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1.
Maria José Calhorda Author Vitae Paulo J. Costa Author Vitae Karl A. Kirchner Author Vitae 《Inorganica chimica acta》2011,374(1):24-35
The mechanism of the RuCp(COD)Cl catalyzed cyclotrimerization of acetylene, as well as the cyclocotrimerization of two alkynes with one molecule of ethylene, R-CN (R = H, Me, Cl, COOMe), CX2 (X = O, S, Se), and HNCX (X = O, S) investigated by means of high level DFT/B3LYP calculations, has been reviewed. The key reaction step is in all cases the oxidative coupling of two alkyne ligands to give a metallacyclopentatriene intermediate (or metallacyclopentadiene in other systems). This metallacycle adds unsaturated molecules, containing CC, CC and CX bonds, or RCN, CX2, and HNCX, in a concerted fashion, directly to the RuC bond, forming bicyclic carbenes. The cycle is completed by a rearrangement followed by an exothermic displacement of the arene or pyridine, by two acetylene molecules regenerating the catalytically active species. Small differences are found depending on the molecules and bonds involved. These reactions are reviewed and the proposed mechanisms compared with other available studies. 相似文献
2.
Florian Kessler 《Inorganica chimica acta》2011,374(1):278-6282
The platinum(0) complex [Pt(PPh3)4] reacts with brominated propargylic amides and esters in benzene by oxidative addition to give trans-[Br(PPh3)2Pt-CC-C(O)R] complexes whereas no reaction occurs when halogenated solvents (CH2Cl2, CHCl3) are used. The cis-ligands PPh3 can be replaced by P(iPr)3 and the bromide by trifluoroacetate. O-Alkylation of those trans-[X(PR′3)2Pt-CC-C(O)R] complexes (X = Br, CF3COO; R′ = Ph, iPr) derived from propargylic amides with MeOTf or [Me3O]BF4 in CH2Cl2 gives the first cationic monoallenylidene complexes of platinum, trans-[X(PR′3)2PtCCC(OMe)NR2]+Y− (Y = OTf, BF4). In contrast, trans-[Br(PPh3)2Pt-CC-C(O)OMenthyl] derived from a propargylic ester does not react with MeOTf in CH2Cl2. However, in acetonitrile instead of O-methylation the substitution of acetonitrile for the bromide ligand to yield the cationic acetonitrile alkynyl platinum complex trans-[MeCN(PPh3)2Pt-CC-C(O)OMenthyl]+OTf− is observed. The related palladium complexes trans-[X(PR′3)2Pd-CC-C(O)OR] (X = Br, CF3COO; R′ = Ph, iPr, R = menthyl, Et) react with MeOTf or [Et3O]BF4 analogously affording trans-[MeCN(PR′3)2Pd-CC-C(O)OR]+Y− (Y = OTf, BF4). 相似文献
3.
Raimund W. Lass 《Inorganica chimica acta》2011,369(1):288-291
The labile iridium(I) precursor trans-[IrCl(C8H14)(PiPr3)2] (2), prepared in situ from [IrCl(C8H14)2]2 (1) and PiPr3, reacted with equimolar amounts of 1,4-C6H4(CCSiMe3)2 (3) at 60 °C to give the mononuclear vinylidene complex trans-[IrCl(CC(SiMe3)C6H4CCSiMe3)(PiPr3)2] (4). From 2 and 3 in the molar ratio of 2:1, the dinuclear compound trans,trans-[(PiPr3)2ClIr(CC(SiMe3)C6H4C(SiMe3)C)IrCl(PiPr3)2] (5) was obtained. Reaction of 4 with [RhCl(PiPr3)2]2 (6) at room temperature afforded the heterodinuclear alkyne(vinylidene) complex trans,trans-[(PiPr3)2ClIr(CC(SiMe3)C6H4CCSiMe3)RhCl(PiPr3)2] (7), which on heating at 45 °C was converted to the bis(vinylidene) isomer trans,trans-[(PiPr3)2ClIr(CC(SiMe3)C6H4C(SiMe3)C)RhCl(PiPr3)2] (8). 相似文献
4.
