Coordinating properties of [M(CO)5(CN)] [M=Cr; Mo; W] ligands: formation of ion pairs or dinuclear cyanide-bridged complexes, spectroscopic and X-ray diffraction studies

The reaction of sodium cyanopentacarbonylmetalates Na[M(CO)₅(CN)] (M=Cr; Mo; W) with cationic Fe(II) complexes [Cp(CO)(L)Fe(thf)][O₃SCF₃], [L=PPh₃ (1a), CN-Benzyl (1b), CN-2,6-Me₂C₆H₃ (1c); CN-Bu^t (1d), P(OMe)₃ (1e), P(Me)₂Ph (1f)] in acetonitrile solution, yielded the metathesis products [Cp(CO)(L)Fe(NCCH₃)][NCM(CO)₅] [M=W, L=PPh₃ (2a), CN-Benzyl (2b), CN-2,6-Me₂C₆H₃ (2c); CN-Bu^t (2d), P(OMe)₃ (2e), P(Me)₂Ph (2f); M=Cr, L=(PPh₃) (3a), CN-2,6-Me₂C₆H₃ (3c); M=Mo, L=(PPh₃) (4a), CN-2,6-Me₂C₆H₃ (4c)]. The ionic nature of such complexes was suggested by conductivity measurements and their main structural features were determined by X-ray diffraction studies. Well-resolved signals relative to the [M(CO)₅(CN)] moieties could be distinguished only when ¹³C NMR experiments were performed at low temperature (from −30 to −50 °C), as in the case of [Cp(CO)(PPh₃)Fe(NCCH₃)][NCW(CO)₅] (2a) and [Cp(CO)(Benzyl-NC)Fe(NCCH₃)][NCW(CO)₅] (2b). When the same reaction was carried out in dichloromethane solution, neutral cyanide-bridged dinuclear complexes [Cp(CO)(L)FeNCM(CO)₅] [M=W, L=PPh₃ (5a), CN-Benzyl (5b); M=Cr, L=(PPh₃) (6a), CN-2,6-Me₂C₆H₃ (6c), CO (6g); M=Mo, L=CN-2,6-Me₂C₆H₃ (7c), CO (7g)] were obtained and characterized by infrared and NMR spectroscopy. In all cases, the room temperature ¹³C NMR measurements showed no broadening of cyano pentacarbonyl signals and, relative to tungsten complexes [Cp(CO)(PPh₃)FeNCW(CO)₅] (5a) and [Cp(CO)(CN-Benzyl)FeNCW(CO)₅] (5b), the presence of ¹⁸³W satellites of the ¹³CN resonances (J_CW ∼ 95 Hz) at room temperature confirmed the formation of stable neutral species. The main ¹³C NMR spectroscopic properties of the latter compounds were compared to those of the linkage isomers [Cp(CO)(PPh₃)FeCNW(CO)₅] (8a) and [Cp(CO)(CN-Benzyl)FeCNW(CO)₅] (8b). The characterization of the isomeric couples 5a-8a and 5b-8b was completed by the analyses of their main IR spectroscopic properties. The crystal structures determined for 2a, 5a, 8a and 8b allowed to investigate the geometrical and electronic differences between such complexes. Finally, the study was completed by extended Hückel calculations of the charge distribution among the relevant atoms for complexes 2a, 5a and 8a.     

Formation and structural characterization of novel polynuclear palladium selenolato complexes [Pd3Se(SePh)3(PPh3)3]Cl and [Pd6Cl2Se4(SePh)2(PPh3)6]

In addition to well-known dinuclear phenylselenolato palladium complexes, the reaction of [PdCl₂(PPh₃)₂] and NaSePh affords small amounts of novel trinuclear and hexanuclear complexes [Pd₃Se(SePh)₃(PPh₃)₃]Cl (1) and [Pd₆Cl₂Se₄(SePh)₂(PPh₃)₆] (2). Complex 1 is triclinic, P1?, a=13.6310(2), b=16.2596(2), c=16.9899(3) Å, α=83.1738(5), β=78.9882(5), γ=78.7635(5)°. Complex 2 is monoclinic, C2/c, a=25.7165(9), b=17.6426(8), c=27.9151(14) Å, β=110.513(2)°. There are no structural forerunners for 1, but the hexanuclear complex 2 is isostructural with [Pd₆Cl₂Te₄(TeR)₂(PPh₃)₆] (R=Ph, C₄H₃S) that have been observed as one of the products in the oxidative addition of R₂Te₂ to [Pd(PPh₃)₄]. Mononuclear palladium complexes may play a significant role as building blocks in the formation of the polynuclear complexes.     

