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1.
The photochemical reactions of the title complexes were studied in air-free benzene solution. In both cases photolysis leads to the production of complexes of the formula (η 5-C 5H 5)M(PPh 3) 2. Both reactions are the result of the initial loss of a methyl radical from the excited state. The primary photoproduct, (η 5-C 5H 5)MPPh 3 (M=CO, Ni), then scavenges neutral ligands from the solution to yield, in the case of PPh 3, (η 5-C 5H 5)M(PPh 3) 2. In the absence of uncoordinated ligand in the reaction solution, the cobalt derivative reacts with the starting material to yield (η 5-C 5H 5)Co(PPh 3) 2, a methyl radical and (η 5-C 5H 5)Co(solvent) n. 相似文献
2.
Thermal displacement of coordinated nitriles RCN (R = CH 3, C 2H 5 or n-C 3H 7) in [C 5H 5Fe(L 2)(NCR)]X complexes (L 2 = P(OCH 3) 3) 2, (P(OC 6H 5) 3) 2 or (C 6H 5) 2PC 2H 4P(C 6H 5) 2 (DPPE)) by E(CH 3) 2 affords high yields of [C 5H 5Fe(L 2)(E(CH 3) 2)]X compounds (E = S, Se and Te; X = BF 4 or PF 6). Spectroscopic data and ligand displacement reactions are presented and discussed together with related observations on [C 5H 5Fe(CO) 2(E(CH 3) 2)]BF 4 compounds. The molecular structure of [C 5H 5Fe(P(OCH 3) 3) 2(S(CH 3) 2)]PF 6 was determined by a single-crystal X-ray diffraction study: monoclinic, space group P2 1/ n- C52h (No. 14) with a = 8.4064(12), b = 11.183(2), c = 50.726(8) Å, β = 90.672(13)° and Z = 8 molecules per unit cell. The coordination sphere of the iron atom is pseudo-tetrahedral with an Fe---S bond distance of 2.238 Å. 相似文献
3.
The reactions of the half-sandwich molybdenum(III) complexes CpMo(η 4-C 4H 4R 2)(CH 3) 2, where Cp=η 5-C 5H 5 and R=H or CH 3, with equimolar amounts of B(C 6F 5) 3 have been investigated in toluene. EPR monitoring shows the formation of an addition product which does not readily react with Lewis bases such as ethylene, pyridine, or PMe 3. The analysis of the EPR properties and the X-ray structure of a decomposition product obtained from dichloromethane, [CpMo(η 4-C 4H 6)(μ-Cl)(μ-CH 2)(O)MoCp][CH 3B(C 6F 5) 3], indicate that the borane attack has occurred at the methyl position. 相似文献
4.
The mechanism of the transformation of (η 5-C 5H 5) 2NbCl 2 to (η 5-C 5H 5) 2NbH 3 by hydridoaluminate reducing agents has been investigated. Results suggest disproportionation of a niobium(IV) hydrite, leading to the trihydride product and a niobium(III) hydridoaluminate, (η 5-C 5H 5) 2NbH 2AlR 2, which in turn is converted to the trihydride on hydrolysis. (η 5-C 5H 5) 2NbH 2AlH 2 has been isolated; deuterium labelling shows that hydrogens exchange between ring and metal-bridging positions in this molecule. 相似文献
5.
Mechanisms of RN 3 (R=CH 3, CH 3CH 2, (CH 3) 2CH, (CH 3) 3C) dissociations are proposed based on CAS, MP2 and B3LYP methods. The energy gaps between the ground-state reactants RN 3 and the intersystem crossing (ISC) points are only a little lower than respective potential energy barriers of the spin-allowed reactions, 1RN 3 → 1RN + 1N 2. The ISC point, therefore, is considered as a transition state of the spin-forbidden reactions, 1RN 3 → 3RN + 1N 2. The methods of IRC and topological analysis of electron density are used to explain and predict the thermal dissociation pathways of the reactions studied. 相似文献
6.
Reactions of CpMoIr 3( μ-CO) 3(CO) 8 (1) with stoichiometric amounts of phosphines afford the substitution products CpMoIr 3( μ-CO) 3(CO) 8−x (L) x (L = PPh 3, x = 1 (2), 2 (3); L = PMe 3, x = 1 (4), 2 (5), 3 (6)) in fair to good yields (23–54%); the yields of both 3 and 6 are increased on reacting 1 with excess phosphine. Products 2–5 are fluxional in solution, with the interconverting isomers resolvable at low temperatures. A structural study of one isomer of 2 reveals that the three edges of an MoIr 2 face of the tetrahedral core are spanned by bridging carbonyls, and that the iridium-bound triphenyiphosphine ligates radially and the molybdenum-bound cyclopentadienyl coordinates axially with respect to this Molr 2 face. Information from this crystal structure, 31P NMR data (both solution and solid-state), and results with analogous tungsten—triiridium and tetrairidium clusters have been employed to suggest coordination geometries for the isomeric derivatives. 相似文献
7.
