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1.
The reactions of PhCboSeNa (Cbo = o-C2B10H10), prepared by reductive cleavage of Se-Se bond in (PhCboSe)2 by NaBH4 in methanol, with Na2PdCl4, MCl2(PR3)2 and [M2Cl2(μ-Cl)2(PR3)2] afforded a variety of complexes, viz., [Pd(SeCboPh)Cl] (1), [M(SeCboPh)2(PR3)2], [M2Cl2(μ-SeCboPh)(μ-Cl)(PR3)2] (M = Pd, Pt) and [Pd2Cl(SeCb0Ph)(μ-Cl)(μ-SeCboPh)(PEt3)2] (7) have been isolated. These complexes were characterized by elemental analyses and NMR (1H, 31P, 77Se, 195Pt) spectroscopy. The structures of [Pd(SeCboPh)2(PEt3)2] (2), [Pt(SeCboPh)2(PMe2Ph)2] (3), [Pd2Cl2(μ-SeCboPh)(μ-Cl)(PMe2Ph)2] (5) and [Pd2Cl(SeCboPh)(μ-Cl)(μ-SeCboPh)(PEt3)2] (7) were established by X-ray crystallography. The latter represents the first example of asymmetric coordination of selenolate ligands in binuclear bis chalcogenolate complexes of palladium and platinum. Thermolysis of [Pd(SeCboPh)2(PEt3)2] (2) in HDA (hexadecylamine) at 330 °C gave nano-crystals of Pd17Se15.  相似文献   

2.
Three new Pd(II) complexes of Schiff base ligands, namely, [Pd4(L1)4] (1), [Pd2(L2)2Cl2] (2) and [Pd(L3)2Cl2] (3) [HL 1 ?=?N-(benzylidene)-2-aminophenol; L 2 ?=?N-(2,4-dichlorobenzylidene)-2,6-diethylbenzenamine, L 3 ?=?4-(2,4-dichlorobenzylide-neamino)phenol] have been synthesized using solvothermal methods and characterized by elemental analysis, spectroscopy and single crystal X-ray diffraction. The crystal structures of the free ligands were also determined. The ??-oxygen-bridged tetranuclear cyclometallated Pd(II) complex (1) contains four nearly planar units, in which PdII is four-coordinate. Complex 2 is a ??-chloro-bridged dinuclear cyclometallated Pd(II) complex, whereas complex 3 is mononuclear. The Heck reactions of bromobenzene with acrylic acid catalyzed by complexes 1?C3 have also been studied.  相似文献   

3.
The reaction of tetranuclear Pd4(μ-COOCH3)4(μ-CO)4 cluster (1a) with p- and o-chloronitrosobenzenes was found to give dinuclear nitrosoamide complexes, Pd2(OAc)2(p-ClC6H4N[p-ClC6H3NO])2 (4) and Pd2(OAc)2(o-ClC6H4N[o-ClC6H3NO])2 (5), respectively. The formation of complexes 4 and 5 is accompanied by evolution of CO2, resulting from oxidation of CO coordinated in cluster 1. Complexes 4 and 5 were characterized by elemental analysis and IR and 1H NMR spectroscopy; their structures were studied by EXAFS. The reactions of dinuclear complex 4 with molecular hydrogen and CO were studied. The major products of reduction of 4 with hydrogen include metallic palladium, acetic acid, cyclohexanone, and molecular nitrogen. Treatment of complex 4 with CO under mild conditions (1 atm, 20 °C) affords p-chlorophenyl isocyanate.  相似文献   

4.
The reactions of [M2Cl2(μ-Cl)2(PMe2Ph)2] with mercapto-o-carboranes in the presence of pyridine afforded mono-nuclear complexes of composition, [MCl(SCb°R)(py)(PMe2Ph)] (M = Pd or Pt; Cb° = o-C2B10H10; R = H or Ph). The treatment of [PdCl2(PEt3)2] with PhCb°SH yielded trans-[Pd(SCb°Ph)2(PEt3)2] (4) which when left in solution in the presence of pyridine gave another substitution product, [Pd(SCb°Ph)2(py)(PEt3)] (5). The structures of [PdCl(SCb°Ph)(py)(PMe2Ph)] (1), [Pd(SCb°Ph)2(PEt3)2] (4) and [Pd(SCboPh)2(py)(PEt3)] (5) were established unambiguously by X-ray crystallography. The palladium atom in these complexes adopts a distorted square-planar configuration with neutral donor atoms occupying the trans positions. Thermolysis of [PdCl(SCb°)(py)(PMe2Ph)] (2) in TOPO (trioctylphosphine oxide) at 200 °C gave nanocrystals of TOPO capped Pd4S which were characterized by XRD pattern and SEM.  相似文献   