Synthesis and characterization of cyclometallated palladium(II) and platinum(II) complexes with amide-thiolate ligands

The redox reaction of bis(2-benzamidophenyl) disulfide (H₂L-LH₂) with [Pd(PPh₃)₄] in a 1:1 ratio gave mononuclear and dinuclear palladium(II) complexes with 2-benzamidobenzenethiolate (H₂L⁻), [Pd(H₂L-S)₂(PPh₃)₂] (1) and [Pd₂(H₂L-S)₂ (μ-H₂L-S)₂(PPh₃)₂] (2). A similar reaction with [Pt(PPh₃)₄] produced only the corresponding mononuclear platinum(II) complex, [Pt(H₂L-S)₂(PPh₃)₂] (3). Treatment of these complexes with KOH led to the formation of cyclometallated palladium(II) and platinum(II) complexes, [Pd(L-C,N,S)(PPh₃)]⁻ ([4]⁻) and [Pt(L-C,N,S) (PPh₃)]⁻ ([5]⁻). The molecular structures of 2, 3 and [4]⁻ were determined by X-ray crystallography.     

Designed synthesis of metal-organic frameworks containing gold(I) cations supported in phosphazene-phosphine polymeric matrices

The reaction of the polyphosphazenes {[NP(O₂C₁₂H₈)]_1−x[NP(OC₆H₄PPh₂)₂]_x}_n, x = 0.15 (1a), 0.25 (1b), 0.35 (1c), with [Au(THT)Cl] (THT = tetrahydrothiophene) in dichloromethane gave the polymers {[NP(O₂C₁₂H₈)]_1−x[NP(OC₆H₄PPh₂AuCl)₂]_x}_n, x = 0.15, (2a), 0.25 (2b), 0.35 (2c), respectively. The reaction of (1a) with [Au(PPh₃)₂]PF₆ in refluxing THF led to the replacement of the PPh₃ ligands giving a metal-organic framework of idealized formula {[NP(O₂C₁₂H₈)]_1−x[NP(OC₆H₄PPh₂)₂(AuPF₆)_0.5]_x}_n, x = 0.15, (3a), 0.25 (3b) containing cationic [-Ph₂P-Au⁺-PPh₂-] cross-linking sites. The insoluble polymeric matrix (3a), having pendant PPh₂ groups, was reacted with [Au(THT)Cl] to give the new polymeric framework of composition {[NP(O₂C₁₂H₈)]_0.85[NP(OC₆H₄PPh₂)₂(AuPF₆)_0.5(AuCl)_0.5]_0.15}_n (4).     

Alkyne activation by half-sandwich ruthenium(II) complexes bearing the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane (PTA)

Complex [RuCl{κ³(N,N,N)-Tp}(PPh₃)(PTA)] (κ³(N,N,N)-Tp = hydridotris(pyrazolyl)borate) containing the water-soluble phosphane 1,3,5-triaza-7-phosphatricyclo[3.3.1.1^3,7]decane (PTA) reacts with terminal alkynes producing to the corresponding neutral alkynyl complexes [Ru(CCR){κ³(N,N,N)-Tp}(PPh₃)(PTA)] (R = Ph (1a), ⁿBu (1b), 1-cyclopentenyl (1c), p-methoxyphenyl (1d), 6-methoxynaft-2-yl (1e)). When halide is extracted from complex [RuCl{κ³(N,N,N)-Tp}(PPh₃)(PTA)] followed by treatment with propargyl alcohols, the corresponding allenylidene complexes [Ru{κ³(N,N,N)-Tp}(PPh₃)(PTA)(CCCPh₂)][X] (X = PF₆ (2a), CF₃SO₃ (2b)) and [Ru{κ³(N,N,N)-Tp}(PPh₃)(PTA)(CCCC₁₂H₈)][PF₆] (3) result. Electrophilic attack on the complexes thus obtained leads chemoselectively to the alkynyl complexes [Ru(CCR){κ³(N,N,N)-Tp}(PPh₃)(1-CH₃-PTA)][CF₃SO₃] (R = Ph (4a), ⁿBu (4b), and 1-cyclopentenyl (4c)) and to the dicationic allenylidene complexes [Ru{κ³(N,N,N)-Tp}(PPh₃)(1-H-PTA)(CCCC₁₂H₈)][PF₆]₂ (5) and [Ru{κ³(N,N,N)-Tp}(PPh₃)(1-CH₃-PTA)(CCCPh₂)][CF₃SO₃]₂ (6).     