Philipp Mücke Author Vitae Author Vitae Stanislav Záliš Author Vitae Author Vitae 《Inorganica chimica acta》2011,374(1):36-50
The present account summarizes our work on mononuclear vinyl ruthenium complexes of the type RuCl(CHCHR′)(CO)(PR3)2L, divinyl-bridged diruthenium complexes {RuCl(CO)(PR3)2L}2(μ-CHCH-bridge-CHCH) and on heterobinuclear systems where only one of the two redox-active metal-organic moieties is of the vinyl ruthenium type. The favourable electrochemical properties of the {RuCl(CO)(PR3)2L(CHCH-) tag and the various spectroscopic handles offered by that unit provide detailed insights into the charge and spin delocalization over the {MCl(CO)(PR3)2L} and CHCHR′ constituents in their associated radical cations. They also offer a convenient means for measuring electronic coupling in the mixed-valent radical cations of the homo- and heterodinuclear vinyl-bridged complexes and, under favourable circumstances, on the rate of intramolecular electron transfer between the individual redox sites. Aspects of this work include examples of complexes showing time-dependent valence trapping, complexes aimed at delineating the efficiencies of through-space versus through-bond pathways for electron delocalization, complexes where electrostatic effects on the redox splitting ΔE1/2 dominate over those from the resonance contribution and systems that exhibit extensive charge and spin delocalization between two dislike endgroups despite their intrinsically different redox potentials. 相似文献
5.
Normen Szesni 《Inorganica chimica acta》2006,359(2):617-632
Bis(alkoxy)allenylidene complexes, [(CO)5MCCC(OR′)OR], as well as mono(alkoxy)allenylidene complexes, [(CO)5MCCC(OR′)Ph], of chromium and tungsten are accessible from propynones [HCCC(O)Ph] or propynoic acid esters [HCCC(O)OR; R = Et, (−)-menthyl, endo-bornyl] by the following reaction sequence: (a) deprotonation of the alkynes, (b) reaction with [(CO)5M-THF] (M = Cr, W), and (c) alkylation of the resulting alkynyl metallate, [(CO)5MCCC(O)R], with Meerwein salts. Vinylidene complexes, [(CO)5MCC(R′)C(O)OR], are formed as a by-product by Cβ-alkylation of the alkynyl metallate. Dimethylamine displaces one alkoxy substituent of the bis(alkoxy)allenylidene complexes to give dimethylamino(alkoxy)allenylidene complexes, [(CO)5MCCC(OR)NMe2]. The analogous reaction of dimethylamine with a mono(alkoxy)-substituted allenylidene complex affords the aminoallenylidene complex [(CO)5CrCCC(NMe2)Ph]. When the amine is used in large excess, the α,β-unsaturated aminocarbene complex [(CO)5CrC(NMe2)C(H)C(NMe2)Ph] is additionally formed by addition of the amine across the CαCβ-bond of the allenylidene ligand. The reaction of [(CO)5MCCC(OEt)2] with dimethyl ethylenediamine offers access to bis(amino)allenylidene complexes, in which Cγ is part of a five-membered heterocycle. Photolysis of bis(alkoxy)allenylidene complexes in the presence of triphenylphosphine yields tetracarbonyl- and tricarbonyl{bis(phosphine)}allenylidene complexes. Diethylaminopropyne inserts into the CβCγ bond of [(CO)5MCCC(OEt)OMethyl] to give alkenylallenylidene complexes. Subsequent acid-catalyzed intramolecular cyclization affords a pyranylidene complex. 相似文献
6.