5.
The diamagnetic complexes [Pd2(H2L1)Cl4] (I), [Pd2(H2L2)Cl4] (II), and Pd2(H2L3)Cl4(III) with chiral ligands derived from the natural monoterpenoid (R)-(+)-limonene are obtained (H2 L1 is ethylenediamine dioxime, H2L2 is piperazine dioxime, and H2L3 is propylenediamine dioxime). According to X-ray diffraction data, the crystal structures of complexes I and II are composed of binuclear acentric molecules. The coordination polyhedra PdN2Cl2 are trapeziums (squares distorted in a tetrahedral manner) made up of two N atoms of the tetradentate bridging cyclic ligands H2L1 and H2L2 and two Cl atoms. The fragments PdCl2 are trans in the complexes. The 13C and 1H NMR spectra of complexes I and II in CDCl3 also suggest their binuclear structures.  相似文献   

6.
A diselenide, (MeOOCCH2CH2Se)2 (1) has been prepared by esterification of (HOOCCH2CH2Se)2 in methanol. The reductive cleavage of Se-Se bond in 1 by NaBH4 in methanol generates MeOOCCH2CH2SeNa. The latter in different stoichiometries reacts with [M2Cl2(μ-Cl)2(PR3)2] to give a variety of products of compositions [M2Cl2(μ-SeCH2CH2COOMe)2(PR3)2] (2); [M2Cl2(μ-Cl)(μ-SeCH2CH2COOMe)(PR3)2] (3); [Pd2(SeCH2CH2COOMe)2(μ-SeCH2CH2COOMe)2(PR3)2] (4);[Pd3Cl2(μ-SeCH2CH2COOMe)4(PR3)2] (5). Treatment of complexes 2 with [M2Cl2(μ-Cl)2(PR3)2] affords complexes 3 in nearly quantitative yield. The formation of various products in these reactions is sensitive to stoichiometric ratio of reactants employed. This enables interconversion of various complexes by manipulating mole ratios of appropriate starting materials. A homoleptic palladium complex, [Pd(SeCH2CH2COOMe)2]6 (6) was isolated from a reaction between Na2PdCl4 and MeOOCCH2CH2SeNa. All these complexes have been characterized by elemental analysis, IR, UV-Vis and NMR (1H, 13C, 31P, 77Se, 195Pt) spectroscopy. Structures of trans-[Pd2Cl2(μ-SeCH2CH2COOMe)2(PPh3)2] (2d), [Pt2Cl2(μ-Cl)(μ-SeCH2CH2COOMe)(PnPr3)2] (3e), [Pd3Cl2(μ-SeCH2CH2COOMe)4(PnPr3)2] (5) and [Pd(SeCH2CH2COOMe)2]6 (6) have been established unambiguously by X-ray crystallography. In these complexes, there are bridging selenolate ligands with their uncoordinated ester groups. Compound 6 has a centrosymmetric Pd6Se12 hexagon in which every two palladium atoms are bridged by selenolate ligands. Thermal behaviour of some complexes has been investigated. Pyrolysis of compound 2b in tributylphosphate at 195 °C gave Pd17Se15 nanoparticles which were characterized by XRD and EDAX.  相似文献   