Synthesis,spectral characterization,properties and structures of copper(I) complexes containing novel bidentate iminopyridine ligands

Four new ligands, (4-methyl-phenyl)-pyridin-2-ylmethylene-amine (A), (2,3-dimethyl-phenyl)-pyridin-2-ylmethylene-amine (B), (2,4-dimethyl-phenyl)-pyridin-2-ylmethylene-amine (C) and (2,5-dimethyl-phenyl)-pyridin-2-ylmethylene-amine (D), and their corresponding copper(I) complexes, [Cu(A)₂]ClO₄ (1a), [Cu(B)₂]ClO₄ (1b), [Cu(C)₂]ClO₄ (1c), [Cu(D)₂]ClO₄ (1d), [Cu(A)(PPh₃)₂]ClO₄ (2a), [Cu(B)(PPh₃)₂]ClO₄ (2b), [Cu(C)(PPh₃)₂]ClO₄ (2c) and [Cu(D)(PPh₃)₂]ClO₄ (2d), have been synthesized and characterized by CHN analyses, ¹H and ¹³C NMR, IR and UV–Vis spectroscopy. The crystal structures of [Cu(B)₂]ClO₄ (1b), [Cu(C)₂]ClO₄ (1c) and [Cu(A)(PPh₃)₂]ClO₄ · 1/2CH₃CN (2a) were determined from single crystal X-ray diffraction. The coordination polyhedron about the copper(I) center in the three complexes is best described as a distorted tetrahedron. A quasireversible redox behavior is observed for the complexes.     

Orthopalladation of phosphorus ylides in endo position with bidentate ligands

The ortho-metallated complexes [Pd₂{κ²(C,C)-C₆H₄(PPh₂CHC(O)C₆H₅R}₂(μ-Cl)₂] (R = Ph (1a), NO₂ (1b), Br (1c)) were prepared by refluxing equimolar mixtures of Ph₃PCHC(O)C₆H₅R, (R = Ph, NO₂, Br) and Pd(OAc)₂ in MeOH, followed by an excess of NaCl. The dinuclear complexes (1a-1c) react with silver trifluoromethylsulfonate and bidentate ligands [L = bipy (2,2′-bipyridine), phen (phenanthroline), dppe (bis(diphenylphosphino)ethane), dppp (bis(diphenylphosphino)propane)] giving the mononuclear stabilized orthopalladated complexes in endo position [Pd{κ²(C,C)-C₆H₄(PPh₂CHC(O)R}L](OTf) [R = Ph, L = phen (2a), bipy (3a), dppe (4a), dppp (5a); R = NO₂, L = phen (2b), bipy (3b), dppe (4b), dppp (5b); R = Br, L = phen (2c), bipy (3c), dppe (4c), dppp (5c); OTf = trifluoromethylsulfonate anion]. Orthometalation and ylidic C-coordination are demonstrated by an X-ray diffraction study of 2c and 3c. In the structures, the palladium atom shows a slightly distorted square-planar coordination geometry.     

Examining the thermolysis reactions of nanoscopic Mn12 single molecule magnets

The thermal behavior of three Mn₁₂ single molecule magnets [Mn₁₂O₁₂(O₂CC₆H₅)₁₆(H₂O)₄]·CH₂Cl₂·C₆H₅CO₂H (1), [Mn₁₂O₁₂(O₂C^tBu)₁₆(H₂O)₄] (2) and [Mn₁₂O₁₂(O₂CCHCl₂)₁₆(H₂O)₄] (3) is reported. Aromatic ligands allow the complex 1 to be stable up to 300 °C whereas alkyl groups decrease drastically the domain of thermal stability for the complexes 2 and 3. Moreover, the thermal decarboxylation of complexes 2 and 3 generates [Mn₆O₂(O₂CR)₁₀L₄] (L=H₂O, HO₂CR) complexes as characterized by single crystal X-ray diffraction when R=^tBu.     

