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1.
The complexes Pt(nb)3-n(P-iPr3)n (n=1, 2, nb=bicyclo[2.2.1]hept-2-ene), prepared in situ from Pt(nb)3, are useful reagents for addition of Pt(P-iPr3)n fragments to saturated triruthenium clusters. The complexes Ru3Pt(CO)11(P-iPr3)2 (1), Ru3Pt(-H)(3-3-MeCCHCMe)(CO)9(P-iPr3) (2), Ru3Pt(3-2-PhCCPh)(CO)10(P-iPr3) (3), Ru3Pt(-H)(4-N)(CO)10(P-iPr3) (4) and Ru3Pt(-H)(4-2-NO)(CO)10(P-iPr3) (5) have been prepared in this fashion. All complexes have been characterized spectroscopically and by single crystal X-ray determinations. Clusters 1–3 all have 60 cluster valence electrons (CVE) but exhibit differing metal skeletal geometries. Cluster 1 exhibits a planar-rhomboidal metal skeleton with 5 metal–metal bonds and with minor disorder in the metal atoms. Cluster 2 has a distorted tetrahedral metal arrangement, while cluster 3 has a butterfly framework (butterfly angle=118.93(2)°). Clusters 4 and 5 posseses 62 CVE and spiked triangular metal frameworks. Cluster 4 contains a 4-nitrido ligand, while cluster 5 has a highly unusual 4-2-nitrosyl ligand with a very long nitrosyl N–O distance of 1.366(5) Å.  相似文献   

2.
Co2(CO)8与4个二硫代双(烷基硫代甲酰胺)类前配体[R2NC(S)S]2反应,得4个含烷基硫代甲酰胺基的三核钴羰基硫簇合物.通过元素分析、IR、1H NMR和MS等方法表征了它们的结构,用X射线衍射法测定了其中一个簇合物Co3(CO)7(μ3-S)[μ,η2-SCN(i-Pr)2](Ⅲ)的晶体结构.晶体属单斜晶系,P21/n空间群,晶胞参数a=1.145 2(2)nm,b=1.502 8(3)nm,c=1.2144(2)nm,a=90°,β=92.15(3)°,γ=90°,V=2.088 5(7)nm3,Z=4,F(000)=1 096,Dc=1.747 mg·m-3,GOF(F2)=0.835,μ=2.588 nm-1.最终因子R[I>2σ(I)]=0.040 7,Rw=0.062 4.  相似文献   

3.
Although the palladium-catalyzed Tsuji-Trost allylic substitution reaction has been intensively studied, there is a lack of general methods to employ simple benzylic nucleophiles. Such a method would facilitate access to "α-2-propenyl benzyl" motifs, which are common structural motifs in bioactive compounds and natural products. We report herein the palladium-catalyzed allylation reaction of toluene-derived pronucleophiles activated by tricarbonylchromium. A variety of cyclic and acyclic allylic electrophiles can be employed with in situ generated (η(6)-C(6)H(5)CHLiR)Cr(CO)(3) nucleophiles. Catalyst identification was performed by high throughput experimentation (HTE) and led to the Xantphos/palladium hit, which proved to be a general catalyst for this class of reactions. In addition to η(6)-toluene complexes, benzyl amine and ether derivatives (η(6)-C(6)H(5)CH(2)Z)Cr(CO)(3) (Z = NR(2), OR) are also viable pronucleophiles, allowing C-C bond-formation α to heteroatoms with excellent yields. Finally, a tandem allylic substitution/demetalation procedure is described that affords the corresponding metal-free allylic substitution products. This method will be a valuable complement to the existing arsenal of nucleophiles with applications in allylic substitution reactions.  相似文献   

4.
Abstract

The kinetics for isomerization of HRu333-EtSCCMeCMe)(CO)9 TO Ru3(μ-SEt) (μ33-CCMeCHMe)(CO)9, were determined. The overall process involves C[sbnd]H elimination, C[sbnd]S and Ru[sbnd]Ru bond cleavage and Ru2(μ-S) bond formation. Activation parameters were determined from the temperature dependence (ΔH? = 127(3) kJ/mol, ΔS?= 56(11) J/mol-K) and from the pressure dependence (0[sbnd]207 MPa, ΔV? 0 +12.7(1.1) cm3/mol, Δβ? = +0.037(0.012) cm3/(mol-MPa)) of the rate constant. The data are consistent with an intramolecular reaction involving significant metal-metal or carbon-sulfur bond cleavage in the transition state. The activation volume is too large to be accommodated by C[sbnd]H elimination alone and CO dissociation is not involved.  相似文献   