7.
The interaction of the enantiopure (R)- and (S)-1-phenyl-N,N-bis(pyridine-3- ylmethyl)ethanamine ligands, R-L 1 and S-L 1 , with copper(II) chloride followed by addition of hexafluorophosphate resulted in the isolation of the corresponding enantiomeric complexes [Cu(R-L 1 )Cl](PF6) (1), [Cu(S-L 1 )Cl](PF6) (2) and [Cu(S-L 1 )Cl](PF6)??0.5Et2O (3), in which dimerization occurs through two long Cu??????Cl interactions, the ??-chloro bridges being thus strongly asymmetric. The organic ligand is bound to the metal centre via its N3-donor dipyridylmethylamine fragment in a planar fashion, such that each copper centre is in a square planar environment (or distorted square pyramidal with a long axial bond length if the additional interaction is considered). When R,S-L 1 was employed in a parallel synthesis, the similar racemic complex [Cu(R,S-L 1 )Cl](PF6)??0.5MeOH (4) was obtained, in which the L 1 ligands in each dimeric unit have opposite hands. In contrast to the complexes of L 1 , the reaction of Cu(II) chloride with the related ligand, (R)-1-cyclohexyl-N,N-bis(pyridine-3-ylmethyl)ethanamine (R-L 2 ), yielded the mononuclear complex [Cu(R,S-L 2 )Cl2] (5), displaying a distorted square pyramidal coordination geometry. The structure of this product along with its corresponding circular dichroism spectrum revealed that racemisation of the starting R-L 2 ligand has occurred under the relatively mild (basic) conditions employed for the synthesis. A temperature-dependent magnetic studies of the complexes 1, 2 and 5 indicate that a week ferromagnetic interaction is operative in each dicopper core in 1 and 2 with 2J?=?1.2?cm?1. On the other hand, a week antiferromagnetic intermolecular interaction is operative for 5.  相似文献   

8.
Specific chiral ligands have been designed by Trost et al. to perform enantioselective Pd-catalyzed allylic alkylations. It is shown that the Pd(0) complex formed by addition of the Trost ligand (4) to Pd0(dba)2 is not stable in most solvents (acetone, DMF, CH2Cl2). Indeed, Pd0(dba)(4) leads to the formation of a stable PdII complex 5 (X-ray structure), likely by activation of the two N-H bonds of the ligand by the Pd0 centre. The formation of the PdII complex competes with the reaction of Pd0(4) with (E)-PhCHCH-CH(OAc)-Ph, excluding any investigation of the kinetics of the latter reaction. The ionization steps from intermediate (η2-PhCHCH-CH(OAc)-Ph)Pd0(4) were found to be very slow. The cationic P,P complex [(η3-Ph-CH-CH-CH-Ph)Pd(4)]+, expected to be generated by addition of 2 equiv. of 4 to the precursor [(η3-Ph-CH-CH-CH-Ph)Pd(μ-Cl)]2, in the presence of a chloride scavenger, leads to a complex mixture whereas addition of 1 equiv. of 4 affords a stable bis-cationic PdII complex {[(η3-Ph-CH-CH-CH-Ph)Pd]2(4)]}2+, (X-ray structure) via a P,O complexation of each allyl-Pd moieties. This dissymmetric P,O coordination will favour the enantioselectivity of Pd-catalyzed allylic alkylation of (E)-PhCHCH-CH(OAc)-Ph by the control of the regioselectivity of the nucleophilic attack onto the allylic ligand which is responsible of the enantioselectivity of the overall catalytic reaction.  相似文献   

9.
Reactions of palladium derivatives in combination with phosphine ligands make possible the production of new species of high nuclearity. Here both the production and further characterization of a new high-nuclear cluster, Pd23(CO)22(PEt3)10 is described.  相似文献   

