Vinyliden-Übergangsmetallkomplexe XXVI. Synthese und struktur kationischer Carbonyl-, Alken-, Vinyliden-, Alkinyl- und Alkin-Rhodiumkomplexe mit der Baueinheit trans-[Rh(PPr3)2]

The complex trans-[Rh(CO)(NH₃)(PiPr₃)₂]PF₆ (2) was prepared from [(η³-C₃H₅)Rh(PⁱPr₃)₂] (1), NH₄PF₆ and CO or from 1 and NH₄PF₆ in presence of an excess of methanol. With an excess of CO, the dicarbonyl and tricarbonyl compounds trans-[Rh(CO)₂(PⁱPr₃)₂]PF₆ (3) and [Rh(CO)₃(PⁱPr₃)₂]PF₆ (4) were obtained. Displacement of one CO ligand in 3 by pyridine and acetone led to the formation of trans-[Rh(CO)(py)PⁱPr₃)₂]PF₆ (5a) and trans-[Rh(CO) (O=CMe₂(PⁱPr₃)₂]PF₆ (6), respectively. Treatment of 1 with [pyH]BF₄ and pyridine gave trans-[Rh(py)₂(PⁱPr₃)₂]BF₄ (7); in presence of H₂ the dihydrido complex [RhH₂(py)₂(PⁱPr₃)₂]BF₄ (8) was formed. The reaction of 1 with NH₄PF₆ and ethylene produced trans [Rh(C₂H₄(NH₃(PⁱPr₃)₂]PF₆(9) whereas with methylvinylketone and acetophenone the octahedral hydridorhodium(III) complexes [RhH(η²-CH=CHC(=O)CH₃ (NH₃(PⁱPr₃)₂]PF₆(11) and [RhH(η2-C₆H₄C(=O)CH₃(NH₃(Pⁱpr₃)₂]PF₆ (13) were obtained. The synthesis of the cationic vinylidenerhodium(I) compounds trans-[Rh(=C=CHR)(py)(PⁱPr₃)₂]BF₄ (14–16) and trans-[Rh(=C=CHR)(NH₃)(PⁱPr₃) ₂]PF6 (17–19) was achieved either on treatment of 1 with [pyH]BF₄ or NH₄PF₆ in presence of 1-alkynes or by ethylene displacement from 9 by HCCR. With tert-butylacetylene as substrate, the alkinyl(hydrido)rhodium(III) complex [RhH(CC^tBu)(NH₃)(O=CMe₂)(PⁱPr₃) ₂]PF₆ (20) was isolated which in CH₂Cl₂ solution smoothly reacted to give 19 (R =^tBu). The cationic but-2-yne compound trans-[Rh(MeCCMe)(NH₃)(Pⁱ Pr₃)₂]PF₆ (21) was prepared from 1, NH₄PF₆ and C₂Me₂. The molecular structures of 3 and 14 were determined by X-ray crystallography; in both cases the square-planar coordination around the metal and the trans disposition of the phosphine ligands was confirmed.

Abstract

Der Komplex trans-[Rh(CO)(NH₃)(PⁱPr₃)₂]PF₆ (2) wurde aus [(η³-C₃H₅)Rh(PⁱPr₃)₂] (1), NH₄PF₆ und CO oder aus 1, NH₄PF₆ und Methanol hergestellt. In Gegenwart von überschüssigem CO wurden die Dicarbonyl- und Tricarbonyl-Verbindungen trans-[Rh(CO)₂(PⁱPr₃)₂]PF₆ (3) und [Rh(CO)₃(PⁱPr₃)₂]PF₆ (4) erhalten. Die Verdrängung eines CO-Liganden in 3 durch Pyridin oder Aceton führte zur Bildung von trans-[Rh(CO)(py)(PⁱPr₃)₂]PF₆ (5a) bzw. trans-[Rh(CO)(O=CMe₂)(PⁱPr₃)₂]PF₆ (6). Bei Einwirkung von [pyH]BF₄ und Pyridin auf 1 entstand trans-[Rh(py)₂(PⁱPr₃)₂]BF₄ (7); in Gegenwart von H₂ bildete sich der Dihydrido-Komplex [RhH₂(py)₂(PⁱPr₃) ₂]BF₄ (8). Die Reaktion von 1 mit NH₄PF₆ und Ethen lieferte trans-[Rh(C₂H₄)(NH₃)(PⁱPr₃)₂] PF₆ (9) während mit Methylvinylketon und Acetophenon die oktaedrischen Hydridorhodium(III)-Komplexe [RhH(η²-CH=CHC(=O)CH₃ (NH₃)-(PⁱPr₃)₂]PF₆ (11) und [RhH(η-²-C₆H₄C(=O)CH₃(NH₃)(PⁱPr₃)₂)₂]PF₆ (13) erhalten wurden. Die Synthese der kationischen Vinyli-denrhodium(I)-Verbindungen trans-[Rh(=C=CHR(py)(PⁱPr₃)₂]BF₄ (14–16) und trans-[Rh(=C=CHR)(NH₃)(PⁱPr₃)₂]PF₆ (17–19) gelang durch Einwirkung von [pyH]BF₄ bzw. NH₄PF₆ auf 1 in Gegenwart von 1-Alkinen oder durch Ethen-Verdrängung aus 9 mit HCCR. Mit tert-Butylacetylen als Reaktionspartner wurde der Alkinyl(hydrido)rhodium(III)-Komplex [RhH(CC^tBu)(NH₃(O=CMe₂)(PⁱPr₃)₂]PF₆ (20) isoliert, der in CH₂Cl₂-Lösung sofort zu 19 (R =^tBu) reagiert. Die kationische 2-Butin-Verbindung trans -[Rh(MeCCMe)(NH₃)PⁱPr₃)₂]PF₆ (21) wurde aus 1, NH₄PF₆ und C₂Me₂ hergestellt. Die Strukturen von 3 und 14 wurden kristallographisch bestimmt; in beiden Fa len ließ sich die quadratisch-planare Koordination des Metalls und die trans-Anordnung der Phosphanliganden bestätigen.     

