PF6 Salts Research Articles

Cationic and neutral diphenyldiazomethanerhodium(I) complexes as catalytically active species in the C-C coupling reaction of olefins and diphenyldiazomethane

Cationic rhodium(I) complexes cis-[Rh(acetone)2(L)(L')]+ (2: L = L'=C8H14; 3: L=C8H14; L'=PiPr3; 4: L=L'=PiPr3), prepared from [RhCl(C8H14)2]2] and isolated as PF6 salts, catalyze the C-C coupling reaction of diphenyldiazomethane with ethene, propene, and styrene. In most cases, a mixture of isomeric olefins and cyclopropanes were obtained which are formally built up by one equivalent of RCH=CH2 (R = H, Me, Ph) and one equivalent of CPh2. The efficiency and selectivity of the catalyst depends significantly on the coordination sphere around the rhodium(I) center. Treatment of 4 with Ph2CN2 in the molar ratio of 1:1 and 1:2 gave the complexes trans-[Rh(PiPr3)2(acetone)(eta1-N2CPh2)]PF6 (8) and trans-[Rh(PiPr3)2(eta1-N2CPh2)2]PF6 (9), of which 8 was characterized by X-ray crystallography. Since 8 and 9 not only react with ethene but also catalyze the reaction of C2H4 and free Ph2CN2, they can be regarded as intermediates (possibly resting states) in the C-C coupling process. The lability of 8 and 9 is illustrated by the reactions with pyridine and NaX (X=Cl, Br, I, N3) which afford the mono(diphenyldiazomethane)rhodium(I) compounds trans-[Rh(PiPr3)2(py)(eta1-N2CPh2)]PF6 (10) and trans-[RhX(eta1-N2CPh2)(PiPr3)2] (11-14), respectively. The catalytic activity of the neutral complexes 11 - 14 is somewhat less than that of the cationic species 8, 9 and decreases in the order Cl > Br> I > N3.

Structural characterisation of new RuII[9]aneS3 polypyridylic complexes †

A large number of new [RuII([9]aneS3)(L)Cl]+ complexes (where L is a polypyridyl bidentate ligand) were synthesized from the precursor [Ru([9]aneS3)(dmso)Cl2] in the search for new DNA intercalators. The ancillary ligands used have different molecular architectures which include cross bridges, pyridyl units, phenanthroline and diamine derivatives. The related complex [Ru([9]aneS3)(ind)Cl2], containing the monodentate ligand indazole, was also prepared. The diimine complexes [Ru([9]aneS3)(pdi)Cl]+ and [Ru([9]aneS3)(phi)Cl]+ were prepared in situ from the ligands pda (o-phenylenediamine) and dap (phenanthrene-9,10-diamine), respectively, via Ru assisted amine/imine oxidation. All complexes were characterised through 1H NMR, IR, UV-Vis and electrospray mass spectrometry. Furthermore, the PF6 salts of seven [Ru([9]aneS3)(L)Cl]+ and [Ru([9]aneS3)(dip)Cl]BF4 (dip = 4,7-diphenylphenanthroline) have been investigated by X-ray single crystal diffraction. The crystal structures are presented and analysed in terms of the molecular assemblies of the complex cations and anions and the molecular hydrogen bonding interactions. The π-stacking geometric arrangements of the extended aromatic systems dppz (dipyrido[3,2-a∶2′,3′-c]phenazine) and dip in their metal complexes are also discussed.

A Series of Neutral and Cationic Mesityleneosmium(II) Complexes Containing Bulky Phosphines with Various Functionalities as Ligands

