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1.
Experimental data on conformational energies of the molecules FH2CHCCH2, FH2CFCCH2, FH2C(CH3)C&.dbnd;CH2 trans-FH2CHCC(CH3)H have been used to establish parameter values for the nonbonding atom ⋯ atom interaction F ⋯ C(sp2) within the Morse potential formulation. Torsional potentials have been calculated for the four molecules mentioned above and in addition for cis- and trans-FH2CHCCHF, (FH2C)2CCH2, cis-FH2CHCCHCH2F, CH3FCHHCCH2 and FH2CCH2HCCH2. Calculated results have been compared with experimental values. Torsional force constants for the molecules have been obtained. A comparison between fluoro, chloro and bromo compounds is presented. 相似文献
2.
Ethyl but-3-ynoate undergoes electrophilic additions of BrCl and of ICl to give CHXCClCH2COOEt E (X = Br or I). The addition of sulfenyl halides RSY follows the opposite orientation and leads to CHYCSRCH2COOEt E (Y = Cl or Br, R = Et or Ph). In the case of IBr, both CHICBrCH2COOEt E and CHBrClCH2;COOEt E are obtained.A mechanistic interprétation of these results is supported by both the orientation and the kinetic order of the addition: PhSCl reacts by an AdE2 process, whereas ICl addition involves a combination of AdE3 and AdE4 mechanisms. 相似文献
3.
The preparations of CH2SF4 and CH3CHSF4 are presented and the structures are discussed. Addition reactions of polar species give a wide range of new compounds, like Hg(CH2SF5)2, F4AsCH2SF5, cisBrSF4CH3, cisF5SeOSF4CH2Br, a.o. While CH2SF4 decomposes at room temperature slowly to CH2CH2 and SF4, at high temperatures HF and CSF2 are formed. CH3CHSF4 gives mainly CH3CHF2 at room temperature. The “saturated” compounds CH3SF5 and C2H5SF5 have been prepared. They react with SbF5 in SO2 at low temperatures to form the cations CH3SF4+ and C2H5SF4+. The CH3SF4+ ion has been investigated in detail by nmr methods at low temperatures. It decomposes to CH3 and SF4, which react further in the SO2/SbF5 system to CH3OSO+ and SF3+. 相似文献
4.
The charge distributions in the ions (CH3CHR) and in the molecules CH3CHRLi (RNO2, CN, COOCH3, C6H5, CHCH2, H, NH2 or OCH3), modelling the active centres of the two extreme types in anionic polymerization, were calculated by the CNDO/2 method. The geometry of these compounds was partly optimized. Both the geometry and the charge distribution in anions were found to exhibit no strong dependence on R. This suggests that in free ion polymerization, the equality r1r2 = 1 holds. The active centres of the polarized bond type are fairly varied. Two reasons for their reactivity may exist: the polarity of their CLi bond and their geometry facilitating the insertion of a monomer. The electronic structure of the neutral molecules considered correlates with the low degree of association of the living chains. 相似文献
5.
J. Kuyper L.G. Hubert-Pfalzgraf P.C. Keijzer K. Vrieze 《Journal of organometallic chemistry》1976,108(2):271-280
The preparation and properties are described of trans-[(Ph3P)2(CO)M(RNSNR)] [ClO4] (M RhI, IrI; R Me, Et, i-Pr, t-Bu) and of cis- or trans-[L2Pt(RNSNR)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
6.
Terminally unsaturated dimers and co-dimers of vinyl monomers having the general formula CH2CCCR were synthesized, where X = Y or X ≠ Y, X and Y being COO R or CN groups, RCH3 or H. NMR and base catalyzed isomerization of the 1-olefins prepared is discussed. 相似文献
7.