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
8.
An unexpected trimanganese(I) tetrathiolate-bridged complex, [Mn 3(CO) 9(μ-SC 6H 5) 4] −, with an incomplete cubane structure, was obtained by thermal reaction of [Mn 2(CO) 10] with [Mo(η 5-C 5H 5) 2(SC 6H 5) 2]. The structure, established by single-crystal X-ray diffraction studies, shows the cation, [Mo(η 5-C 5H 5) 2(H)CO] +, directed towards the vacant site of the cubane structure. Possible routes by which the anion and the cation could be formed are discussed. 相似文献
9.
A series of heterodimetallic complexes of general formula (C 5R 5)M(μ-CO) 3RuC 5Me 5 (M = Cr, Mo, W; R = Me, Et) has been prepared in good yields by the reaction of [C 5R 5M(CO) 3] − with [C 5Me 5Ru(CH 3CN) 3] +. (C 5Me 4Et)W(μ-CO) 3Ru(C 5Me 5) was characterized by a crystal structure determination. The W---Ru bond length of 2.41 Å is consistent with the formulation of a metal-metal triple bond, while the unsymmetrical bonding mode of the three bridging carbonyl groups reflects the inherent non-equivalence of the two different C 5R 5M-units. Using [CpRu(CH 3CN) 3] + or [CpRu(CO) 2(CH 3CN)] + as the cationic precursor leads to the formation of dimetallic species (C 5R 5)M(CO) 5RuC 5H 5 with both bridging and terminal carbonyl groups. 相似文献
10.
The reaction between metallic barium and fluoroisopropanol or alcoholysis of [Ba(OPr i) 2] produces a pentanuclear fluoroalkoxide. Its X-ray structure determination showed its formulation to correspond to Ba 5(μ 5-OH)[μ 3-OCH(CF 3) 2] 4[μ 2-OCH(CF 3) 2] 4 [OCH(CF 3) 2](THF) 4(H 2O)·THF. The metallic core is based on a square pyramid encapsulating an hydroxo ligand. In addition to the barium---alkoxide bonds [2.53(3)–2.86(3) Å] neutral O-donors, four THF [2.82(2)–2.86(3) Å] and one H 2O [2.79(3) Å] and secondary barium---fluorine interactions [2.99(2)–3.31(2) Å] ensure high coordination numbers, from 9 to 11 for the metal centers. Hydrogen bonding between the apical fluoroisopropoxide, the water molecule and one THF molecule, non-bonded to a metal center, accounts for the stability of the hydrate and illustrates the Lewis acidity of fluoroalkoxides. Thermal decomposition leads to BaF 2. 相似文献
11.
The hydroxo-complexes [{PdR(PPh 3)(μ-OH)} 2] (R = C 6F 5 or C 6Cl 5) have been obtained by reaction of the corresponding [{PdR(PPh 3)(μ-Cl)}2] complexes with NBu 4OH in acetone. In this solvent, the reaction of the hydroxo-bridged complexes with pyrazole (Hpz) and 3,5-dimethylpyrazole (Hdmpz) in 1:2 molar ratio leads to the formation of the new complexes [{Pd(C 5F 5)(PPh 3)(μ-azolate)}2] and [{Pd(C 6Cl 5)(PPh 3)} 2(μ-OH)(μ-azolate)] (azolate = pz or dmpz). The reaction of the bis(μ-hydroxo) complexes with Hpz and Hdmpz in acetone in 1:1 molar ratio has also been studied, and the resulting product depends on the organic radical (C 6F 5 or C 6Cl 5) as well as the azolate (pz or dmpz). The identity of the isomer obtained has been established in every case by NMR ( 1H, 19F and 31P) spectroscopy. The reaction of the bis(μ-hydroxo) complexes with oxalic (H 2Ox) and acetic (HOAc) acids yields the binucle ar complexes [{PdR(PPh 3)}2(μ-Ox)] (R = C 6F 5 or C 6Cl 5) and [{Pd(C 6F 5)(PPh 3)(μ-OAc)}2], respectively. [{Pd(C 6F 5)(PPh 3)(μ-OH)} 2] reacts with PPh 3 in acetone in 1:2 ratio giving the mononuclear complex trans-[Pd(C 6F 5) (OH)(PPh 3) 2], whereas the pentachlorophenylhydroxo complex does not react with PPh 3, even under forcing conditions. 相似文献
12.
