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1.
Abstract

Hindered rotation in alkyldithiocarbamates of the type RR′NC(= S)SR″ [R, R′, R″ = Me, Me, Et (1); PhCH2, Me, Et (2); PhCH2, H, Et (3); PhCH2, H, Me (4) and O(CH2CH2)2, Et (5)′ has been investigated using variable-temperature 1H NMR spectroscopy in CDCl3, C6D6, and DMSO-d6 solutions. Rotational parameters were calculated by the coalescence temperature method. Nitrogen substituent effects on the free energy of activation and on the equilibrium constant of unsymmetrical conformers at room temperature are discussed.  相似文献   

2.
The complexes [MHCl(CO)(PPh3)3] (M = Ru or Os) readily undergo substitution at the site trans to the hydride ligand to afford phosphinite-, phosphonite-, or phosphite-containing products [MHCI(CO)(PPh3)2L] [L = P(OR)Ph2, P(OR)2Ph or P(OR)3 respectively; R = Me or Et]. The ruthenium complexes alone undergo further substitution to afford complex cations [RuH(CO)(PPh3)nL4?n]+ [n = 2, L = P(OMe)3; n = 1, L = P(OR)3; n = 0, L = P(OR)2Ph or P(OR)Ph2] which were isolated and characterised as their tetraphenylborate salts. Synthesis of the cationic complexes [IrHL5][BPh4]2 [L = P(OR)3, R = Me or Et] is also reported. Stereochemical assignments based on NMR data are given, and second order 31P and high field 1H NMR patterns are analysed.  相似文献   

3.
A variety of very bulky amido magnesium iodide complexes, LMgI(solvent)0/1 and [LMg(μ‐I)(solvent)0/1]2 (L=‐N(Ar)(SiR3); Ar=C6H2{C(H)Ph2}2R′‐2,6,4; R=Me, Pri, Ph, or OBut; R′=Pri or Me) have been prepared by three synthetic routes. Structurally characterized examples of these materials include the first unsolvated amido magnesium halide complexes, such as [LMg(μ‐I)]2 (R=Me, R′=Pri). Reductions of several such complexes with KC8 in the absence of coordinating solvents have afforded the first two‐coordinate magnesium(I) dimers, LMg?MgL (R=Me, Pri or Ph; R′=Pri, or Me), in low to good yields. Reductions of two of the precursor complexes in the presence of THF have given the related THF adduct complexes, L(THF)Mg?Mg(THF)L (R=Me; R′=Pri) and LMg?Mg(THF)L (R=Pri; R′=Me) in trace yields. The X‐ray crystal structures of all magnesium(I) complexes were obtained. DFT calculations on the unsolvated examples reveal their Mg?Mg bonds to be covalent and of high s‐character, while Ph???Mg bonding interactions in the compounds were found to be weak at best.  相似文献   

4.
Novel η1-vinyl complexes of the type Cp(CO)(L)FeC(OMe)C(R)R′ (R = R′ = H, Me; R = H, R′ = Me; L = Me3P, Ph3P) are obtainied via methylation of the acyl complexes Cp(CO)(L)FeC(O)R (R = Me, Et, i-Pr) with MeOSO2F and subsequent deprotonation of the resulting carbene complexes [Cp(CO)(L)FeC(OMe)R]SO3F with the phosphorus ylide Me3PCH2. The same procedure can be applied for the synthesis of the pentamethylcyclopentadienyl derivative C5Me5(CO)(Me3P)FeC(OMe)CH2, while treatment of the hydroxy or siloxy carbene complexes [Cp(CO)(L)FeC(OR)Me]X (R = H, Me3Si; X = SO3CF3) with Me3CH2 results in the transfer of the oxygen bound electrophile to the ylidic carbon. Some remarkable spectroscopic properties of the new complexes are reported.  相似文献   