Synthese und dynamisches Verhalten von [Rh2(μ-H)3H2(PiPr3)4]+. Beiträge zur Reaktivität des Tetrahydridodirhodium-Komplexes [Rh2H4(PiPr3)4]

Synthesis and Dynamic Behaviour of [Rh₂(μ-H)₃H₂(PiPr₃)₄]⁺. Contributions to the Reactivity of the Tetrahydridodirhodium Complex [Rh₂H₄(PiPr₃)₄] An improved synthesis of [Rh₂H₄(PiPr₃)₄] ( 2 ) from [Rh(η³-C₃H₅)(PiPr₃)₂] ( 1 ) or [Rh(η³-CH₂C₆H₅)(PiPr₃)₂] ( 3 ) and H₂ is described. Compound 2 reacts with CO or CH₃OH to give trans-[RhH(CO)(PiPr₃)₂] ( 4 ) and with ethene/acetone to yield a mixture of 4 and trans-[RhCH₃(CO)(PiPr₃)₂] ( 5 ). The carbonyl(methyl) complex 5 has also been prepared from trans-[RhCl(CO)(PiPr₃)₂] ( 6 ) and CH₃MgI. Whereas the reaction of 2 with two parts of CF₃CO₂H leads to [RhH₂(η²-O₂CCF₃) · (PiPr₃)₂] ( 8 ), treatment of 2 with one equivalent of CF₃CO₂H in presence of NH₄PF₆ gives the dinuclear compound [Rh₂H₅(PiPr₃)₄]PF₆ ( 9a ). The reactions of 2 with HBF₄ and [NO]BF₄ afford the complexes [Rh₂H₅(PiPr₃)₄]BF₄ ( 9b ) and trans-[RhF(NO)(PiPr₃)₂]BF₄ ( 11 ), respectively. In solution, the cation [Rh₂(μ-H)₃H₂(PiPr₃)₄]⁺ of the compounds 9a and 9b undergoes an intramolecular rearrangement in which the bridging hydrido and the phosphane ligands are involved.     

Synthese,Struktur und Photochemie von Olefiniridium(I)‐Komplexen mit Acetylacetonatoliganden

Synthesis, Structure, and Photochemical Behavior of Olefine Iridium(I) Complexes with Acetylacetonato Ligands The bis(ethene) complex [Ir(κ²‐acac)(C₂H₄)₂] ( 1 ) reacts with tertiary phosphanes to give the monosubstitution products [Ir(κ²‐acac)(C₂H₄)(PR₃)] ( 2 – 5 ). While 2 (R = iPr) is inert toward PiPr₃, the reaction of 2 with diphenylacetylene affords the π‐alkyne complex [Ir(κ²‐acac)(C₂Ph₂)(PiPr₃)] ( 6 ). Treatment of [IrCl(C₂H₄)₄] with C‐functionalized acetylacetonates yields the compounds [Ir(κ²‐acacR^1,2)(C₂H₄)₂] ( 8 , 9 ), which react with PiPr₃ to give [Ir(κ²‐acacR^1,2)(C₂H₄)(PiPr₃)] ( 10 , 11 ) by displacement of one ethene ligand. UV irradiation of 5 (PR₃ = iPr₂PCH₂CO₂Me) and 11 (R² = (CH₂)₃CO₂Me) leads, after addition of PiPr₃, to the formation of the hydrido(vinyl)iridium(III) complexes 7 and 12 . The reaction of 2 with the ethene derivatives CH₂=CHR (R = CN, OC(O)Me, C(O)Me) affords the compounds [Ir(κ²‐acac)(CH₂=CHR)(PiPr₃)] ( 13 – 15 ), which on photolysis in the presence of PiPr₃ also undergo an intramolecular C–H activation. In contrast, the analogous complexes [Ir(κ²‐acac)(olefin)(PiPr₃)] (olefin = (E)‐C₂H₂(CO₂Me)₂ 16 , (Z)‐C₂H₂(CO₂Me)₂ 17 ) are photochemically inert.     