Mono- and dihydridoosmium(II) compounds with [(mes)Os{iPr2P(CH2)nY}] (mes = mesitylene, 1,3,5-trimethylbenzene; n = 2, Y = NMe2, OMe; n = 3, Y = NMe2) as a molecular unit are prepared from the dichloro derivatives [(mes)OsCl2{iPr2P(CH2)nY}] and magnesium amalgam in THF in the presence of ethanol. Upon treatment of [(mes)Os(X)Cl{κ1(P)-iPr2P(CH2)2Y}] (X = H, Cl) with AgPF6 in CH2Cl2 cationic complexes with iPr2P(CH2)2Y as a chelating ligand are obtained. The compounds with Y = OMe react (for X = Cl) with L = CO and CNMe by opening of the chelate bond to give the PF6 salts [(mes)Os(L)Cl{κ1(P)-iPr2P(CH2)2Y}]PF6 and (for X = H) with KOtBu by fragmentation of the functionalized phosphine to afford the neutral complex [(mes)OsH(OMe)(iPr2PCHCH2)]. The reaction of the chelate compound [(mes)OsCl{κ2(P,O)-iPr2PCH2C(OMe)O}]PF6 with KOtBu leads to the formation of the corresponding uncharged phosphanyl ester enolate−osmium(II) complex by proton abstraction from the PCH2 unit. The ester enolate complex reacts with phen...

Crystal Structures and Conducting Properties of PF6 and AsF6 Salts of a Novel Benzo[c]furan-Extended Donor: The Role of Inter-Column Interactions

Abstract The PF6 and AsF6 salts of a new benzo[c]furan-extended donor have been prepared. It has been clarified that the inter-column interactions connecting the tetrameric donor columns play an important role in the conduction of these salts.

Alkene Complexes of Divalent and Trivalent Ruthenium Stabilized by Chelation. Dependence of Coordinated Alkene Orientation on Metal Oxidation State

Zinc amalgam reduction of tris(acetylacetonato)ruthenium(III), [Ru(acac)3], in the presence of the chelating olefinic N- and O-donor ligands (LL‘) 2-vinyl-N,N-dimethylaniline, o-CH2CHC6H4NMe2 (1), 2-isopropenyl-N,N-dimethylaniline, o-CH2C(CH3)C6H4NMe2 (2), 3-butenyldimethylamine, CH2CHCH2CH2NMe2 (3), 2-allylpyridine, CH2CHCH2C5H4N (4), isomesityl oxide (4-methyl-4-penten-2-one), CH2C(CH3)CH2COCH3 (5), 2-methoxystyrene, o-CH2CHC6H4OMe (6), and 3-butenylmethyl ether, CH2CHCH2CH2OCH3 (7) gives the corresponding bis(acetylacetonato)ruthenium(II) complexes [Ru(acac)2(LL‘)] (8−14). These undergo one-electron oxidation by cyclic voltammetry to the corresponding cations [Ru(acac)2(LL‘)]+, the process being reversible at both room temperature and −60 °C. The cations were isolated as deep blue, paramagnetic PF6 or SbF6 salts from the oxidation of the ruthenium(II) precursors 8−12 and 14 with Ag+ or [FeCp2]+ salts; they are the first stable alkene complexes of ruthenium(III). At both oxidation levels, coordination of the prochiral alkene gives rise to a pair of diastereomers, labeled a, b at the Ru(II) level, a+, b+ at the Ru(III) level, whose redox potentials E1/2 (Ru3+/2+) differ by ca. 100 mV. The equilibrium a/b ratio at the Ru(II) level is ca. 1:9, although for 8, 10, and 11 this is established only after several hours at ca. 100 °C, the ratio in the complexes immediately after isolation being ca. 2:3. Selective removal of the more easily oxidized diastereomer of the 2-vinyl-N,N-dimethylaniline complex 8a by treatment of a 2:3 mixture with ca. 0.5 equiv of Ag+ provides pure 8b, which undergoes reversible one-electron oxidation at −60 °C to 8b+. Above −10 °C, 8b+ isomerizes to an equilibrium mixture (ca. 85:15) of 8a+ and 8b+, as shown by UV−visible spectroelectrochemistry. Thus, both diastereomeric preference and rate of interconversion are strongly dependent on the oxidation state (number of metal d-electrons). The metrical parameters pertaining to alkene coordination in the diastereomers 8a and 8b do not differ significantly, the metal−carbon distances being 2.159(4), 2.144(4) Å (8a), 2.142(2), 2.153(3) Å (8b) and the CC distances being 1.383(5) Å (8a) and 1.382(4) Å (8b). The corresponding distances in the Ru(III) complex [8a]+[SbF6]- [Ru−C = 2.239(6), 2.236(7) Å; CC = 1.355(9) Å] indicate that the alkene is more weakly bound than in either of its diastereomeric Ru(II) precursors.

