The photolysis of [I2H2 (PMe2 Ph)2] gives ethylene and but-1-ene as volatile products, the latter probably being formed via a five-coordinate platinum intermediate. However, the formation of propene from the photolysis of [Cl2H2 (1,10-phenanthroline) appears to involve a direct transfer of a hydrogen atom between neighbouring CH2 groups in the ring. Other gaseous products, e.g. cyclopropane, ethylene, may be formed via a platinum ion radical. 相似文献
The kinetics of the reaction of alkenes (e.g. cis-pent-2-ene, hex-1-ene, cyclopentene) with [H2)(THF)2] (X = Cl or Br, THF = tetrahydrofuran) or with [H2)(THF)2] in THF solution have been studied. The reactions occur with displacement of cyclopropane or phenylcyclopropane to give [PtCl2(olefin)(THF)], and follow essentially second order kinetics, first order in both platinum complex and olefin. The mechanism of reaction is discussed. 相似文献
The kinetics of the reaction of arylcyclopropanes (4-XC6H4C3H5, X = H, Me, EtO) with either [Pt2Cl2(μ-Cl)2(C2H4)2] or [{H2)} in tetrahydrofuran to give in each case [{H2)}4] and ethylene or cyclopropane, respectively, have been studied. The reactions are essentially first order in both arylcyclopropane and platinum complexes. The order of reactivity follows the series X = EtO > > Me > H, and [Pt2Cl2(μ-Cl)2(C2H4)2]> [{H2)}4] and the rate is accelerated in polar solvents. Mechanisms in which the arylcyclopropane first coordinates to platinum and then undergoes ring opening reactions are proposed. 相似文献
The platinacyclobutane complexes PtCl2L2(C3H5Me)], L pyridine, CD3CN, or tetrahydrofuran, exist as mixtures of isomers containing PH2 or P groups in rapid equilibrium. Decomposition occurs in some cases to give [PtCl2L(CH3CH2CHCH2)]. Stereospecific skeletal isomerisation also occurs in metallocyclobutanes containing the groups PH2 PHR, when R aryl further decomposition gives ν-allylplatinum complexes. 相似文献
C5H5FeC5H4CH2NMe2 reacts with sodium chloropalladate(II) in the presence of sodium acetate to give the internally metallated binuclear species [Me2}2] (X = Cl). The corresponding iodide was prepared as were mononuclear species [Me2}] and [Me2}L] L = PMe2Ph, AsMe2Ph, P(OMe)3 or PPh3. 1H NMR data are given. 相似文献
The products of the photolysis of a number of platinacyclopentanes in solution at 25°C under a variety of conditions have been determined. With [I2PH2(L2)] (L = PMe2Ph, PPh3) in CH2Cl2, CH2Br2 and (CH3)2SO the hydrocarbon products are exclusively ethylene and but-1-ene. Formation of the latter through a 1,3-hydrogen shift is preceded by phosphine ligand dissociation. The photolysis of [ICH3PH2(L2)] gave methane, ethylene, but-1-ene and n-pentane together with a little n-butane, the methane being formed from internal hydrogen abstraction by the CH3 group in the excited reactant molecule. Photodecomposition of the platinum(II) compounds [PH2(L2)] (L = (PMe2Ph)2, (PPh3)2, Ph2PCH2CH2PPh2) gave ethylene, but-1-ene, pent-1-ene (with the halogenated solvents) and with some systems appreciable yields of n-butane, the latter being the results of internal abstraction of two hydrogen atoms by the C4H8 moiety. The formation of pentene is probably preceeded by the addition of CH2Cl2 or CH2Br2 to the excited reactant molecule. Addition of diphenylphosphine promotes the production of n-butane. 相似文献
The interaction of azobenzene and MnR(CO)5 (R Me, Et, CH2Ph, CH2-C6Me5, COCF3, COCH2C6F5, COCH2OPh, Ph or C6F5) affords MPh)-(CO)4, together with a binuclear complex Mn2(CO)6(C12H10N2) in some cases. The metallation reaction is shown to proceed most readily with Mn-(CH2Ph)(CO)5; with this reagent, the metallated complexes MMe2)-(CO)3[PMe2(CH2Ph)] (two isomers) and MsMe2(CO)4 have been obtained on treatment with EMe2(CH2Ph) (E P and As, respectively). 相似文献
