Carbyne-fluoro complexes of rhenium. Single-pot synthesis of trans-[ReF(CCH2R)-(Ph2PCH2CH2PPh2)2][BF4]

Treatment of a THF solution of trans-[ReCl(N₂)(dppe)₂] (dppe = Ph₂PCH₂CH₂PPh₂) with a 1-alkyne HCCR (R =^tBu, CO₂Me, CO₂Et, or C₆H₄Me-4), in the presence of Tl[BF₄]/[NH₄][BF₄], under sunlight, affords the corresponding carbyne-fluoro complexes trans-[ReF(CCH₂R)(dppe)₂][BF₄] in an unprecedented single-pot synthesis. Further reaction with [BU₄N]OH leads to the vinylidenefluoro compounds trans-[ReF(=C=CHR)(dppe)₂] (R = CO₂Me, CO₂Et, or C₆H₄Me-4).     

Synthesis of trans-[Re(NO)2-(Ph2PCH2CH2PPh2)2][BF4], a formal dinitrosyl complex of rhenium(-I) and its protic denitrosylation. X-Ray structure of trans-[ReF(NO)-(Ph2PCH2CH2PPh2)2][BF4]

Treatment of a THF solution of trans-[ReCl(N₂)(dppe)₂] (dppe = Ph₂PCH₂CH₂PPh₂) with NO, in the presence of Tl[BF₄], forms trans-[Re(NO)₂(dppe)₂][BF₄], a rare formal 20-electron d⁸-rhenium nitrosyl complex which, by reaction with HX (X = BF₄, Cl or HSO₄), gives trans-[ReF(NO)(dppe)₂][BF₄] (2) (the X-ray structure of which is reported) or trans-[ReX(NO)(dppe)₂]X (3, X = Cl or HSO₄), respectively, as well as nitrous oxide.     

A study of the protonation and alkylation oft-butyl isocyanide intrans-[M(CNBu-t 2(Ph2PCH2CH2PPh2)2] (M = Mo or W): Formation of carbyne-type complexes and theirtrans- tocis-isomerization

Summary Treatment of complexestrans-[M(CNBu-t)₂(dppe)₂][(1) M = Mo or W, dppe = Ph₂PCH₂CH₂PPh₂] with protic acid gives a mixture of the aminocarbyne complexestrans- pluscis-[M(CNHBu-t)(CNBu-t)(dppe)₂]⁺ (2) and the hydridocompounds [MH(CNBu-t)₂(dppe)₂]⁺ (3), whereas reaction with an alkylating agent (R⁺) appears to give the dialkylaminocarbyne compounds [M(CNRBu-t)(CNBu-t)(dppe)₂]⁺ (4) also as a mixture of thetrans andcis isomers.     

The cis-Re(Ph2PCH2CH2PPh2)2)+ metal centre. Synthesis and molecular structure of the dinitrile complex cis-[Re(NCC6H4Me-4 2(Ph 2 PCH 2 CH 2 PPh 2 2 ][BF4]

Reaction of NCC₆H₄X-4 (X  Me, OMe, or Cl) with trans-[ReCl(N₂)(dppe)₂] (dppe  Ph₂PCH₂CH₂PPh₂), at room temperature, in the presence of Tl[BF₄], gives the corresponding complexes cis-[Re(NCC₆H₄X-4)₂(dppe)₂][BF₄] (1); the crystal structure of 1 (X  Me) has been determined by single crystal X-ray diffraction analysis.     

