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1.
Summary Complexes [Rh(COD)(L-L)]ClO4 are prepared by reaction of [Rh(COD)2]ClO4 with the appropriate ligand L-L (4,7-Ph2Phen, 2,9-Me2-4,7-Ph2Phen, 2,9-Me2Phen or 5,6-Me2Phen). Treatment of these complexes with carbon monoxide gives [Rh(CO)2(L-L)]ClO4. When the carbonylation reaction is performed in the presence of P(4-RC6H4)3, pentacoordinate complexes [Rh(CO)(L-L){P(4-RC6-H4)}3 2]ClO4 (R=Me, H, F or Cl) are formed. The use of [Rh(COD)(L-L)]ClO4 as homogeneous hydroformylation catalyst precursors was studied (50 atm, 80°C). Under these conditions no hydrogenation of the olefin or of the aldehydes is observed, but isomerisation reactions are significant.  相似文献   

2.
The catalytic activity of a series of [Rh L-L chel]X complexes, in which we have varied the unsaturated ligand [L-L = cis, cis-cycloocta 1,5-diene(cod) or 2,5-norbornadiene(nbd) the nitrogen chelating ligand [chel = 2,2′-bipyridine(bipy), 2,2′-dipyridylamine(dipyam), 2,2′-bipyrazine (bipz), 4,4′-dimethyl-2,2′-bipyridine (4,4′-Me2bipy)] and the counter ion [X = PF6, ClO4, BPh4], has been examined in reactions with phyenylacetylene (PA). The catalytic behaviour of the [Rh(cod)Cl2],tmeda (tmeda = N,N,N′,N′tetramethylethylendiamine), [Rh(cod)Cl2],teda] (teda = triethylendiamine), of the dimer [Rh(cod)Cl]2, and the use of NaOH as cocatalyst in different reaction conditions was also examined. The influence of the ligands on the catalytic activity of these RhI complexes is discussed. 1H and 13C NMR spectra have shown that highly stereoregular polyphenylacetilene can be obtained. Conditions for homogeneous doping of PPA, to obtain materials whose conductivity varies over 10–11 magnitude orders, are proposed. The stability of the doped polymers is also discussed.  相似文献   

3.
We report the development of a series of rhenium(I) polypyridine complexes appended with an electron‐rich diaminoaromatic moiety as phosphorogenic sensors for nitric oxide (NO). The diamine complexes [Re(N^N)(CO)3(py‐DA)][PF6] (py‐DA=3‐(N‐(2‐amino‐5‐methoxyphenyl)aminomethyl)pyridine; N^N=1,10‐phenanthroline (phen) ( 1 a ), 3,4,7,8‐tetramethyl‐1,10‐phenanthroline (Me4‐phen) ( 2 a ), 4,7‐diphenyl‐1,10‐phenanthroline (Ph2‐phen) ( 3 a )) have been synthesized and characterized. In contrast to common rhenium(I) diimines, these diamine complexes were very weakly emissive due to quenching of the triplet metal‐to‐ligand charge‐transfer (3MLCT) emission by the diaminoaromatic moiety through photoinduced electron transfer (PET). Upon treatment with NO, the complexes were converted into the triazole derivatives [Re(N^N)(CO)3(py‐triazole)][PF6] (py‐triazole=3‐((6‐methoxybenzotriazol‐1‐yl)methyl)pyridine; N^N=phen ( 1 b ), Me4‐phen ( 2 b ), Ph2‐phen ( 3 b )), resulting in significant emission enhancement (I/I0≈60). The diamine complexes exhibited high reaction selectivity to NO, and their emission intensity was found to be independent on pH. Also, these complexes were effectively internalized by HeLa cells and RAW264.7 macrophages with negligible cytotoxicity. Additionally, the use of complex 3 a as an intracellular phosphorogenic sensor for NO has been demonstrated.  相似文献   

4.
Reactions of fluoro-and chloromesitylene π-complexes [(η6-1-Hlg-2,4,6-Me3C6H2)(η5-C5EtMe4)Rh]-(BF4)2 (Hlg = F, Cl) with diethyl malonate anion in THF or acetone-d 6 at 20°C initially (within the first 5–30 min) involve nucleophile addition at unsubstituted carbon atom in the arene ligand with formation of π-cyclohexadienyl complexes {[η5-1-(EtOCO)2CH-1-H-3-Hlg-2,4,6-Me3C6H2](η5-C5EtMe4)Rh}(BF4). The subsequent replacement of the halogen atom yields {[η6-1-(EtOCO)2CH-2,4,6-Me3C6H2](η5-C5EtMe4)Rh}(BF4)2, where the arene ligand is readily withdrawn from π-coordination by the action of chloride ion or the solvent. Dimethyl mesitylmalonate was isolated in 76% yield. Likewise, the reactions with anions derived from malononitrile and ethyl cyanoacetate gave 25–38% of the corresponding derivatives 1-R-2,4,6-Me3C6H2 where R = (NC)2CH or EtOCO(NC)CH.  相似文献   