The reaction between the platinacyclobutanes [H2)L2] (X Cl, Br; L C5H5N, 4-CH3C5H4N; R, R′ H, CH3; R H, R′ CH3, C6H5) and iodide and thiocyanate ions in methyl cyanide solution has been studied. The C3 moiety is eliminated as the cyclopropane and the process is first order with respect to the platinacyclobutanes and zero to half order with respect to the salt (MY). With the iodides the rate increases in the order Li < Na < K, Et4N, and methyl substitution in the cyclobutane ring reduces the rate of reaction with Et4NI. Added pyridine retards the reaction when L C5H5N (X Cl; R, R′ H) and added dimethylsulphoxide accelerates it.The mechanism suggested involves dissociation of an L ligand and attack of Y? ions and of M+Y? ion pairs on the five-coordinate intermediate formed. 相似文献
Chelate complexes of the type (CO)4MiX2 (X = Me, Cl) have been prepared from Na[Mn(CO)5] and HMn (CO)5, respectively, by two-step reactions with the ligands Me2PCH2CH2SiX2R′ using alkali salt, amine or HCl elimination. (CO)4MiCl2 is also obtained by cleavage of Mn2(CO)10 with Me2PCH2CH2SiCl3. IN the case of HMn (CO)5 the intermediates (CO)4Mn (H) L [L = Me2PSiMe3, Me2PCH2CH2SiMe2 (NMe2), Me2PCH2CH2SiCl2 (NMe2] can be isolated. The new compounds were identified by analytical and spectroscopic (IR, PMR, MS) methods. 相似文献
The amine substituted phosphines (C6H5)2PN(H)CH2CH3 and (C6H5)2PN(H)CH2C6H5 react with C5H5Fe(CO)2CH(C6H5) (OCH3) photolytically to give moderate yields of the four-membered chelate ring complexes C5H5H (C6H5)] and C5H5H(C6H5)], respectively. Photolysis of C5H5Fe(CO)2CH(C6H5) (OCH3) in the presence of (S)-(?)-diphenyl(1-phenylethylamino)phosphine leads to the isolation of C5H5Fe(CO)[(C6H5)2PNC(CH3) (C6H5)]CH2C6H5 which is proposed to arise from a formally 1,3-hydrogen shift rearrangement of an intermediate four-membered chelate ring complex. 相似文献
The η-hexamethylbenzenehydridoruthenium(II) complexes RuHCl(η-C6Me6)L (L = PPh3 (11), AsPh3 (12), P(C6H4-p-F)3 (14), P(C6H4-p-Me)3 (15), P(C6H4-p-OMe)3 (16), P-t-BuPh2 (17), P-i-PrPh2 (18), P-i-Pr3 (19), PCy3 (20) and P-t-BuMe2 (21)) have been made by heating [RuCl2(η-C6Me6)]2, the ligand and sodium carbonate in propan-2-ol. The triarylphosphine complexes 11, 14 and 15 react with methyllithium to give aryl ortho-metallated hydridoruthenium(II) complexes such as Ph2)(η-C6Me6) (22) and 19 similarly gives the isopropyl cyclometallated complex -i-Pr2(η-C6Me6) (29) as a mixture of diastereomers. Reaction of 17 with methyllithium gives initially the t-butyl cyclometallated complex Ph2)(η-C6Me6) (25) which isomerizes by a first order process (k.2 h?1 in C6D6 or THF-d8 at 50°C) to the aryl ortho-metallated complex -t-BuPh)(η-C6Me6) (26). The similarly generated isopropyl cyclometallated complex Ph2)(η-C6Me6) (27) has not been isolated in a pure state owing to rapid isomerization to -i-PrPh)(η-C6Me6) (28); both 27 and 28 exist as a pair of diastereomers. The formation of the cyclometallated complexes and the isomerizations are thought to involve intermediate 16-electron ruthenium(O) complexes Ru(η-C6Me6)L. 相似文献
Unstable transition metal compounds formed from hydridosilacyclobutanes are described: 1-methyl-1-silacyclobutane reacts with nonacarbonyldiiron to give the complexes [Fe(CO)4(H){H2}] and [(H)Me}(CO)4], and with bis(triphenylphosphine)(ethylene)platinum(0) to give [Pt(H)(PPh3)2{H2}]. 相似文献
The colourless, six- and seven-membered manganacycloalkanes (OC)4H2 are obtained by reaction of Na2[(OC)4MnPR2O] with the bis(triflate)alkanes (YCH2)2X (R = C6H5; X = CH2, C(CH3)2, CH2CH2; Y = CF3SO3). CO or SO2 can be inserted into the reactive MnC-σ bonds under ring expansion. Some characteristic IR and 1H NMR data are discussed. (OC)4H2 crystallizes monoclinic in the space group P21/c with Z = 4. 相似文献