10.
The diiron ynamine complex [Fe2(CO)7{μ-CR)C(NEt2)}] (1:R=Me,2:R = C3H5.3:R=SiMe3.4:R = Ph) reacts at room temperature with diphenyldiazomethane Ph2CN2, in hexane to yield complexes [Fe2(CO)6{C(R)C(NEt2)N (NCPh2)] (5a:R=Me,6a:R=C3H5.7a R=SiMe3.8a:R=Ph) resulting from the insertion of the terminal nitrogen atom into the Fe=C carbene bond. Insertion the second nitrogen atom and formation of compounds [Fe2(CO)6zμ-C(R)C(NEt2)NN(CPh2)}] (5b:R=Me,6b:R=C3H5,7b:R=SiMe3,8b:R=Ph) is observed when compounds5a-5a are treated in refluxing hexane. Transformation of compoundsa tob is also obtained at room temperature within a few days. All compounds were identified by their1H NMR spectra. Compounds6a, 7a, 8a, and8b were characterized by single crystal X-ray diffraction analyses. Crystal data: for6a: space group = P21/n,a=12.853(1) A,b=24.800(7) A,c=8.947(6) A,β=99.29(3)°,Z=4, 2227 rellectionsR=0,038; for7a: space group=Pl,a=ll.483(4) A,b=14.975(4) A,c = 17.890(8) A,α = 82.80(3)°,β=94.29(7)°,γ=85.42(2),Z = 4, 5888 reflectionR = 0.035: for8a: space group = Pcab.a = 31.023(8) A.b=20.137(1) A.c=9.686(2) A.Z=8. 1651 reflections,R=0.071; for8b: space group=P21/n,a=21.459(4),b=10,100(3) A,c=28,439(8) A,ß=103.86(4)°,Z=8. 2431 reflections.R=0.057.  相似文献   

11.
It has been shown for the first time that the reaction of bi-valent tin acetyl-acetonate with palladium carbonylphosphine clusters, Pd4(CO)5(PPh3)4 (I), Pd4(CO)5(PEt3)4 (II) and Pd3(CO)3(PPh3)4 (III), results in the formation of heterometal pentanuclear clusters of general formula Pd3Sn2(acac)4(CO)2(PR3)3; R  Ph (IV), Et (V). X-ray analysis of Pd3Sn2(acac)4(CO)2(PPh3)3 at 20°C (λ(Mo), 4396 reflections, space group P21/n, Z = 4, R = 0.037) shows that IV in the form of the crystalline hydrate, Pd3Sn2(acac)4(CO)2(PPh3)3 · χH2O (χ ∼ 1), contains a distorted “propeller”-shaped Pd3Sn2 metal frame with PdSn distances of 2.679–2.721(1) Å; two short PdPd bonds, 2.708 and 2.720(1) Å, bridged by μ2-CO ligands, and an elongated central Pd(1)Pd(2) bond of 2.798 Å. Sn atoms have distorted octahedral coordination, the dihedral angles formed by Pd3 moieties and two Pd2Sn triangles are 127.6 and 106.5°; and the angle between Pd2Sn moieties is 126.0°.  相似文献   

12.
[2 + 3] Cycloaddition reactions of the di(azido)-PdII complex trans-[Pd(N3)2(PPh3)2] (1) with an organonitrile RCN (2), under heating for 12 h, give the bis(tetrazolato) complexes trans-[Pd(N4CR)2(PPh3)2] (3) [R = Me (3a), Ph (3b), 4-ClC6H4 (3c), 4-FC6H4 (3d), 2-NC5H4 (3e), 3-NC5H4 (3f), 4-NC5H4 (3g)]. The reaction of trans-[Pd(N3)2(PPh3)2] (1) with propionitrile (2h) also affords, apart from trans-[Pd(N4CEt)2(PPh3)2] (3h), the unexpected mixed cyano-tetrazolato complex trans-[Pd(CN)(N4CEt)(PPh3)2] (3h′) which is derived from the reaction of the bis(tetrazolato) 3h with propionitrile, with concomitant formation of 5-ethyl-1H-tetrazole, via a suggested unusual oxidative addition of the nitrile to PdII. The [2 + 3] cycloadditions of [Pd(N3)2(PTA)2] (4) (PTA = 1,3,5-triaza-7-phosphaadamantane) with RCN (2), under heating for 12 h, give the bis(tetrazolato) complexes trans-[Pd(N4CR)2(PTA)2] (5) [R = Ph (5a), 2-NC5H4 (5b), 3-NC5H4 (5c), 4-NC5H4 (5d)]. All these reactions are greatly accelerated by microwave irradiation (1 h, 125 °C, 300 W). Taking advantage of the hydro-solubility of PTA, a simple liberation of 5-phenyl-1H-tetrazole from the coordination sphere of trans-[Pd(N4CPh)2(PTA)2] (5a) was achieved. The complexes were characterized by IR, 1H, 13C{1H} and 31P{1H} NMR spectroscopies, ESI+-MS, elemental analyses and, for 3b, also by X-ray structure analysis. Weak agostic interactions between the CH groups of the triphenylphosphines and the palladium(II) centre were found.  相似文献   