Bis(ferrocenyl)-substituted allenylidene complexes, [(CO)5MCCCFc2] (1a-c, Fc = (C5H4)Fe(C5H5), M = Cr (a), Mo (b), W (c)) were obtained by sequential reaction of Fc2CO with Me3Si-CCH, KF/MeOH, n-BuLi, and [(CO)5M(THF)]. For the synthesis of related mono(ferrocenyl)allenylidene chromium complexes, [(CO)5CrCCC(Fc)R] (R = Ph, NMe2), three different routes were developed: (a) reaction of the deprotonated propargylic alcohol HCCC(Fc)(Ph)OH with [(CO)5Cr(THF)] followed by desoxygenation with Cl2CO, (b) Lewis acid induced alcohol elimination from alkenyl(alkoxy)carbene complexes, [(CO)5CrC(OR)CHC(NMe2)Fc], and (c) replacement of OMe in [(CO)5CrCCC(OMe)NMe2] by Fc. Complex 1a was also formed when the mono(ferrocenyl)allenylidene complex [(CO)5CrCCC(Fc)NMe2] was treated first with Li[Fc] and the resulting adduct then with SiO2. The replacement route (c) was also applied to the synthesis of an allenylidene complex (7a) with a CC spacer in between the ferrocenyl unit and Cγ of the allenylidene ligand, [(CO)5CrCCC(NMe2)-CCFc]. The related complex containing a CHCH spacer (9a) was prepared by condensation of [(CO)5CrCCC(Me)NMe2] with formylferrocene in the presence of NEt3. The bis(ferrocenyl)-substituted allenylidene complexes 1a-c added HNMe2 across the Cα-Cβ bond to give alkenyl(dimethylamino)carbene complexes and reacted with diethylaminopropyne by regioselective insertion of the CC bond into the Cβ-Cγ bond to afford alkenyl(diethylamino)allenylidene complexes, [(CO)5MCCC(NEt2)CMeCFc2]. The structures of 5a, 7a, and 9a were established by X-ray diffraction studies. 相似文献
7.
A series of triphenylphosphine coordinated silver α,β-unsaturated carboxylates of type [Ag(O2CR)(PPh3)n: n = 1, R = CH3CHCH (2a), (CH3)2CCH (2b), CH3CH2CHCH (2c), CH3CH2CH2CHCH (2d), PhCHCH (2e), CH2CH (2f); n = 2, CH3CHCH (3a), (CH3)2CCH (3b), CH3CH2CHCH (3c), CH3CH2CH2CHCH (3d)] were prepared by reaction of relative silver carboxylates (1a-1f) with triphenylphosphine in chloroform. These complexes were obtained in high yields and characterized by elemental analysis, 1H NMR, 13C NMR, 31P NMR and IR spectroscopy. Thermal stability of the complexes has been determined by TG analysis. The molecular structure of [Ag((O2CCHC(CH3)2))(PPh3)2] (3b) shows that the senecioato ligand is chelated with silver atom and generate, a distorted tetrahedron. 相似文献
8.
James D.E.T. Wilton-Ely Ming Wang Sanaz J. Honarkhah Derek A. Tocher 《Inorganica chimica acta》2005,358(11):3218-3226
The Schiff base, 2-chlorophenylsalicylaldimine (HL1), is formed readily from salicylaldehyde and 2-chloroaniline. After deprotonation, this ligand is found to react as a bidentate mixed-donor chelate with the complexes [RuRCl(CO)(BTD)(PPh3)2] (R = H, CHCHC6H5, CHCHC6H4Me-4, CHCHtBu, CCCPhCHPh; BTD = 2,1,3-benzothiadiazole) to form the compounds [RuR(L1)(CO)(PPh3)2] through displacement of the chloride and BTD ligands. An analogous reaction occurs with the osmium complex [OsHCl(CO)(BTD)(PPh3)2] to provide [OsH(L1)(CO)(PPh3)2]. The compound [Ru(CHCHC6H4Me-4)(L2)(CO)(PPh3)2] is formed through reaction of salicylaldehyde (HL2) with [Ru(CHCHC6H4Me-4)Cl(CO)(BTD)(PPh3)2] in the presence of base. Two further ligands were investigated to extend the study to encompass 5- and 4-membered chelates; 8-hydroxyquinoline (HL3) and 2-hydroxy-4-methylquinoline (HL4) react with [Ru(CHCHPh)Cl(CO)(BTD)(PPh3)2] and [Ru(CHCHC6H4Me-4)Cl(CO)(BTD)(PPh3)2] in the presence of base to yield the complexes [Ru(CHCHPh)(L3)(CO)(PPh3)2] and [Ru(CHCHC6H4Me-4)(L4)(CO)(PPh3)2], respectively. The crystal structure of [Ru(CHCHC6H4Me-4)(L1)(CO)(PPh3)2] is reported. 相似文献
9.