Mono and Bimetallic Complexes of Molybdenum(ii) and Tungsten(ii) Containing 4,4′-Diphenylenecarbonitrile

The complexes [MI₂(CO)₃(NCMe)₂] (M=Mo or W) react in CH₂Cl₂ at room temperature with two equivalents of 4,4'-diphenylenecarbonitrile (dpc) to afford the new seven-coordinate complexes, [MI₂(CO)₃(4,4'-dpc-N)₂] (1 and 2) in good yield. Equimolar quantities of [MI₂(CO)₃(NCMe)₂] and PPh₃ give [MI₂(CO)₃(NCMe)(PPh₃)], which react in situ with 4,4'-dpc to yield the mono-4,4'-diphenylenecarbonitrile complexes, [MI₂(CO)₃(4,4'-dpc-N)(PPh₃)] (3 and 4). Treatment of the bis(alkyne) complexes, [WI₂(CO)(NCMe)(η ²-RC₂R)₂] (R=Me and Ph) with one equivalent of 4,4'-dpc in CH₂Cl₂ at room temperature affords the acetonitrile displaced products, [WI₂(CO)(4,4'-dpc-N)(η ²-RC₂R)₂] (5 and 6). Reaction of equimolar quantities of [WI₂(CO)(NCMe)(η ²-PhC₂Ph)₂] and 2 in CH₂Cl₂ at room temperature gives the 4,4'-dpc-bridged complex, [WI₂(CO){WI₂(CO)₃(4,4'-dpc-N)(4,4'-dpc- N,N')}(η ²-PhC₂Ph)₂] (7) in good yield. Similarly, equimolar amounts of [WI₂(CO)(NCMe)(η ²-RC₂R)₂] (R=Me and Ph) and (4) react in CH₂Cl₂ to afford the bimetallic complexes, [WI₂(CO){WI₂(CO)(4,4'-dpc-N,N')(PPh₃)}(η ²-RC₂R)₂] (8 and 9). The new bimetallic 4,4'-dpc-bridged alkyne complexes, [WI₂(CO){WI₂(CO)(4,4'-dpc-N,N')(η ²-MeC₂Me)₂}(η ²-MeC₂Me)₂] [(10), [WI₂(CO){WI₂(CO)(4,4'-dpc-N,N')(η ²-PhC₂Ph)₂}(η ²-PhC₂Ph)₂] (11) and [WI₂(CO){WI₂(CO)(4,4'-dpc-N,N')(η ²-MeC₂Me)₂}(η ²-PhC₂Ph)₂] (12) are also described.     

Synthesis of the cyanamide-derived bis(cyanoimido) complexes trans-[M(NCN)2(Ph2PCH2CH2PPh2)2] (M = Mo or W) and crystal structure of the molybdenum compound

Reaction of cyanamide (NCNH₂) with trans-[M(N₂)₂(dppe)₂] (M = Mo or W, dppe = PH₂PCH₂CH₂PPh₂) leads to the formation of the bis(cyanoimido) complexes trans-[M(NCN)₂(dppe)₂]. The crystal structure of trans-[Mo(NCN)₂(dppe)₂] has been determined by an X-ray diffraction study.     

Syntheses,characterization, and crystal structures of ruthenium(II)/(III) complexes with tridentate salicylaldiminato ligands

Treatment of [Ru(PPh₃)₃Cl₂] with one equivalent of tridentate Schiff base 2-[(2-dimethylamino-ethylimino)-methyl]-phenol (HL) in the presence of triethylamine afforded a ruthenium(III) complex [RuCl₃(κ²-N,N-NH₂CH₂CH₂NMe₂)(PPh₃)] as a result of decomposition of HL. Interaction of HL and one equivalent of [RuHCl(CO)(PPh₃)₃], [Ru(CO)₂Cl₂] or [Ru(tht)₄Cl₂] (tht = tetrahydrothiophene) under different conditions led to isolation of the corresponding ruthenium(II) complexes [RuCl(κ³-N,N,O-L)(CO)(PPh₃)] (2), [RuCl(κ³-N,N,O-L)(CO)₂] (3), and a ruthenium(III) complex [RuCl₂(κ³-N,N,O-L)(tht)] (4), respectively. Molecular structures of 1·CH₂Cl₂, 2·CH₂Cl₂, 3 and 4 have been determined by single-crystal X-ray diffraction.     