5.
Summary Bidentate ligands can readily replace acetone in thefac-[Mn(CO)3(chel)(OCMe2)]+ complexes or the perchlorate group fromfac-[Mn(CO)3(chel)(OClO3)] yieldingfac-[Mn(CO)3(chel)(L-L)]+ or [{fac-Mn(CO)3(chel)}2(L-L)]2+ [chel = 1,10-phenanthroline (phen), 2,2-bipyridine (bipy), 1,2-bis(diphenylphosphine)ethane (dpe); L-L = bis(diphenylphosphine)methane (dpm), dpe, 1,4-bis(diphenylphosphine)butane (dpb), succinonitrile (suc), and glutaronitrile (glu)]. Some of these mononuclear complexes are precursors for binuclear complexes which are linked by bridging phosphines or nitriles.  相似文献   

6.
In polymerization reactions of phenylacetylene three different types of polyphenylacetylene (PPA) were prepared by using Rh and Pt complexes as catalysts in different reaction conditions. Type I PPA is obtained with [Rh (COD) Chel] PF6 complexes (COD = cis,cis-cycloocta 1,5-diene; chel = 2,2′-bipyridine, 1,10-phenanthroline, 2,9-dimethyl-1,10-phenanthroline, 5,6-dimethyl-1,10-phenanthroline, 3,4,7,8-tetramethyl-1,10-phenanthroline) in bulk, benzene methanol, while type II PPA is obtained with the same catalysts in p-dioxane and type III PPA in the presence of [Pt (? C?CPh)2(PPh3)2] in bulk. Type I, II, and III PPA exhibit different IR and 1H-NMR spectra, which have been compared with literature data. Correlations proposed by different Authors between spectral properties of PPA and chain structures are also discussed.  相似文献   

7.
Alternative Ligands. XXIII Rhodium(I) Complexes with Donor/Acceptor Ligands of the Type (Me2PCH2CH2)2SiX2 and (2-Me2PC6H4)SiXMe2 (X = F, Cl) Donor/acceptor ligands of the type (Me2PCH2CH2)2SiX2 and (2-Me2PC6H4)SiXMe2 (X = F, Cl) react with [Rh(CO)2Cl]2 (1) to give the mononuclear complexes RhCl(CO)(Me2PCH2CH2)2SiX2 [X = F( 4 ), Cl ( 5 )] and RhCl(CO)[2-Me2PC6H4)SixMe2]2 [X = F ( 8 ), Cl ( 9 )], respectively. In case of the ligands (Me2PCH2CH2)2SiCl2 ( 3 ) and (2-Me2PC6H6)SiClMe2 ( 7 ) the Rh(I) complexes formed in the first step partly undergo oxidative addition reactions of SiCl bonds yielding rhodium(III) compounds of low solubility. Only for 8 the coordination shifts Δδ = δ(complex)?δ(ligand) and coupling constants give some indication to possible Rh→Si interactions. However, the molecular structure of 8 determined by X-ray diffraction does not show RhSi or RhF bonding contacts. The new compounds were characterized by analytical (C, H) and spectroscopic investigations (MS, IR,-NMR).  相似文献   

8.
Taking inspiration from yeast alcohol dehydrogenase (yADH), a benzimidazolium (BI+) organic hydride‐acceptor domain has been coupled with a 1,10‐phenanthroline (phen) metal‐binding domain to afford a novel multifunctional ligand ( L BI+) with hydride‐carrier capacity ( L BI++H?? L BIH). Complexes of the type [Cp*M( L BI)Cl][PF6]2 (M=Rh, Ir) have been made and fully characterised by cyclic voltammetry, UV/Vis spectroelectrochemistry, and, for the IrIII congener, X‐ray crystallography. [Cp*Rh( L BI)Cl][PF6]2 catalyses the transfer hydrogenation of imines by formate ion in very goods yield under conditions where the corresponding [Cp*Ir( L BI)Cl][PF6] and [Cp*M(phen)Cl][PF6] (M=Rh, Ir) complexes are almost inert as catalysts. Possible alternatives for the catalysis pathway are canvassed, and the free energies of intermediates and transition states determined by DFT calculations. The DFT study supports a mechanism involving formate‐driven Rh?H formation (90 kJ mol?1 free‐energy barrier), transfer of hydride between the Rh and BI+ centres to generate a tethered benzimidazoline (BIH) hydride donor, binding of imine substrate at Rh, back‐transfer of hydride from the BIH organic hydride donor to the Rh‐activated imine substrate (89 kJ mol?1 barrier), and exergonic protonation of the metal‐bound amide by formic acid with release of amine product to close the catalytic cycle. Parallels with the mechanism of biological hydride transfer in yADH are discussed.  相似文献   