Alessandro Donoli Roberta Cardena Mauro Bassetti Chiara Pasquini Saverio Santi 《Inorganica chimica acta》2011,374(1):442-446
The electrochemical and near-IR properties of a series of (bis)ferrocenyl complexes, in which the ferrocenyl moieties are spanned by enyne (E)-(-CHCH-CC-), diyne (-CC-)2, or diene (E)-(-CHCH-)2 C4 unsaturated spacers, were investigated. The experiments performed on 1,4-diferrocenyl-(E)-1-buten-3-yne revealed behaviors indicative of through-bridge/metal-metal electron transfer. The enyne bridged (bis)ferrocenyl cation displays charge transfer properties intermediate between the dienyl and diynyl systems and can be assigned to weakly coupled Class II mixed valence species. The analysis of the collected data according to the classical two-state Hush theory revealed that the efficiency of the electron transfer increases from wholly sp-C to wholly sp2-C bridged complexes. Therefore, the degree of communication is modulated according to the structure of the bridging ligand. 相似文献
10.
The reactions of [κ2(C1,C4)-CRCRCRCR](PPh3)2Ir(Cl) (9, R = CO2Me) with propargyl alcohol derivatives (2-propyn-1-ol, 2-methyl-3-butyn-2-ol, 1-ethynylcyclopentanol, and 1-ethynylcyclooctanol), in the presence of water leads to the formation of iridium(III)-vinyl complexes bearing the general structure [κ2(C1,C4)-CRCRCRCR](PPh3)2Ir(CO)(κ1-vinyl) where vinyl = -CHCH2, -(E)-CHCHMe, -CHC(CH2)4, or -CHC(CH2)7. In these, the CO ligand was derived from the terminal carbon of the starting alkyne and the oxygen atom from water. Under anhydrous conditions, 9 undergoes reaction with 2-propyn-1-ol to give trimethyl 1,3-dihydro-3-oxo-4,5,6-isobenzofurantricarboxylate, the result of a cycloaromatization/transesterification involving the buta-1,3-dien-1,4-diyl ligand in 9 and 2-propyn-1-ol. 相似文献
11.
Normen Szesni 《Inorganica chimica acta》2005,358(5):1645-1656
The aminoallenylidene(pentacarbonyl)chromium complexes [(CO)5CrCCC(NR1R2)Ph] (1a-c) react with dimethylamine by addition of the amine to the C1C2 bond of the allenylidene ligand to give alkenyl(amino)carbene complexes [(CO)5CrC(NMe2)CHC(NR1R2)Ph] (2a-c) (R1 = Me: R2 = Me (a), Ph (b); R1 = Et: R2 = Ph (c)). In contrast, addition of a large excess (usually 20 equivalents) of ammonia or primary amines, H2NR, to solutions of [(CO)5CrCCC(NMe2)Ph] (1a) affords the aminoallenylidene complexes [(CO)5CrCCC(NHR)Ph] (1d-w) in which the dimethylamino group is replaced by NH2 or NHR, respectively. In addition to simple amines such as methylamine, butylamine, and aniline, amines carrying a functional group (allylamine, propargylamine) and amino acid esters as well as amino terpenes and amino sugars can be used to displace the NMe2 substituent. Usually the Z isomer (with respect to the partial C3-N double bond) is formed exclusively. Products derived from addition of H2NR to the C1C2 bond of 1a are not observed. The amino group in 1d-w is rapidly deprotonated by excess of amine to form iminium alkynyl chromates [1d-w]−, thus protecting 1d-w from addition of free amine to either C3 or across the C1C2 bond. The iminium alkynyl chromates are readily reprotonated by acids or by chromatography on wet SiO2 to reform 1d-w. 相似文献
12.