μ-Oxo and alkoxo complexes of gold(III) with 6-alkyl-2,2′-bipyridines. Synthesis, characterization and X-ray structures

The reactivity of a series of gold(III) adducts [Au(HL)Cl3] 1a–4a with 6-alkyl-2,2′-bipyridines HL (N2C10H7R, R = CH2Me 1, CHMe2 2, CMe3 3 and CH2CMe3 4) has been studied. The reactions of 1a–4a with silver(I) ions or MeCO2Na afford cationic complexes [Au2(HL)2(µ-O)2]2+ 1b–4b (as BF4 or PF6 salts) having the gold atom bonded to the nitrogen atoms of the bipyridine and to two oxygen atoms. The crystal structure of 4b[PF6]2, solved by X-ray diffraction, shows that the cation is a centrosymmetric dimer with two oxo (O2–) groups bridging two [Au{N2C10H7(CH2CMe3)-6}] moieties. In the case of 2a, besides the oxo species, mononuclear ionic derivatives [Au(L*)Cl]+ 2*c [HL* = N2C10H7(CMe2OH)-6; BF4, PF6 or AuCl4 salts] have been isolated. The latter complexes contain an unexpected Au–O bond. The spectroscopic data and the crystal structure of 2*c[AuCl4] indicate a tridentate N,N,O behaviour of the ligand which forms a [5,5]-fused ring system.

PLATINUM, IRIDIUM AND RHODIUM COMPLEXES WITH SUBSTITUTED BIS-(DIPHENYLPHOSPHINO)METHANE LIGANDS PH2PCH(R)PPH2 (R = ME, PH OR SIME3)

Substituted phosphines of the type Ph2PCH(R)PPh2 and their PtII complexes [PtX2{Ph2PCH(R)PPh2}] (R = Me, Ph or SiMe3; X = halide) were prepared. Treatment of [PtCl2(NCBut)2] with Ph2PCH(SiMe3)-PPh2 gave [PtCl2(Ph2PCH2PPh2)], while treatment with Ph2PCH(Ph)PPh2 gave [Pt{Ph2PCH(Ph)PPh2}2]Cl2. Reaction of p-MeC6H4C≡CLi or PhC≡CLi with [PtX2{Ph2PCH(Me)PPh2}] gave [Pt(C≡CC6H4Me-p)2-{Ph2PCH(Me)PPh2}] (X = I) and [Pt{Ph2PC(Me)PPh2}2](X = Cl),while reaction of p-MeC6H4C≡CLi with [Pt{Ph2PCH(Ph)PPh2}2]Cl2 gave [Pt{Ph2PC(Ph)PPh2}2]. The platinum complexes [PtMe2(dpmMe)] or [Pt(CH2)4(dpmMe)] fail to undergo ring-opening on treatment with one equivalent of dpmMe [dpmMe = Ph2PCH(Me)PPh2]. Treatment of [Ir(CO)Cl(PPh3)2] with two equivalents of dpmMe gave [Ir(CO)(dpmMe)2]Cl. The PF6 salt was also prepared. Treatment of [Ir(CO)(dpmMe)2]Cl with [Cu(C≡CPh)2], [AgCl(PPh3)] or [AuCl(PPh3)] failed to give heterobimetallic complexes. Attempts to prepare the dinuclear rhodium complex [Rh2(CO)3(μ-Cl)(dpmMe)2]BPh4 using a procedure similar to that employed for an analogous dpm (dpm = Ph2PCH2PPh2) complex were unsuccessful. Instead, the mononuclear complex [Rh(CO)(dpmMe)2]BPh4 was obtained. The corresponding chloride and PF6 salts were also prepared. Attempts to prepare [Rh(CO)(dpmMe)2]Cl in CHCl3 gave [RhHCl(dpmMe)2]Cl. Recrystallization of [Rh(CO)(dpmMe)2]BPh4 from CHCl3/EtOH gave [RhO2(dpmMe)2]BPh4. Treatment of [Rh(CO)2Cl2]2 with one equivalent of dpmMe per Rh atom gave two compounds, [Rh(CO)(dpmMe)2]Cl and a dinuclear complex that undergoes exchange at room temperature between two formulae: [Rh2(CO)2(μ-Cl)(μ-CO)(dpmMe)2]Cl and [Rh2(CO)2-(μ-Cl)(dpmMe)2]Cl.

