共查询到20条相似文献,搜索用时 439 毫秒
1.
Frank Herwig Köhler Hans Jürgen Kalder Ernst Otto Fischer 《Journal of organometallic chemistry》1976,113(1):11-22
The nuclear spin coupling constants1J(183W13C) and in some cases 2J(183W13C) and 3J(183W13C) are determined for 10 tungsten carbene and 9 tungsten carbyne complexes. 1J is of analytical importance, being characteristically greater for WC than for WC bonds. This is due to different hybridisation at the carbon atom, and provides information about bond angles and polarities of WC and WCR units.Substituents R and R' in (CO)5WCRR' and X(CO)4WCR as well as the halogens X lead to minor changes in 1J. These changes are comparable to those of 1J(13C1H) in correspondingly substituted methanes. Unexpectedly 1J in_ creases with X = Cl, Br, I. 2J(183W13C) though being much smaller than 1J reflects different hydridisation at the β carbon atom. 相似文献
2.
R. Usón L.A. Oro D. Carmona M.A. Esteruelas C. Foces-Foces F.H. Cano S. García-Blanco A.Vázquez De Miguel 《Journal of organometallic chemistry》1984,273(1):111-128
A new series of cationic areneiridium(I) complexes of formula [Ir(barrelene)(arene)]+ or [Ir(barrelene)(PhNRPh)]+ (R= Ph or H) have been synthesized from neutral iridium complexes of the type [IrY(barrelene)]x (barrelene = Me3TFB, Y = Cl or OMe (x = 2), Y = acac (x = 1); barrelene = TFB, Y = OMe (x = 2), Y = acac (x = 1)). The crystal structures of [Ir(Me3TFB)(1,4-C6H4Me2)]ClO4 and [Ir(TFB)(PhNPh2)]BF4·CH2Cl2 have been determined by X-ray diffraction. They crystallize in the space groups Pbca and Pna21 respectively with lattice constants of 17.6947(11), 15.8072(10), 16.0019(11) Å and 9.8059(2), 20.8097(9), 14.3367(4) Å. Final R factors were 0.063 and 0.042 for the observed data. Both complexes show a staggered arrangement between the arene and the TFB moieties and deviation from planarity of the coordinated arene ligands. In the second complex the IrC and NC distances, the CNC angle, the type of arene puckering, and the spectroscopic data indicate a distortion of the coordinated arene towards a η5-coordinated iminocyclohexadienyl form. 相似文献
3.
The reaction between acrylonitrile and the RuH bond in HRu(CO)Cl(PPh3)3 results in the formation of a binuclear ruthenium(II) complex having chlorine bridges which are easily broken by sodio-derivatives of bidentate chelating ligands giving mononuclear hexacoordinated ruthenium(II) compounds. The RuC bond in these new complexes has been found to be stable towards nucleophilic reagents. The stereochemistry for these complexes has been suggested on the basis of IR, 1H and 31P NMR spectra. 相似文献
4.
The complexes (η5-C5H5)Fe(CO)2(η1-acenaphthenyl) (I), (η5-C5H5)Fe(CO)2 (η1-trans-β-deuterioacenaphthenyl) (II), and (η-C5D5)Fe(CO)2, (η1-acenaphthenyl) (XIII) have been prepared and their thermal decomposition studied in vacuo and in refluxing toluene. All three complexes decompose to produce mixtures of acenaphthene (VII), acenaphthylene (VIII), and [C5H5Fe(CO)2]2 (VI). Biacenaphthenyl (IX) is also obtained from the thermolysis of I in toluene. The formation of alkene VIII, and, to a lesser extent, alkane VII is suppressed by external CO. Thermolysis of I in toluene-d8 and of II in vacuo and in toluene produces deuterium-enriched VII. The acenaphthene generated from the decomposition of XIII also contains deuterium. The above observations are accomodated by a mechanistic scheme involving competing β-elimination, ironcarbon bond homolysis to produce the acenaphthenyl radical, and CpH abstraction by an undetermined pathway. 相似文献
5.