Synthesis,spectroscopic investigation,structural characterization,and DFT calculations of [ReX2(N2COPh)(CH3PhCN)(PPh3)2] (X=Cl,Br)

Reactions of [ReX₂(η ²-N₂COPh-N′,O)(PPh₃)₂] with 3-methylbenzonitrile give two iso-structural complexes, [ReX₂(N₂COPh)(CH₃PhCN)(PPh₃)₂] (X?=?Cl, Br). The crystal and molecular structures of [ReCl₂(N₂COPh)(CH₃PhCN)(PPh₃)₂] (1) and [ReBr₂(N₂COPh)(CH₃PhCN)(PPh₃)₂]?·?CH₂Cl₂ (2) were determined. The electronic structures were examined with density functional theory (DFT). The spin-allowed electronic transitions were calculated with the time-dependent DFT method, and the UV-Vis spectrum has been discussed.     

THE REACTIONS OF [MoCl(GeCl3)(CO)3(NCMe)2] WITH NEUTRAL BI- AND TERDENTATE DONOR LIGANDS

Abstract

The reaction of [MoCl(GeCl₃)(CO)₃(NCMe)₂] with an equimolar quantity of L?L {L?L = 2,2′-bipy, 1,10-phen, Ph₂P(CH₂)_nPPh₂ (n = 1 or 2)} in CH₂Cl₂ at room temperature gave either [MoCl(GeCl₃)(CO)₃(L?L)] (L?L = 2,2′-bipy or 1,10-phen) (1 and 2) or [MoCl(GeCl₃)(CO)₂ (NCMe)(L?L)]{L?L = Ph₂P(CH₂)_nPPh₂ (n = 1 or 2) (3 or 4), respectively. Equimolar quantities of [MoCl(GeCl₃)(CO)₂(NCMe){Ph₂P(CH₂)PPh₂}] (3) and L?L {L?L = 2,2′-bipy or Ph₂P(CH)₂PPh₂} react in CH₂Cl₂ at room temperature to afford the cationic complexes [Mo(GeCl₃)(CO)₂{Ph₂P(CH₂) PPh₂}(L?L)]Cl (5 and 6) in good yield. The cationic nature of 6 was established by chloride exchange by reacting Na[BPh₄] with 6 in acetonitrile to give the tetraphenylborate complex [Mo(GeCl₃)(CO)₂{Ph₂P(CH₂)PPh₂}₂][BPh₄] (7). Reaction of equimolar quantities of [MoCl(GeCl₃) (CO)₃(NCMe)₂] and PhP(CH₂CH₂PPh₂)₂ in CH₂Cl₂ at room temperature afforded the dicarbonyl complex [MoCl(GeCl₃)(CO)₂{PhP(CH₂CH₂PPh₂)₂}] (8) in good yield.     

Metal catalysed Brooke rearrangement of 3-Halo-1-(trimethylsilyl) propan-2-one (Halo = Cl or Br)

The complexes [IrH(CO)(PPh₃)₃], trans-[IrCI(CO)- (PPh₃)₂], [RhH(PPh₃)₄], [Pd(PPh₃)₄], [Pt(trans-stilbene)(PPh₃)₂] and [Pt(η³-CH₂-COCH₂)-(PPh₃)₂] catalyse the rearrangement of Me₃SiCH₂C(O)CH₂Cl to CH₂?C(OSiMe₃)-CH₂Cl.     

The formation of alkyne and alkynyl complexes by reaction of 1-alkynes with trans-[M(N2)2(PH2PCH2CH2PPh2)2] (M  Mo OR W) and with [Mo(Ph2PCH2PPh2)3]: X-ray structure of trans-[Mo(CCPh)2(PH2PCH2CH2PPh2)2]

Reaction of RCCH (R  Ph, CO₂Meor CO₂Et) with trans-[M(N₂)₂(dppe)₂] (M  Mo or W; dppe  Ph₂PCH₂CH₂PPh₂) or [Mo(dppm)₃] (dppm  Ph₂PCH₂PPh₂) gives the alkyne complexes [M(RCCH)₂(diphos)₂] (diphos  dppe, M  Mo, R = Ph; dihpos  dppm, M  Mo, R  Ph or CO₂Me) and the alkynyl complexes trans-[M(cCR)₂(dppe)₂], [MH₂(CCR)₂ (dppe)₂] (M  Mo or W. R  Ph, CO₂Me or CO₂Et) and cis-[WH(CCCO₂Me)(dppe)₂]: the X-ray structure of trans-[Mo(CCPh)₂(dppe)₂] is reported.     