The First Peralkylated Phosphino(stibino)methanes and Their Organometallic Rhodium Complexes

AbstractThe first representatives of phosphino(stibino)methanes R2PCH2Sb‐R′2 (3–5) with bulky alkyl or cycloalkyl groups R and R′ were prepared in two steps from Ph3SnCH2I via the isolated stannylated phosphanes Ph3SnCH2PR2 (1, 2) as intermediates. X‐ray structural analysis of 5 (R = C6H11, R′ = tBu) reveals that the lone pairs and the substituents R and R′ at phosphorus and antimony and the hydrogen atoms of the CH2 bridge adopt staggered conformations. Treatment of [{C8H12RhCl}2] with 3–5 affords the neutral compounds [Rh‐Cl(η4‐C8H12)(κ‐P‐R2PCH2SbR′2)] (6–8), of which 7 and 8 react with CH3MgI to give the corresponding methylrhodium derivatives [RhCH3(η4‐C8H12)(κ‐P‐R2‐PCH2SbR′2)] (9, 10). Cationic complexes [Rh(η4‐C8H12)(η2‐P,Sb‐R2PCH2SbR′2)]‐X (X = PF6: 11a, 12a, 13; X = BPh4: 11b, 12b) containing the phosphino(stibino)methanes as chelating ligands were obtained either from [{C8H12RhCl}2], R2PCH2SbR′2 and MX, or (for 13) from 8 and AgPF6. Compound 12a (R = iPr, R′ = tBu) was characterized by X‐ray crystallography. The PF6 salts 11a, 12a, and 13 react with CH2N2 by insertion of CH2 into the Rh–Sb bond to yield the complexes 14–16, the first examples of transition‐metal compounds with Sb ylides as ligands. Treatment of BPh4 salts 11b and 12b with H2 gives the half‐sand‐wich‐type complexes [(η6‐C6H5BPh3)Rh(κ2‐P,Sb‐R2PCH2SbR′2)] (17, 18), in which the tetraphenylborate is coordinated like a substituted arene to the metal center.

Crystal Structures of Cation-Radical Salts of a Bis(1,3-dithiole) Donor Containing a 1,2,5-Thiadiazole Unit

Abstract X-Ray analyses of PF6 and BF4 cation-radical salts of 4,7-bis(4,5-dimethyl-1,3-dithiol-2-ylidene)-4,7-dihydro-2,1,3-benzothiadiazole reveal that the PF6 salt showing a metallic behavior has a uniform stacking of donor molecules, while the BF4 salt showing a semiconducting behavior has a dimeric structure.

Synthese und Reaktionen der Metall‐Base [(C5Me4H)Co(PMe3)2

Synthesis and Reactions of the Metal Base [(C5Me4H)Co(PMe3)2]The (tetramethylcyclopentadienyl)cobalt complex [(C5Me4H)Co(PMe3)2] (1), which is prepared from [CoCl(PMe3)3] and LiC5Me4H in 75% yield, behaves like a Lewis base and reacts with NH4PF6, CH3I, or CF3SO3CH3 by oxidative addition to give the cations [(C5Me4H)CoX(PMe3)2]+ (X = H, I, CH3; 2–4) isolated as PF6 salts. From 3 (X = I) and excess LiCH3 the dimethylcobalt(III) compound [(C5Me4H)Co(CH3)2(PMe3)] (5) is obtained. Treatment of the corresponding trifluoroacetato derivative [(C5Me4H)Co(PMe3)(OCOCF3)2] (6) with PMe3, P(OMe)3, and 1,2‐C6H4(PPh2)2 leads, in the presence of NH4PF6, to the formation of the cationic complexes 7–9. The displacement of the two PMe3 ligands in 1 by (Ph2P)2NMe gives the rather unstable chelate compound {(C5Me4H)Co[(Ph2P)2NMe]} (10), which on treatment with NH4PF6 is transformed into the stable complex {(C5Me4H)CoH[(Ph2P)2NMe]}PF6 (11). The structure of 11 has been determined by X‐ray diffraction methods.