5.
Ruthenium halides (Cl and Br) react with monotertiary arsines-Ph2RAs (R=Me, Et, Pr n ) in methoxyethanol, in the presence of aq. formaldehyde to give monocarbonyl complexes of ruthenium(II) of the type RuX2(CO) (Ph2RAs)3. Carbonylation of an ethanolic solution containing ruthenium trichloride and the arsine at room temperature yieldtrans dicarbonyl compounds of the formula RuCl2(CO)2 (Ph2RAs)2. The osmium monocarbonyls OsX2(CO) (Ph2RAs)3 (X=Cl, Br; R=Me, Et) react with NaBH4 in methanol to yield complexes of the composition OsHX(CO) (Ph2RAs)3. The ruthenium analogues RuHCl(CO) (Ph2RAs)3 have also been made. Structures have been assigned to all these compounds on the basis of IR and NMR spectral results.  相似文献   

6.
The first examples of late transition metal η5-arsolyls (L = CO, P(OMe)3; R = Ph, Me, Et, SiMe3; R′ = Ph, H, Me, Et, Me) serve as ditopic donors to extraneous metal centres (M = PtII, AuI, HgII) through both conventional As → M and polar-covalent (dative) Co → M interactions.

Cobalt carbonyl reacts with arsoles to provide the first late transition metal η5-arsolyls. These serve as ditopic donors to extraneous metal centres (M = PtII, AuI, HgII) through both conventional AsM and polar-covalent (dative) CoM interactions.  相似文献   

7.
Fe2(CO)9 and R2P(S)P(S)R2 (R = Et, n-Pr, n-Bu, Ph) react to form two types of cluster complexes Fe3(CO)93-S)2 (1), Fe2(CO)6(μ-SPR2)2 (2A)–(2D), [2A, R = Et; 2B, R = n-Pr; 2C, R = n-Bu; 2D, R = Ph]. The complexes result from phosphorus–phosphorus bond scission; in the former sulfur abstraction has also occurred. The complexes have been characterized by elemental analyses, FT-IR and 31P-[1H]-NMR spectroscopy and mass spectrometry.  相似文献   

8.
《Polyhedron》1999,18(20):2665-2671
The reaction of [PtCl2(dppe)] [dppe=1,2-bis(diphenylphosphino)ethane] with two equivalents of the thioureas NHRC(S)NHR (R=H, Me, Et) in the presence of NH4PF6 led to substitution of both chlorides and formation of the complexes [Pt(dppe){SC(NHR)2}2](PF6)2 (1a, R=H; 1b, R=Me; 1c, R=Et). In contrast, the reaction of [PtCl2(dppe)] with one equivalent of the potentially bidentate thiosemicarbazides NHRC(S)NHNR′2 (R=Me, R′=H; R=Et, R′=H; R=Ph, R′=H; R=Me, R′=Me) in the presence of NH4PF6 led to substitution of only one chloride and formation of the complexes [PtCl(dppe){SC(NHR)NHNR2′-S}](PF6) (2a, R=Me, R′=H; 2b, R=Et, R′=H; 2c, R=Ph, R′=H; 2d, R=Me, R′=Me). An X-ray analysis of complex 2d revealed that an intramolecular N–H⋯Cl hydrogen bond [N(2)⋯Cl(1)=3.29(2) Å] helps to stabilise the monodentate co-ordination mode. The chloride ligand can be abstracted from complex 2d by treatment with TlPF6, and this reaction led to formation of [Pt(dppe){SC(NHMe)NHNMe2-S,N}](PF6)2 3d. Reaction of [PtCl2(dppe)] with unsubstituted thiosemicarbazide NH2C(S)NHNH2 in the presence of NH4PF6 resulted in a mixture of products containing mono- and bidentate co-ordinated ligands, [PtCl(dppe){SC(NH2)NHNH2-S}](PF6) 2e and [Pt(dppe){SC(NH2)NHNH2-S,N}](PF6)2 3e. [PtCl2(dppe)] also reacts with two equivalents of NHMeC(S)NHNMe2 in the presence of NH4PF6 to yield [Pt(dppe){SC(NHMe)NHNMe2-S}2](PF6)2 1d, in which the thiosemicarbazide is acting as an S-donor, directly analogous to the thiourea ligands in complexes 1a–c.  相似文献   