NEW RUTHENIUM(II) COMPLEXES CONTAINING ORGANODISULFIDE LIGANDS

Abstract

The new complexes [CpRu(PPh₃)₂(RSSR)PF₆ R=CH₃, iso-Pr, CH₂C₆H₅ and C₆H₅ have been prepared from the reaction of CpRu(PPh₃)₂Cl with RSSR in CH₃OH in presence of NH₄Cl. This result contrasts with the oxidative additions of RSSR to CpFe(dppe)1 dppe=PPh₂ (CH₂)₂PPh₂ to give [CpFe(dppe)SR]PF₆ (C. Diaz et al., J. Organomet. Chem. 516, 59 (1996)). Huckel calculations on model fragments CpFe(PPh₃)₂ and CpRu(PPh₃)₂ suggest that the higher electron density of iron could explain the differences observed in reactivity. Possible biological implications are discussed.     

Cationic rhodium(I) and iridium(I,III) complexes of cinnamonitrile and their catalytic activities

Summary Reactions of cinnamonitrile (trans-PhCH=CHCN) with [M(ClO₄)(CO)(PPh₃)₂] (M=Rh or Ir) produce hydrogenation oftrans-PhCH=CHCN to PhCH₂CH₂CN at 100°C under 3 atm of hydrogen.     

Synthesis and crystal structure of [MoH3(CCBut)(Ph2PCH2CH2PPh2)2], a trihydrido-alkynyl complex

Reaction of Bu^tCCH with trans-[Mo(N₂)₂(dppe)₂] (dppe = Ph₂PCH₂CH₂PPh₂) gives [MoH₃(CCBu^t)(dppe)₂], whose X-ray structure is reported.     

Synthesis and structural characterization of ruthenium complexes with 1-aryl-imidazole-2-thione

Treatment of [RuCl₂(PPh₃)₃] with 2 equiv. Himt^MPh (Himt^MPh?=?1-(4-methyl-phenyl)-imidazole-2-thione) in the presence of MeONa afforded cis-[Ru(κ ²-S,N-imt^MPh)₂(PPh₃)₂] (1), while interaction of [RuCl₂(PPh₃)₃] and 2 equiv. Himt^MPh in tetrahydrofuran (THF) without base gave [RuCl₂(κ ¹-S-Himt^MPh)₂(PPh₃)₂] (2). Treatment of [RuHCl(CO)(PPh₃)₃] with 1 equiv. Himt^MPh in THF gave [RuHCl(κ ¹-S-Himt^MPh)(CO)(PPh₃)₂] (3), whereas reaction of [RuHCl(CO)(PPh₃)₃] with 1 equiv. of the deprotonated [imt^MPh]^? or [imt^NPh]^? (imt^NPh?=?1-(4-nitro-phenyl)-2-mercaptoimidazolyl) gave [RuH(κ ²-S,N-imt^RPh)(CO)(PPh₃)₂] (R?=?M 4a, R?=?N 4b). The ruthenium hydride complexes 4a and 4b easily convert to their corresponding ruthenium chloride complexes [RuCl(κ ²-S,N-imt^MPh)(CO)(PPh₃)₂] (5a) and [RuCl(κ ²-S,N-imt^NPh)(CO)(PPh₃)₂] (5b), respectively, in refluxing CHCl₃ by chloride substitution of the RuH. Photolysis of 5a in CHCl₃ at room temperature afforded an oxidized product [RuCl₂(κ ²-S,N-imt^MPh)(PPh₃)₂] (6). Reaction of 6 with excess [imt^MPh]^? afforded 1. The molecular structures of 1·EtOH, 3·C₆H₁₄, 4b·0.25CH₃COCH₃, and 6·2CH₂Cl₂ have been determined by single-crystal X-ray crystallography.     