Synthesis,characterization and crystal structure of triphenylphosphine copper(I) methylpyruvate thiosemicarbazones

This paper reports the synthesis of a series of methylpyruvate thiosemicarbazone derivatives containing, on the terminal nitrogen, substituents of different nature and size and namely, ethyl, phenyl and methylphenyl. These ligands were reacted with bis(triphenylphosphine)copper(I) nitrate and acetate to produce the respective complexes: [Cu(PPh₃)₂(Et-Hmpt)]₂(NO₃)₂ (1), [Cu(PPh₃)₂(Ph-Hmpt)]NO₃ (2), [Cu(PPh₃)₂(MePh-Hmpt)]NO₃ (3), [Cu₂(O₂CCH₃)(Et-pt)(PPh₃)₂] · H₂O (4), [Cu(Ph-mpt)(PPh₃)] (5) and [Cu₂(MePh-mpt)₂(PPh₃)₂] (6). All of them were characterized by elemental analysis, IR, ¹H NMR, EPR spectroscopy and, for compounds 1, 2, 4, and 6, by X-ray crystallography. The characterization revealed that the coordinating behaviour of the ligands is influenced by a series of factors, predominant among which is the hard soft nature of the atoms involved in the interactions with the metal centre. The complexes obtained from the nitrate copper(I) salt are formed by cationic molecules with a nitrate as a counterion, while those derived from the acetate salt present deprotonated ligands and a few unexpected features. In particular, one of the compounds (4) is a mixed valence dinuclear complex with an acetate oxygen and the thiosemicarbazone sulfur acting as bridging between the two Cu(I) and Cu(II) ions. Another one (6) presents instead a Cu(I)–Cu(I) sulfur bridged binuclear cluster.     

Reactivity of cationic methyl rhodium(III) complexes cis-[Rh(β-diket)(PPh3)2(CH3)(CH3CN)][BPh4] toward ligands of different character: pyridine, carbon monoxide, and triphenylphosphine

Cationic methyl complex of rhodium(III), cis-[Rh(Acac)(PPh₃)₂(CH₃)(Py)][BPh₄] (1) as a single isomer with Py in the trans to PPh₃ position, is formed upon the reaction of cis-[Rh(Acac)(PPh₃)₂(CH₃)(CH₃CN)][BPh₄] with pyridine in methylene chloride solution.Complex 1 was characterized by elemental analysis and by ³¹P{¹H} and ¹H NMR spectra.Cationic pentacoordinate acetyl complexes, trans-[Rh(Acac)(PPh₃)₂(COCH₃)][BPh₄] (2) and trans-[Rh(BA)(PPh₃)₂(COCH₃)][BPh₄] (3), are prepared by action of carbon monoxide on cis-[Rh(Acac)(PPh₃)₂(CH₃)(CH₃CN)][BPh₄] and cis-[Rh(BA)(PPh₃)₂(CH₃)(CH₃CN)][BPh₄], respectively, in methylene chloride solutions.Complexes 2 and 3 were characterized by elemental analysis and by IR, ³¹P{¹H}, ¹³C{¹H} and ¹H NMR. According to NMR data, 2 and 3 in solution are non-fluxional trigonal bipyramids with β-diketonate and acetyl ligands in the equatorial plane and axial phosphines.In solutions, 2 and 3 gradually isomerize into octahedral methyl carbonyl complexes trans-[Rh(Acac)(PPh₃)₂(CO)(CH₃)][BPh₄] (4) and trans-[Rh(BA)(PPh₃)₂(CO)(CH₃)][BPh₄] (5), respectively.Complexes 4 and 5 were characterized by IR, ³¹P{¹H}, ¹³C{¹H} and ¹H NMR, without isolation.Upon the action of PPh₃ on cis-[Rh(Acac)(PPh₃)₂(CH₃)(CH₃CN)][BPh₄] and cis-[Rh(BA)(PPh₃)₂(CH₃)(CH₃CN)] [BPh₄], reductive elimination of the methyl ligand as a phosphonium salt, [CH₃PPh₃][BPh₄], occurs to give square planar rhodium(I) complexes [Rh(Acac)(PPh₃)₂] and[Rh(BA)(PPh₃)₂], respectively. The reaction products were identified in the reaction mixtures by ³¹P{¹H} and ¹H NMR.     