9.
《Polyhedron》1999,18(23):2961-2969
Reactions between Ph3SnCl and the sodium salts of 5-mercapto-1-methyltetrazole (MTS-H), 2-mercaptobenzoxazole (MBZ-H), 2-mercaptobenzothiazole (MBT-H) and 2-mercapto-1-methylimidazole (MMI-H) gave Ph3Sn(MTS) (5: R=Ph, R′=Me), Ph3Sn(MBZ) 6, Ph3Sn(MBT) 7 and Ph3Sn(MMI) 8, respectively. Characterisation has been carried out for all compounds by IR, Mössbauer, 1H, 13C and 119Sn NMR spectroscopy as well as by X-ray crystallography for (5: R=Ph, R′=Me) and 6. Both (5: R=Ph, R′=Me) and 6, in the solid state, have cis-trigonal bipyramidal geometries due to intramolecular Sn–N(2) interactions. Mössbauer data for 7 was interpreted as indicating a similar cis-trigonal bipyramid geometry. The chelating ability of nitrogen-containing heteroarenethiolato groups, based on the strength of Sn–N inter-molecular bonds in Ph3SnS-heteroarenes, decreases in the sequence: pyridine-2-thiolato>pyrimidine-2-thiolato>1-methylimidazole-2-thiolato>benzoxazole-2-thiolato>1-methyltetrazole-5-thiolato>1-phenyltetrazole-5-thiolato. On dissolution, the Sn–N interactions in 58 undergo at least partial breakage.  相似文献   

10.
Sulfur Dioxide as Ligand and Synthon. IX. Reactions of Cobalt Carbonyls with Sulfur Dioxide – Synthesis and Characterization of Alkoxysulfinyl-Cobalt Carbonyl Complexes Reactions of phosphine substituted Co2(CO)8, (Ph2P–(CH2)n–PPh2: n = 1, dppm; n = 2, dppe; n = 3, dppp; n = 4, dppb), alkylcobalt carbonyls and alkoxycobalt carbonyls with sulfur dioxide have been investigated. The SO2 containing cobalt complexes are characterized by means of I.R., 1H-NMR, and mass spectra. Further on synthesis and properties of new alkoxysulfinylphosphine-cobalttricarbonyl complexes of the type ROS(O)Co(CO)3PR31 (R = Ph3Si, Me; R1 = Et, i-Pr, Ph) are described.  相似文献   

11.
New complexes [Cr(CO)4(R2P(S)P(S)R2)] and [Cr2(CO)10(-R2P(S)P(S)R2)] (R = Me, Et, Pr n , Bu n ), (1a)–(1d) and (2a)–(2d) [(1a), R = Me; (1b), R = Et; (1c), R = Pr n ; (1d), R = Bu n ; (2a), R = Me; (2b), R = Et; (2c), R = Pr n ; (2d), R = Bu n ] have been prepared by the photochemical reaction of Cr(CO)6 with R2P(S)P(S)R2 (R = Me, Et, Pr n and Bu n ) and characterized by elemental analyses, FT-i.r., 31P-[1H]-n.m.r. spectroscopy and FAB-mass spectrometry. The spectroscopic data suggest cis-chelate bidentate coordination of the ligand in [Cr(CO)4(R2P(S)P(S)R2)] and cis-bridging bidentate coordination of the ligand between two metals in [Cr2(CO)10(-R2P(S)P(S)R2)] (R = Me, Et, Pr n and Bu n ).  相似文献   

12.
《Polyhedron》1999,18(5):729-733
Equimolar quantities of [Mo (CO) (η2-RC2R′)2Cp] [BF4] (R=R′=Me Ph R=Me R′=Ph) and L L′ or L″ {L L′ or L″= [WI2 (CO){PhP(CH2CH2PPh2)2-PP′} (η2-RC2R′)]} (L R=R′=Me L′ R=R′=Ph L″ R=Me R′=Ph) react in CH2Cl2 at room temperature to give the new bimetallic complexes[Mo (CO) (L L′ or L″–P) (η2-RC2R′)Cp] [BF4] (1–9) via displacement of the alkyne ligand on the molybdenum centre The complexes have been characterised by elemental analysis IR and 1 H NMR spectroscopy and in selected cases by 31 P NMR spectroscopy.  相似文献   