Preparation and Properties of Molybdenum and Tungsten Dinitrogen Complexes. 30.1 Syntheses of Zero-Valent Molybdenum Complexes with the DMF Ligand: The Crystal Structure of Trans-[Mo(CO)(DMF)(Ph2PCH2CH2PPh2)2]

Abstract

Treatment of trans-[Mo(N₂)₂(dpe)(dpm)] (dpe = Ph₂PCH₂CH₂PPh₂, dpm = Ph₂PCH₂PPh₂) or trans-[Mo(N₂)₂(dpe)(dpp)] (dpp = Ph₂PCH₂CH₂CH₂PPh₂) with excess DMF in benzene at reflux under Ar resulted in the formation of trans-[Mo(CO)(DMF)(dpe)(dpm)] or trans-[Mo(CO)(DMF)(dpe)(dpp)]. X-ray structural analysis of trans-[Mo(CO)(DMF)(dpe)₂] was performed using single crystals isolated as the minor product from the reaction mixture of trans-[Mo(N₂)₂(dpe)(dpp)] and DMF. Crystal data: C₅₆H₅₅O₂NP₄Mo, monoclinic, space group P2₁, a = 11.145(4), b = 23.425(5), c = 10.516(3) Å, β = 117.17(2)° V = 2442.6(13) ų, D _calcd = 1.35 g/cm³ for Z = 2. This disclosed the relatively long C O bond distance of the carbonyl ligand and the significantly short C=O bond length in the DMF ligand. When recrystallized from benzene/hexane under N₂, trans-[Mo(CO)(DMF)(dpe)(dpm)] was converted into trans-[Mo(CO)(N₂)(dpe)(dpm)].     

Coordination,oligomerisation and transfer hydrogenation of acetylenes by some ruthenium and osmium carboxylates: Crystal and molecular structures of bis(trifluoroacetato)carbonyl-(methanol) bis(triphenylphosphine)ruthenium(II) and (1,4-diphenylbut-1-en-3-yn-2-yl)trifluoroacetato-(carbonyl) bis(triphenylphosphine)ruthenium(II)

The hydrides [MH(O₂CCF₃)(CO)(PPh₃)₂] (M = Ru or Os) react with disubstituted acetylenes PhCCPh and PhCCMe to afford vinylic products [M{C(Ph)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] and [M{C(Ph)CHMe}(O₂CCF₃)(CO) (PPh₃)₂]/[M{C(Me)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] respectively. Acidolysis of these products with trifluoroacetic acid in cold ethanol liberates cis-stilbene and cis-PhHCCHMe respectively thus establishing the cis-stereochemistry of the vinylic ligands. The complexes [M(O₂CCF₃)₂(CO)(PPh₃)₂] formed during the acidolysis step undergo facile alcoholysis followed by β-elimination of aldehyde to regenerate the parent hydrides [MH(O₂CCF₃)(CO)(PPh₃)₂] and thereby complete a catalytic cycle for the transfer hydrogenation of acetylenes. The molecular structure of the methanol-adduct intermediate, [Ru(O₂CCF₃)₂(MeOH)(CO)(PPh₃)₂] has been determined by X-ray methods and shows that the coordinated methanol is involved in H-bonding with the monodentate trifluoroacetate ligand [MEO-H---OC(O)CF₃; O...O = 2.54 Å]. The hydrides [MH(O₂CCF₃)(CO) (PPh₃)₂]react with 1,4-diphenylbutadiyne to afford the complexes [M{C(CCPh)CHPh} (O₂CCF₃)(CO)(PPh₃)₂]. The ruthenium product, which has also been obtained by treatment of [RuH(O₂CCF₃)(CO)(PPh₃)₂] with phenylacetylene, has been shown by X-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand. The osmium complexes [Os(O₂CCF₃)₂(CO)(PPh₃)₂], [OsH(O₂CCF₃)(CO)(PPh₃)₂] and [Os{C(CCPh)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] all serve as catalysts for the oligomerisation of phenylacetylene. Acetylene reacts with [Ru(O₂CCF₃)₂(CO)(PPh₃)₂] in ethanol to afford the vinyl complex [Ru(CHCH₂)(O₂CCF₃)(CO)(PPh₃)₂].     