9.
Selectivity in reductive elimination of ethane and RMe has been observed for benzyl and phenacyl complexes Me2RPd(L2)Br (L2 = bipy, phen), with product ratios dependent upon R and L2, and cationic intermediates detected by 1H NMR spectroscopy for oxidative addition of CD3I and phenacyl bromides to Me2Pd(L2). The crystal structure of fac-Me2(p-BrC6H4CH2)Pd(phen)Br has been determined.  相似文献   

10.
Summary Diphenyl(2-pyridyl)phosphine (PPh2pyl), phenylbis(2-pyridyl)-phosphine (PPhpyl2) and tris(2-pyridyl)-phosphine (Ppyl3) react with [Rh(acac)(CO)2] (acac=acetylacetonate) and Rh(8-oxy)(CO)2(8-oxy=8-hydroxyquinolinate) yielding [Rh(chel)(CO)(PPhxpyl3–x)]. The properties of these complexes were examined by spectral (i.r.,u.v.-vis,31P n.m.r.) and chemical methods.  相似文献   

11.
The effect of the phenanthroline substituents on the structure and reactivity of platinum(II) and platinum(IV) complexes has been investigated. The X-ray crystal structures of the compounds [PtI(2)(4,7-Ph(2)phen)].CHCl(3) (1dz.CHCl(3)), [PtI(4)(4,7-Ph(2)phen)].CHCl(3) (2dz.CHCl(3)), [PtI(2)(2,9-Me(2)-4,7-Ph(2)phen)] (1fz), and [PtI(4)(2,9-Me(2)-4,7-Ph(2)phen)].I(2) (2fz.I(2)) have shown that complexes 1fz and 2fz, containing ortho-substituted phenanthrolines, exhibit a remarkable displacement of the equatorial iodine atoms from the N-Pt-N' plane (average 0.477(2) and 0.199(2) ?, respectively), a bending of the phenanthroline [angle between outer rings of 19.9(7) and 14.2(7) degrees, respectively] and a rotation of the N-C-C'-N' plane with respect to the N-Pt-N' plane [32.3(10) and 26.5(9) degrees, respectively]. Comparison between the structures of 1fz and 2fz, both having the phenanthroline with methyl substituents in the ortho position, indicates that, in the latter case, because of the presence of the two axial iodine ligands, the displacements of the ligands from the equatorial plane are smaller and find a compensation in a narrowing of the I(1)-Pt-I(1') angle (5 degrees ) and a lengthening of the Pt-N bonds (0.07 ?). The electrochemical behavior of the four-coordinate platinum(II) complexes shows that compounds possessing regular planar geometry have access to the one-electron reduced species, whereas those with distorted coordination geometry are irreversibly reduced by collapsing of the complex geometry. This is in sharp contrast with the behavior of related nickel complexes for which the pseudo-tetrahedral coordination imposed by bulky 2,9-substituents of phenanthroline stabilizes the nickel(I) species. Spectroscopic results allow us to assign a significant Pt(I) character to [1d](-) monoanions. The electrogenerated, plus one electron, complexes are not indefinitely stable and, because of conjugation with the phen ligand, progressively restore the Pt(II) oxidation state by transferring the electron to the peripheral organic ligand. The latter process can involve multiple electron additions in the macroelectrolysis time scale. The related platinum(IV) complexes [PtX(4)(L)] undergo irreversible two-electron reduction accompanied by fast release of the axial ligands and formation of the corresponding platinum(II) species.  相似文献   