5.
Reaction of the cluster Os3(μ-CO)(CO)93112-Me3SiC2Me) with HC≡CCOOMe in benzene at 70 °C results in Os3(CO)931122-C(SiMe3)C(Me)C(COOMe)CH× (5), Os3(CO)931122-C(SiMe3)C(Me)C(H)C(COOMe)CH× (6), Os3(CO)9{μ-η114-C(SiMe3)C(Me)C(H)C(COOMe)CH× (7), and Os3(CO)δ31141-C(SiMe3)C(Me)C(H)C(COOMe)× complexes (8), containing an osmacyclopentadiene moiety. Complexes5–8 were characterized by1H NMR and IR spectroscopy. The structure of clusters5 and8 was confirmed by X-ray analysis. Complex7 is formed from cluster5 as a result of a new intramolecular rearrangement and complex8 is obtained by decarbonylation of compound6. Complex8 adds PPh3 to give Os3(CO)δ(PPh3){μ-η114-C(SiMe3)C(Me)C(H)C(COOMe)×.  相似文献   

6.
The electron distributions and bonding in Ru3(CO)9( 3- 2, 2, 2-C6H6) and Ru3(CO)9( 3- 2, 2, 2-C60) are examined via electronic structure calculations in order to compare the nature of ligation of benzene and buckminsterfullerene to the common Ru3(CO)9 inorganic cluster. A fragment orbital approach, which is aided by the relatively high symmetry that these molecules possess, reveals important features of the electronic structures of these two systems. Reported crystal structures show that both benzene and C60 are geometrically distorted when bound to the metal cluster fragment, and our ab initio calculations indicate that the energies of these distortions are similar. The experimental Ru–Cfullerene bond lengths are shorter than the corresponding Ru–Cbenzene distances and the Ru–Ru bond lengths are longer in the fullerene-bound cluster than for the benzene-ligated cluster. Also, the carbonyl stretching frequencies are slightly higher for Ru3(CO)9( 3- 2, 2, 2-C60) than for Ru3(CO)9( 3- 2, 2, 2-C6H6). As a whole, these observations suggest that electron density is being pulled away from the metal centers and CO ligands to form stronger Ru–Cfullerene than Ru–Cbenzene bonds. Fenske-Hall molecular orbital calculations show that an important interaction is donation of electron density in the metal–metal bonds to empty orbitals of C60 and C6H6. Bonds to the metal cluster that result from this interaction are the second highest occupied orbitals of both systems. A larger amount of density is donated to C60 than to C6H6, thus accounting for the longer metal–metal bonds in the fullerene-bound cluster. The principal metal–arene bonding modes are the same in both systems, but the more band-like electronic structure of the fullerene (i.e., the greater number density of donor and acceptor orbitals in a given energy region) as compared to C6H6 permits a greater degree of electron flow and stronger bonding between the Ru3(CO)9 and C60 fragments. Of significance to the reduction chemistry of M3(CO)9( 3- 2, 2, 2-C60) molecules, the HOMO is largely localized on the metal–carbonyl fragment and the LUMO is largely localized on the C60 portion of the molecule. The localized C60 character of the LUMO is consistent with the similarity of the first two reductions of this class of molecules to the first two reductions of free C60. The set of orbitals above the LUMO shows partial delocalization (in an antibonding sense) to the metal fragment, thus accounting for the relative ease of the third reduction of this class of molecules compared to the third reduction of free C60.  相似文献   