Electrochemical studies of gold(I) and gold(III) complexes of bis(diphenylphosphines)

Cyclic voltammograms of gold complexes of bis(diphenylphosphines) were recorded using a gold working electrode. The E½ values vs. a saturated calomel electrode (s.c.e.)(and the peak-to-peak separations) for the PF6 salts of the following complexes were obtained: bis[1,2-bis(diphenylphosphino)benzene]gold(I), 0.463 (37); bis[1,2-bis(diphenylphosphino)ethene]gold(I), 0.572 V (37); bis[1,2-bis(diphenylphosphino)ethane]gold(I), 0.458(30); bis[1,3-bisdiphenylphosphino)propane]gold(I), 0.752 V (35 Mv). The first couple is electrochemically reversible and the last three show quasi-reversibility for the two-electron redox process to form the corresponding gold(III) complex. Spectroelectrochemistry of bis[1,2-bis(diphenylphosphino)benzene]gold(I) revealed only two u.v.-absorbing species in solution, and the limiting spectra are those of the tetrahedral gold(I) complex and the square-planar gold(III) complex. A facile pseudo-rotation between the two geometries is proposed. Cyclic voltammetry of the chloride or bromide salt of bis[1,2-bis(diphenylphosphino)benzene]gold(I) demonstrated that halide ion adds to the gold (III) complex but dissociates from it upon reduction back to the starting gold(I) complex. Based on electrochemical behaviour, the order of increasing lability of the gold(III) complexes is as listed above.

ChemInform Abstract: Organotransition‐Metal Complexes of Multidentate Ligands. Part 7. Polypyrazolylamine Complexes of Chromium(II), Molybdenum(II), and Tungsten(II). Stereochemically Nonrigid and Rigid Pseudooctahedral Molecules.

AbstractTricarbonyl metal complexes of the dipyrazolylamines react with allyl bromide in MeCN (20 °C for Cr, 82 °C for Mo and W) to give the title complexes, isolated as their PF6 salts.

The Novel Complex [LRuIV(μ‐O)3RuIVL][PF6]2·H2O–a Molecular Section of the Structures of BaRuIVO3 (High‐Pressure Phase) and Ba5/6Sr1/6RuIVO3

A better understanding of the magnetic properties of ternary oxides such as BaRuO3 and of metal–metal interactions might be offered by complex 3 and the two other new compounds 1 and 2. These compounds were synthesized as PF6 salts. Blue 1 can be oxidized to green 3 via 2 (yellow). Compounds 1 and 3 contain short Ru-Ru bonds. Compound 3 can be converted electrochemically into the mixed valence RuIVRuv and RuIIIRuIV complexes. In 3, two unpaired electrons are present per formula unit (L = N,N′,N″-trimethyl-1,4,7-triazacyclononane).

ChemInform Abstract: Molecular Helicity in Inorganic Complexes; Double Helical Binuclear Complexes of 2,2′:6′,2′′:6′′,2′′′:6′′′,2′′′′‐Quinquepyridine (L): Crystal Structures of (Cu2L2(O2CMe)) (PF6)3·H2O and (Cu2L2) (PF6)3·2 MeCN.

AbstractThe Cu complex (I) and its Ni and Zn analogues are prepared from the title ligand and the metal acetates in boiling MeOH and isolated as PF6 salts (60‐80% yield).

Electron-Donating Radialenes. Potential Donors for Molecular Organic (Super) Conductors and Ferromagnets

ABSTRACTThe electron-donating [n]radialenes (n=3,4,5) were prepared with the aim of developing both new type of organic (super)conductors and unprecedented organic/molecular ferromagnets. The charge-transfer (CT) complexes of 1,3-dithiole[4]radialene with TCNQ and of 1,3-benzodithiole-[4]radialene with TCNQF4 and DDQ showed comparatively high electrical conductivities in compressed pellets. The single crystals of PF6 and CIO4 salts of 1,3-benzodithiole[4]radialene radical cation revealed temperature change of electrical conductivity characteristic of a semiconductor. The magnetic properties of the bis(trifluoroacetate)salt of thioxanthene[3]-radialene dication and of the CT complexes of 1,3-benzodithiole[5]-radialene with DDQ, TCNQF4, and hexacyanohexamethylenecyclopropane, were also investigated from the ESR and/or magnetic susceptibility measurements.

