共查询到20条相似文献,搜索用时 15 毫秒
1.
The singlet-triplet separations for the edge-sharing bioctahedral (ESBO) complex W 2(μ-H)(μ-Cl)(Cl 4(μ-dppm) 2 · (THF) 3 (II) has been studied by 31P NMR spectroscopy. The structural characterization of [W 2(μ-H) 2(μ-O 2CC 6H 5) 2Cl 2(P(C 6H 5) 3) 2] (I) by single-crystal X-ray crystallography has allowed the comparison of the energy of the HOMOLUMO separation determined using the Fenske-Hall method for a series of ESBO complexes with two hydride bridging atoms, two chloride bridging atoms and the mixed case with a chloride and hydride bridging atom. The complex representing the mixed case, [W 2(μ-H)(μ-Cl)Cl 4(μ-dppm) 2 · (THF) 3] (II), has been synthesized and the value of −2 J determined from variable-temperature 31P NMR spectroscopy. 相似文献
3.
Asymmetric ditertiary stibine sulfides (C 6H 5)(CH 3)(S)SbCH 2Sb(CH 3)(C 6H 5) and [(C 6H 5)(CH 3)(S)Sb] 2(CH 2) 3 have been prepared. It was found that they exist as only one of two possible diastereomers in the crystalline state. However, isomerization to the other form takes place in solution, resulting in an equilibrium mixture. A possibility of configurational lability of tertiary stibine sulfide was suggested for the first time. 相似文献
4.
Reduction of (C 5H 5) 2TiCl 2 with Zn in presence of benzyl cyanide gives the (μ-alkyl-ideneamido)titanocene complex [(C 5H 5) 2TiCl] 2[μ-{N=C(CH 2C 6H 5)---C(CH 2C 6H 5)=N}] with C---C bond formation between two benzyl cyanide molecules. X-ray structure investigation indicates a symmetrical structure. The C=N distances are smaller than usual, the Ti---N distances are very short, and the Ti---N---C angle differs only a little from 180°, which infers a heteroallene structure of the complex. 相似文献
5.
The reaction between Ru 3(CO) 12 and a cyclic olefin ( cis-cyclooctene or trans-cyclododecene) at 100 °C for several hours gives the title compounds (μ-H) 2RU 3(CO) 9(μ 3-η 2-C 8H 12) (1), and (μ-H)RU 3(CO) 9(μ 3-η 3-C 12H 19) (2), both of which have been characterized by X-ray diffraction studies, IR and NMR spectral measurements and elemental analysis. The prolonged reaction between Ru 3(CO) 12 and cis-cyclooctene gives compound HRu 3(CO) 9(C 8H 11) (3). Compound 3 has been characterized with IR and NMR spectral analyses. In 1 the cyclooctene ring is linked via a μ 3-η 2-alkyne type of bonding to the face of the Ru 3 cluster. It is formally σ-bonded to two of the three Ru atoms and π-bonded to the third Ru. The two hydrides in 1 are bridging Ru---Ru bonds. In 2 the cyclododecene ring is bonded to the Ru 3 face via the μ 3-η 3-CCHC linkage. There are two formal σ-bonds from the allyl part to the hydrido-bridged Ru atoms and the η 3-allyl linkage to the third Ru atom. 相似文献
6.
Structures of non metal-metal bonded phosphido-bridged heterobimetallic complexes, including CpFe(CO) 2(μ-PPh 2)W(CO) 5 (1-W) and metal-metal bonded CpFe(CO)(μ-CO)(μ-PPh 2)W(CO) 4 (2), were determined by a single crystal X-ray diffraction study. In 1-W, the long distance between Fe and W indicates no metal-metal bond to exist. In 2, a Fe---W bond with bond length 2.851 Å and a semibridging carbonyl with W---C---O angle 153° were observed. Mössbauer spectra of 1-W and 2 were taken at 77 K. Isomer shifts of 1-W and 2 were − 0.0203 mm s −1 and 0. 1917 mm s −1 respectively. 相似文献
7.