The structural parameters of the completely relaxed 4–21G ab initio geometries of more than 30 basic organic compounds are compared to experimental results. Some ranges for systematic empirical corrections, which relate 4–21G bond distances to experimental parameters, are associated with total energy increments. In general, for the currently feasible comparisons, the following corrections can be given which relate calculated distances to experimental rg parameters and calculated angles to rs-structures For CC single bond distances, deviations between calculated and observed parameters (rg) are in the ranges of ?0.006(2) to ?0.010(2) Å for normal or unstrained hydrocarbons; ?0.011(3) to ?0.016(3) Å for cyclobutane type compounds; and +0.001(5) to +0.004(4) Å for CH3 conjugated with CO. For CO single bonds the ranges are ?0.006(9) to +0.002(3) Å for CO conjugated with CO; and ?0.019(3) to ?0.027(9) Å for aliphatic and ether compounds. A very large and exceptional discrepancy exists for the highly strained ethylene oxide, rs — re = ?0.049(5) Å and in CH3OCH3 and C2H5OCH3 the rs — re differences are ?0.029(5), ?0.040(10) and ?0.025(10) Å. Some of these discrepancies may also be due to deficiencies of the microwave substitution method caused by atomic coordinates close to inertial planes. For CN bonds, two types of NCH3 corrections are from +0.005(6) to ?0.006(6) and from ?0.009(2) to ?0.014(6) Å; and the range for NCO is +0.012(3) to +0.028(4) Å. For isolated CC double bonds the range is + 0.025(2) to +0.028(2) Å. For conjugated CC double bonds the correction is less positive (+0.014(1) Å for benzene). For CO double bonds the corrections are ?0.004(3) to +0.003(3) Å. For bond angles of type HCH, CCH, CCC, CCO, CCO, OCO, NCO and CCC the corrections are of the order of magnitude about 1–2° (or better). Angles centered at heteroatoms are less accurate than that, when hydrogen atoms are involved. Differences in HOC and NHC angles were found in a range of ?2.3(5)° to ?6.2(4)°. 相似文献
8.
《Journal of organometallic chemistry》1987,323(3):371-384
The reactions of mononuclear carbene complexes of W and Fe of the type CO)mMC(OR)(CH2nCHCR′″ (M = FE, W; m = 4 and 5; n = 0, 2, 3; R′, R″ = C, CH3, OEt) with Fe(CO)5 have been studied. In all cases the reaction leads to new hetero (WFe) or homo (FeFe) μ-alkylidene complexes, the position of the double bond depending strongly on n. 相似文献
9.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1986,42(4):411-425
The complete assignment of the vibrational spectra of 2,5-dimethyl-2,4-hexadiene, 4-methyl-1,3-pentadiene and (E)-2-methyl-1,3-pentadiene was obtained from a comparative analysis of their i.r. and Raman spectra (solid, liquid and gas) in the range 3200-50 cm−1. It is shown that particular vibrational motions strongly interact to give rise to very characteristic modes depending on the site of methyl substitution. The comparison of our results with those of analogous shorter and larger polyenes and polyenals allows us to discuss the various local coupled motions characteristic of unsubstituted (CHCH CH)CH and methyl substituted (CHC(CH3)CH), ((CH3)2CCH) or (CH3CHCH) fragments in polyenic chains. 相似文献
10.
Renzo Ross Rino A. Michelin Raymond Bataillard Raymond Roulet 《Journal of organometallic chemistry》1978,161(1):75-90
Reactions of the PtH and/or PtC bonds of the hydridocyanoalkyl complexes cis- or trans-PtH[(CH2)nCN]L2 (n = 1, 3; L2 = 2 PPh3, Ph2PCHCHPPh2) are described, viz. reductive elimination induced by CO, PhCCPh, PEt3, PPhMe2, cis-Ph2PCHCHPPh2 to give Pt(CO)2L2, PtL2(PhCCPh), PtL2, PtL(PPhMe2)3, PtL2(Ph2PCHCHPPh2) (L = PPh3), respectively, and cleavages by acids, halogens and alkyl halides.The monomeric hydroxo complexes cis-Pt(OH)[(CH2)nCN]L2 were shown to be intermediates in the synthesis of PtH[(CH2)nCN]L2 from cationic cyanoalkyl complexes in alcoholic NaOH. Their characterisation and the reactions of the PtOH bond with activated methyl groups are reported. 相似文献
11.
