Truly cationic metallocenes with the parent cyclopentadienyl ligand are so far unknown for the Group 14 elements. Herein we report on an almost “naked” [SnCp]+ cation with the weakly coordinating [Al{OC(CF3)3}4]− and [{(F3C)3CO}3Al−F−Al{OC(CF3)3}3]− anions. [SnCp][Al{OC(CF3)3}4] was used to prepare the first main‐group quadruple‐decker cation [Sn3Cp4]2+ again as the [Al{OC(CF3)3}4]− salt. Additionally, the toluene adduct [CpSn(C7H8)][Al{OC(CF3)3}4] was obtained. 相似文献
Truly cationic metallocenes with the parent cyclopentadienyl ligand are so far unknown for the Group 14 elements. Herein we report on an almost “naked” [SnCp]+ cation with the weakly coordinating [Al{OC(CF3)3}4]− and [{(F3C)3CO}3Al−F−Al{OC(CF3)3}3]− anions. [SnCp][Al{OC(CF3)3}4] was used to prepare the first main‐group quadruple‐decker cation [Sn3Cp4]2+ again as the [Al{OC(CF3)3}4]− salt. Additionally, the toluene adduct [CpSn(C7H8)][Al{OC(CF3)3}4] was obtained. 相似文献
In a new oxidative route, Ag+[Al(ORF)4]? (RF=C(CF3)3) and metallic indium were sonicated in aromatic solvents, such as fluorobenzene (PhF), to give a precipitate of silver metal and highly soluble [In(PhF)n]+ salts (n=2, 3) with the weakly coordinating [Al(ORF)4]? anion in quantitative yield. The In+ salt and the known analogous Ga+[Al(ORF)4]? were used to synthesize a series of homoleptic PR3 phosphane complexes [M(PR3)n]+, that is, the weakly PPh3‐bridged [(Ph3P)3In–(PPh3)–In(PPh3)3]2+ that essentially contains two independent [In(PPh3)3]+ cations or, with increasing bulk of the phosphane, the carbene‐analogous [M(PtBu3)2]+ (M=Ga, In) cations. The MI? P distances are 27 to 29 pm longer for indium, and thus considerably longer than the difference between their tabulated radii (18 pm). The structure, formation, and frontier orbitals of these complexes were investigated by calculations at the BP86/SV(P), B3LYP/def2‐TZVPP, MP2/def2‐TZVPP, and SCS‐MP2/def2‐TZVPP levels. 相似文献
The synthesis and characterization of the first supramolecular aggregates incorporating the organometallic cyclo‐P3 ligand complexes [CpRMo(CO)2(η3‐P3)] (CpR=Cp (C5H5; 1a ), Cp* (C5(CH3)5; 1b )) as linking units is described. The reaction of the Cp derivative 1a with AgX (X=CF3SO3, Al{OC(CF3)3}4) yields the one‐dimensional (1D) coordination polymers [Ag{CpMo(CO)2(μ,η3:η1:η1‐P3)}2]n[Al{OC(CF3)3}4]n ( 2 ) and [Ag{CpMo(CO)2(μ,η3:η1:η1‐P3)}3]n[X]n (X=CF3SO3 ( 3a ), Al{OC(CF3)3}4 ( 3b )). The solid‐state structures of these polymers were revealed by X‐ray crystallography and shown to comprise polycationic chains well‐separated from the weakly coordinating anions. If AgCF3SO3 is used, polymer 3a is obtained regardless of reactant stoichiometry whereas in the case of Ag[Al{OC(CF3)3}4], reactant stoichiometry plays a decisive role in determining the structure and composition of the resulting product. Moreover, polymers 3a, b are the first examples of homoleptic silver complexes in which AgI centers are found octahedrally coordinated to six phosphorus atoms. The Cp* derivative 1b reacts with Ag[Al{OC(CF3)3}4] to yield the 1D polymer [Ag{Cp*Mo(CO)2(μ,η3:η2:η1‐P3)}2]n[Al{OC(CF3)3}4]n ( 4 ), the crystal structure of which differs from that of polymer 2 in the coordination mode of the cyclo‐P3 ligands: in 