Isostructural heterotrinuclear complexes (C 5H 5CrSCMe 3) 2S · M(CO) 5 (II–IV) were isolated from photochemical reactions between the antiferromagnetic complex (C 5H 5CrSCMe 3) 2S (I) (with the Cr---Cr bond 2.689 Å long and with the exchange parameter −2 J = 430 cm −1) and metal hexacarbonyls, M(CO) 6, where M is Cr, Mo, or W. According to the X-ray structural data on III and IV, complex I plays the role of an unusual antiferromagnetic ligand L bound to M through the sulphide bridge (M–S 2.58(2) Å). Its geometry remains practically unaffected by the complex formation (the Cr---Cr bond length in III and IV is 2.73(1) Å). The exchange parameter, −2 J (410, 440 and 440 cm −1 in II to IV, respectively), also shifts only insignificantly from that of I, which probably means that indirect exchange via the sulphide bridge in I is of minor importance compared with the direct Cr---Cr exchange. The Cr---Cr bond length may thus be correlated with the observed overall exchange coupling. 相似文献
8.
Treatment of closo-[Ru 4(μ 4-PPh) 2(μ 2-CO)(CO) 10] with acetylene under ambient conditions leads to the insertion of the acetylene into the skeletal framework of the cluster and the formation of [Ru 4(μ 4-PPh){μ 4-η 3-P(Ph)CHCH}(μ 2-CO)(CO) 10], the structure of which has been determined X-ray crystallographically. 相似文献
9.
The crystal and molecular structure of hexaphenylditin selenide (C 6H 5) 3SnSeSn(G 6H 5) 3 was determined by X-ray diffraction data and was refined to R 0.055. The compound is monoclinic, space group P2 1, with a 9.950(4), b 18.650(7), c 18.066(6) Å, β 106.81(4)°, Z 4. The two molecules in the asymmetric unit differ slightly in their conformations, both having approximate C2 symmetry. Bond lengths and angles are: SnSe 2.526 (2.521(3) ? 2.538(3)) Å; SnC 2.138 (2.107(16)?2.168(19)) Å; SnSeSn 103.4(1)°, 105.2(1)°. There are only slight angular distortions at the SnSeC 3 tetrahedra (SeSnC angles: 104.3(5)?114.8(4)°). The bond data indicate essentially single bonds around the Sn atoms. 相似文献
10.
IntroductionSince K pf[1]discovered that dicyclopenta die-nyltitanium dichloride possesses antitumour action in1979,a large number of cyclopentadienyltitanium com-plexes with different substituents have been synthe-sized[2,3].The experimental data reveal … 相似文献
11.
The thermal decomposition of the complexes trans-[Pt(X)(CH 3)L 2] (L P(C 2H 5) 3; X Cl, Br, I, CN) in decalin at 170 and 200°C affords methane platinum metal and [Pt(X) 2L 2]. The kinetics of the decomposition of the complexes were determined by monitoring the appearance of methane by GLC. The observed first-order rate constant was found to be independent on the nature of the ligand X. The thermal decomposition of the trideuteriomethyl complexes [Pt(X)(CD 3)L 2] (X I, CN) in decalin- d18 at 170 and 200°C was studied by GLC/MS. The thermolysis affords CD 3H and CD 4 in ratios which are independent of the nature of X and of the temperature used. The mass spectra of the complexes were also examined. A relative scale of platinum-to-methyl bond dissociation energies has been established by measuring the appearance potential of the fragment ion [Pt(X)L 2] + and the ionization energies in the series [Pt(X)(CH 3)L 2]. Ionization potentials and PtCH 3 bond energies show a clear dependence on the nature of X which is not reflected in corresponding changes in the decomposition rates. 相似文献
12.
The title complex Mn 2(CO) 6(μ-H){μ-S(SC 3H 5)C=C(PP r3i)S} was synthesized by allyation of the homobinuclear anion [Mn 2(CO) 6(μ-H){μ-S(SC 3H 5)C=C(PP r3i)S}] −1, and characterized by elemental analysis, IR, 1H NMR and 31P NMR spectra. The molecular structure shows that it contains a novel fairly planar ligand S(S)C=C(PPr 3i)S, and the two Mn(CO) 3 fragments are symmetrically placed at both sides of the plane of the ligand. 相似文献
13.
en Two differnt crystal modifications of hexaphenyldigermanium sulfide (C 6H 5GeSGe(C 6H 5) 3 (I and II were obtained by crystallization from hot benzene/methanol or form ethanol at 20°C. Single crystal X-ray structural analyses for both I (low temperature data at ?130°C) and II (at 20°C) (I, R = 0.046; II, R = 0.048) were performed. I is monoclinic, P2 1/c, with a = 11.020(3), b = 15.473(3), c 18.606(3) »,π = 106.92(2)°, Z = 4; II is orthorhombic, P2 12 12 1, with a = 2.617(2), b = 17.345(3), c = 18.408(3) », Z = 4.The molecules have different conformeric structures with respect to a rotation of the (C 6H 6) 3Ge groups around the Ge bonds with very similar bond lenghts and angles. Bond data for I(II) are: GeS 2.212(1) and 2.261(1) » (2.227(2) and 2.240(2) »); GeC 1.933(4) ? 1.971(4), mean 1.945(5) » (1.931(7)?1.954(7), mean 1.943(4) »); GeSGe 111.2(1)° (110.7(1)°). The Ge bond lenghts are comparable to those in thiogermanates and do not indicate significant π-bond contributions. 相似文献
14.