M.J. Cooper A.K. Holliday P.H. Makin R.J. Puddephatt P.J. Smith 《Journal of organometallic chemistry》1974,65(3):377-382
207Pb chemical shifts are reported for the compounds (CH3)4?nPb Xn, where n = 1 · 4, X = 4-FC6H4; n = 1, 2, 4, X = CH3 CC; n = 1, 4, X = CH2CH; n = 1, X = Cl, CH3O, CH3CO2. A correlation between δ(207Pb) and δ(19F) for the 4-fluorophenyl derivatives is discussed, and solvent effects on δ(207Pb) for the propynyl derivatives are interpreted in terms of complex formation. 相似文献
12.
C.T. Mortimer M.P. Wilkinson R.J. Puddephatt 《Journal of organometallic chemistry》1975,102(4):C43-C45
The enthalpy of the reaction: Pt(PPh3)2(CH2CH2)(cryst.) + CS2(g) → Pt(PPh3)2(CS2)(cryst.) + CH2CH2(g) has been determined as ΔH = ? 4.40 ± 2.2 kJ mol?1 from solution calorimetry, and the bond dissociation energy D(PtCS2) shown to be slightly greater than D(PtC2H4). 相似文献
13.
Nigel J. Kermode Michael F. Lappert Brian W. Skelton Allan H. White John Holton 《Journal of organometallic chemistry》1982,228(3):C71-C75
The reaction of [Pt(PEt3)3] with CH2I2 affords trans-[Pt(CH2PEt3)I(PEt3)2]I and is believed to proceed via the α-functionalised alkyl cis-[Pt(CH2I)I(PEt3)2], because similar ylides are obtained from cis- or trans-[PT(CH2X)(PPh3)2X] (XCl, Br, or I) with PR3 (PEt3, PBu3n, PMePh2, PEtPh2, or PPh3); cis-[Pd(CH2I)-I(PPh3)2] does not react with excess PPh3, but with PEt3 yields trans-[Pd(CH2PEt3)I(PPh3)2]I; the X-ray structure of trans-[Pt(CH2PEt3)I(PEt3)2]I (current R = 0.045) shows PtP(1) 2.332(7), PtP(2) 2.341(8), PtC 2.08(2), and PtI 2.666(2) Å, and angles (a) C(1)PtI, P(1), P(2): 176.9(8), 91.6(6), 93.4(6), (b) IPtP(1), P(2): 87.1(2), 88.5(2), and (c) P(1)P(2), 166.8(3), and (d) PtC(1)P(3), 118(1)°. 相似文献
14.
《Polyhedron》1988,7(18):1785-1788
Molecular oxygen reacts rapidly with Co2Cl4-x,(eHTP)x+ [x = 0 or 2; eHTP = (Et2PCH2CH2)2PCH2P(CH2CH2PEt2)2] in dry acetonitrile to produce in approximately 66% yield the fully-oxygenated phosphine oxide eHTP (eHTPO) Co(II) complex [Co(eHTPO)2+][CoCl42−. The X-ray structure on this novel system shows an extended chain system in which the monomeric repeating unit has an octahedral Co(II) centre. The eHTPO ligand is adopting an unusual conformation with the phosphine oxide groups P(2)P(1)P(3) (P(1) is one of the internal phosphorus atoms) forming a P(1)P(2) chelate to the metal atom while P(3) bridges to another Co(eHTPO)2+ monomer unit making up the extended chain, instead of acting as an independent bis chelating group. The third unique coordination site on the cobalt centre is occupied by a phosphine oxide group from the other half of the eHTPO ligand which bridges over to the cobalt centre forming a facial set of three PO donor ligands. This mixed bridging/chelating conformation gives rise to fused seven- and nine-membered ring systems with a CoCo separation of 7.613(0) Å between symmetry related cobalt sites on the extended chain. This structure is the first reported for a Co(R3PO)6n+ (R = alkyl, phenyl) system. 相似文献
15.