Iridium(I)‐ und Iridium(III)‐Komplexe mit Triisopropylarsan als Ligand

Iridium(I) and Iridium(III) Complexes with Triisopropylarsane as Ligand The ethene complex trans‐[IrCl(C₂H₄)(AsiPr₃)₂] ( 2 ), which was prepared from [IrCl(C₂H₄)₂]₂ and AsiPr₃, reacted with CO and Ph₂CN₂ by displacement of ethene to yield the substitution products trans‐[IrCl(L)(AsiPr₃)₂] ( 3 : L = CO; 4 : L = N₂). UV irradiation of 2 in the presence of acetonitrile gave via intramolecular oxidative addition the hydrido(vinyl)iridium(III) compound [IrHCl(CH=CH₂)(CH₃CN)(AsiPr₃)₂] ( 5 ). The reaction of 2 with dihydrogen led under argon to the formation of the octahedral complex [IrH₂Cl(C₂H₄)(AsiPr₃)₂] ( 7 ), whereas from 2 under 1 bar H₂ the ethene‐free compound [IrH₂Cl(AsiPr₃)₂] ( 6 ) was generated. Complex 6 reacted with ethene to afford 7 and with pyridine to give [IrH₂Cl(py)(AsiPr₃)₂] ( 8 ). The mixed arsane(phosphane)iridium(I) compound [IrCl(C₂H₄)(PiPr₃)(AsiPr₃)] ( 11 ) was prepared either from the dinuclear complex [IrCl(C₂H₄)(PiPr₃)]2 ( 9 ) and AsiPr₃ or by ligand exchange from [IrCl(C₂H₄)(PiPr₃)(SbiPr₃)] ( 10 ) und triisopropylarsane. The molecular structure of 5 was determined by X‐ray crystallography.     

A Capped Octahedral MHC6 Compound of a Platinum Group Metal

A MHC₆ complex of a platinum group metal with a capped octahedral arrangement of donor atoms around the metal center has been characterized. This osmium compound OsH{κ²‐C,C‐(PhBIm‐C₆H₄)}₃, which reacts with HBF₄ to afford the 14 e^? species [Os{κ²‐C,C‐(PhBIm‐C₆H₄)}(Ph₂BIm)₂]BF₄ stabilized by two agostic interactions, has been obtained by reaction of OsH₆(PiPr₃)₂ with N,N′‐diphenylbenzimidazolium chloride ([Ph₂BImH]Cl) in the presence of NEt₃. Its formation takes place through the C,C,C‐pincer compound OsH₂{κ³‐C,C,C‐(C₆H₄‐BIm‐C₆H₄)}(PiPr₃)₂, the dihydrogen derivative OsCl{κ²‐C,C‐(PhBIm‐C₆H₄)}(η²‐H₂)(PiPr₃)₂, and the five‐coordinate osmium(II) species OsCl{κ²‐C,C‐(PhBIm‐C₆H₄)}(PiPr₃)₂.     

Der Dihydridoiridium(III)‐Komplex [IrH2Cl(PiPr3)2] als Molekülbaustein für unsymmetrische Rhodium–Iridiumund Iridium–Iridium‐Zweikernverbindungen

The Dihydridoiridium(III) Complex [IrH₂Cl(P i Pr₃)₂] as a Molecular Building Block for Unsymmetrical Binuclear Rhodium–Iridium and Iridium–Iridium Compounds The title compound [IrH₂Cl(PiPr₃)₂] ( 3 ) reacts with the chloro‐bridged dimers [RhCl(PiPr₃)₂]₂ ( 1 ) and [IrCl(C₈H₁₄)(PiPr₃)]₂ ( 5 ) by cleavage of the Cl‐bridges to give the unsymmetrical binuclear complexes 4 and 6 with Rh(μ‐Cl)₂Ir and Ir(μ‐Cl)₂Ir as the central building block. The reactions of 3 with the bis(cyclooctene) and (1,5‐cyclooctadiene) compounds [MCl(C₈H₁₄)₂]₂ ( 7 , 8 ) and [MCl(η⁴‐C₈H₁₂)]₂ ( 9 , 10 ) (M = Rh, Ir) occur analogously and afford the rhodium(I)‐iridium(III) and iridium(I)‐iridium(III) complexes 11 – 14 in 70–80% yield. Treatment of [(η⁴‐C₈H₁₂)M(μ‐Cl)₂IrH₂(PiPr₃)₂] ( 13 , 14 ) with phenylacetylene leads to the formation of the substitution products [(η⁴‐C₈H₁₂)M(μ‐Cl)₂IrH(C≡CPh)(PiPr₃)₂] ( 15 , 16 ) without changing the central molecular core. Similarly, the compound [(η⁴‐C₈H₁₂)Rh(μ‐Br)₂IrH(C≡CPh)(PiPr₃)₂] ( 18 ) has been prepared; it was characterized by X‐ray crystallography.     