Reaction of the Et 3NH + salts of the [(μ-RS)(μ-CO)Fe 2(CO) 6] − anions (R=Bu t, Ph or PhCH 2) with (μ-S 2)Fe 2(CO) 6 gives reactive intermediates [(μ-RS)(μ-S){Fe 2(CO) 6} 2(μ 4-S)] −. Reactions of the latter with alkyl halides, acid chlorides and Cp(CO) 2FeI have been studied. X-Ray structure of (μ-Bu tS)(μ-PhCH 2S)[Fe 2(CO) 6] 2(μ 4-S) was determined. 相似文献
15.
The energy-localized CNDO/2 molecular orbitais have been calculated for the clusters containing molybdenum, > {Mo 3S 42Mo} 8+ and> Mo 3S 4]CuI> 4+, versus the prototype arene-metal sandwich (C 6H 6) 2Cr and half-sandwich complexes C 6H 6Cr(CO) 3. The bonding characteristics of these compounds are described from a localization bonding viewpoint. There are two typical M-arene and M-[Mo 3S 4] bondings. One is formed by electron donation from the three-center two-electron π-bonds in the arene or [Mo 3S 4] 4+ ligands into the vacant hybrid orbitais of the “stranger” metal atom. In the other M-arene or M-[Mo 3S 4] bond there is very little donation by the lone electron pair occupying the d AOs of the “stranger” metal atom to the arene or [Mo 3S 4] 4+ ligands. The analogy of the ligand [Mo 3S 4] 4+ in the clusters studied with the ligand benzene is also briefly discussed. 相似文献
16.
A new metal-metal bonded binuclear iron system [Me 2SiCH 2CH 2SiMe 2][η 5-C 5H 4Fe(CO) 2] 2 ( 2) has been prepared by treating two equivalents of NaCp with one equivalent of ClSi(Me) 2CH 2CH 2SiClMe 2 obtaining the intermediate (C 5H 5)Si(Me) 2CH 2CH 2Si(Me) 2(C 5H 5) which then is directly allowed to react with Fe(CO) 5 given 2 in 30% yield. From this cyclopentadienyldisilyl linked system three new binuclear irom complexes are formed. Treatment of 2 with Na/Hg in THF produced the dianion [Me 2SiCH 2CH 2SiMe 2][η 5-C 5H 4Fe(CO) 2?] 2 which is quenched with CH 3I giving [Me 2SiCH 2CH 2SiMe 2][η 5-C 4H 4Fe(CO) 2CH 3] 2 ( 4) in 76% yield. Complex 2 is oxidized with 1.2 equivalent of I 2 to give [Me 2SiCH 2CH 2SiMe 2][η 5-C 5H 4Fe(CO) 2I] 2 ( 5) in 85% yield. Photolysis of 5 (1 equiv.) and PPh 3 (3 equiv.) results in the formation of the bis-substituted compound [Me 2SiCH 2CH 2SiMe 2][η 5-C 5H 4Fe(CO)(PPh 3)I] 2 ( 6). These four new binuclear iron complexes are characterized by 1H, 13C, and 31P NMR and IR spectroscopy. 相似文献
17.
The cationic diphenylphosphido-bridged compound [Ru 2(μ-PPh 2)(μ-OH) 2(η 6- p-cymene) 2][PF 6) (2) has been prepared by reaction of the tri-μ-hydroxo complex [Ru 2(μ-OH) 3(η- p-cymene) 2][PF 6] (1) with diphenylphosphine. Complex 2 eliminates water on reaction with protic acids, incorporating the conjugate base of the added acid as a bridging ligand. Formic acid, acetic acid, phenol, and aniline react with 2 to give the monosubstituted compounds [Ru 2(μ-PPh 2)(μ-OH)(μ-L)(η 6- p-cymene) 2]PF 6] (L = HCO 2, MeCO 2, OPh, or NHPH), whereas methanol, thiophenol, 1,2-benzenedithiol, hydrochloric acid and isopropanol afford the disubstituted derivatives [Ru 2(μ-PPh 2)(μ-L) 2(η 6- p-cymene) 2]PF 6] (L = OMe, SPh,
S 2C 6H 4, Cl, or H). 相似文献
18.