7.
Treatment of the electronically unsaturated 4-methylquinoline triosmium cluster $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu_3\hbox{-}\upeta^{2}\hbox{-}\hbox{C}_{9}\hbox{H}_{5} \hbox{(4-Me)N})(\upmu\hbox{-H})]$ (1) with tetramethylthiourea in refluxing cyclohexane at 81°C gave $[\hbox{Os}_{3}\hbox{(CO)}_{8}(\upmu\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{5} \hbox{(4-Me)N})(\upeta^2\hbox{-SC}(\hbox{NMe}_2\hbox{NCH}_2\hbox{Me})(\upmu \hbox{-H})_2]$ (2) and $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{5}\hbox{(4-Me)N})(\upeta^1\hbox{-SC}(\hbox{NMe}_2)_2)(\upmu\hbox{-H})]$ (3). In contrast, a similar reaction of the corresponding quinoline compound $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu_{3}\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{6}\hbox{N})(\upmu\hbox{-H})]$ (4) with tetramethylthiourea afforded $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{6}\hbox{N})(\upeta^{1}\hbox{-SC(NMe}_{2})_{2})(\upmu\hbox{-H)}]$ (5) as the only product. Compound 2 contains a cyclometallated tetramethylthiourea ligand which is chelating at the rear osmium atom and a quinolyl ligand coordinated to the Os3 triangle via the nitrogen lone pair and the C(8) atom of the carbocyclic ring. In 3 and 5, the tetramethylthiourea ligand is coordinated at an equatorial site of the osmium atom, which is also bound to the carbon atom of the quinolyl ligand. Compounds 3 and 5 react with PPh3 at room temperature to give the previously reported phosphine substituted products $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu \hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{5}\hbox{(4-Me)N)(PPh}_{3})(\upmu\hbox{-H)}]$ (6) and $[\hbox{Os}_{3}\hbox{(CO}_{9}(\upmu \hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{6}\hbox{N)(PPh}_{3})(\upmu\hbox{-H)}]$ (7) by the displacement of the tetramethylthiourea ligand.  相似文献   

8.
η2-C60[RhCl(CO)(PPh3)2]配合物的合成与表征   总被引:2,自引:0,他引:2  
从1985年Smalley等[1]发现C60等富勒烯至1996年富勒烯的发现者获诺贝尔化学奖期间, 在化学、 材料、 物理等领域形成了富勒烯的研究热潮[2~5]. 现在科学工作者正以较大的注意力投向富勒烯的化学修饰, 研究富勒烯各类衍生物的结构与性能之间内在联系规律, 以期望在开发应用方面取得突破性进展, 为此也十分重视对具有特殊组成与结构的富勒烯衍生物的研究. 本文首次合成出η2-C60[RhCl(CO)(PPh3)2]配合物, 并对其结构进行了表征.  相似文献   

9.
The trinuclear osmium carbonyl cluster, [Os3(CO)10(MeCN)2], is allowed to react with 1 equiv. of [IrCp1Cl2]2 (Cp1 = pentamethylcyclopentadiene) in refluxing dichloromethane to give two new osmium–iridium mixed-metal clusters, [Os3Ir2(Cp1)2(μ-OH)(μ-CO)2(CO)8Cl] (1) and [Os3IrCp1(μ-OH)(CO)10Cl] (2), in moderate yields. In the presence of a pyridyl ligand, [C5H3N(NH2)Br], however, the products isolated are different. Two osmium–iridium clusters with different coordination modes of the pyridyl ligand are afforded, [Os3IrCp1(μ-H)(μ-Cl)(η33-C5H2N(NH2)Br)(CO)9] (3) and [Os3IrCp1(μ-Cl)223-C5H3N(NH)Br)(CO)7] (4). All of the new compounds are characterized by conventional spectroscopic methods, and their structures are determined by single-crystal X-ray diffraction analysis.  相似文献   

10.
《Polyhedron》1999,18(6):811-815
Oxidative addition of H–R (H--Ph and H2) to trans-Ir(--Ph)(CO)(PPh3)2 (2) gives the initial products, cis, cis-Ir(H)(--Ph)2(CO)(PPh3)2 (3a) and cis, cis-Ir(H)2(--Ph)(CO)(PPh3)2 (3b), respectively. Both cis-bis(PPh3) complexes, 3a and 3b undergo isomerization to give the trans-bis(PPh3) complexes, trans, trans-Ir(H)(--Ph)2(CO)(PPh3)2 (4a) and cis, trans-Ir(H)2(--Ph)(CO)(PPh3)2 (4b). The isomerization, 3b4b is first order with respect to 3b with k1=6.37×10−4 s−1 at 25°C under N2 in CDCl3. The reaction rate (k1) seems independent of the concentration of H2. A large negative entropy of activation (ΔS=−24.9±5.7 cal deg−1 mol−1) and a relatively small enthalpy of activation (ΔH=14.5±3.3 kcal mol−1) were obtained in the temperature range 15∼35°C for the isomerization, 3b4b under 1 atm of H2.  相似文献   