Vielseitige Koordinationschemie von Vanadium(V): Substitutionsreaktionen,Umlagerungen und Kondensationsreaktionen von Oxovanadium(V)‐Komplexen des tripodalen Sauerstoffliganden LOMe− = [η5‐(C5H5)Co{P(OMe)2(O)}3]−

Multifaceted Coordination Chemistry of Vanadium(V): Substitution, Rearrangement Reactions, and Condensation Reactions of Oxovanadium(V) Complexes of the Tripodal Oxygen Ligand L_OMe^? = [η⁵‐(C₅H₅)Co{P(OMe)₂(O)}₃]^? The octahedral oxovanadium(V) complex [V(O)F₂L_OMe] of the tripodal oxygen ligand L_OMe^? = [η⁵‐(C₅H₅)Co{P(OMe)₂(O)}₃]^? reacts with alcohols and phenol with substitution of one fluoride ligand to form alkoxo complexes [V(O)F(OR)L_OMe], R = Me, Et, i‐Prop, Ph. In the presence of water, however, both fluoride ions are substituted and a complex with the composition VO₂L_OMe can be isolated. The crystal structure shows that the oxo‐bridged trimer [{V(O)(L_OMe)O}₃] was synthesized. In the presence of BF₃ the fluoride ligand in the alkoxo‐complex [V(O)F(OEt)L_OMe] can be exchanged for pyridine to yield [V(O)(OEt)pyL_OMe]BF₄. Analogous attempts to exchange the fluoride ligand for tetrahydrofuran and acetonitrile induces a rearrangement reaction that leads to the vanadium complex [V(O)(L_OMe)₂]BF₄. The crystal structure of this compound has been determined. Its ¹H and ³¹P‐NMR spectra show that it is a highly fluxional vanadium complex at ambient temperature in solution. The two tripodal ligands L_OMe^? coordinate the vanadium centre as bidentate or tridentate ligands. The exchange bidentate/tridentate becomes slow on the NMR time scale below about 200 K.     

Ruthenium Complexes of an Abnormally Bound,Anionic N‐Heterocyclic Carbene

The abnormally bound, anionic NHC–borane complex [Ru(IDipp‐BF₃)(p‐cymene)Cl]₂ ( 4 ; IDipp‐BF₃=1,3‐(2,6‐iPr₂C₆H₃)₂‐2‐BF₃(C₃HN₂)‐4‐yl) was synthesized by transmetalation from Li[(IDipp‐BF₃)₂Ag]. Addition of donors gave species of the form [Ru(IDipp‐BF₃)(p‐cymene)(L)Cl], whereas halide abstraction with Ag(Et₂O)[B(C₆F₅)₄] gave C?H activation of the methine position of the IDipp?BF₃ ligand.     

Preparation of Hydride‐Ethylene Complexes of Osmium

Ethylene complexes [OsH(η²‐CH₂=CH₂)L₄]Y ( 1 , 2 ) [L = PPh(OEt)₂, P(OEt)₃; Y = OTf, BPh₄] were prepared by reacting the dihydride OsH₂L₄ first with methyl triflate CH₃OTf and then with ethylene (1 atm). Alternatively, the compound [OsH(η²‐CH₂=CH₂){PPh(OEt)₂}₄]OTf was prepared by allowing the dinitrogen derivative [OsH(N₂){PPh(OEt)₂}₄]OTf to react with ethylene. Acrylonitrile CH₂=C(H)CN reacts with OsH(OTf)L₄ [L = P(OEt)₃] to give the complex [OsH{κ¹‐NCC(H)=CH₂}{P(OEt)₃}₄]BPh₄ ( 3 ). The complexes were characterized spectroscopically (IR and ¹H, ¹³C, ³¹P NMR) and by X‐ray crystal structure determination of the [OsH(η²‐CH₂=CH₂){PPh(OEt)₂}₄]BPh₄ derivative.     

Preparation and reactivity of osmium(II) hydride complexes with phosphites and polypyridyls