13.
Treatment of pyridine‐stabilized silylene complexes [(η5‐C5Me4R)(CO)2(H)W?SiH(py)(Tsi)] (R=Me, Et; py=pyridine; Tsi=C(SiMe3)3) with an N‐heterocyclic carbene MeIiPr (1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene) caused deprotonation to afford anionic silylene complexes [(η5‐C5Me4R)(CO)2W?SiH(Tsi)][HMeIiPr] (R=Me ( 1‐Me ); R=Et ( 1‐Et )). Subsequent oxidation of 1‐Me and 1‐Et with pyridine‐N‐oxide (1 equiv) gave anionic η2‐silaaldehydetungsten complexes [(η5‐C5Me4R)(CO)2W{η2‐O?SiH(Tsi)}][HMeIiPr] (R=Me ( 2‐Me ); R=Et ( 2‐Et )). The formation of an unprecedented W‐Si‐O three‐membered ring was confirmed by X‐ray crystal structure analysis.  相似文献   

14.
The preparation and properties are described of trans-[(Ph3P)2(CO)M(RNSNR)] [ClO4] (M  RhI, IrI; R  Me, Et, i-Pr, t-Bu) and of cis- or trans-[L2Pt(RNSNR)X] [ClO4] (X  Cl?, L  Et2S, PhMe2As, PhMe2P, R  Me, t-Bu; X  CH3, L  PhMe2P, R  Me).1H and 13C NMR data show the existence of various isomers in solution which may interconvert via intra- and inter-molecular exchange processes. A general reaction scheme for the intramolecular exchange processes is discussed.  相似文献   

15.
Two series of diorganotin(IV) dialkyldithiophosphates, [RR′Sn{SSP(OR″)2}2](R = Me or Et; R′= Ph; R″ = Et, Prn, Pri or Bun) and [RR′Sn(Cl){SSP(OR″)2}] (R = R′= Me, Et or Ph; R″ = Ph; R″ = Et, Pri or Bun) were prepared and characterised by i.r. and NMR (1H, 13C, 31P, 199Sn) spectroscopy. The NMR data indicate five and six coordinate geometries for [RR′Sn(Cl){SSP(OR″)2}] and [RR′Sn{SSP(OR″)2}2] complexes, respectively. The chloro complexes showed 2J (PSn) whereas such couplings were not observed in the spectra of [RR′Sn{SSP(OR″)2}2].  相似文献   

16.
Upon heating solid monoalkylamino(silyl)carbene complexes (CO)5MC(NHR′)SiR3 (M = W: SiR3 = SiPh3, R′ = Me, Et, Bun, C6H11, Ph; SiR3 = SiMePh2, R′ = Me, Et. M = Mo, Cr: R = Ph, R′ = Me, Et) beyond their melting points, HSiR3 elimination with formation of the isonitrile complexes (CO)5MNCR′ and (CO)4M(CNR′)2 and (CO)6M takes place quantitatively. Deuteration experiments show that the silane hydrogen stems from the NH group and that the reaction partially or exclusively proceeds by an intermolecular pathway.  相似文献   

17.
The reaction of [Cp(CO)(dppm)Fe]BF4 (1a) with the phosphorus ylide Me3PCH2 yields the novel bis(phosphino)methanideiron complex Cp(CO)Fe(Ph2PCHPPh2) (2), which upon photolysis in the presnece of Me3P is converted into Cp(Me3P)Fe(Ph2PCHPPh2 (3). Reaction of 2 with MeOSO2CF3 gives a mixture of the iron salts [(Cp(CO)Fe(Ph2PCR(R′)PPh2)]CF3SO3 (R = R′ = H (1b), R = R′ = Me (6) and R = H, R′ = Me (syn/anti-4)).  相似文献   