13.
Di-t-butyl(ferrocenylmethyl)phosphine (1) has been isolated and structurally characterized. This ligand was found to be reasonably air stable as a solid and it has been shown to possess electron donating ability similar to that of tri-i-propylphosphine. A palladium catalyst bearing this ligand performed room temperature Suzuki-Miyaura coupling reactions with aryl bromides. Modest Heck coupling reactivity with aryl bromides was also observed at 100 °C. Complexation of 1 with Pd2(dba)3 led to formation of (1)2Pd0. Addition of 4-bromoanisole to solutions containing both 1 and Pd2(dba)3 led to formation of an oxidative addition product when 1:Pd ratios were ?1. With a 2:1 ratio of 1:Pd, monophosphine complex formation and oxidative addition were significantly inhibited.  相似文献   

14.
A chirality-memorizing saddle-shaped porphyrin (12H) with 3,5-dipyridylphenyl side arms at the opposite meso positions underwent supramolecular polymerization in CH2Cl2 with a chiral Pd(II) complex of 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (PdII(BINAP)), forming a ladder-shaped polymer (32H) with a prevailing one-handed helical chirality. When this polymer was poured into AcOH containing 1,3-bis(diphenylphosphino)propane (DPPP) as a decomplexing agent, 32H was depolymerized in a stereochemically retentive way to give optically active 12H, hydrogen-bonded with AcOH. Although a cyclodimeric reference of 32H, formed from 22H having two 3-pyridylphenyl meso substituents in conjunction with PdII(BINAP), behaved similar to 32H, the translation efficiency of helical chirality was lower than that in the case with 32H.  相似文献   

15.
Water-soluble functionalized bis(phosphine) ligands L (ah) of the general formula CH2(CH2PR2)2, where for a: R = (CH2)6OH; bg: R = (CH2)nP(O)(OEt)2, n = 2–6 and n = 8; h: R = (CH2)3NH2 ( Scheme 1), have been prepared photochemically by hydrophosphination of the corresponding 1-alkenes with H2P(CH2)3PH2. Water-soluble palladium complexes cis-[Pd(L)(OAc)2] (18) were obtained by the reaction of Pd(OAc)2 with the ligands ah in a 1:1 mixture of dichloromethane:acetonitrile. The water-soluble phosphine ligands and their palladium complexes were characterized by IR, 1H and 31P NMR. A crystallographic study of complex 1 shows that the Pd(II) ion has a square planar coordination sphere in which the acetate ligands and the diphosphine ligand deviate by less than 0.12 Å from ideal planar.  相似文献   

16.
Two Pd(II) complexes involving Schiff base ligands, namely, [Pd(L1)2] (1), [Pd2(L2)Cl2] (2) [HL1 = 2-((2,6-diisopropylphenylimino)methyl)-4,6-dibromophenol, L2 = N-(4-isopropylbenzylidene)-2,6-diisopropylbenzenamine] have been synthesized using solvothermal methods and characterized by elemental analysis, IR-spectroscopy, thermogravimetric analysis, powder X-ray diffraction, UV–vis absorption spectra, and single-crystal X-ray diffraction. Complex 1 is a mononuclear cyclometalated Pd(II) complex, whereas complex 2 is a μ-chloro-bridged dinuclear. Both 1 and 2 display photoluminescence in the solid state at 298 K and possess fluorescence lifetimes (τ 1 = 86.40 ns, τ 2 = 196.21 ns, τ 3 = 1,923.31 ns at 768 nm for 1, τ 1 = 69.92 ns, τ 2 = 136.40 ns, τ 3 = 1,714.26 ns at 570 nm for 2). The Suzuki reactions of 4-bromotoluene with phenylboronic acid by complexes 12 have also been studied.  相似文献   