11.
Abstract

Syntheses and structures of penta- and hexaphosphorus analogues of ferrocene have been described recently1. Unlike their simple ferrocene analogues, these complexes have further ligating potential towards other transition metal centres by virtue of the availability of the ring phosphorus lone-pair electrons that are not involved in the η5-coordination. We now describe the first examples of coordination compounds of the triphospha-ferrocene [Fe(η5-C5Me5) (η5-C2 tBu2P3]. In the ruthenium complex [Fe(η5-C5Me5)(η5-C2 tBu2P3) Ru3(CO)9] 2 two adjacent phosphorus atoms of the η5-C2 tBu2P3 ring are interlinked by a ruthenium carbonyl cluster in which all three ruthenium atoms interact with the phosphorus atoms. The tetrametallic nickel complex [Fe(η5-C5Me5)(η5-C2 tBu2P3)Ni(CO)2]2 3 represents the first example of intermolecular interlinkage of two phospha-ferrocene systems by two metal centres.  相似文献   

12.
Addition of the ·P(O)(OPri)2, Me·, Et·, ·But, and Cl3C· radicals to the (ν2-C60)Os(CO)-(PPh3)2(CNBut) complex (1) was studied by ESR spectroscopy. The spectral parameters of the spin-adducts of these radicals with complex 1 were determined. The predominant direction of the attack by the ·P(O)(OPri)2, ·But, and Cl3C· radicals are the cis-1 and cis-2 bonds of the fullerene molecule. The stability of the spin-adducts depends substantially on the nature of the added radical. The addition rate constants of the ·P(O)(OPri)2, ·But, and Cl3C· radicals to complex 1 and the dimerization rate constants for these spin-adducts were determined. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 301–307, February, 2008.  相似文献   

13.
The metallation of the η5-C5H5(CO)2Fe-η15-C5H4Mn(CO)3 complex with BunLi (THF, ?78 °C) followed by the treatment of the lithium derivative with Ph2PCl afforded the η5-Ph2PC5H4(CO)2Fe-η15-C5H4Mn(CO)3 complex. The reaction of the latter with η5-C5H5(CO)3WCl in the presence of Me3NO produced the trinuclear complex η5-C5H5Cl(CO)2W-η15-(Ph2P)C5H4(CO)2Fe-η15-C5H4Mn(CO)3. The structure of the latter complex was established by IR, UV, and 1H and 31P NMR spectroscopy and X-ray diffraction. The reaction of MeSiCl3 with three equivalents of LiC5H4(CO)2Fe-η15-C5H4Mn(CO)2PPh3 gave the hexanuclear complex MeSi[C5H4(CO)2Fe-η15-C5H4Mn(CO)2PPh3]3.  相似文献   

14.
η2-C70[RhCl(CO)(PPh3)2]n配合物的合成和表征   总被引:1,自引:0,他引:1  
从1985年Kroto等^[1]发现C60等富烯至1996年富勒烯发现者获诺贝尔化学奖期间,在化学、物理、材料等领域掀起了富勒烯研究热潮^[2~8],此后,化学工作者致力于富勒烯的化学修饰,探索富勒烯各类衍生物的结构与性能之间的依赖关系,并在此基础上合成出具有独特结构与笥能的富勒烯衍生物,以期望在富勒烯及其衍生物的开发利用方面取得突破性进展。  相似文献   

15.
First Suzuki-Miyaura coupling reactions applied to (η(5)-chloro-cyclohexadienyl)Mn(CO)3 complexes are described and lead to the syntheses of (η(5)-aryl-cyclohexadienyl)Mn(CO)3 and of cationic (η(6)-arene)Mn(CO)3 complexes after rearomatization. The structures of two of the new complexes have been investigated by X-ray diffraction study.  相似文献   

16.
17.
Diyne FcCmCC.CFc (Fc is ferrocenyl) reacts with Ru3(CO)12 in boiling hexane to yield binuclear complexes Ru2 and Ru2(CO)6(C4Fc2(C=CFc)2C=O) containing ruthenacyclopentadiene and diruthenacycloheptadienone rings, respectively. The isomerism of the complexes is due to the different ways of coupling of the alkyne fragments of the diyne, namely, head-to-head, head-to-tail or tail-to-tail. The reaction of enyne PhC=CCH=CHPh with Ru3(CO)12 under similar conditions gives isomeric binuclear complexes Ru2(CO)6(C4Ph2(CH=CHPh)2) and trinuclear clusters Ru3(CO)6(w-CO)2(C4Ph2(CH=CHPh)2) and Ru3(CO)8(3-,1-1-4-2 C4Ph2(CH=CHPh)2). The structure of the latter was determined by X-ray diffraction analysis. The Ru3 triangle coordinates eight terminal CO groups and the organic ligand resulting from the head-to-head dimerization of enyne molecules; the ruthenacyclopentadiene moiety is 4-coordinated to the Ru(CO)2 group, and the third ruthenium atom is 2-bound to one of the PhCH=CH groups.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1261–1267, May, 1996.  相似文献   