12.
Summary The seven-coordinate complexes [MI2(CO)3(NCMe)2] (M=Mo or W) react with two equivalents of L(L=py, 4Me-py, 3Cl-py or 3Br-py) or one equivalent of NN {NN=2,2-bipyridine(bipy), 1,10-phenanthroline(phen), 5,6-dimethyl-1, 10-phenanthroline (5,6-Me2-1, 10-phen), 5-Nitro-1, 10-phenanthroline (5-NO2-1, 10-phen) and C6H4(o-NH2)2 (o-diam) (for M=Mo only)} in CH2Cl2 at room temperature to give the substituted products [MI2(CO)3L2] or [MI2(CO)3(NN)] (1–17) in high yield. The compounds [MI2(CO)3(NCMe)2] react with two equivalents of NN (for M=W, NN=bipy; for M=Mo, NN=phen) to give the dicationic salts [M(CO)3(NN)2]2I(18–19). The compounds [MI2(CO)3(NCMe)2] (M=Mo or W) react with two equivalents of 5,6-Me2-1, 10-phen to yield the monocationic dicarbonyl compounds [MI(CO)2(5,6-Me2-phen)2]I (20 and21). The dicationic mixed ligand complexes [M(CO)3(bipy)(5,6-Me2-phen)]2I (22 and23) are prepared by reacting [MI2(CO)3(NCMe)2] with one equivalent of bipy, followed by anin situ reaction with 5,6-Me2-1, 10-phen to afford the products22 and23. The complexes (1–23) described in this paper have been characterised by elemental analysis (C, H and N), i.r. spectroscopy and, in selected cases,1Hn.m.r. spectroscopy. Magnetic susceptibility measurements show the compounds to be diamagnetic.  相似文献   

13.
Selective two-electron reduction of dioxygen (O2) to hydrogen peroxide (H2O2) has been achieved by two saddle-distorted N,N’-dimethylated porphyrin isomers, an N21,N’22-dimethylated porphyrin ( anti -Me2P ) and an N21,N’23-dimethylated porphyrin ( syn -Me2P ) as catalysts and ferrocene derivatives as electron donors in the presence of protic acids in acetonitrile. The higher catalytic performance in an oxygen reduction reaction (ORR) was achieved by anti -Me2P with higher turnover number (TON=250 for 30 min) than that by syn -Me2P (TON=218 for 60 min). The reactive intermediates in the catalytic ORR were confirmed to be the corresponding isophlorins ( anti -Me2Iph or syn -Me2Iph ) by spectroscopic measurements. The rate-determining step in the catalytic ORRs was concluded to be proton-coupled electron-transfer reduction of O2 with isophlorins based on kinetic analysis. The ORR rate by anti -Me2Iph was accelerated by external protons, judging from the dependence of the observed initial rates on acid concentrations. In contrast, no acceleration of the ORR rate with syn -Me2Iph by external protons was observed. The different mechanisms in the O2 reduction by the two isomers should be derived from that of the arrangement of hydrogen bonding of a O2 with inner NH protons of the isophlorins.  相似文献   

14.
The reactions of the complex (η-9-Me2S-7,8-C2B9H10)Rh(η-cod) (cod is 1,5-cyclo-octadiene) with HX acids (X=Cl, Br, or I) in acetone afforded rhodacarborane halide complexes [(η-9-Me2S-7,8-C2B9H10)RhX2]2, which are carborane analogs of cyclopentadienyl halide rhodium complexes [(η-C5R5)RhX2]2. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1817–1819, September, 1999.  相似文献   

15.
Optically active amidophosphite with the peripheral imino group (R)-(Et2N)2POCH2CH(Et)N=CHPh is synthesized through one-stage phosphorylation of the corresponding imino alcohol. Its reaction with [Rh(CO)2Cl]2 (at P : Rh = 1) yields the mononuclear chelate [Rh(CO)(P^N)Cl]. Structures of the compounds are determined by IR, 31P, and 13C NMR spectroscopy, mass spectrometry, and polarimetry.  相似文献   

16.
Oxidation of rhodium(I) carbonyl chloride, [Rh(CO)2Cl]2, with copper(II) acetate or isobutyrate in methanol solutions yields binuclear double carboxylato bridged rhodium(II) complexes with RhRh bonds, [Rh(μ-OOCRκO)(COOMeκC)(CO)(MeOH)]2, where R=CH3 or i-C3H7. According to X-ray data, surrounding of each rhodium atom in these complexes is close to octahedral and consists of another rhodium atom, two oxygens of carboxylato ligands, terminal carbonyl group, C-bonded methoxycarbonyl ligand, and axial CH3OH. Methoxycarbonyl ligand is shown to originate from CO group of the parent [Rh(CO)2Cl]2 and OCH3 group of solvent. N- and P-donor ligands L (p-CH3C6H4NH2, P(OPh)3, PPh3, PCy3) readily replace the axial MeOH yielding [Rh(μ-OOCRκO)(COOMeκC)(CO)(L)]2. The X-ray data for the complex with R=i-C3H7, L=PPh3 showed the same molecular outline as with L=MeOH. Electronic effects of axial ligands L on the spectral parameters of terminal carbonyl group are essentially the same as in the known series of rhodium(I) complexes (an increase of δ13C and a decrease of ν(CO) with strengthening of σ-donor and weakening of π-acceptor ability of L).  相似文献   