Reactivity differences between nickel and palladium complexes bearing 1,2-diphosphino-1,2-dicarba-dodecaborane ligand

AgOTf (OTf = trifluoromethanesulfonate) shows the reactivity differences when it reacts with carborane complexes [MCl₂{(PPh₂)₂(C₂B₁₀H₁₀)}] (M = Ni (2), Pd (3)). The reaction of AgOTf with the palladium complex 3 affords [Pd₂(μ-OTf)₂{(PPh₂)₂(C₂B₉H₁₀)}₂] (4) in high yields, while corresponding reaction between the nickel complex 2 and AgOTf leads to the formation of binuclear complexes [Ni{(PPh₂)₂(C₂B₉H₁₀)}](μ-Cl)₂[Ag{(PPh₂)₂(C₂B₁₀H₁₀)}] (5) and [Ag₂(μ-Cl)₂ {(PPh₂)₂ (C₂B₁₀H₁₀)}₂] (6). The carborane cage of complexes 4 and 5 were broken to form nido-carboranes. It is believed the group 10 metals themselves play an important role in opening the closo-carborane skeleton. Directly stirring [(PPh₂)₂(C₂B₁₀H₁₀)] with AgOTf afforded [Ag₂(μ-OTf)₂{(PPh₂)₂(C₂B₁₀H₁₀)}₂] (7), which is also used to react with 2 and 3. The reaction between 2 and 7 gives only 4 in high yields, however, stirring the mixture of 3 and 7 affords [Pd₂(μ-Cl)₂{(PPh₂)₂(C₂B₉H₁₀)}₂] (8), [Pd{(PPh₂)₂(C₂B₉H₁₀)}₂] (9) and 6. All these complexes have been characterized by IR, ¹H NMR, ¹¹B NMR and elemental analyses. Complexes 2, 4-9 have also been determined by single-crystal X-ray diffraction analyses.     

Air-stable μ2-hydroxyl bridged cationic binuclear complexes of zirconocene perfluorooctanesulfonates: their structures,characterization and application

Three air-stable zirconocene perfluoro-octanesulfonates were successfully synthesized by treatment of C₈F₁₇SO₃Ag with (RCp)₂ZrCl₂ [R?=?H, n-Bu, t-Bu]. According to X-ray analysis, they have μ²-hydroxyl bridged cationic binuclear structures: (i) [CpZr(OH₂)₃]₂(μ²-OH)₂(OSO₂C₈F₁₇)₄·2THF·4H₂O (1a·2THF·4H₂O), (ii) [n-BuCpZr(OH₂)₃]₂(μ²-OH)₂(OSO₂C₈F₁₇)₄·6H₂O (2a·6H₂O), and (iii) [t-BuCpZr(OH₂)₃]₂(μ²-OH)₂(OSO₂C₈F₁₇)₄·2C₃H₆O·8H₂O (3a·2C₃H₆O·8H₂O). The ligands of water and organic molecules in the complexes originated from the moist air and solvent during their recrystallization. These complexes were characterized with different techniques, and found to show water tolerance, air/thermal stability as well as strong Lewis acidity. Moreover, the complexes showed highly catalytic activity in various reactions of CC bond formation. With good recyclability, they should find wide applications in organic chemistry.     