Hydrocarbon solutions of PtPCy 3(C 2H 4) 2 (Cy = cyclohexyl) react rapidly with 8-quinolinecarboxaldehyde (1 equiv.) to yield tricyclohexylphosphine quinolinecarboxyl platinum hydride ( 1) and CH 2CH 2 (2 equiv.). Compound 1 reacts with CCl 4 in hydrocarbons to give PtPCy 3(NC 9H 6CO)Cl ( 2) and CHCl 3. The compound PtPCy 3(C 2H 4) 2 also reacts with Ph 2P(C 6H 4- o-CHO) and Ph 2As(C 6H 4- o-CHO) to give PCy 3PtPh 2P(C 6H 4- o-CO)(H) ( 3) and PCy 3PtPh 2As(C 6H 4- o-CO)(H) ( 4), respectively. Compounds 1, 2, 3, and 4 were characterized by infrared and 1H NMR spectra, and the crystal structure of 3 was determined by X-ray diffraction. Crystals of 3 are monoclinic, with space group P2 1/ n and Z = 4 with the unit cell dimensions a 9.7936(17), b 14.844(35), c 23.530(64) Å, β 91.817 (18)°, and V 3419.09(1.36) Å 3. The structure is refined to final discrepancy factors of R = 0.055, and Rw = 0.064. The molecular structure of 3 is that ligating atoms are in a plane containing Pt. The position of the hydride was not located crystallographically, but the 1H NMR spectrum of 3, supports the presence of a terminal hydride that is cis to the carbonyl. The IR band of 3 at 2023 cm ?1 which is assigned to ν(PtH), and the hydride cleavage reaction of 1 with CCl 4, provide evidence for the PtH bond. 相似文献
19.
LnCl 3 (Ln=Nd, Gd) reacts with C 5H 9C 5H 4Na (or K 2C 8H 8) in THF (C 5H 9C 5H 4 = cyclopentylcyclopentadienyl) in the ratio of 1 : to give (C 5H 9C 5H 4)LnCl 2(THF) n (orC 8H 8)LnCl 2(THF) n], which further reacts with K 2C 8H 8 (or C 5H 9C 5H 4Na) in THF to form the litle complexes. If Ln=Nd the complex (C 8H 8)Nd(C 5H 9C 5H 4)(THF) 2 (a) was obtained: when Ln=Gd the 1 : 1 complex [(C 8H 8)Gd(C %H 9)(THF)][(C 8H 8)Gd(C 5H 9H 4)(THF) 2] (b) was obtained in crystalline form. The crystal structure analysis shows that in (C8H8)Ln(C5H9C5H4)(THF)2 (Ln=Nd or Gd), the Cyclopentylcyclopentadieny (η5), cyclooctatetraenyl (η8) and two oxygen atoms from THF are coordinated to Nd3+ (or Gd3+) with coordination number 10. The centroid of the cyclopentadienyl ring (Cp′) in C5H9C5H4 group, cyclooctatetraenyl centroid (COTL) and two oxygens (THF) form a twisted tetrahedron around Nd3+ (or Gd3+). In (C8H8)Gd(C5H9C5H4)(THF), the cyclopentyl-cyclopentadienyl (η5), cyclooctatetraenyl (η8) and one oxygen atom are coordinated to Gd3+ with the coordination number of 9 and Cp′, COT and oxygen atom form a triangular plane around Gd3+, which is almost in the plane (dev. -0.0144 Å). 相似文献
20.
The 31P chemical shift of the (C 6H 5) 3-nPX n ligands (X = Cl, Br, I; n = 0–3) is dominated by the electronegativity of the substituents. π bonding is only important for derivatives with three strongly electronegative substituents. The 31P chemical shift of the corresponding complexes (C 6H 5) 3-nPX nCr(CO) 5 is governed by the simultaneous effects of the electronegativity, steric hindrance and π bonding. The resonance parameter, δ', indicates an increasing ( pring → dp)π and ( dcr→ dp)π electron delocalization with halogen substitution. 相似文献
|