Summary The 4-hydroxyphenylthiocarboxyhydrazide (Hoth) ligand has been characterized by i.r.,1H and13C spectral studies. Its metal complexes with FeII, CoII,III, NiII, CuII and ZnII have been prepared and characterized on the basis of elemental analyses, molar conductance, magnetic susceptibility. Mössbauer, visible, e.s.r., i.r.,1H and13C n.m.r. spectral studies. The bonding and stereochemistry of the complexes are discussed. Hoth and its CuII complexes have been screened towards bacteria, viruses and fungi. 相似文献
6.
The complexes of trans-[Co(III)(R,CH3-dioxH)2(py)2]I2 (R = CH3, C2H5, n-C3H7 and n-C4H9) were investigated in solution by 1H and 13C NMR spectra and 13C spin-lattice relaxation time measurements. The 1H and 13C-resonances of the R = C2H5, n-C3H7 and n-C4H9) groups were shifted to higher field than those of the free ligands by the complexation; it was attributable to the ring current shielding due to the axial pyridine ligands of the complexes. 13C spin-lattice relaxation times were interpreted as due to movement of the axial pyridine ligands as if they twist around the CoN (pyridine nitrogen) bond axis and the above R groups were moving segmentally. These segmental movements allowed the R groups to approach closely toward the axial pyridine ring plane to experience the ring current shielding. 相似文献
7.
Michael Arthurs Haroon Karodia Mark Sedgwick D.Antony Morton-Blake Christine J. Cardin Hans Parge 《Journal of organometallic chemistry》1985,291(2):231-251
A 1H NMR study of monosubstituted η-cyclopentadienyl-rhodium(I) complexes of type LLRh(C5H4X) and -iridium(I) complexes of type L2Ir(C5H4X) (L = ethene, LL = 1,3- or 1,5-diolefin; X = C(C6H5)3, CHO, or COOCH3) has been carried out. For complexes of both metals in which the neutral ligand is ethene or a non-conjugated diolefin the NMR spectra of the cyclopentadienyl protons are unusual in that H(2), H(5) resonate to high field either at room temperature or below.The corresponding NMR spectra for the cyclopentadienyl ring protons of complexes where the neutral ligand is a conjugated diene are, with one exception, normal.A single crystal X-ray structural analysis of (η4-2,4-dimethylpenta-1,4-diene)(η5-formylcyclopentadienyl)rhodium(I) (which exhibits an abnormal 1H NMR spectrum) reveals substantial localisation of electron density in the C(3)C(4) Cp ring bond (1.283(33) Å) which may be consistent with a contribution from an ‘allyl-ene’ rotamer to the ring—metal bonding scheme. An extended Hückel calculation with self consistent charge iteration was performed on this complex.The results predict a greater Mulliken overlap population for the C(3)C(4) bond in the cyclopentadienyl ring and show that the localisation is dependent on both the Cp ring substituent and the nature of the diolefin. The mass spectral fragmentation patterns of some representative diene complexes of iridium(I) and rhodium(I) are presented. 相似文献
8.
The diastereomers of the complexes η3-allyl-cis- and -trans-2,3-diphenyl-1,3-oxaphosphorian—palladium chloride formed from chiral phosphines can be detected in the NMR spectra (1H, 31P) below 300 K). The cross-peaks of the 2D-1H-NOE-NMR spectra display a transformation of diastereomers through conversion into the σ-allyl form together with rotation both around the CPd-axis and the CC-axis of the σ-allyl group. 相似文献
9.
Kunio Miki Masahiro Yama Yasushi Kai Nobutami Kasai 《Journal of organometallic chemistry》1982,239(2):417-428
The molecular structure of a three-coordinate palladium(II)-styrene complex, [Pd(η5-C5H5)(PEt3)(styrene)]BF4 has been determined by means of X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c, with four formula units in a cell of dimensions: a 10.229(3), b 11.262(3), c 18.760(5) Å and β 103.77(2)°. The structure was solved by the heavy atom method, and refined by the least-squares procedure to R = 0.050 for 3635 observed reflections. The palladium atom is surrounded by the cyclopentadienyl group, the triethylphosphine ligand and the olefinic bond of styrene in the cationic complex. In the palladiumstyrene bonding, the olefinic bond is inclined by 77.3° to the coordination plane defined by the Pd and P atoms and the center of the cyclopentadienyl ring (PdC(1) 2.176(6), PdC(2) 2.234(5) and C(1)C(2) 1.369(8) Å). 相似文献
10.