Preparation and characterization of cobalt-containing P,N-ligands and an unusual palladium complex ion pair: their applications in amination reactions

Several cobalt-containing P,N-ligands, alkyne-bridged dicobalt phosphines [(μ-PPh₂CH₂PPh₂)Co₂(CO)₄(μ,η-Me₂NCH₂CCPR₂)] (4a: R=^tBu; 4b: R=Ph; 4c: R=Cy), were prepared from the reactions of corresponding alkynylphosphines Me₂NCH₂CCPR₂ (2a: R=^tBu; 2b: R=Ph; 2c: R=Cy) with a dppm-bridged dicobalt complex [Co₂(CO)₆(μ-P,P-PPh₂CH₂PPh₂)] 3. A unique palladium complex ion pair [(μ-PPh₂CH₂PPh₂)Co₂(CO)₄(μ,η-Me₂NCH₂CCP (^tBu)₂)Pd(η³-C₃H₅)]⁺[(η³-C₃H₅)PdCl₂]⁻7a was obtained from the reaction of 4a with [(η³-C₃H₅)PdCl]₂. Compounds 4a, 4b, and 4c are authentic cobalt-containing P,N-bidentate ligands and can be used for ligation of palladium from various sources such as Pd(OAc)₂ or [(η³-C₃H₅)PdCl]₂. Satisfactory efficiencies were observed for the amination reactions of aryl bromides with morpholine employing either a 4a-chelated palladium complex formed in situ or pre-formed 7a as the catalytic precursor.     

Catalytic and anticancer activities of sawhorse-type diruthenium tetracarbonyl complexes derived from fluorinated fatty acids

The reaction of fluorinated fatty acids, perfluorobutyric acid (C₃F₇CO₂H), and perfluorododecanoic acid (C₁₁F₂₃CO₂H), with dodecacarbonyltriruthenium (Ru₃(CO)₁₂) under reflux in tetrahydrofuran, followed by addition of two-electron donors (L) such as pyridine, 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane, or triphenylphosphine, gives stable diruthenium complexes Ru₂(CO)₄(μ₂-η²-O₂CC₃F₇)₂(L)₂ (1a, L?=?C₅H₅N; 1b, L?=?PTA; 1c, L?=?PPh₃) and Ru₂(CO)₄(μ₂-η²-O₂CC₁₁F₂₃)₂(L)₂ (2a, L?=?C₅H₅N; 2b, L?=?PTA; 2c, L?=?PPh₃). The catalytic activity of the complexes for hydrogenation of styrene under supercritical carbon dioxide has been assessed and compared to the analogous triphenylphosphine complexes with non-fluorinated carboxylato groups Ru₂(CO)₄(μ₂-η²-O₂CC₃H₇)₂(PPh₃)₂ (3) and Ru₂(CO)₄(μ₂-η²-O₂CC₁₁H₂₃)₂(PPh₃)₂ (4). In addition, the cytotoxicities of the fluorinated complexes 1 were also evaluated on several human cancer cell lines (A2780, A549, Me300, HeLa). The complexes appear to be moderately cytotoxic, showing greater activity on the Me300 melanoma cells. Single-crystal X-ray structure analyses of 1a and 3 show the typical sawhorse-type arrangement of the diruthenium tetracarbonyl backbone with two bridging carboxylates and two terminal ligands occupying the axial positions.     

Transition metal chemistry of phosphorus based ligands. Ruthenium(II) chemistry of bis(phosphino)amines, X2PN(R)PX2 (R=H or Ph, X=Ph; R=Ph, X2=O2C6H4)

Reactions of CpRuCl(PPh₃)₂ with bis(phosphino)amines, X₂PN(R)PX₂ (1 R=H, X=Ph; 2 R=X=Ph; 3 R=Ph, X₂=O₂C₆H₄) give neutral or cationic mononuclear complexes depending on the reaction conditions. Reaction of 1 with CpRuCl(PPh₃)₂ gives one neutral complex, [CpRu(Cl)(η²-Ph₂PN(H)PPh₂)] (4) and two cationic complexes, [CpRu(η²-Ph₂PN(H)PPh₂)(η¹-Ph₂PN(H)PPh₂)]Cl (5) and [CpRu(PPh₃)(η²-Ph₂PN(H)PPh₂)]Cl (6), whereas the reaction of 2 with CpRuCl(PPh₃)₂ leads only to the isolation of cationic complex, [CpRu(PPh₃)(η²-Ph₂PN(Ph)PPh₂)]Cl (7). The catechol derivative 3, in a similar reaction, affords an interesting mononuclear complex [CpRu(PPh₃){η¹-(C₆H₄O₂)PN(Ph)P(O₂H₄C₆)}₂]Cl (8) containing two monodentate bis(phosphino)amine ligands. The structural elucidation of the complexes was carried out by elemental analyses, IR and NMR spectroscopic data.     