Konstantin B. Borisenko Sergej V. Gruener David W.H. Rankin 《Inorganica chimica acta》2008,361(2):467-472
Molecular structures of dimethylbis(trimethylsilylketyl)silane (Me2Si[C(SiMe3)CO]2), dimethylbis(trimethylgermylketyl)silane (Me2Si[C(GeMe3)CO]2), and dimethylbis(trimethylstannylketyl)germane (Me2Ge[C(SnMe3)CO]2) have been studied in the gas phase by electron diffraction accompanied by high level ab initio and DFT calculations. Extensive theoretical conformational analyses of the molecules in the vapour predicted a possibility of existence of two types of conformers with small energy differences. The first type had gauche-gauche arrangements of the ketenyl groups in the central C(CO)XC(CO) fragments directed away from each other. The second type had nearly syn-gauche arrangements of the ketenyl groups. In addition, the energy differences were found to depend on the level of computations used. The experimental analysis, in turn, was unable to distinguish between different conformers due to the large number of similar overlapping distances. The experimental data were fitted by an averaged single-conformer model, which nevertheless allowed reliable determination of bonds and bonded angles in the molecules. Main experimental (rh1) structural parameters for Me2Si[C(SiMe3)CO]2, Me2Si[C(GeMe3)CO]2, and Me2Ge[C(SnMe3)CO]2, i.e. Me2X[C(YMe3)CO]2 (X,Y = Si, Ge, Sn), are (X-C)mean 187.7(1) pm, 194.6(2) pm, 216.1(3) pm; (Y-C)mean, 187.7(1) pm, 188.8(8) pm, 194.6(4) pm; (CC)mean, 135.3(5) pm, 131.6(5) pm, 131.5(13) pm; (CO)mean, 117.0(7) pm, 117.4(7) pm, 119.0(11) pm; (C-H)mean, 110.6(7) pm, 110.0(4) pm, 109.1(13) pm; (X(Y)-CC)mean, 114.4(2)°, 115.6(1)°, 115.6(2)°; (C-X(Y)-CMe)mean, 108.3(3)°, 108.4(3)°, 108.9(13)°; C(2)-C(1)-Y(4)-C(10), −19(6)°, 5(4)°, −9(10)°; C(7)-C(6)-Y(9)-C(38),−22(7)°, −32(3)°, −9(10)°; C(2)-C(1)-X(5)-C(6), 128(4)°, 142(1)°, 108(9)°; C(7)-C(6)-X(5)-C(1), 92(6)°, 115(2)°, 108(9)°, respectively. 相似文献
13.
Bimetallic alkylidene complexes of molybdenum (RF3O)2(ArN)MoCH-SiMe2-CHMo(NAr)(ORF3)2 (1) and (RF3O)2(ArN)MoCH-SiPhVin-CHMo(NAr)(ORF3)2 (2) (Ar = 2,6-C6H3; RF3 = CMe2CF3) have been prepared by the reactions of vinyl silicon reagents Me2Si(CHCH2)2 and PhSi(CHCH2)3 with known alkylidene compound PhMe2C-CHMo(NAr)(ORF3)2. Complexes 1 and 2 were structurally characterized. Ring opening metathesis polymerization (ROMP) of cyclooctene using compounds 1 and 2 as initiators led to the formation of high molecular weight polyoctenamers with predominant trans-units content in the case of 1 and predominant cis-units content in the case of 2. 相似文献
14.
Alejandro J. Arce Michele R. Chierotti Roberto Gobetto Rubén Machado 《Inorganica chimica acta》2009,362(1):291-294
Reaction of 3,4-difluoropyrrole with the labile triosmium cluster [Os3(CO)10(CH3CN)2] affords products in which C-H, N-H and C-F bonds are cleaved under mild conditions. C-H and N-H bonds are cleaved to give [Os3H(NCCFCFCH2)(CO)10] (1) a non-aromatic stabilised form of 3,4-difluoropyrrole. Thermolysis of 1 affords in moderate yields the compounds [Os3H2(CCCFCHNH)(CO)9] (2) and [Os3H2(NCHCFCFC)(CO)9] (3). For compound 3, C-H and N-H bonds are cleaved with concomitant migration of H atoms to the metal framework. In contrast, for compound 2 activation of C-H and C-F bonds leads to coordination of the ligand through the carbon atoms, acting as a four-electron donating species. 相似文献
15.