Martin Minelli J.H. Enemark Andrew Bell Richard A. Walton 《Journal of organometallic chemistry》1985,284(1):25-34
The 95Mo NMR spectra of a series of seven-coordinate molybdenum(II) isocyanide complexes of the types [Mo(CNR)7-nLn](PF6)2 (R = CH3, CHMe2, CMe3, C6H11, CH2Ph; L = py, bpy, Me2bpy, phen, dppe, P-n-Bu3; n = 0,1,2) [Mo(CNC-Me3)6X]PF6 (X = Cl, Br, I) and [{Mo(CNCMe3)4(NN)}2(μ-CN)](PF6)3 (NN = bpy, Me2bpy, phen) have been studied. The 95Mo chemical shift range for this group of complexes is about 1100 ppm. An increase in the size of the R group attached to the isocyanide ligand generally tends to shield the 95Mo nucleus. Replacement of the isocyanide ligand with a phosphorus ligand also increases the shielding, whereas the replacement of isocyanide with a heterocyclic nitrogen donor leads to deshielding by 800–900 ppm. This group of complexes shows a normal halogen dependence, i.e. replacement of Cl? by Br? and I? increases the shielding of the 95Mo nucleus. The cyano-bridged cations [{Mo(CNCMe3)4(NN)}2(μ-CN)]3+ (NN = bpy, Me2bpy, or phen) show two 95Mo NMR signals, one for the molybdenum coordinated to the carbon of the bridging CN and one for the N-coordinated molybdenum. Comparison of the chemical shifts and linewidths of the cyano-bridged species with those of the corresponding mononuclear molybdenum(II) complexes [Mo(CNCMe3)5(NN)](PF6)2 leads to the assignment of the more deshielded signal to the N-coordinated molybdenum. The 14N and 31P NMR spectra for these complexes have also been measured, as have the 13C NMR spectra of the pairs of complexes [Mo(CNCMe3)5(NN)](PF6)2 and [{Mo(CNCMe3)4(NN)}2(μ-CN)](PF6)3 (NN = bpy or phen). The 183W NMR spectra for [W(CNR)5(bpy)](PF6)2 (R = CMe3 and CH2Ph), show that the δ(183W)/δ(95Mo) chemical shift ratios for isocyanide complexes are different from the ratio found for M0 and MVI. 相似文献
11.
The 13P and 13C spectra of the triply 13C labelled molecules (CH3)3P, (CH3)3PO, (CH3)3PS and (CH3)3PSe oriented in a nematic phase are reported. The CPC bond angles have been measured. The 13P chemical shift tensor shows a large anisotropy except in the case of (CH3)3P. The abnormal large value observed for the PSe bond length suggests a large anisotropy of the 1J(PSe) spin coupling. 相似文献
12.
Alberto Albinati Urs Von Gunten Paul S. Pregosin Hubert J. Ruegg 《Journal of organometallic chemistry》1985,295(2):239-256
195Pt, 119Sn and 31P NMR characteristics of the complexes trans-[Pt(SnCl3)(carbon ligand)(PEt3)2] (1a-1e) are reported, (carbon ligand = CH3 (1a), CH2Ph (1b), COPh (1c), C6Cl5 (1d), C6Cl4Y (e); Y = meta- and para-NO2, CF3, Br, H, CH3, OCH3, or Pt(SnCl3)(PEt3)2. The values of 1J(195Pt, 119Sn) vary from 2376 to 11895 Hz with the COPh ligand having the smallest and the C6Cl5 ligand the largest value, making a total range for this coupling constant, when the dimer syn-trans-[PtCl(SnCl3)(PEt3)]2 is included, of ca. 33000 Hz. In the meta- and para-substituted phenyl complexes 1J(195Pt, 119Sn) (a) is greater for electron-withdrawing substituents, (b) varies more for the meta-substituted derivatives (5634 to 7906 Hz) than for the para analogues (6088 to 7644 Hz) and (c) has the lowest values when the Pt(SnCl3)(PEt3)2 group is the meta- or para-substituent. The direction of the change in 1J(195Pt, 119Sn) is opposite to that found for 1J(195Pt, 119P). For the aryl complexes linear correlations are observed between δ(119Sn), 1J(195Pt, 119Sn), 1J(195Pt, 31P), 1J(119Sn, 31P) and the Hammett substituent constant σn. δ(119Sn) and 1J(195Pt, 119Sn) are related linearly to v(Pt-H) in the complexes trans-[PtH(C6H4Y)(PEt3)2]; δ(119Sn) and δ(1H) (hydride) are also linearly related. Based on 1J(195Pt, 119Sn), the acyl ligand is suggested to have a very large NMR trans influence. The differences in the NMR parameters for (1a-e) are rationalized in terms of differing σ- and π-bonding abilities of the carbon ligands.The structure of 1c has been determined by crystallographic methods. The complex has a slightly distorted square planar geometry with trans-PEt3 ligands. Relevant bond lengths (Å) and bond angles (°) are: PtSn, 2.634(1), PtP, 2.324(4) and 2.329(4), PtC, 2.05(1); PPtP, 170.7(6), SnPtC, 173.0(3), SnPtP, 92.1(1), 91.7(1), PPtC, 88.8(4) and 88.3(4). The PtSn bond separation is the longest yet observed for square-planar platinum trichlorostannate complexes, and would be consistent with a large crystallographic trans influence of the benzoyl ligand. The PtSn bond separation is shown to correlate with 1J(195Pt, 119Sn). 相似文献
13.