Reactivity of C(sp)-Pd and C(sp)-Pd bonded palladacycles with diphosphines. Crystal and molecular structure of the novel A-frame complex [{Pd[2,5-Me2C6H2C(H)N(2,4,6-Me3C6H2)-C6]}2(μ-Ph2PCH2PPh2)2(μ-Cl)][PF6]

Treatment of the halogen-bridged complexes [Pd{2,5-Me₂C₆H₂C(H)N(2,4,6-Me₃C₆H₂)-C6,N}(μ-X)]₂ (1a, X = Cl; 2a, X = Br) with the tertiary diphosphine Ph₂PCH₂PPh₂ (dppm), regardless of the molar ratio used, gave a mixture of two complexes: [Pd{2,5-Me₂C₆H₂C(H)N(2,4,6-Me₃C₆H₂)-C6}(μ-Ph₂PCH₂PPh₂)₂(μ-X)]₂[PF₆] (5a, X = Cl; 6a, X = Br), which presents an A-frame structure, and [Pd{2,5-Me₂C₆H₂C(H)N(2,4,6-Me₃C₆H₂)-C6,N}(Ph₂PCH₂PPh₂-P,P)][PF₆], 3a, with the diphosphine as chelating. The mixture could be separated and the corresponding complexes isolated. However, reaction of 1a and 2a with the diphosphine Ph₂PC(CH₂)PPh₂ (vdpp) exclusively gave the mononuclear complex [Pd{2,5-Me₂C₆H₂C(H)N(2,4,6-Me₃C₆H₂)-C6,N}{Ph₂PC(CH₂)PPh₂-P,P}][PF₆], 4a, analogous to 3a. Treatment of the halogen-bridged complexes [Pd{1-CH₂-2-[HCN(2,4,6-Me₃C₆H₂)]-4-MeC₆H₃-C,N}(μ-X)]₂ (1a′, X = Cl; 2a′, X = Br) with dppm or vdpp in a cyclometallated complex/diphosphine 1:2 M ratio, gave mononuclear complexes with the chelating diphospines [Pd{1-CH₂-2-[HCN(2,4,6-Me₃C₆H₂)]-4-MeC₆H₃-C,N}(Ph₂PCH₂PPh₂-P,P)][PF₆], 3a′, and [Pd{1-CH₂-2-[HCN(2,4,6-Me₃C₆H₂)]-4-MeC₆H₃-C,N}{Ph₂PC(CH₂)PPh₂-P,P}][PF₆], 4a′. When the reaction was carried out using a cyclometallated complex/diphosphine 1:1 M ratio the dinuclear complexes [{Pd[1-CH₂-2-{HCN(2,4,6-Me₃C₆H₂)}-4-MeC₆H₃-C,N]}₂(μ-X)(μ-Ph₂PCH₂PPh₂)][Cl], (5a′, X = Cl; 7a′, X = Br) and [{Pd[1-CH₂-2-{HCN(2,4,6-Me₃C₆H₂)}-4-MeC₆H₃-C,N]}₂(μ-Cl){μ-Ph₂PC(CH₂)PPh₂}][Cl], 6a′, were obtained. The molecular structures of complexes 3a, 4a, 5a and 6a′ were determined by X-ray single crystal diffraction.     

系列Ln(Ⅲ)配位聚合物(Ln=Eu,Sm,Tb,Pr,Gd)的合成及其荧光分析

采用水热法合成了4个具有1D结构的Ln(Ⅲ)配位聚合物,[Eu₂(C₉H₇O₂)₆(C₉H₇O₂H)(C₂H₅OH)]n(1)、[Sm(C₉H₇O₂)₃]n(2)、[Tb(C₉H₇O₂)₃]n(3)和[Gd(C₉H₇O₂)₃]n(4)(C₉H₈O₂=肉桂酸)。 通过X射线单晶衍射确定了它们的结构。 这4个Ln(Ⅲ)配合物中,Ln(Ⅲ)的配位数均为9,桥配体均为肉桂酸根,但其配位方式有差异。 对配合物进行了IR、UV-Vis-NIR和荧光光谱等表征。 分析了各配合物的荧光发射,结果表明,在可见区,配合物1发射较明显的红光,配合物2、3发射绿光,配合物4发射蓝光,但很弱。 讨论了具有刚柔相混杂性质的肉桂酸配体对配位聚合物的构筑及稀土离子发光的影响。     