2 , the Ag+ cations are bridged by the cyclo‐P3 ligands in a η1:η1 (edge bridging) fashion whereas in 4 , they are bridged exclusively in a η2:η1 mode (face bridging). Thus, one third of the phosphorus atoms in 2 are not coordinated to silver while in 4 , all phosphorus atoms are engaged in coordination with silver. Comprehensive spectroscopic and analytical measurements revealed that the polymers 2 , 3a , b , and 4 depolymerize extensively upon dissolution and display dynamic behavior in solution, as evidenced in particular by variable temperature 31P NMR spectroscopy. Solid‐state 31P magic angle spinning (MAS) NMR measurements, performed on the polymers 2 , 3b , and 4 , demonstrated that the polymers 2 and 3b also display dynamic behavior in the solid state at room temperature. The X‐ray crystallographic characterisation of 1b is also reported. 相似文献
The electronic structures of the five members of the electron transfer series [Mo(bpy)3]n (n=3+, 2+, 1+, 0, 1?) are determined through a combination of techniques: electro‐ and magnetochemistry, UV/Vis and EPR spectroscopies, and X‐ray crystallography. The mono‐ and dication are prepared and isolated as PF6 salts for the first time. It is shown that all species contain a central MoIII ion (4d3). The successive one‐electron reductions/oxidations within the series are all ligand‐based, involving neutral (bpy0), the π‐radical anion (bpy.)1?, and the diamagnetic dianion (bpy2?)2?: [MoIII(bpy0)3]3+ (S=3/2), [MoIII(bpy.)(bpy0)2]2+ (S=1), [MoIII(bpy.)2(bpy0)]1+ (S=1/2), [MoIII(bpy.)3] (S=0), and [MoIII(bpy.)2(bpy2?)]1? (S=1/2). The previously described diamagnetic dication “[MoII(bpy0)3](BF4)2” is proposed to be a diamagnetic dinuclear species [{Mo(bpy)3}2(μ2‐O)](BF4)4. Two new polynuclear complexes are prepared and structurally characterized: [{MoIIICl(Mebpy0)2}2(μ2‐O)]Cl2 and [{MoIV(tpy.)2}2(μ2‐MoVIO4)](PF6)2?4 MeCN. 相似文献
Naked copper…?? A newly developed simple two‐step route to weakly coordinated CuI starting materials that were used to prepare novel copper–cyclosulfur adducts, including the first M+–S12 complex (see figure, RF= C(CF3)3, C(CH3)(CF3)2, or CH(CF3)2). Reactions with the [Al{OC(CF3)3}4]? counterion mimic gas‐phase chemistry inside a mass spectrometer (to form [Cu(S12)]+).
The betain‐like carbodiphosphorane CS2 adduct S2CC(PPh3)2 ( 1 ) reacts with Ag(I) salts which contain weakly coordinating anions such as [BF4]? or [Al{OC(CF3)3}4]? to produce the cluster compounds [Ag6{S2CC(PPh3)2}4][BF4]6 ( 2 ) and [Ag4{S2CC(PPh3)2}4][Al{OC(CF3)3}4]4 ( 3 ), respectively, as orange yellow crystals containing solvent molecules. In the solid state the Ag4 unit in 3 forms a tetrahedron, and in the Ag6 core of 2 two of the opposite edges of the tetrahedron are bridged by Ag+ ions. The clusters are held together by argentophilic interactions, and each sulfur atom of 1 is coordinated to four (as in 2 ) or three (as in 3 ) silver atoms. The compounds are characterized by IR and 31P NMR spectroscopic studies and by X‐ray diffraction analyses. 相似文献