Bernhard E. Reichert 《Journal of organometallic chemistry》1974,72(2):305-308
The 13C NMR spectra of some methylplatinum(IV) Schiff-base and related complexes have been recorded. The results are interpreted in terms of the differing effects of various donor atoms on a platinumcarbon bond in the trans position. 相似文献
14.
《Polyhedron》1988,7(9):695-703
The copper(II) and zinc(II) complexes of Schiff base ligands L1 and L2 derived from the condensation of 2,6-diacetylpyridine with 2 mol of phenylalanine methyl ester or tyrosine ethyl ester have been prepared. The IR spectral data indicate that the ester group undergoes hydrolysis in the formation of the Zn(II) complexes more readily than that of the Cu(II). The 1H and 13C NMR spectra of the Zn(II) complexes of L1 and L2 as well as those derived from condensation of 2,6-diacetylpyridine and histidine methyl ester (L3), histamine (L4) and 2-(2-aminoethyl)-pyridine (L5) were examined. Differences in IR spectral properties as well as in chemical shifts of similar 1H and 13C nuclei in these five types of complexes have been attributed to significant Zn(II)-carboxylate oxygen interactions in complexes of L1 and L2. 相似文献
15.
Victor M. Ishchenko Boris M. Bulychev Grigori L. soloveichik Vitali K. Belsky Olga G. Ellert 《Polyhedron》1984,3(7):771-774
The reduction of copper (II) chloride by molybdenum and rhenium biscyclopentadienyl hydrides upon their interaction in donor-type solvents has been studied by NMR, X-ray diffraction, and magnetic methods. It is established that the ionic complex [(η5-C5H5)2Re]+[CuCl2]? forms ortho rhombic crystals with a - 13.696(2) Å, b = 7.317(1) Å, c = 5.969(1) Å, space group Pm21n, Z = 2. The cyclopentadienyl rings make a bent-sandwich with an angle between the ring centres and Re atom of 150.1°; the ClCuCl angle being 174.8° and the ReCu minimum distance 4.346(29) Å. The solution of [(η5-C5H5)2Re]+ [CuCl2]? seems to activate the CH bond of the C5H5 rings, which results in the addition of the [(C5H5)(C5H4)ReH]+ hydride ion. 相似文献
16.
The crystal and molecular structure of η5-cyclopentadienyliodomethyl(methylthio)carbene(triphenylphosphine)iridium(III) iodide [IrI{C(Me)SMe}(η5-C5H5)(PPh3)]I has been determined from three dimensional X-ray data in order to clarify the contribution of the α-sulphur atom to the bonding in this carbenoid complex.The compound crystallizes in space group Pbc21 with four formula units in a cell of dimensions a 9.745(6), b 15.201(8), and c 17.364(10) Å. Least-squares refinement of the structure has led to the final discrepancy index R = 0.047 for the 1655 symmetry-independent observable reflections. The coordination geometry about the iridium atom is approximately tetrahedral; the coordination positions are occupied by the η5-C5H5 ring center, the phosphorus, the iodide I(1) and the carbon C(6) of the C(Me)SMe ligand (IrRc 1.89, IrP 2.280(7), Ir(1) 2.651(2) and IrC(6) 2.03(3) Å).The bonding of the C(Me)SMe group indicates that this complex must be formulated as a C(Me)SMe complex of iridium(III). 相似文献
17.