Chloro-complexes [OsCl(N-N)P₃]BPh₄ (1, 2) [N-N=2,2^′-bipyridine (bpy) and 1,10-phenanthroline (phen); P=P(OEt)₃ and PPh(OEt)₂] were prepared by allowing OsCl₄(N-N) to react with zinc dust in the presence of phosphites. Treatment of the chloro-complexes 1, 2 with NaBH₄ yielded, in the case of bpy, the hydride [OsH(bpy)P₃]BPh₄ (4) derivatives. Mono-phosphite [OsCl(bpy)₂P]BPh₄ (3) complexes were also prepared by reacting the [OsCl₂(bpy)₂]Cl compound with zinc dust in the presence of phosphite. Protonation reaction of the hydride [OsH(bpy)P₃]⁺ (4) cations with Brønsted acid was studied and led to thermally unstable (above 0 °C) dihydrogen [Os(η²-H₂)(bpy)P₃]²⁺ (4*) derivatives. The presence of the H₂ ligand is supported by variable-temperature NMR spectra and T_1min measurements. Carbonyl [Os(CO)(bpy){P(OEt)₃}₃](BPh₄)₂ (5), nitrile [Os(CH₃CN)(bpy){P(OEt)₃}₃](BPh₄)₂ (6), and hydrazine [Os(bpy)(NH₂NH₂){P(OEt)₃}₃](BPh₄)₂ (7) complexes were prepared by substituting the H₂ ligand in the η²-H₂ (4*) derivatives. Aryldiazene complex [Os(C₆H₅NNH)(bpy){P(OEt)₃}₃](BPh₄)₂ (8) was also obtained by allowing the hydride [OsH(bpy)P₃]BPh₄ to react with phenyldiazonium cation.     

Kinetics and mechanisms of homogeneous catalytic reactions. Part 5. Regioselective reduction of heteroaromatic nitrogen compounds catalysed by [OsH(CO)(NCMe)2(PPh3)2]BF4

The [OsH(CO)(NCMe)₂(PPh₃)₂]BF₄ complex (1) is an efficient and regioselective precatalyst for the hydrogenation of the nitrogen-containing ring of quinoline (Q), isoquinoline (iQ), 5,6- and 7,8-benzoquinoline (BQ), and acridine (A) under mild reaction conditions (125 °C and 4 atm H₂). Kinetic studies of the hydrogenation of Q and iQ to give tetrahydroquinoline (THQ) and tetrahydroisoquinoline (THiQ), respectively, lead to the rate law r = K ₁ k ₂/(1 + K ₁[H₂])[Os][H₂]², which becomes r = K ₁ k ₂[Os][H₂]², at low hydrogen concentrations (below 1 atm H₂); the catalytically active species is of the type [OsH(CO)(L)( ¹-N)(PPh₃)₂]BF₄ [(2a): L = NCMe, N = Q; (2b): L = N = iQ]. The generic mechanisms involve a rapid and partial hydrogenation of the coordinated substrate (N) of complex (2) to yield the corresponding dihydroderivative (DHN) species [OsH(CO)(L)( ¹-DHN)(PPh₃)₂]BF₄ [(3a): L = NCMe, DHN = DHQ; (3b): L = iQ or THiQ, DHN = DHiQ], followed by the rate-determining second hydrogenation of the DHN ligand, which yield [OsH(CO)(L)( ¹-THN)(PPh₃)₂]BF₄ [(4a): L = NCMe, THN = THQ; (4b): L = iQ or THiQ, THN = THiQ]; substitution of the THN ligand by a new molecule of the respective substrate regenerates the active species and restarts the catalytic cycle. For the hydrogenation of acridine to give 9,10-dihidroacridine (acridane), the rate law was r = k ₁[Os][H₂]; the mechanism involves the hydrogenation of the active species [OsH(CO)(NCMe)( ¹-A)(PPh₃)₂]BF₄ (2c) to yield acridane and the unsaturated species [OsH(CO)(NCMe)(PPh₃)₂]BF₄ as the rate-determining step.     

Cycloadditionsreaktionen von Organometall-Komplexen : XV. [2 + 31- und [2 + 1]-Cycloadditionsreaktionen von Carbonylrhodium- und Carbonylcobalt-Komplexen mit Nitriloxiden und Aziden. Die Kristall- und Molekülstruktur von C5H5(PPr3) (C6H5)

The reaction of C₅H₅Rh(CO)(PⁱPr₃) (1] which is prepared from C₅H₅Rh(CO)₂ and neat P¹Pr₃, with the nitriloxides 2-RC₆H₄CNO (R = H, Cl) leads to the formation of the metallaheterocycles C₅H₅(P¹Pr₃) ) (2, 3) in 90–95% yield. Compound 1 reacts with tosylazide to give the C,N-bound isocyanate complex C₅ H₅(PⁱPr₃)Rh(η²-TosN=C=O) (6). Analogously, on treatment of C₅Me₅Co(CO)(PMe₃) with phenylazide the phenylisocyanate derivative C₅Me₅(PMe₃)Co(η²-PhN=C=O) (7) is formed. Protonation of 7 with CF₃CO ₂H affords the non-ionic carbamoylcobalt complex C₅Me₅(PMe₃)Co[C(O)NHPh](O₂CCF₃) (8). The X-ray structural analysis of 2 reveals the presence of an almost planar heterocycle in which the two Rh-C distances differ by 0.045 Å     

Preparation and reactivity with azo-species of hydride and dihydrogen complexes of osmium stabilised by tris(pyrazolyl)borate and phosphite ligands