A new cumulene diiron complex related to the Fe-only hydrogenase active site [(μ-SCH2C(S)CCH2)Fe2(CO)6] (1) was obtained by treatment of (μ-LiS)2Fe2(CO)6 with excess 1,4-dichloro-2-butyne. By controllable CO displacement of 1 with PPh3 and bis(diphenylphosphino)methane (dppm), mono- and di-substituted complexes, namely [(μ-SCH2C(S)CCH2)Fe2(CO)5L] (2: L = PPh3; 3: L = dppm) and [(μ-SCH2C(S)CCH2)Fe2(CO)4L2] (4: L = PPh3; 5: L = dppm) could be prepared in moderate yields. Treatment of 1 with bis(diphenylphosphino)ethane (dppe) afforded a double butterfly complex [(μ-SCH2C(S)CCH2)Fe2(CO)5]2(μ-dppe) (7). With dppm in refluxing toluene, a dppm-bridged complex [(μ-SCH2C(S)CCH2)Fe2(CO)4(μ-dppm)] (6) was obtained. These model complexes were characterized by IR, 1H, 31P NMR spectra and the molecular structures of 1, 2 and 5-7 were determined by single crystal X-ray analyses. The electrochemistry of 1-3 was studied and the electrocatalytic property of 1 was investigated for proton reduction in the presence of HOAc. 相似文献
16.
In this paper it is reported the synthesis of the phosphonium salts [Ph2P(CH2)n(Ph)2PCH2COOMe]Br (n = 1 (1), 2 (2)) and [Ph2P(CH2COOMe)(CH2)n(Ph)2PCH2COOMe]Br2 (n = 3 (3)) derived from the reactions of the diphosphines dppm, dppe and dppp with methyl bromoacetate. By reaction of the monophosphonium salt of dppm and dppe with the strong base Na[N(SiMe3)2] the corresponding carbonyl stabilized ylides Ph2P(CH2)n(Ph)2PCHCOOMe (n = 1 (4), 2 (5)) were obtained. The Ph2P(CH2)2(Ph)2PCHCOOMe (5) ylide was reacted with Pd(II) and Pt(II) substrates. From these reactions were isolated exclusively complexes in which the ylide was chelated to the metal through the free phosphine group and the ylidic carbon atom. A further reaction of the Ph2P(CH2)2(Ph)2PCHCOOMe (5) ylide with 1.5 equiv. of Na[N(SiMe3)2] gives the bifunctionalized ketenylidene Ph2P(CH2)2(Ph)2PCCO (6) system. This cumulenic ylide reacts with Pt(II) complexes to form a chelated derivative in which IR and NMR spectra suggest the breaking of the CC bond of the -CCO group. 相似文献
17.
Rhodium(III) and iridium(III) octahedral complexes of general formula [MCl3{R2PCH2C(But)NNC(But)CH2PR2}] (M = Rh, Ir; R = Ph, c-C6H11, Pri, But; not all the combinations) were prepared either from the corresponding diphosphinoazines and RhCl3 · 3H2O or by the oxidation of previously reported bridging complexes [{MCl(1,2-η:5,6-η-CHCHCH2CH2CHCHCH2CH2)}2{μ-R2PCH2C(But)NNC(But)CH2PR2}] with chlorine-containing solvents. Depending on the steric properties of the ligands, complexes with facial or meridional configuration were obtained. Crystal and molecular structures of three facial and two meridional complexes were determined by X-ray diffraction. Hemilability of ligand in the complex fac-[RhCl3{(C6H11)2PCH2C(But)NNC(But)CH2P(C6H11)2}] consisting in reversible decoordination of the phosphine donor group in the six-membered ring was observed as the first step of isomerization between fac and mer isomers. 相似文献
18.