The complex series [Ru(pap)(Q)2]n ([ 1 ]n–[ 4 ]n; n=+2, +1, 0, ?1, ?2) contains four redox non‐innocent entities: one ruthenium ion, 2‐phenylazopyridine (pap), and two o‐iminoquinone moieties, Q=3,5‐di‐tert‐butyl‐N‐aryl‐1,2‐benzoquinonemonoimine (aryl=C6H5 ( 1+ ); m‐(Cl)2C6H3 ( 2+ ); m‐(OCH3)2C6H3 ( 3+ ); m‐(tBu)2C6H3 ( 4 +)). A crystal structure determination of the representative compound, [ 1 ]ClO4, established the crystallization of the ctt‐isomeric form, that is, cis and trans with respect to the mutual orientations of O and N donors of two Q ligands, and the coordinating azo N atom trans to the O donor of Q. The sensitive C? O (average: 1.299(3) Å), C? N (average: 1.346(4) Å) and intra‐ring C? C (meta; average: 1.373(4) Å) bond lengths of the coordinated iminoquinone moieties in corroboration with the N?N length (1.292(3) Å) of pap in 1 + establish [RuIII(pap0)(Q.?)2]+ as the most appropriate electronic structural form. The coupling of three spins from one low‐spin ruthenium(III) (t2g5) and two Q.? radicals in 1 +– 4 + gives a ground state with one unpaired electron on Q.?, as evident from g=1.995 radical‐type EPR signals for 1 +– 4 +. Accordingly, the DFT‐calculated Mulliken spin densities of 1 + (1.152 for two Q, Ru: ?0.179, pap: 0.031) confirm Q‐based spin. Complex ions 1 +– 4 + exhibit two near‐IR absorption bands at about λ=2000 and 920 nm in addition to intense multiple transitions covering the visible to UV regions; compounds [ 1 ]ClO4–[ 4 ]ClO4 undergo one oxidation and three separate reduction processes within ±2.0 V versus SCE. The crystal structure of the neutral (one‐electron reduced) state ( 2 ) was determined to show metal‐based reduction and an EPR signal at g=1.996. The electronic transitions of the complexes 1 n– 4 n (n=+2, +1, 0, ?1, ?2) in the UV, visible, and NIR regions, as determined by using spectroelectrochemistry, have been analyzed by TD‐DFT calculations and reveal significant low‐energy absorbance (λmax>1000 nm) for cations, anions, and neutral forms. The experimental studies in combination with DFT calculations suggest the dominant valence configurations of 1 n– 4 n in the accessible redox states to be [RuIII(pap0)(Q.?)(Q0)]2+ ( 1 2+– 4 2+)→[RuIII(pap0)(Q.?)2]+ ( 1 +– 4 +)→[RuII(pap0)(Q.?)2] ( 1 – 4 )→[RuII(pap.?)(Q.?)2]? ( 1 ?– 4 ?)→[RuIII(pap.?)(Q2?)2]2? ( 1 2?– 4 2?). 相似文献
3‐(4‐carboxyphenyl)‐1‐methyltriazene N‐oxide reacts with KOH in methanol/pyridine to give {K[O2C‐C6H4‐N(H)NN(CH3)O]·4H2O}n, Potassium‐3‐(4‐carboxylatophenyl)‐1‐methyltriazene N‐oxide). The terminal carboxylato group of the anion does not interact with the cation. In the crystal lattice of {K(C8H8N3O3)·4H2O}n each three of the four water molecules interact with two potassium cations, every K+ ion being the centre of six bridging K···O interactions. Potassium cations interact further with the terminal N‐oxigen atom of single [C8H8N3O3]? anions achieving two parallel {C8H8N3O3?K+}n chains, which are linked through water molecules. The resulting polymeric, one‐dimensional chain, is operated by a screw axis 21 parallel to the crystallographic direction [010], along and equidistant to the K+ centres. The coordination of the K+ centres involves a distortion of the boat conformation of elementary sulfur (S8) with the ideal C2v symmetry. 相似文献