Preparation of trans-[Pcb2MCl2]-type complexes (Pcb= o-HCB10H10CCH2PPh2 M = Pd, Pt), which readily undergo intramolecular metallation through the BH bonds of the carborane cage to form exocyclic compounds involving a bond system, is described. Both monomeric compounds, trans-[MCl(B-P)Pcb], and bridged complexes, such as [Pd2Cl2(BP)2], are formed, where (BP) is intramolecular-metallated carborane phosphine. The bridging bond is readily cleaved under the action of various ligands (pyridine, PEt3, etc.) to form monomeric compounds. 相似文献
18.
Anthony Fratiello Vicki Kubo-Anderson Deborah J. Lee Tai Mao Kwok Ng Scott Nickolaisen Richard D. Perrigan Victor San Lucas Wayne Tikkanen Annie Wong Kenneth Wong 《Journal of solution chemistry》1998,27(4):331-359
A study of zinc(II) and cadmium(II) complexes with isothiocyanate ion has been completed, using a low-temperature, multinuclear magnetic resonance technique that permits the observation of separate resonance signals for bound and free ligand, and Cd(II) metal ion. The Zn2+–NCS– complexes were studied by 1H, 13C, and 15N NMR spectroscopy. In the 1H spectra, the intensity of the coordinated water signal, corresponding to a Zn(II) hydration number of six in the absence of NCS–, decreases dramatically as this anion is added, indicating the complexing process involves more than a simple 1:1 ligand replacement. The 13C and 15N NMR spectra reveal signals for four species, most reasonably assigned to a series of tetrahedrally coordinated Zn2+–NCS– complexes. In the Cd2+–NCS– solution spectra, the 13C and 15N signals for four complexes also are observed and they are three line patterns, corresponding to a doublet from 113Cd J-coupling, and a dominant central peak, resulting from bonding to magnetically inactive Cd isotopes. The 113Cd spectra, showing signals for four complexes, correlate well in all respects with the 13C and 15N results, including coupling in specific cases. The spectral results for both metal ions reflect binding at the nitrogen atom of NCS–, with the complexes changing from an octahedral to a tetrahedral configuration when doing so. Confirming evidence for these conclusions also was provided by several infrared measurements of these metal–ion systems. 相似文献
19.
Shakir M Abbasi A Azam M Khan AU 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1866-1875
The Schiff base ligand, N,N'-bis-(2-thiophenecarboxaldimine)-3,3'-diaminobenzidine (L) obtained from condensation of 2-thiophenecarboxaldehyde and 3,3'-diaminobenzidine, was used to synthesize the complexes of type, [M2L2]Cl4 [M=Co(II), Ni(II), Cu(II), Cd(II) and Hg(II)]. The newly synthesized ligand (L) was characterized on the basis of the results of elemental analysis, FT-IR, 1H NMR, 13C NMR, mass spectroscopic studies and single crystal X-ray crystallography. The characteristic resonance signals in 1H NMR and 13C NMR spectra indicated the presence of azomethine group as a result of condensation reaction. The stoichiometry, bonding and stereochemistries of complexes were ascertained on the basis of results of elemental analysis, magnetic susceptibility measurements, molar conductance and spectroscopic studies viz., FT-IR, 1H and 13C NMR, UV-vis and EPR. EPR, UV-vis and magnetic moment data revealed an octahedral geometry for complexes with distortion in Cu(II) complex and conductivity data show 1:2 electrolytic nature of complexes. Absoption and fluorescence spectroscopic studies supported that Schiff base ligand L and its Co(II), Ni(II) and Cu(II) complexes exhibited significant binding to calf thymus DNA. The complexes exhibited higher affinity to calf thymus DNA than the free Schiff base ligand L. 相似文献
20.
The relationship between one-bond 13C-1H coupling constants and internuclear CCC bond angles (n) in hydrocarbons of the type R2CH2 is best approximated by a quadratic expression. 相似文献