Leticia Naya Margarita López-Torres Antonio Rodríguez José M. Vila 《Inorganica chimica acta》2011,370(1):89-97
Reaction of the Schiff base ligands 2-Br-4,5-(OCH2O)C6H2C(H)NCH2CH2NMe2 (a) and 4,5-(OCH2CH2)C6H3C(H)NCH2CH2NMe2 (b) with Pd(OAc)2 or K2[PdCl4] leads to the mononuclear cyclometallated compounds [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N,N}(OCOMe)] (1a) and [Pd{4,5-(OCH2CH2)C6H2C(H)NCH2CH2NMe2-C6,N,N}(Cl)] (1b), derived from C-H activation at the C6 carbon. Treatment of a with Pd2(dba)3 gave [Pd{4-5-(OCH2O)C6H2C(H)NCH2CH2NMe2-C2,N,N}(Br)] (2a), via C-Br activation.The metathesis reaction of 1a with aqueous sodium chloride gave [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N,N}(Cl)] (3a), with exchange of the acetate group by a chloride ligand. Treatment of the cyclometallated monomers 1a-3a with PPh3 in a 1:1 molar ratio yielded the mononuclear complexes [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N}(L)(PPh3)] (L: OAc, 4a; Cl, 5a) and [Pd{4-5-(OCH2O)C6H2C(H)NCH2CH2NMe2-C2,N}(Br)(PPh3)] (6a), with Pd-NMe2 bond cleavage. However, treatment of a solution of 3a or 2a with silver trifluoromethanesulfonate, followed by reaction with PPh3 in acetone yielded the cyclometallated complexes [Pd{2-Br-4,5-(OCH2O)C6HC(H)NCH2CH2NMe2-C6,N,N}(PPh3)][CF3SO3] (7a) and [Pd{4-5-(OCH2O)C6H2C(H)NCH2CH2NMe2-C2,N,N}(PPh3)][CF3SO3] (8a), respectively, where the Pd-NMe2 bond was retained.The reaction of the ligands 2-Br-4,5-(OCH2O)C6H2C(H)N(2′-OH-5′-tBuC6H3) (c) and 4,5-(OCH2CH2)C6H3C(H)N(2′-OH-5′-tBuC6H3) (d) with Pd(OAc)2 gave the tetranuclear complexes [Pd{2-Br-4,5-(OCH2O)C6HC(H)N(2′-O-5′-tBuC6H3)-C6,N,O}]4 (1c) and [Pd{4,5-(OCH2CH2)C6H2C(H)N(2′-O-5′-tBuC6H3)-C6,N,O}]4 (1d), respectively. Treatment of 1c with PPh3 in 1:4 molar ratio, gave the mononuclear species [Pd{2-Br-4,5-(OCH2O)C6HC(H)N(2′-(O)-5′-tBuC6H3)-C6,N,O}(PPh3)] (2c) with opening of the polynuclear structure after P-Obridging bond cleavage.The structure of compounds 2a, 1c and 1d has been determined by X-ray diffraction analysis. 相似文献
19.
Elizabeth Erasmus 《Inorganica chimica acta》2011,378(1):95-101
Chalcones of the type Mc-CO-CHCH-Ph, Ph-CO-CHCH-Mc and Mc-CO-CHCH-Mc with Mc = Fc = ferrocenyl or Rc = ruthenocenyl, and Ph = phenyl were synthesized. Synthesis was achieved by base catalyzed Claisen-Schmidt condensation of the appropriated acetyl and aldehyde in ethanol. Cyclic voltammetry in CH3CN in the presence of 0.1 mol dm−3 [N(Bu)4][PF6] revealed chemical and electrochemical reversible behaviour for the Fc/Fc+ couple and irreversible electrochemistry for the two electron Rc/Rc2+ couple. The potential ranges for the Fc/Fc+ couple varied in the range 138 ? E°′ ? 302 mV while Epa for Rc/Rc2+ couple was between 358 and 510 mV vs. FcH/FcH+, the internal standard. Chalcones with the carbonyl group adjacent to the metallocene, are more difficult to oxidize. 相似文献
20.
Treatment of diphenyl-di(phenylethynyl)germane with two equivalents of di(tert-butyl)aluminum hydride afforded the corresponding dialkenyl derivative, Ph2Ge[C(AltBu2)C(H)-Ph]2 (1) by dual hydroalumination. The aluminum atoms of 1 are attached to the carbon atoms in α-position to germanium. They are coordinatively unsaturated and are able to act as chelating Lewis-acids and to coordinate donors such as chloride or bromide anions in a chelating manner (2, 3). The analogous reaction of the corresponding silicon-centered dialkyne with two equivalents of dimethylaluminum hydride gave a mixture of unknown compounds. Interestingly, equimolar quantities of the hydride and the dialkyne resulted in dismutation and the formation of the unprecedented compound MeAl[C(CH-Ph)-SiPh2-CC-Ph]2 (4). Compound 4 has two alkenyl groups bonded to the central aluminum atom and a terminal alkynyl group attached to each silicon atom. An attempt to reduce the remaining triple bonds by reaction with di(tert-butyl)aluminum hydride resulted in cleavage and isolation of the monoalkenyl compound tBu2Al-C[C(H)-Ph]-SiPh2-CC-Ph (5). The molecular structure of 5 showed a close interaction between the α-carbon atom of the triple bond and the coordinatively unsaturated aluminum atom. 相似文献