(C 5Me 5) 2Sm(THF) 2 reacts with 1,2-epoxybutane in toluene to form, in addition to the toluene soluble [(C 5 Me 5) 2Sm] 2(μ-O), 1, the hexane soluble [(C 5Me 5) 2Sm(THF)] 2(μ-O), 2. In hexane, 2 loses THF to form 1 as a precipitate, but 1 cannot be converted to 2 by addition of THF at room temperature. Compound 1 does convert to 2 in low yield in THF at reflux. The reaction of (C 5Me 5) 2SM(phthalan) with 1,2-epoxybutane generates 1 and a phthalan analog of 2, [(C 5Me 5) 2Sm(phthalan)] 2(μ,-O), 3. Compound 2 reacts with Me 3CCN to form [(C 5Me 5) 2Sm(NCCMe 3)] 2(μ-O), 4, by displacement of THF. 相似文献
13.
The reaction between RMgCl (two equivalents) and 1,2-W 2Cl 2(NMe 2) 4 in hydrocarbon solvents affords the compounds W 2R 2(NMe 2) 4, where R = allyl and 1− and 2-methyl-allyl. In the solid state the molecular structure of W 2(C 3H 5) 2(NMe 2) 4 has C2 symmetry with bridging allyl ligands and terminal W---NMe 2 ligands. The W---W distance 2.480(1) Å and the C---C distances, 1.47(1) Å, imply an extensive mixing of the allyl π-MOs with the WW π-MOs, and this is supported by an MO calculation on the molecule W 2(C 3H 5) 2(NH 2) 4 employing the method of Fenske and Hall. The most notable interaction is the ability of the (WW) 6+ centre to donate to the allyl π *-MO (π 3). This interaction is largely responsible for the long W---W distance, as well as the long C---C distances, in the allyl ligand. The structure of the 2-methyl-allyl derivative W 2(C 4H 7) 2(NMe 2) 4 in the solid state reveals a gauche-W 2C 2N 4 core with W---W = 2.286(1) Å and W---C = 2.18(1) Å, typical of WW and W---C triple and single bonds, respectively. In solution (toluene-d 8) 1H and 13C NMR spectra over a temperature range −80°C to +60°C indicate that both anti- and gauche- W 2C 2N 4 rotamers are present for the 2-methyl-allyl derivative. In addition, there is a facile fluxional process that equilibrates both ends of the 2-methyl-allyl ligand on the NMR time-scale. This process leads to a coalescence at 100°C and is believed to take place via an η 3-bound intermediate. The 1-methyl-allyl derivative also binds in an η 1 fashion in solution and temperature-dependent rotations about the W---N, W---C and C=C bonds are frozen out at low temperatures. The spectra of the allyl compound W 2(C 3H 5) 2(NMe 2) 4 revealed the presence of two isomers in solution—one of which can be readily reconciled with the presence of the bridging isomer found in the solid state while the other is proposed to be W 2(η 3-C 3H 5) 2(NMe 2) 4. The compound W 2R 2(NMe 2) 4 where R = 2,4-dimethyl- pentadiene was similarly prepared and displayed dynamic NMR behaviour explainable in terms of facile η 1 = η 3 interconversions. 相似文献
14.
The complex (di-η 5-C 5H 4CH 2CH 2CH 2C 5H 4)Ti(η 1-C 5H 5) 2 (I) can be obtained unambiguously starting from the corresponding bridged titanocene dichloride. Attempts to synthesize the isomeric compounds (η 5-C 5H 5) 2 Ti(di-η 1-C 5H 4-CH 2CH 2CH 2C 5H 4) (I′) by the action of a convenient bridged dianion on (C 5H 5) 2 TiCl 2 afford several compounds, one of them is the complex I. The possibility of interconversion of these complexes by a fluctional process is discussed. 相似文献
15.
Reaction of ansa-cyclopentadienyl pyrrolyl ligand (C 5H 5)CH 2(2-C 4H 3NH) (2) with Ti(NMe 2) 4 affords bis(dimethylamido)titanium complex [(η 5-C 5H 4)CH 2(2-C 4H 3N)]Ti(NMe 2) 2 (3) via amine elimination. A cyclopentadiene ligand with two pendant pyrrolyl arms, a mixture of 1,3- and 1,4-{CH 2(2-C 4H 3NH)} 2C 5H 4 (4), undergoes an analogous reaction with Ti(NMe 2) 4 to give [1,3-{CH 2(2-C 4H 3N)} 2(η 5-C 5H 3)]Ti(NMe 2) (5). Molecular structures of 3 and 5 have been determined by single crystal X-ray diffraction studies. 相似文献
16.
The ruthenium(II) complexes (η-R 5C 5)Ru(CO) 2X with R = H, CH 3 and X = Cl, Br, I undergo a facile reaction with nitric oxide under UV irradiation to afford ruthenium(IV) nitrosyl derivatives of the general type (η-R 5C 5)Ru(NO)X 2. 相似文献
17.