Syntheses and NMR Spectroscopic Ivestigations of Salts containing the Novel Anions [PtXn(CF3)6‐n]2— (n = 0 ‐ 5, X = F, OH, Cl, CN) and Crystal Structure of K2[(CF3)2F2Pt(μ‐OH)2PtF2(CF3)2]·2H2O The first syntheses of trifluoromethyl‐complexes of platinum through fluorination of cyanoplatinates are reported. The fluorination of tetracyanoplatinates(II), K2[Pt(CN)4], and hexacyanoplatinates(IV), K2[Pt(CN)6], with ClF in anhydrous HF leads after working up of the products to K2[(CF3)2F2Pt(μ‐OH)2PtF2(CF3)2]·2H2O. The structure of the salt is determined by a X‐ray structure analysis, P21/c (Nr. 14), a = 11.391(2), b = 11.565(2), c = 13.391(3)Å, β = 90.32(3)°, Z = 4, R1 = 0.0326 (I > 2σ(I)). The reaction of [Bu4N]2[Pt(CN)4] with ClF in CH2Cl2 generates mainly cis‐[Bu4N]2[PtCl2(CF3)4] and fac‐[Bu4N]2[PtCl3(CF3)3], but in contrast that of [Bu4N]2[Pt(CN)6] with ClF in CH2Cl2 results cis‐[Bu4N]2[PtX2(CF3)4], [Bu4N]2[PtX(CF3)5] (X = F, Cl) and [Bu4N]2[Pt(CF3)6]. In the products [Bu4N]2[PtXn(CF3)6‐n] (X = F, Cl, n = 0—3) it is possibel to exchange the fluoro‐ligands into chloro‐ and cyano‐ligands by treatment with (CH3)3SiCl und (CH3)3SiCN at 50 °C. With continuing warming the trifluoromethyl‐ligands are exchanged by chloro‐ and cyano‐ligands, while as intermediates CF2Cl and CF2CN ligands are formed. The identity of the new trifluoromethyl‐platinates is proved by 195Pt‐ and 19F‐NMR‐spectroscopy. 相似文献
We report the time‐resolved supramolecular assembly of a series of nanoscale polyoxometalate clusters (from the same one‐pot reaction) of the form: [H(10+m)Ag18Cl(Te3W38O134)2]n, where n=1 and m=0 for compound 1 (after 4 days), n=2 and m=3 for compound 2 (after 10 days), and n=∞ and m=5 for compound 3 (after 14 days). The reaction is based upon the self‐organization of two {Te3W38} units around a single chloride template and the formation of a {Ag12} cluster, giving a {Ag12}‐in‐{W76} cluster‐in‐cluster in compound 1 , which further aggregates to cluster compounds 2 and 3 by supramolecular Ag‐POM interactions. The proposed mechanism for the formation of the clusters has been studied by ESI‐MS. Further, control experiments demonstrate the crucial role that TeO32?, Cl?, and Ag+ play in the self‐assembly of compounds 1 – 3 . 相似文献
CF3S(O)F, (CF3)2SO, CF3SF3, (CF3)2SF2, and SF4 react in different manner with XeF+MF6? (M?As, Sb). An oxidative fluorination is observed by CF3S(O)F forming the persulfonium salt CF3S(O)F2+SbF6?, whereas by (CF3)2SO a simple addition product containing xenon can be isolated in form of the sulfonium salt (CF3)2SOXeF+SbF6?. On the contrary, the Lewis-acidic character of the XeF+-cation predominates against (CF3)nSF4?n (n = 0 ? 2) leading to the corresponding fluorosulfonium salts (CF3)nSF3?n+MF6? (M?As, Sb) and XeF2. 相似文献
Sterically unprotected thiophene/phenylene co‐oligomer radical cation salts BPnT.+[Al(ORF)4]? (ORF=OC(CF3)3, n=1–3) have been successfully synthesized. These newly synthesized salts have been characterized by UV/Vis‐NIR absorption and EPR spectroscopy, and single‐crystal X‐ray diffraction analysis. Their conductivity increases with chain length. The formed meso‐helical stacking by cross‐overlapping radical cations of BP2T.+ is distinct from previously reported face‐to‐face overlaps of sterically protected (co‐)oligomer radical cations. 相似文献