Mixed-ligand OsCl(Tp)L(PPh₃) complexes 1 [Tp = hydridotris(pyrazolyl)borate; L = P(OMe)₃, P(OEt)₃ and PPh(OEt)₂] were prepared by allowing OsCl(Tp)(PPh₃)₂ to react with an excess of phosphite. Treatment of chlorocomplexes 1 with NaBH₄ in ethanol afforded hydride OsH(Tp)L(PPh₃) derivatives 2. Stable dihydrogen [Os(η²-H₂)(Tp)L(PPh₃)]BPh₄ derivatives 3 were prepared by protonation of hydrides 2 with HBF₄ · Et₂O at −80 °C. The presence of the η²-H₂ ligand is supported by short T_1 min values and J_HD measurements on the partially deuterated derivatives. Treatment of the hydride OsH(Tp)[P(OEt)₃](PPh₃) complex with the aryldiazonium salt [4-CH₃C₆H₄N₂]BF₄ afforded aryldiazene [Os(4-CH₃C₆H₄NNH)(Tp){P(OEt)₃}(PPh₃)]BPh₄ derivative 4. Instead, aryldiazenido [Os(4-CH₃C₆H₄N₂)(Tp)[P(OEt)₃](PPh₃)](BF₄)₂ derivative 5 was obtained by reacting the hydride OsH(Tp)[P(OEt)₃](PPh₃) first with methyltriflate and then with aryldiazonium [4-CH₃C₆H₄N₂]BF₄ salt. Spectroscopic characterisation (IR, ¹⁵N NMR) by the ¹⁵N-labelled derivative strongly supports the presence of a near-linear Os-NN-Ar aryldiazenido group. Imine [Os{η¹-NHC(H)Ar}(Tp){P(OEt)₃}(PPh₃)]BPh₄ complexes 6 and 7 (Ar = C₆H₅, 4-CH₃C₆H₄) were also prepared by allowing the hydride OsH(Tp)[P(OEt)₃](PPh₃) to react first with methyltriflate and then with alkylazides.     

Synthesis,Interionic Structure,and Reactivity toward CO and p‐Methylstyrene of Palladacyclic Compounds Bearing α‐Diimine Ligands

Palladacyclic compounds [Pd(C₆H₄(C₆H₅C?O)C?N? R)(N? N)] [X] (R = Et, ⁱPr, 2,6‐ⁱPr₂C₆H₃; N? N = bpy = 2,2′‐bipyridine, or 1,4‐(o,o′‐dialkylaryl)‐1,4‐diazabuta‐1,3‐dienes; [X]^? = [BF₄]^? or [PF₆]^?) were synthesized from the dimers [{Pd(C₆H₄(C₆H₅C?O)C?N? R)(μ‐Cl)}₂] and N? N ligands. Their interionic structure in CD₂Cl₂ was determined by means of ¹⁹F,¹H‐HOESY experiments and compared with that in the solid state derived from X‐ray single‐crystal studies. [Pd(C₆H₄(C₆H₅C?O)C?N? R)(N? N)] [X] complexes were found to copolymerize CO and p‐methylstyrene affording syndiotactic or isotactic copolymers when bpy or 1,4‐(o,o′‐dimethylaryl)‐1,4‐diazabuta‐1,3‐dienes were used, respectively. The reactions with CO and p‐methylstyrene of the bpy derivatives were investigated. Two intermediates derived from a single and a double insertion of CO into the Pd? C bonds were isolated and completely characterized in solution.     

Ein‐ und zweikernige Rhodiumkomplexe mit Arsino(phosphino)methanen in unterschiedlichen Koordinationsformen

Mono‐ and Dinuclear Rhodium Complexes with Arsino(phosphino)methanes in Different Coordination Modes The cyclooctadiene complex [Rh(η⁴‐C₈H₁₂)(κ²‐tBu₂AsCH₂PiPr₂)](PF₆) ( 1a ) reacts with CO and CNtBu to give the substitution products [Rh(L)₂(κ²‐tBu₂AsCH₂PiPr₂)](PF₆) ( 2 , 3 ). From 1a and Na(acac) in the presence of CO the neutral compound [Rh(κ²‐acac)(CO)(κ‐P‐tBu₂AsCH₂PiPr₂)] ( 4 ) is formed. The reactions of 1a , the corresponding B(Ar_F)₄‐salt 1b and [Rh(η⁴‐C₈H₁₂)(κ²‐iPr₂AsCH₂PiPr₂)](PF₆) ( 5 ) with acetonitrile under a H₂ atmosphere affords the complexes [Rh(CH₃CN)₂(κ²‐R₂AsCH₂PiPr₂)]X ( 6a , 6b , 7 ), of which 6a (R = tBu; X = PF₆) gives upon treatment with Na(acac‐f₆) the bis(chelate) compound [Rh(κ²‐acac‐f₆)(κ²‐tBu₂AsCH₂PiPr₂)] ( 8 ). From 8 and CH₃I a mixture of two stereoisomers of composition [Rh(CH₃)I(κ²‐acac‐f₆)(κ²‐tBu₂AsCH₂PiPr₂)] ( 9/10 ) is generated by oxidative addition, and the molecular structure of the racemate 9 has been determined. The reactions of 1a and 5 with CO in the presence of NaCl leads to the formation of the “A‐frame” complexes [Rh₂(CO)₂(μ‐Cl)(μ‐R₂AsCH₂PiPr₂)₂](PF₆) ( 11 , 12 ), which have been characterized crystallographically. From 11 and 12 the dinuclear substitution products [Rh₂(CO)₂(μ‐X)(μ‐R₂AsCH₂PiPr₂)₂](PF₆) ( 13 ‐ 16 ) are obtained by replacing the bridging chloride for bromide, hydride or hydroxide, respectively. While 12 (R = iPr) reacts with NaI to give the related “A‐frame” complex 18 , treatment of 11 (R = tBu) with NaI yields the mononuclear chelate compound [RhI(CO)(κ²‐tBu₂AsCH₂PiPr₂)] ( 20 ). The reaction of 20 with CH₃I affords the acetyl complex [RhI₂{C(O)CH₃}(κ²‐tBu₂AsCH₂PiPr₂)] ( 21 ) with five‐coordinate rhodium atom.     