Pentamethylcyclopentadienyl ruthenium(II) complexes of para-substituted N-(pyrid-2-ylmethylene)-phenylamine ligands: syntheses,spectral and structural studies

The reaction of [(η⁵-C₅Me₅)Ru(PPh₃)₂Cl] (1) with acetonitrile in the presence of excess NH₄PF₆ leads to the formation of the cationic ruthenium(II) complex [(η⁵-C₅Me₅)Ru(PPh₃)₂(CH₃CN)]PF₆ (2). The complex (2) reacts with a series of N,N′ donor Schiff base ligands viz. para-substituted N-(pyrid-2-ylmethylene)-phenylamines (ppa) in methanol to yield pentamethylcylopentadienyl ruthenium(II) Schiff base complexes of the formulation [(η⁵-C₅Me₅)Ru(PPh₃)(C₅H₄N-2-CHN-C₆H₄-p-X)]PF₆ [3a]PF₆–[3f]PF₆, where C₅Me₅ = pentamethylcylopentadienyl, X = H, [3a]PF₆, Me, [3b]PF₆, OMe, [3c]PF₆, NO₂, [3d]PF₆, Cl, [3e]PF₆, COOH, [3f]PF₆. The complexes were isolated as their hexafluorophosphate salts. The complexes were fully characterized on the basis of elemental analyses and NMR spectroscopy. The molecular structure of a representative complex, [(η⁵-C₅Me₅)Ru(PPh₃)(C₅H₄N-2-CHN-C₆H₄-p-Cl)]PF₆ [3e]PF₆, has been established by X-ray crystallography.     

Synthesis and reactivity of hydride and dihydrogen complexes of ruthenium with tris(pyrazolyl)borate and phosphite ligands

Chloro phosphite complexes RuClTpL(PPh₃) (1a, 1b) [L = P(OEt)₃, PPh(OEt)₂] and RuClTp[P(OEt)₃]₂ (1c) [Tp = hydridotris(pyrazolyl)borate] were prepared by allowing RuClTp(PPh₃)₂ to react with an excess of phosphite. Treatment of the chloro complexes 1 with NaBH₄ in ethanol yielded the hydride RuHTpL(PPh₃) (2a, 2b) and RuHTp[P(OEt)₃]₂ (2c) derivatives. Protonation reaction of 2 with Brønsted acids was studied and led to thermally unstable (above 10 °C) dihydrogen [Ru(η²- H₂)TpL(PPh₃)]⁺ (3a, 3b) and [Ru(η²-H₂)Tp{P(OEt)₃}₂]⁺ (3c) complexes. The presence of the η²-H₂ ligand is indicated by short T_1 min values and J_HD measurements of the partially deuterated derivatives. Aquo [RuTp(H₂O)L(PPh₃)]BPh₄ (4), carbonyl [RuTp(CO)L(PPh₃)]BPh₄ (5), and nitrile [RuTp(CH₃CN)L(PPh₃)]BPh₄ (6) derivatives [L = P(OEt)₃] were prepared by substituting H₂ in the η²-H₂ derivatives 3. Vinylidene [RuTp{CC(H)R}L(PPh₃)]BPh₄ (7, 8) (R = Ph, ^tBu) and allenylidene [RuTp(CCCR1R2)L(PPh₃)]BPh₄ (9-11) complexes (R1 = R2 = Ph, R1 = Ph R2 = Me) were also prepared by allowing dihydrogen complexes 3 to react with the appropriate HCCR and HCCC(OH)R1R2 alkynes. Deprotonation of vinylidene complexes 7, 8 with NEt₃ was studied and led to acetylide Ru(CCR)TpL(PPh₃) (12, 13) derivatives. The trichlorostannyl Ru(SnCl₃)TpL(PPh₃) (14) compound was also prepared by allowing the chloro complex RuClTpL(PPh₃) to react with SnCl₂ · 2H₂O in CH₂Cl₂.