18.
Terminal alkynes (HCCR) (R=COOMe, CH2OH) insert into the metal-carbyne bond of the diiron complexes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO)(NCMe)(Cp)2][SO3CF3] (R=Xyl, 1a; CH2Ph, 1b; Me, 1c; Xyl=2,6-Me2C6H3), affording the corresponding μ-vinyliminium complexes [Fe2{μ-σ:η3-C(R)CHCN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Xyl, R=COOMe, 2; R=CH2Ph, R=COOMe, 3; R=Me, R=COOMe, 4; R=Xyl, R=CH2OH, 5; R=Me, R=CH2OH, 6). The insertion is regiospecific and C-C bond formation selectively occurs between the carbyne carbon and the CH moiety of the alkyne. Disubstituted alkynes (RCCR) also insert into the metal-carbyne bond leading to the formation of [Fe2{μ-σ:η3-C(R)C(R)CN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Me, R=Xyl, 8; R=Et, R=Xyl, 9; R=COOMe, R=Xyl, 10; R=COOMe, R=CH2Ph, 11; R=COOMe, R=Me, 12). Complexes 2, 3, 5, 8, 9 and 11, in which the iminium nitrogen is unsymmetrically substituted, give rise to E and/or Z isomers. When iminium substituents are Me and Xyl, the NMR and structural investigations (X-ray structure analysis of 2 and 8) indicate that complexes obtained from terminal alkynes preferentially adopt the E configuration, whereas those derived from internal alkynes are exclusively Z. In complexes 8 and 9, trans and cis isomers have been observed, by NMR spectroscopy, and the structures of trans-8 and cis-8 have been determined by X-ray diffraction studies. Trans to cis isomerization occurs upon heating in THF at reflux temperature. In contrast to the case of HCCR, the insertion of 2-hexyne is not regiospecific: both [Fe2{μ-σ:η3-C(CH2CH2CH3)C(Me)CN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Xyl, 13; R=Me, 15) and [Fe2{μ-σ:η3-C(Me)C(CH2CH2CH3)CN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Xyl, 14, R=Me, 16) are obtained and these compounds are present in solution as a mixture of cis and trans isomers, with predominance of the former.  相似文献   

19.
Mono-cyclopentadienyl complexes CpVX2(PR3)2 and Cp′VX2 (PR3)2 (Cp = η5- C5H5; Cp′ = η5-C5H4Me; R = Me, Et; X = Cl, Br) have been prepared by reaction of VX3(PR3)2 with CpM (M = Na, T1, SnBun3, 1/2 Mg) or Cp′Na. Attempts to prepare analogous complexes with other phosphine ligands, PPh3, PPh2 Me, PPhMe2, Pcy3, DMPE and DPPE failed. Reduction of CpVCl2(PEt3)2 with zinc or aluminium under CO (1 bar) offers a simple method for the preparation of CpV(CO)3(PEt3). The crystal structure of the trimethylphosphine complex CpVCl2(PMe3)2 is reported.  相似文献   

20.
《Polyhedron》1988,7(14):1289-1298
The following adducts of Group III trialkyls with phosphines have been prepared, either by direct reaction in hydrocarbon solution or by displacement of ether from the metal trialkyl etherate: Me3M·PPh3 (M = Ga, In); Me3In·P(2-MeC6H4)3; (R3M)2·(Ph2PCH2)2 (R = Me, M = Al, Ga, In; R = Et, M = Ga, In; R = Bui, M = Al); (Me3M)3·(Ph2PCH2CH2)2PPh (M = Al, Ga, In) and (Me3M)4·(Ph2PCH2CH2PPhCH2)2 (M = Al, Ga, In). The compounds were analysed by 1H and 31P NMR spectra of (Me3M)2·(Ph2PCH2)2 (M = Ga, In) showed little change between 193 K and room temperature. Thermal dissociation of the adducts in vacuo gave the free metal trialkyl with no detectable contamination by the respective phosphine. Crystals of (Me3M)2·(Ph2PCH2)2 (M = Al, Ga, In) are iso-structural and the molecules contain two distorted tetrahedral metals bridged by the (Ph2PCH2)2; the MP distances are 2.544(4), 2.546(4) and 2.755(4) Å, respectively. The X-ray crystal structure of (Me3Al)3·(Ph2PCH2CH2)2PPh shows the molecule to contain distorted tetrahedral aluminium atoms bonded to each of the three phosphorus atoms, with AlP distances of 2.536(9) and 2.510(9) Å for the terminal and central moieties, respectively; the unit cell contains two such molecules plus one benzene molecule (the crystallizing solvent).  相似文献   

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