Halbsandwichkomplexe des Iridiums mit Tetramethylcyclopentadienyl als Ringligand

Halfsandwich‐Type Complexes of Iridium with Tetramethylcyclopentadienyl as Ligand The iridium(I) complexes [(η⁵‐C₅HMe₄)Ir(C₂H₄)₂] ( 2 ) and [(η⁵‐C₅HMe₄)Ir(CO)₂] ( 4 ), which have been prepared from [IrCl(C₂H₄)₂]₂ or [IrCl(CO)₃]_n and LiC₅HMe₄, react with tosylchloride as well as with X₂ (X = Cl, Br, I) by oxidative addition to yield the corresponding iridium(III) compounds. Treating the complexes [(η⁵‐C₅HMe₄)IrX₂]_n ( 7 — 9 ) with CO or PR₃ leads to a cleavage of the halide bridges and to the formation of the mononuclear products [(η⁵‐C₅HMe₄)IrX₂(CO)] ( 10 , 11 ) and [(η⁵‐C₅HMe₄)IrX₂(PR₃)] ( 12 — 20 ), respectively. The molecular structure of [(η⁵‐C₅HMe₄)IrBr₂(PiPr₃)] ( 18 ) was determined crystallographically. The reactions of 8 (X = Br) and 9 (X = I) with Ph₂P(CH₂)_nPPh₂ (n = 1 or 2) afford the bridged compounds [{(η⁵‐C₅HMe₄)IrX₂}₂{μ‐Ph₂P(CH₂)_nPPh₂}] ( 21—23 ). The dihalide complexes [(η⁵‐C₅HMe₄)IrI₂(PPh₃)] ( 16 ) and [(η⁵‐C₅HMe₄)IrX₂(PiPr₃)] ( 17—19 ) react with hydride sources to give the dihydrido‐ and monohydrido derivatives [(η⁵‐C₅HMe₄)IrH₂(PPh₃)] ( 24 ) and [(η⁵‐C₅HMe₄)IrH(X)(PiPr₃)] ( 25—27 ). The related dimethyl and monomethyl compounds [(η⁵‐C₅HMe₄)Ir(CH₃)₂(PiPr₃)] ( 28 ) and [(η⁵‐C₅HMe₄)IrCH₃(I)(PiPr₃)] ( 29 ) have been obtained from the dihalide precursors 18 or 19 and CH₃MgI in the molar ratio of 1:2 or 1:1, respectively.     

Erratum

The hydrido-thiocarbonyl osmium(II) complexes OsH₂(CS)(PPh₃)₃, OsHCl(CS)(PPh₃)₃, OsH(OClO₃)(CS)(PPh₃)₃, OsHCl(CS)(CNR)(PPh₃)₂ and [OsH(CS)(CO)(PPh₃)₃]⁺, (R = p-tolyl), have been derived from OsCl₂(CS)(PPh₃)₃ and [OsH(CS)(CO)(PPh₃)₃]⁺, the latter can be deprotonated to give the zerolavent complex, Os(CS)(CO)(PPh₃)₃.     

Neue Kupferkomplexe mit Phosphaalkenliganden. Molekülstruktur von [Cu{P(Mes*)C(NMe2)2}2]BF4 (Mes* = 2,4,6‐tBu3C6H2)