When (t-Bu)2PCH2CHCH2CH2 is combined with [IrCl(C8H14)2]2 in toluene, the σ-bound cyclopropane complexes (P(t-Bu)2CH2H2) (1a, 1b) are formed. Complexes 1a,1b react readily with H2 to form IrClH2P(t-Bu)2CH2H2)2 (2). In polar solvents 1a,1b isomerize to the σ-vinyl chelated complex H)(P(t-Bu)2CH2H2) (3). The structure of this 5-coordinate, 16-electron IrIII complex was deduced from spectroscopic data, reaction chemistry, and from the crystal structure of its CO adduct (4). Compound 4 crystallizes in the monoclinic space group C2h5-P21/n (a 15.610(14), b 15.763(16), c 11.973(13) Å, and β 104.74(5)°) with 4 molecules per unit cell. The final agreement indices for 2326 reflections having Fo2 > 3σ(Fo2) are R(F) = 0.089 and Rw(F) = 0.095 (271 variables) while R(F2) is 0.148 for the 3423 unique data. Bond lengths in the 5-atom chelate ring are IrP 2.341(4), PC 1.857(26), CC 1.520(30), CC 1.341(25), and CIr 1.994(21) Å. The IrCl distance is 2.479(5) Å. 相似文献
The six- and seven-membered rhenacycloalkanes (OC)4RH2 (R = CH3, CoH5; X = CH2, CH2CH2) are obtained by reaction of the binuclear anions [(OC)4RePR2O]22? with the alkanediylbis(triflouromethanesulfonates) X(CH2Y)2 (Y = CF3SO2O) in dimethoxyethane. In the Reσ bond of (OC)4RH2SO2 can be inserted under ring expansion. The rhenacycloheptanes (OC)4RH2 (R = CH3, CoH5) are thermally unstable and decompose by cleavage of the α-CC bond. The heterolytic cleavage of the ReRe bond in [(OC)4RePR2O]22? results in the open chain, ionic intermediate products [R2(O)PRe(CO)4CH2XCH2Y]?, which in competition with the cyclisation, are liable to a β-hydrogen transfer. The mechanisms which are responsible for the formation of the hdrido complexes [HRe(CO)4PR2O]? and HRe(CO)4PR2OCH2XCH3, are discussed. 相似文献
The cyclometallation of p-RC6H4CHNCH2C6H2, (R = H, Cl, NO2) by PdX2 (X = Cl, AcO) has been studied.In every case the cyclometallation occurs with formation of a five-membered ring containing the methine group. The structure of these compounds [CH2C6H5)]2, derived from 1H NMR spectra, are different from those reported previously. Reaction of these compounds with PEt3 gives the compounds [PdX(p-RC6H3CHNCH2C6H5)(PEt3)2] but with an excess of PPh3 only the complexes [CH2C6H5)(PPh3)] are formed. 相似文献
The addition of trimethylphosphane to five-membered metallacyclic vinylketone complexes of the type ArR) (I) (Ar = η5-aromatic ring system: C5H5, C5H4Me, C5Me5; R = Me, Et, n-Bu; M = Mo, W) in pentane solution results in the formation of the ylidic metallacyclopropane complexes ArH(COR)] (II). In these 1:1 adducts the three-membered ring is stabilized by an electron-donating phosphonium and an electron-attracting acyl substituent. The negative charge in the ylidic complexes II is localized on the central metal providing it with Lewis base properties. An extraordinary high electron density can be observed on the metal of the derivative C5H5H-(COMe)] (III) which is formed by a 1:2 addition of C5H5W(CO)(C2H2)-(COMe) and PMe3. The metallacyclopropane complexes II and III are characterized by IR, 1H NMR, 13C NMR, 31P NMR and mass spectroscopy. For C5H5H(COMe)], the results of an X-ray structure determination are presented. 相似文献
Variable temperature 1H NMR spectroscopy has been used in the study of 1,3-intramolecular shifts of the M(CO)5 moiety in complexes of the general formula [M(CO)5L], (M = Cr or w), L = H2, H2 and H2. For the 1,3,5-trithian complexes precise energy barriers for the process have been obtained by detailed computer simulation of the static and dynamic spectra. Our results suggest that the magnitude of ΔG≠ (298.15 K) for the 1,3-shift is largely dependent upon the skeletal flexibility of the ligand system. In this context we have investigated the X-ray crystal structure of the highly substituted trithian complex [W(CO)5{β-H(Me)}]. 相似文献
Silicon-transition metallic silacyclobutanes CpFe(L2)H2 [L = CO or Ph2MeP; or L2 = (CO)(Ph2MeP)] have been prepared and their reactions (substitution at Si or Fe, Si—Fe cleavage, or ring-opening) studied. 相似文献
Controlled displacement of fluorine from perfluoro-1-azacyclo-hexene (I) by the nucleophilic reagents Me2NH, Et2NH, H, C6Cl5ONa, and (CF3)2NONa provides the derivatives (II) - (IV), respectively. The last of these can also be obtained by treatment of the parent compound (I) with mercuryII bistrifluoromethylnitroxide. 相似文献