The lithium salt of the weakly coordinating alkoxyaluminate anion Li[Al(OC(CF3)2(CH2SiMe3))4] ( 2 ) is soluble in polar and even in non‐polar solvents. Especially the solubility in n‐hexane confirms 2 to be an excellent candidate for Li ion catalysis. Its polymeric structure consists of a seven coordinated Li+ cation, coordinating a [Al(OC(CF3)2(CH2SiMe3)]? anion that serves as hexadentate O2F4 ligand and a further bridging F atom of a second anion. Compound 2 reacts with ClCPh3 giving the [CPh3]+ salt which is at least stable in CD2Cl2 over days at 298 K, but decomposes after storage at 333 K for several days. 相似文献
In an earlier publication (J. Am. Chem. Soc. 2002 , 124, 7111) we showed that polymeric cationic [Ag(P4S3)n]+ complexes (n=1, 2) are accessible if partnered with a suitable weakly coordinating counterion of the type [Al(ORF)4]? (ORF: poly‐ or perfluorinated alkoxide). The present work addresses the following questions that could not be answered in the initial report: How many P4S3 cages can be bound to a Ag+ ion? Why are these complexes completely dynamic in solution in the 31P NMR experiments? Can these dynamics be frozen out in a low‐temperature 31P MAS NMR experiment? What are the principal binding sites of the P4S3 cage towards the Ag+ ion? What are likely other isomers on the [Ag(P4S3)n]+ potential energy surface? Counterion influence: Reactions of P4S3 with Ag[Al{OC(CH3)(CF3)2}4] (Ag[hftb]) and Ag[{(CF3)3CO}3Al‐F‐Al{OC(CF3)3)}3] (Ag[al‐f‐al]) gave [(P4S3)Ag[hftb]]∞ ( 7 ) as a molecular species, whereas [Ag2(P4S3)6]2+[al‐f‐al]?2 ( 8 ) is an isolated 2:1 salt. We suggest that a maximum of three P4S3 cages may be bound on average to an Ag+ ion. Only isolated dimeric dications are formed with the largest cation, but polymeric species are obtained with all other smaller aluminates. Thermodynamic Born–Haber cycles, DFT calculations, as well as solution NMR and ESI mass spectrometry indicate that 8 exhibits an equilibrium between the dication [Ag2(P4S3)6]2+ (in the solid state) and two [Ag(P4S3)3]+ monocations (in the gas phase and in solution). Dynamics: 31P MAS NMR spectroscopy showed these solid adducts to be highly dynamic, to an extent that the 2JP,P coupling within the cages could be resolved (J‐res experiment). This is supported by DFT calculations, which show that the extended PES of [Ag(P4S3)n]+ (n=1–3) and [Ag2(P4S3)2]+ is very flat. The structures of α‐ and γ‐P4S3 were redetermined. Their variable‐temperature 31P MAS NMR spectra are discussed jointly with those of all four currently known [Ag(P4S3)n]+ adducts with n=1, 2, and 3. 相似文献
Attempts to prepare previously unknown simple and very Lewis acidic [RZn]+[Al(ORF)4]? salts from ZnR2, AlR3, and HO?RF delivered the ion‐like RZn(Al(ORF)4) (R=Me, Et; RF=C(CF3)3) with a coordinated counterion, but never the ionic compound. Increasing the steric bulk in RZn+ to R=CH2CMe3, CH2SiMe3, or Cp*, thus attempting to induce ionization, failed and led only to reaction mixtures including anion decomposition. However, ionization of the ion‐like EtZn(Al(ORF)4) compound with arenes yielded the [EtZn(arene)2]+[Al(ORF)4]? salts with arene=toluene, mesitylene, or o‐difluorobenzene (o‐DFB)/toluene. In contrast to the ion‐like EtZn(η3‐C6H6)(CHB11Cl11), which co‐crystallizes with one benzene molecule, the less coordinating