of the lactam ring, 5–7; X=Br or I) were prepared both by the direct method from metallic tin and the correspondingN-(halomethyl)lactams and by the reactions of dichlorides [L(n )]2SnCl2 with lithium halides. According to the data of X-ray diffraction analysis, the tin atom in [L(n)]2SnBr2 (n=5–7) and [L(n)]2SnI2 (n=5 or 6) adopts an octahedral configuration with the carbon atoms intrans positions and the coordinating oxygen and halogen atoms incis-positions with respect to each other. A comparison with the structures of analogous lactamomethyl halide derivatives of five-and six-coordinate Si, Ge, and Sn demonstrates that the spatial structures of the hypervalent fragments containing six-coordinate atoms are less sensitive to the replacement of the halide ligands and the central atom. The covalence of the M−Hal bond increases and the covalence of the M−O bond decreases in the series M=Si, Ge, and Sn. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1988–1998, October, 1999.  相似文献   

16.
Crystal Structure and Bonding of [W(O- t -Bu)4(THF)] [W(O-t-Bu)4(THF)] is formed from [WCl4(SEt2)2] and LiO-t-Bu in boiling tetrahydrofuran and characterized by a crystal structure analysis. The compound crystallizes in the tetragonal space group I4 with Z = 2 and the lattice dimensions a = b = 1158.8(2) and c = 940.7(2) pm at 80 °C. [W(O-t-Bu)4(THF)] shows the molecular structure of a tetragonal pyramid with the oxygen atom of the THF molecule in the apical position. Surprisingly, the tungsten atom is deflected by 34 pm from the plane of the four oxygen atoms of the O-t-butyl groups against the direction of the W–O(THF) bond. The bonding modes are discussed on the basis of MO considerations.  相似文献   

17.
《Polyhedron》1999,18(20):2687-2696
Diorganotin(IV) complexes of the general formula R2SnL (R=Ph, n-Bu and Me) have been prepared from diorganotin(IV) dichlorides (R2SnCl2) and tetradentate Schiff bases (H2L) containing N2O2 donor atoms in the presence of triethylamine in benzene. The Schiff bases, H2L, were derived from salicylaldehyde, 3-methoxysalicylaldehyde (o-vanillin), 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and diamines such as o-phenylenediamine and 1,3-propylenediamine. The complexes were characterized by IR, NMR (1H, 13C, 119Sn) and elemental analysis. The structure of the complex, n-Bu2Sn(Vanophen), was determined using single crystal X-ray diffraction. The tin atom has a distorted octahedral coordination, with the Vanophen ligand occupying the four equatorial positions and the n-butyl groups in the trans axial positions. Six-coordinated distorted octahedral structures have been proposed for all diorganotin(IV) complexes studied here, as they possess similar spectroscopic data.  相似文献   

18.
The heat-promoted reaction of 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene with cyclomanganated 2-[tricarbonyl(η6-phenyl)chromium]pyridine afforded, upon departure of a molecule of CO, a new stable manganese alkylidene complex in which, according to X-ray diffraction analyses, the heterocyclic ligand is anti-facial with respect to the Cr(CO)3 moiety. Similar heat-promoted reactions of unsymmetrically substituted diazoalkanes such as (Me3Si)(H)CN2, (Ph)(Me)CN2, (Ph)(t-Bu)CN2 and (Ph)(FcCH2CH2)CN2, which are precursors of more electrophilic alkylidenes, with cyclomanganated 2-[tricarbonyl(η6-phenyl)chromium]pyridine derivatives afforded new syn-facial heterobimetallic benzyl complexes. The stereoselectivity of these reactions depends on the steric demand of the substituents at the diazoalkane. A phenyl substituent at the diazoalkane favors the formation of syn-facial heterobimetallic benzyl complexes with the Ph group in the endo position. Combining this “phenyl directing effect” to the steric effect operated by a bulky group at the phenyldiazoalkane, like noticed with (Ph)(t-Bu)CN2, led to total stereoselectivity. This study discloses four new X-ray structures of syn-facial Cr,Mn benzyl complexes, which all present the same short Cr-to-Mn distance of ca. 3.04 Å.  相似文献   

19.
Syntheses and solid-state structures of zinc and tin(II) compounds, containing the N-silyl-amide ligands (OtBu)(NR)SiMe2, R = tBu (LtBu), or R = p-tolyl (LpTol), are reported. The N-silyl amines were synthesized by modified published procedures from commercially available Me2SiCl2, tBuOH, and tBuNH2, or p-Me-C6H4NH2, respectively. Treatment of SnCl2 with LiLpTol furnished Sn(LpTol)2, which was X-ray structurally characterized and shown to contain two covalent Sn-N bonds and two asymmetrical O → Sn donor bonds. The single-crystal X-ray structure of Sn(LtBu)2 revealed a much more symmetrically-coordinated, pseudo-trigonal-bipyramidal tin atom. Aminolysis of diethylzinc with HLpTol produced [EtZn(LpTol)]2, which crystallized as a centrosymmetric dimer, containing four-coordinate zinc atoms connected by bridging amides. Zinc dichloride, by contrast, reacted with two equivalents of LiLtBu to produce the homoleptic, pseudo-spirocyclic Zn(LtBu)2.  相似文献   

20.
Silyldiazoalkanes Me3Si(LnM)CN2 (LnM = Me3Si, Me3Ge, Me3Sn, Me3Pb; Me3As, Me3Sb, Me3Bi) have been synthesized by three different routes: (a) reactions of the Me3SiCHN2 with metal amides LnMNR1R2 of Group IVB and VB elements, using Me3SnCl as catalyst; (b) reactions of the in situ prepared organolithium compound Me3SiC(Li)N2 with organometallic chlorides Me3MCl (M = Si, Ge); (c) tincarbon bond cleavage reaction of (Me3Sn)2CN2 with Me3SiN3, affording Me3SnN3, traces of bis(trimethylsilyl)diazomethane (Me3Si)CN2, trimethylsilyl(trimethylstannyl)diazomethane Me3Si(Me3Sn)CN2 and bis(trimethylsilyl)aminoisocyanide (Me3Si)2NNC as the major reaction products. IR and NMR data (1H, 13C, 29Si, 119Sn, 207Pb) of the new heterometal-diazoalkanes are reported and discussed in comparison to relevant compounds of the organometallic diazoalkane series.  相似文献   

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