17.
The ion mobility in new fluoride glasses (mol %) 45ZrF4 · 25BiF3 · 30MF (I) (M = Li, Na, K), (70 - x)ZrF4 · xBiF3 · 30LiF (II) (15 ≤ x ≤ 35), and 45ZrF4 · (55-x)BiF3 · xMF (III) (M = Li, Na; 10 ≤ x ≤ 30) has been studied by 7Li, 19F, and 23Na NMR in the temperature range 250–500 K. The character of ion motion in bismuth fluorozirconate glasses I and III is determined by temperature and the nature and concentration of an alkali-metal cation. Major type of ion mobility in glasses I–III at temperature 400–440 K are local motions of fluorine-containing moieties and diffusion of lithium ions (except for the glass with x = 10). The factors responsible for diffusion in the fluoride sublattice of glasses I have been determined. Sodium ions in glasses I and III are not involved in ion transport.  相似文献   

18.
Reaction between Os(CO)2(PPh3)3 and Me3SnH produces Os(SnMe3)H(CO)2(PPh3)2 (1). Multinuclear NMR studies of solutions of 1 reveal the presence of four geometrical isomers, the major one being that with mutually cis triphenylphosphine ligands and mutually trans CO ligands. Os(SnMe3)H(CO)2(PPh3)2 undergoes a redistribution reaction, at the trimethylstannyl ligand, when treated with Me2SnCl2 giving Os(SnMe2Cl)H(CO)2(PPh3)2 (2). Solutions of 2 again show the presence of four isomers but now the major isomer is that with mutually trans triphenylphosphine ligands and mutually cis CO ligands. The redistribution reaction of 1 with SnI4 produces Os(SnMeI2)H(CO)2(PPh3)2 (3) which exists in solution as only one isomer, that with mutually trans triphenylphosphine ligands and mutually trans CO ligands. Treatment of 3 with I2 cleaves the Os-H bond with retention of geometry giving Os(SnMeI2)I(CO)2(PPh3)2 (4). The crystal structure of 4 has been determined. No isomerization of the trans dicarbonyl complex 4 occurs when 4 is heated, instead there is a formal loss of “MeSnI” and formation of OsI2(CO)2(PPh3)2 (5).  相似文献   

19.
The reaction of R3M (M=Ga, In) with HESiR′3 (E=O, S; R′3=Ph3, iPr3, Et3, tBuMe2) leads to the formation of (Me2GaOSiPh3)2 (1); (Me2GaOSitBuMe2)2 (2); (Me2GaOSiEt3)2 (3); (Me2InOSiPh3)2 (4); (Me2InOSitBuMe2)2 (5); (Me2InOSiEt3)2 (6); (Me2GaSSiPh3)2 (7); (Et2GaSSiPh3)2 (8); (Me2GaSSiiPr3)2 (9); (Et2GaSSiiPr3)2 (10); (Me2InSSiPh3)3 (11); (Me2InSSiiPr3)n (12), in high yields at room temperature. The compounds have been characterized by multinuclear NMR and in most cases by X-ray crystallography. The molecular structures of (1), (4), (7) and (8) have been determined. Compounds (3), (6) and (10) are liquids at room temperature. In the solid state, (1), (4), (7) and (9) are dimers with central core of the dimer being composed of a M2E2 four-membered ring. VT-NMR studies of (7) show facile redistribution between four- and six-membered rings in solution. The thermal decomposition of (1)(12) was examined by TGA and range from 200 to 350°C. Bulk pyrolysis of (1) and (2) led to the formation of Ga2O3; (4) and (5) In metal; (7)(10) GaS and (11)(12) InS powders, respectively.   相似文献   

20.
Three polyoxomolybdate compounds, namely {[MII(HL)2]2(Mo8O26)} n (M = Co (1), Ni (2), Zn (3)) (HL, 3-(2-pyridyl)pyrazole), were designed and synthesized under the hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and TGA. Single-crystal X-ray diffraction analysis results reveal that compounds 13 own the isostructural chain structure consisting of the β-[Mo8O26]4? anions, which are linked by M(HL) 2 2+ units via the terminal oxygen atoms. TGA curves show that the organic ligands separate from the related compounds above ca. 673 K.  相似文献   

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