17.
Reactions of neat 1,3- and 1,4-dibromides with N,N′-diarylformamidines in the presence of diisopropylethylamine (DIPEA) afford corresponding amidinium salts in high yields (>80%). Six- and seven-membered ring amidinium salts bearing bulky Mes (2,4,6-Me3C6H2) and Dipp (2,6-iPr2C6H3) aryl groups were prepared using this method. Free six-membered ring carbene 6-Dipp was generated from amidinium salt using LiHMDS as a base. NHC-Ag(I) complexes were obtained by the reactions of amidinium salts with Ag2O. NHC complexes of Pd and Rh are not accessible by deprotonation of amidinium salts, nor by transmetallation of Ag(I) complexes. However NHC-Cu(I) complexes were obtained by transmetallation of NHC-Ag(I). Thus, transmetallation of six- and seven-membered NHC-Ag(I) complexes was documented for the first time.  相似文献   

18.
The preparation and properties of complexes of general formulae [Rh(CS)-(HL)(PR3)2]ClO4 (HL = pyrazole (HPz), 3-methylpyrazole (H3-MePz), 3,5-dimethylpyrazole (H3,5-Me2Pz), PR3 = triphenylphosphine, tricyclohexylphosphine) and [(PR3)2(CS)Rh(μ-Pz)AuPPh3]ClO4 are reported. Complexes of the first set react with potassium hydroxide to give [Rh(μ-L)(CS)(PPh3)2 or RhPz(CS)(PR3)2 complexes. The structure of the complex [Rh(3,5-Me2Pz)(CS)(PPh3)]2 has been determined by X-ray diffraction methods. The crystals are monoclinic, space group P21/c, with Z = 4 in a unit cell of dimensions a = 12.700(11), b = 17.217(16), c = 23.041(18) Å, β = 116.55(8)°. The structure has been solved by Patterson and Fourier methods and refined by full-matrix least-squares to R = 0.059 for 1978 independent reflections. The structure consists of dimeric complexes, in which each rhodium atom is in a square-planar environment being bonded to a carbon atom of a thiocarbonyl ligand, a phosphorus atom of a triphenylphosphine molecule and to two nitrogen atoms of pyrazolate ligands bridging the metal atoms. The dihedral angle of 71.1° between such two square planes leads to a bent configuration with an intramolecular rhodium-rhodium distance of 3.220 Å. The thiocarbonyl and triphenylphosphine ligands are in a trans disposition.  相似文献   

19.
Summary The synthesis and x-ray crystal structure oftrans-[Co(dmgH)2(Et)(1,5,6-Me3Bzm)] where dmgH=dimethylglyoximate(–1), and 1,5,6-Me3Bzm=1,5,6-trimethylbenzimidazole, is reported. The compound C19H26N6O4Co is monoclinic, space group P21/n;a=11.700(4);b=24.205(6);c=8.500(3) Å and =101.63(3)°. D(calcd) 1.299 g cm–3; Z=4 and R=0.066 for 2359 independent reflections. Comparison of Co-N(axial ligand) bond lengths for compounds of general formulaetrans-[Co(dmgH)2(R)(L)], with L=pyridine or 1,5,6-trimethylbenzimidazole and R=CH(CN)Cl, CH2NO2, Me, Et,i-Pr, cyclo-hexyl or adamantyl is made. The Co–N(1,5,6-Me3Bzm) bond lengths of the trimethylbenzimidazole derivatives show a fairly linear relationship with the electronic parameter of the axial R group, derived from the13C-n.m.r. spectra of their pyridine analogues. The influence of steric effects on the properties of these CoIII compounds is discussed.  相似文献   

20.
Summary The preparations and characterisation of cationic complexes of the type [Rh(CO)(MeCN)(PR3)2]ClO4, [Rh(CO)L(PR3)2]ClO4 (L=py or 2-MeOpy), [Rh(CO)(L-L)(PR3)2]ClO4 (L-L = bipy or phen) and [Rh(CO)(PR3)3]ClO4 with PR3 = P(p-YC6H4)3 (Y=Cl, F, Me or MeO) are described.  相似文献   

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