New Copper Complexes Containing Phosphaalkene Ligands. Molecular Structure of [Cu{P(Mes*)C(NMe₂)₂}₂]BF₄ (Mes* = 2,4,6‐tBu₃C₆H₂) Reaction of equimolar amounts of the inversely polarized phosphaalkene tBuP=C(NMe₂)₂ ( 1a ) and copper(I) bromide or copper(I) iodide, respectively, affords complexes [Cu₃X₃{μ‐P(tBu)C(NMe₂)₂}₃] ( 2 ) (X =Br) and ( 3 ) (X = I) as the formal result of the cyclotrimerization of a 1:1‐adduct. Treatment of 1a with [Cu(L)Cl] (L = PiPr₃; SbiPr₃) leads to the formation of compounds [CuCl(L){P(tBu)C(NMe₂)₂}] ( 4a ) (L = PiPr₃) and ( 4b ) (L = SbiPr₃), respectively. Reaction of [(MeCN)₄Cu]BF₄ with two equivalents of PhP=C(NMe₂)₂ ( 1b ) yields complex [Cu{P(Ph)C(NMe₂)₂}₂]BF₄ ( 5b ). Similarly, compounds [Cu{P(Aryl)C(NMe₂)₂}₂]BF₄ ( 5c (Aryl = Mes and 5d (Aryl = Mes*)) are obtained from ArylP=C(NMe₂)₂ ( 1c : Aryl = Mes; 1d : Mes*) and [(MeCN)₄Cu]BF₄ in the presence of SbiPr₃. Complexes 2 , 3 , 4a , 4b , and 5b‐5d are characterized by means of elemental analyses and spectroscopy (¹H‐, ¹³C{¹H}‐, ³¹P{¹H}‐NMR). The molecular structure of 5d is determined by X‐ray diffraction analysis.     

Platinum Indolylphosphine Fluorido and Polyfluorido Complexes: An Interplay between Cyclometallation,Fluoride Migration,and Hydrogen Bonding

The reaction of [PtCl₂(COD)] (COD=1,5-cyclooctadiene) with diisopropyl-2-(3-methyl)indolylphosphine (iPr₂P(C₉H₈N)) led to the formation of the platinum(ii ) chlorido complexes, cis-[PtCl₂{iPr₂P(C₉H₈N)}₂] ( 1 ) and trans-[PtCl₂{iPr₂P(C₉H₈N)}₂] ( 2 ). The cis-complex 1 reacted with NEt₃ yielding the complex cis-[PtCl{κ²-(P,N)-iPr₂P(C₉H₇N)}{iPr₂P(C₉H₈N)}] ( 3 ) bearing a cyclometalated κ²-(P,N)-phosphine ligand, while the isomer 2 with a trans-configuration did not show any reactivity towards NEt₃. Treatment of 1 or 3 with (CH₃)₄NF (TMAF) resulted in the formation of the twofold cyclometalated complex cis-[Pt{κ²-(P,N)-iPr₂P(C₉H₇N)}₂] ( 4 ). The molecular structures of the complexes 1–4 were determined by single-crystal X-ray diffraction. The fluorido complex cis-[PtF{κ²-(P,N)-iPr₂P(C₉H₇N)}{iPr₂P(C₉H₈N)}] ⋅ (HF)₄ ( 5 ⋅ (HF)₄) was formed when complex 4 was treated with different hydrogen fluoride sources. The Pt(ii ) fluorido complex 5 ⋅ (HF)₄ exhibits intramolecular hydrogen bonding in its outer coordination sphere between the fluorido ligand and the NH group of the 3-methylindolyl moiety. In contrast to its chlorido analogue 3 , complex 5 ⋅ (HF)₄ reacted with CO or the ynamide 1-(2-phenylethynyl)-2-pyrrolidinone to yield the complexes trans-[Pt(CO){κ²-(P,C)-iPr₂P(C₉H₇NCO)}{iPr₂P(C₉H₈N)}][F(HF)₄] ( 7 ) and a complex, which we suggest to be cis-[Pt{C=C(Ph)OCN(C₃H₆)}{κ²-(P,N)-iPr₂P(C₉H₇N)}{iPr₂P(C₉H₈N)}][F(HF)₄] ( 9 ), respectively. The structure of 9 was assigned on the basis of DFT calculations as well as NMR and IR data. Hydrogen bonding of HF and NH to fluoride was proven to be crucial for the existence of 7 and 9 .     

The formal umpolung behaviour of protonic acids containing coordinating anions towards diphosphazane-bridged derivatives of nonacarbonyldiruthenium

Reaction of [Ru₂(μ-CO)(CO)₄{μ-(RO)₂PN(Et)(OR)₂}₂] (R = Me or Prⁱ) with the protonic acids HCl, HBr, HNO₃, H₂BO₂F, CF₃COOH, PhSH/HPF₆, and H₂CO₃/HPF₆ produces [Ru₂A(CO)₅ {μ-(RO)₂PN(Et)(OR)₂}₂]⁺ and/or [Ru₂(μ-A)(CO)₄{μ-(RO)₂PN(Et)(OR)₂}₂]⁺ (A = Cl, Br, ON(O)O, OB(F)OH, OC(CF₃)O, SPh, and OC(OH)O) via [Ru₂H(CO)₅{μ-(RO)₂PN(Et)(OR)₂}₂]⁺ as intermediate; the structure of [Ru₂{μ-OB(F)OH}(CO)₄{-(PrⁱO)₂PN(Et)P(OPrⁱ)₂}]⁺ has been established X-ray crystallographically.