Synthesis of transition-metal Lewis acid adducts of trans-[ReCl(CNR)(Ph2PCH2CH2PPh2)2] (R = alkyl). A chemical and a quantum-chemical study of electrophilic β-addition to ligating isocyanide

Treatment of trans-[ReCl(CNR)(dppe)₂] (R = Me or Bu^t, dppe = Ph₂PCH₂CH₂ PPh₂) with CoCl₂(THF)_1.5, [ReOCl₃(PPh₃)₂] or [WCl₄L₂] (L = PPh₃ or PEtPh₂) affords the dinuclear adducts [ReCl(CN(M)R)(dppe)₂] (M = CoCl₂(THF), ReOCl₃(PPh₃) or WCl₄L, respectively) (formed via electrophilic β-addition of the electron-acceptor molecules to the isocyanide ligands), which undergo dissociation oxidation (for M = CoCl₂(THF) or ReOCl₃(PPh₃)). These reactions are considered in the light of results of extended Hückel calculations.     

The electronic properties of isocyanides at rhenium—dinitrogen binding sites. Preparation and redox properties of the isocyanide complexes trans-[ReCl(CNR)(Ph2PCH2CH2PPh2)2]

The isocyanide complexes trans-[ReCl(CNR)(dppe)₂] (R  Me, Bu^t, C₆H₄CH₃-4, C₆H₄CH₃-2, C₆H₄Cl-4, C₆H₄OCH₃-4 and C₆H₃Cl₂-2,6; dppe  Ph₂PCH₂CH₂PPh₂) have been prepared by isocyanide displacement of dinitrogen from the parent complex trans-[ReCl(N₂)(ddpe)₂]. Their redox properties have been studied by cyclic voltammetry and are interpreted on the basis of the electronic properties and the geometry of the ligating isocyanides which are believed to be bent in these complexes, appearing to exhibit ligand parameter (P_L) values ca. +0.3 V higher than those which would be expected for linear geometry. A very high polarisability (B ? 3.4) is observed for the {ReCl(dppe)₂} site.     

Syntheses and characterization of some new 2-picolylpalladium(II) complexes

The 2-picolylpalladium(II) complex [{Pd(CH₂Py)Cl(PPh₃)}₂] (CH₂Py=2-picolyl) (I), prepared from 2-picolyl chloride and [Pd(PPh₃)₄], was treated with lithium bromide, silver acetate, 4-picoline (pic) and silver perchlorate, thallium acetylacetonate{Tl(acac)}, sodium dimenthyldithiocarbamate-water-(1/2) {Na(dmdc). 2 H₂O}, and 1,2-bis(diphenylphospino)ethane (dppe) to yield [{PdBr(CH₂Py)(PPh₃)}₂] (II), [{Pd(CH₂Py)OAc(PPh₃)}₂] (III), [{Pd(Ch₂Py)(pic)(PPh₃)}₂](ClO₄)₂ (IV), [Pd(CH₂Py)(acac)(PPh₃)] (V), [Pd(CH₂Py)(dmdc)(PPh₃)] (VI), and [Pd(Ch₂Py)Cl(dppe)] (VII), respectively. Halogen abstraction from VII using silver perchlorate afforded an ionic complex [{Pd(CH₂Py)(dppe)}₂](ClO₄)₂ (VIII). It was concluded that the 2-picolyl groups in these eight complexes are σ-bonded to palladium, and that in the dinuclear complexes I, II, III, IV, and VIII, they serve as bridging ligands.