nature of the [Al(ORF)4]? anion allowed the ionization and preparation of the purely organometallic [EtZn(arene)2]+ cation. These stable materials have further applications as, for example, initiators of isobutene polymerization. DFT calculations to compare the Lewis acidities of the zinc cations to those of a large number of organometallic cations were performed on the basis of fluoride ion affinity. The complexation energetics of EtZn+ with arenes and THF was assessed and related to the experiments. 相似文献
Addition of Cationic Lewis Acids [M′Ln]+ (M′Ln = Fe(CO)2Cp, Fe(CO)(PPh3)Cp, Ru(PPh3)2Cp, Re(CO)5, Pt(PPh3)2, W(CO)3Cp to the Anionic Thiocarbonyl Complexes [HB(pz)3(OC)2M(CS)]− (M = Mo, W; pz = 3,5‐dimethylpyrazol‐1‐yl) Adducts from Organometallic Lewis Acids [Fe(CO)2Cp]+, [Fe(CO)(PPh3)Cp]+, [Ru(PPh3)2Cp]+, [Re(CO)5]+, [ Pt(PPh3)2]+, [W(CO)3Cp]+ and the anionic thiocarbonyl complexes [HB(pz)3(OC)2M(CS)]− (M = Mo, W) have been prepared. Their spectroscopic data indicate that the addition of the cations occurs at the sulphur atom to give end‐to‐end thiocarbonyl bridged complexes [HB(pz)3(OC)2MCSM′Ln]. 相似文献
Sequential treatment of 2‐C6H4Br(CHO) with LiC≡CR1 (R1=SiMe3, tBu), nBuLi, CuBr?SMe2 and HC≡CCHClR2 [R2=Ph, 4‐CF3Ph, 3‐CNPh, 4‐(MeO2C)Ph] at ?50 °C leads to formation of an intermediate carbanion (Z)‐1,2‐C6H4{CA(=O)C≡CBR1}{CH=CH(CH?)R2} ( 4 ). Low temperatures (?50 °C) favour attack at CB leading to kinetic formation of 6,8‐bicycles containing non‐classical C‐carbanion enolates ( 5 ). Higher temperatures (?10 °C to ambient) and electron‐deficient R2 favour retro σ‐bond C?C cleavage regenerating 4 , which subsequently closes on CA providing 6,6‐bicyclic alkoxides ( 6 ). Computational modelling (CBS‐QB3) indicated that both pathways are viable and of similar energies. Reaction of 6 with H+ gave 1,2‐dihydronaphthalen‐1‐ols, or under dehydrating conditions, 2‐aryl‐1‐alkynylnaphthlenes. Enolates 5 react in situ with: H2O, D2O, I2, allylbromide, S2Me2, CO2 and lead to the expected C ‐E derivatives (E=H, D, I, allyl, SMe, CO2H) in 49–64 % yield directly from intermediate 5 . The parents (E=H; R1=SiMe3, tBu; R2=Ph) are versatile starting materials for NaBH4 and Grignard C=O additions, desilylation (when R1=SiMe) and oxime formation. The latter allows formation of 6,9‐bicyclics via Beckmann rearrangement. The 6,8‐ring iodides are suitable Suzuki precursors for Pd‐catalysed C?C coupling (81–87 %), whereas the carboxylic acids readily form amides under T3P® conditions (71–95 %). 相似文献
Solvothermal reactions of the calix[4]arene tetraacetic acid (H4CTA) with zinc nitrate in the presence of α,ω‐diaminoalkanes afford two‐dimensional metallopolycapsular networks of the formula {[Me2NH2]2[G@(Zn2(CTA)2)] ? (DMF)2 ? (H2O)4}n (G=+NH3–(CH2)n–NH3+, n=2, 3, 4; DMF=N,N‐dimethylformamide). These metallopolycapsular networks are built up of metallocapsules that consist of two CTA and two ZnII ions. Short alkanediyldiammonium (+NH3–(CH2)n–NH3+, n=2, 3, 4) guest ions are accommodated in each capsule of the metallopolycapsular network through a variety of supramolecular interactions. The thermal behaviours and the solid‐state photoluminescent properties of these complexes were also investigated. 相似文献
下载免费PDF全文