ChemInform Abstract: A Novel Family of Binuclear Cobalt(II) Complexes with Face‐to‐Face Bis(cyclidene) Ligands: Structural Characterization, Unusual Reactions with Dioxygen, and a Distinctive Host‐Guest Complexation with a Bridging Ligand.

AbstractThe title complexes (I) are prepared by the reaction of the macrocyclic ligands (obtained from the corresponding Ni complexes) with Co acetate in MeOH in the presence of Na acetate and isolated as their PF6 salts.

New Series of Organic Metal. Radical Salts of Unsymmetrical Donors Containing Pyrazino Group

Abstract The I3, ClO4, and PF6 salts of unsymmetrical donors containing fused pyrazino groups (DMPDSDTF and DM(DMP)DSDTF) were prepared electrochemically and their electrical conductivities were measured. The I3 salt of DM(DMP)DSDTF exhibited a metallic behavior down to about 120 K. The radical salts of unsymmetrical donors showed much larger conductivities than those of the corresponding symmetrical donors containing pyrazino groups.

ChemInform Abstract: Organodiiron “Electron Reservoir” Complexes Containing a Polyaromatic Ligand: Syntheses, Stabilization, Delocalized Mixed Valences, and Intramolecular Coupling.

AbstractPolyaromatics can be complexed by reaction with η5‐C5Me5Fe(CO)2Br and Al2Cl6 in the melt or in an inert solvent (110‐140 °C, 2 d) to give the new cations (Ib), (II), and (IIIb) isolated as their PF6 salts in 30‐40% yield.

ChemInform Abstract: First Synthesis of a Nitro Complex of Ruthenium(III), as a Key Intermediate in the Oxidation of Nitro Ligand To Give Both Nitrosyl and Nitrato Ligands.

AbstractThe oxidation of the nitrosyl complexes (I) with NaClO under basic conditions yields the monomeric Ru(III) nitro complexes (II) isolated as their ClO4 or PF6 salts.

Synthesis and reactions of [(OC)2Re(µ-dppm)2(µ-Cl)2Rh(η2-C2H4)](dppm = Ph2PCH2PPh2): crystal structure of the 1 : 2 chlorobenzene solvate

Treatment of [ReCl(CO)5] with Ph2PCH2PPh2(dppm) gives mer,cis-[ReCl(CO)2(dppm-PP′)-(dppm-P)](1). The uncomplexed phosphorus of (1) is readily quaternized by [OMe3][BF4] to give mer,cis-[ReCl(CO)2(dppm-PP′)(Ph2PCH2PPh2Me)]BF4(2). Treatment of complex (1) with [Rh2Cl2(C2H4)4] gives [(OC)2Re(µ-dppm)2(µ-Cl)2Rh(η2-C2H4)](3). The ethylene ligand in (3) is readily displaced by allene to give [(OC)2Re(µ-dppm)2(µ-Cl)2Rh(η2-C3H4)](4). When complex (3) is treated with dihydrogen [(OC)2Re(µ-dppm)2(µ-Cl)(µ-H)RhH(Cl)](5) is formed; with CO [Cl(OC)Re(µ-dppm)2(µ-Cl)(µ-CO)Rh(CO)](6) is initially formed but this reacts further to give [(OC)3Re(µ-dppm)2(µ-Cl)Rh(CO)]Cl (7a). The complexes (6) and (7a) were more readily prepared by treating (1) with [Rh2Cl2(CO)4]. The chloride salt (7a) was converted into the corresponding PF6(7b) and BPh4(7c) salts. We also report the corresponding iridium salt [(OC)3Re(µ-dppm)2(µ-Cl)Ir(CO)]PF6(8). N.m.r. and i.r. data are given. Crystals of (3) are monoclinic, space group P21/n(=P21/c, no.14) with a= 1 027.5(8), b= 2 996.5(9), c= 2 142.2(5) pm, and β= 92.50(2)°; final R and R′ values 0.0485 and 0.0518, respectively for 6 816 unique reflections with I > 2.0σ(I). The crystal structure shows an η2-ethylene, terminally bound to the rhodium atom, with an unusually long carbon–carbon distance [150(2) pm].