CdTe@Zn 5(CO 3) 2(OH) 6 composites were synthesized by a hydrothermal method. CdTe@Zn 5(CO 3) 2(OH) 6 composite nanospheres were characterized via X-ray diffraction, scanning electron microscopy, energydispersive X-ray spectroscopy, and photoluminescence (PL). The hydrothermal reaction time and the mole ratios of Zn/Te played important roles in the growth and fluorescence intensity of CdTe@Zn 5(CO 3) 2(OH) 6 composites. The composite powders showed peak PL at 578 nm at 1.6 times the intensity of powdered CdTe QDs. CdTe@Zn 5(CO 3) 2(OH) 6 exhibited a strong yellow fluorescence emission, and its preparation method was easy and economical. Therefore, CdTe@Zn 5(CO 3) 2(OH) 6 offers potential applications in biological markers and light-emitting diodes. 相似文献
18.
The reactions of (Me 2AlH) 3 with Me 2AsNMe 2, MeAs(NMe 2) 2, and As(NMe 2) 3 were investigated as a function of time at room temperature and over the temperature range −90 to 24°C by use of 1H and 13C NMR spectroscopy. (Me 2AlH) 3 was found to be very reactive toward the aminoarsines, even at −90°C, and no stable Me 2AlH-aminoarsine adducts were observed. Instead, the initial stages of the reactions involved AS---N bond cleavage with the generation of highly reactive AlN- and AsH-bonded species. The subsequent course of each reaction and the final arsenic-containing product distribution depended upon the original AL:N stoichiometric ratio and the respective aminoarsine. When the Al:N ratio was 1:1, the reactions were straightforward for each aminoarsine. However, in every case, [Me 2AlNMe 2] 2 was the final AlN-containing product. Independent reactions were carried out to verify many of the proposed decomposition pathways that lead to thermodynamically stable products. The results of this study are compared with those of the analogous, previously reported (Me 3Al) 2-aminoarsine systems. Additionally, a new synthetic route to [Me 2AlAsMe 2] 3 has been established from the reaction of (Me 2AlH) 3 with Me 2AsH. 相似文献
19.
Reaction of C 5H 4(SiMe 3) 2 with Mo(CO) 6 yielded [(η 5-C 5H 3(SiMe 3) 2)Mo(CO) 3] 2, which on addition of iodine gave [(η 5-C 5H 3(SiMe 3) 2Mo(CO) 3I]. Carbonyl displacement by a range of ligands: [L = P(OMe) 3, P(OPr i) 3,P(O- o-tol) 3, PMe 3, PMe 2Ph, PMePh 2, PPh 3, P( m-tol) 3] gave the new complexes [(η 5-C 5H 3(SiMe 3) 2 MO(CO) 2(L)I]. For all the trans isomer was the dominant, if not exclusive, isomer formed in the reaction. An NOE spectral analysis of [(η 5-C 5H 3(SiMe 3) 2)Mo(CO) 2(L)I] L = PMe 2Ph, P(OMe) 3] revealed that the L group resided on the sterically uncongested side of the cyclopentadienyl ligand and that the ligand did not access the congested side of the molecule. Quantification of this phenomenon [L = P(OMe) 3] was achieved by means of the vertex angle of overlap methodology. This methodology revealed a steric preference with the trans isomer (less congestion of CO than I with an SiMe 3 group) being the more stable isomer for L = P(OMe) 3. 相似文献
20.
Reaction of Me 3SiMe 2SiC 5H 5 (4), prepared from Me 3SiMe 2SiCl and C 5H 5Na, with Fe(CO) 5 in refluxing xylene afforded the title compound (3). The silicon-silicon bond in 3 is exceptionally stable in refluxing xylene and also in succeeding reactions to prepare a series of its derivatives. Thus, 3 reacted with I 2 in either chloroform or benzene, giving [η 5-Me 3SiMe 2SiC 5H 4Fe(CO) 2I] (6). Compound 3 was reduced by sodium amalgam and reacted subsequently with CH 3I, PhCH 2Cl, CH 3COCl, PhCOCl, Cy 3SnCl (Cy = cyclohexyl) and Ph 3SnCl, producing [η 5-Me 3SiMe 2SiC 5H 4Fe(CO) 2R][7 : R = CH 3 (a), PhCH 2 (b), CH 3CO (c), PhCO (d), Cy 3Sn (e) and Ph 3Sn (f), respectively]. The molecular structure of 3 has been determined by X-ray diffraction crystallography. It was found that 3 has a trans-configuration with a symmetrical centre located at the middle of the Fe---Fe bond. It is abnormal that the conformation of the disilane part around the Si---Si bond is almost eclipsed rather than staggered. 相似文献
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