18.
用Co2(CO)8分别与两个杂环配体C(S)NHP(S) (C6H4OCH3)OC(Ph)CH (L1)和C(S)NHC(CH3)2P(S) (CI)N(Ph) (L2)反应.合成两个新的三核钴羰基硫簇合物Co3(CO)7(μ3-S) [μ,η2-CNP(S) (C6H4OCH3)OC(Ph)CH] (Ⅰ)和Co3(CO)7(μ3-S) [μ,η2-SCNC(CH3)2P(S) (CI) N(Ph)] (Ⅱ).用元素分析,IR,1H NMR,31P NMR 及 MS谱表征了它们的结构,同时用X射线衍射法测定了它们的晶体分子结构,二者属于三斜晶系,P1空间群,I的晶胞参数为:a=0.84768(1)nm,b=1.19049(3)nm,c=1.43639(1)nm,α=86.926(1)°,β=81.60l(3)°,γ=88.535(2)°,V=1.4318(5)nm3,Z=2,Dc=1.641g@em-3,F(000)=716,μ=1.893mm-1,R=0.0602,Rw=0.1515.Ⅱ的晶胞参数为:a=1.2050(2)nm,b=1.2448(2)nm,c=0.8951(2)nm,α=97.49(1)°,β=93.552(4)°,γ=108.432(3)°,V=1.2554(3)nm3,Z=2,Dc=1.84lg@cm-3,F(000)=690,μ=2.419mm-1,R=0.0423,Rw=0.1075.Ⅰ和Ⅱ的分子骨架Co3S为三角锥构型,S作为面桥基配体,所有C0作为端基配体与三个Co原子成键.I中含有CoCoCN四元环组件,Ⅱ中含有CoCoSCN五元环组件.  相似文献   

19.
The reaction of the heterometallic vinylidene cluster RuCo2(CO)9(3-2-C=CHPh) with the diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) proceeds readily in the presence of Me3NO to furnish the new cluster RuCo2(CO)7(bpcd)(3-2-C=CHPh) as the sole product. This cluster has been isolated by preparative chromatography and characterized in solution by IR spectroscopy. The molecular structure was determined by X-ray diffraction analysis, which has confirmed the chelation of the bpcd ligand to the ruthenium center and the change in the coordination mode exhibited by the vinylidene ligand. RuCo2(CO)7(bpcd)(3-2-C=CHPh) crystallizes in the triclinic space group P , a = 10.5788(9), b = 11.909(1), c = 19.526(2) Å, = 84.491(9)°, = 78.068(8)°, = 63.760(7)°, V = 2158.7(4) Å3, Z = 2, and d calc = 1.581.  相似文献   

20.
Abstract

In this review structural parameters of forty complexes with an inner coordination sphere of Pt(η2-P2L)(η2-S2L) are analyzed and classified These complexes crystallize in three crystal systems: orthorhombic (four examples), triclinic (six examples) and monoclinic (thirty examples). The organodiphosphines create four- (PCP), five- (PC2P), six- (PC3P) and seven- (PC4P) membered metallocyclic rings with mean P-Pt-P bite angle values of 72.5° (PCP) < 85.3° (PC2P) < 93.0° (PC3P) < 97.4° (PC4P). The dithiolates create four- (SCS), five- (SC2S), six- (SC3S; SCSCS; SPNPS; SPCPS) and seven- (SC4S) membered metallocyclic rings with mean S-Pt-S bite angle values of 74.5° (SCS) < 85.8° (SCSCS) < 87.0° (SPNPS) < 89.0° (SC2S) < 92.3° (SC4S) < 93.5° (SC3S) < 97.5° (SPCPS). The mean Pt-P and Pt-S bond distances are 2.257 and 2.328?Å, respectively. The data are compared with those found in complexes with inner coordination spheres of Pt(PL)2(SL)2, Pt(PL)22-S2L) and Pt(η2-P2L)(SL)2.  相似文献   

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