The enthalpy of the reaction: Pt(PPh3)2 (CH2CH2)(cryst.) + C(CN)2C(CN)2 (g) → Pt(PPh3)2 {C(CN)2C(CN)2}(cryst.) + CH2 CH2 (g) has been determined as ΔH298=?155.8±8.0 kJ·mol?1, from solution calorimetry. The interpretation, that the platinumethylene bond is much weaker than the platinumtetracyanoethylene bond, is contrary to conclusions drawn recently from electron emission spectroscopic studies, but in agreement with available structural data. 相似文献
16.
Microwave studies (26.5–40 GHz) of further isotopic species of selenoketene formed by pyrolysis of 1,2,3-selenodiazole (12CH212C76,77,82Se, 12CH213C80Se and 13CH212C80Se) and by pyrolysis of 5-deuterio-1,2,3-selenodiazole (12CHD12C78,80Se) are reported. In conjunction with earlier results for 12CH12C78,80Se an rs structure has been derived with distances SeC (1.706 Å), CC (1.303 Å), CH (1.0908 A) and a HCH bond angle of 119.7°. The geometry of the CH2C moiety of selenoketene is closer to allene, CH2CCH2, than to ketene, CH2CO. 相似文献
17.
Triallyl- and diallyltin carboxylates [(CH2CHCH2)3SnOOCR′ with R′ = CH3 and CH2Cl, (CH2CHCH2)2Sn(OOCR′)2 with R′ = CH2Cl and CHCl2)] and tetraallyl-1,3-diacyloxydistannoxanes {[(CH2CHCH2)2SnOOCR′]2 with R′ = CH2Cl,CHCl2 and CCl3}, have been prepared from the reaction of tetraallytin with carboxylic acids in methanol. 相似文献
18.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1991,47(11):1619-1626
Methylfluorocarbonyl disulphide, FC(O)SSCH3, was prepared for the first time by reaction of FC(O)SCl with CH3SH at room temperature. Infrared data for the vapour and matrices (Ar, Ne and N2) as well as Raman, UV, mass and 19F, 13C and 1H NMR spectra have been obtained and interpreted.From these data, the most stable conformer was deduced to have the gauche conformation with respect to the FC(O) and CH3 groups with the syn conformation between the CO and SS bonds having C1 molecular symmetry. This conformer is in equilibrium with another, possibly the corresponding anti, referring to the CO and SS bonds.The main structure found for FC(O)S-containing compounds seems to be the syn conformation. 相似文献
19.
Novel η1-vinyl complexes of the type Cp(CO)(L)FeC(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)FeC(O)R (R = Me, Et, i-Pr) with MeOSO2F and subsequent deprotonation of the resulting carbene complexes [Cp(CO)(L)FeC(OMe)R]SO3F with the phosphorus ylide Me3PCH2. The same procedure can be applied for the synthesis of the pentamethylcyclopentadienyl derivative C5Me5(CO)(Me3P)FeC(OMe)CH2, while treatment of the hydroxy or siloxy carbene complexes [Cp(CO)(L)FeC(OR)Me]X (R = H, Me3Si; X = SO3CF3) with Me3CH2 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
20.
《Supramolecular Science》1998,5(5-6):479-483
The electrochemical and spectroelectrochemical behaviors of three ferrocene derivatives, (1) (C18H37)2NC6H4CHCHFcCH2OH, (2) (C18H37)2NC6H4CHCHFcCHO, (3) (C18H37)2NC6H4CHCHFcCHC(CN)2, were studied and analyzed on basis of frontier orbital interactions. It was shown that all the three derivatives show two oxidation steps. The first oxidized states of 1 and 2 are stable and show strong LMCT (ligand-to-metal charge transfer) bands. This suggests that they may serve as redox switching of optical properties. In contrast, the first oxidized state of 3 becomes unstable due to strong electron-withdrawing effect of the acceptor substitute. 相似文献