New ruthenocene-based ruthenium pincer complex bearing the C<Subscript>5</Subscript>Me<Subscript>4</Subscript>CF<Subscript>3</Subscript> ligand

The first (trifluoromethyl)tetramethylruthenocene-based ruthenium pincer complex RuCl(CO)[{2,5-(Bu ₂ ^t PCH₂)₂C₅H₂}Ru(C₅Me₄CF₃)] was synthesized by cyclometallation of the bisphosphine ligand {1,3-(Bu ₂ ^t PCH₂)₂C₅H₂}Ru(C₅Me₄CF₃) with RuCl₂(DMSO)₄ in 2-methoxyethanol in the presence of NEt₃. The new complex was fully characterized by ¹H, ¹⁹F, ³¹P{¹H}, ¹³C{¹H} NMR and IR spectroscopy.     

Ruthenium complexes with ferrocene-based P,C,P pincer ligand

First ruthenium complexes with a ferrocene-based pincer ligand were synthesized. The cyclometallation of 1,3-bis[(di-tert-butylphosphino)methyl]ferrocene with RuCl₂(DMSO)₄ in 2-methoxyethanol afforded the RuCl(CO)[{2,5-(Bu^t ₂PCH₂)₂C₅H₂}Fe(C₅H₅)](RuCl(CO) ) complex (5). Complex 5 reversibly binds CO to form the RuCl(CO)₂ complex (6). The analogous reaction in the presence of NaBAr′₄ (Ar′ = 3,5-(CF₃)₂C₆H₃) produced the cationic complex {Ru(CO)₂ }BAr′₄ (7). The structures of complexes 5 and 7 were established by single-crystal X-ray diffraction. The X-ray diffraction study revealed an agostic interaction between one of the C-H bonds of the axial (exo-oriented with respect to the ferrocene iron atom) tert-butyl group and the Ru atom in complexes 5 and 7. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1695–1701, September, 2007.     

(1,3-Diformylindenyl)cyclopentadienyl ruthenium derivatives

The reaction of [CpRu(CH₃CN)₃][PF₆], [Cp*RuCl] _n , and [Cp^FRuCl]n with 1,3-diformylindene results in the predominant formation of zwitter-ionic arene-cyclopentadienyl complexes {η⁶-1,3-(CHO)₂C₉H₅}RuCp (Cp = C₅H₅), {η⁶-1,3-(CHO)₂C₉H₅}RuCp* (Cp* = C₅Me₅), and {η⁶-1,3-(CHO)₂C₉H₅}RuCp^F (Cp^F = C₅Me₄CF₃), respectively. The ruthenocenes {η⁵-1,3-(CHO)₂C₉H₅}RuCp, {η⁵-1,3-(CHO)₂C₉H₅}RuCp*, and {η⁵-1,3-(CHO)₂C₉H₅}RuCpF were synthesized by the reaction of 1,3-diformylindenyl potassium with [CpRu(CH₃CN)₃][PF₆], [Cp*RuCl] _n , and [Cp^FRuCl] _n .     

Homoannular disubstituted ruthenocenes containing a trifluoromethyl(tetramethyl)cyclopentadienyl ligand

The reaction of the divalent ruthenium complexes [Cp^FRuCl]_n and [Cp^FRu(MeCN)₃]PF₆ with substituted pentafulvenes 1,2-(Me₂NCH)(CO₂Et)C₅H₃ and 1,3-(Me₂NCH)(CO₂Et)- C₅H₃ followed by hydrolysis affords new homoannular disubstituted ruthenocenes {1,2- (CO₂Et)(CHO)C₅H₃}RuCp^F and {1,3-(CO₂Et)(CHO)C₅H₃}RuCp^F (Cp^F = C₅Me₄CF₃), re- spectively.     

1,2-Diphosphaferrocene als Liganden in Übergangsmetallkomplexen. Röntgenstrukturanalyse von [(η5-1,3-tBu2C5H3){η5-1,2-[Co2(CO)6]-3,4-(Me3SiO)2-5-(Me3Si)P2C3}]

1,2-Diphosphaferrocenes as Ligands in Transition Metal Complexes. X-Ray Structure Analysis of [(η⁵-1,3-tBu₂C₅H₃){η⁵-1,2-[Co₂(CO)₆]-3,4-(Me₃SiO)₂-5-(Me₃Si)P₂C₃}] Reaction of metallo-1,2-diphosphapropene (η⁵-tBuC₅H₄)(CO)₂Fe? P(SiMe₃)? P?C(SiMe₃)₂ with (Z-cyclooctene)Cr(CO)₅ afforded the pentacarbonylchromium adduct of a 1,2-diphosphaferrocene [(η⁵-tBuC₅C₅H₄){η⁵-1-[Cr(CO)₅]-3,4-(Me₃SiO)₂-5-(Me₃Si)P₂C₃}Fe] ( 1 c ). Diphosphaferrocene [(η⁵-tBuC₅H₄){η⁵-3,4-(Me₃SiO)₂-5-(Me₃Si)P₂C₃}Fe] ( 2 c ) was formed when (η⁵-tBuC₅H₄)(CO)₂FeBr was treated with (Me₃Si)₂P? P?C(SiMe₃)₂ in toluene at 60°C. Photolysis of molybdenum- and tungsten hexacarbonyl in the presence of [(η⁵-1,3-tBu₂C₅H₃){η⁵-3,4-(Me₃SiO)₂-5-(Me₃Si)P₂C₃}Fe] ( 2 b ) gave the pentacarbonylmetal adducts 8 (M = Mo) and 9 (M = W), respectively. A corresponding manganese derivative resulted from the photochemical reaction of 2 b and (MeC₅H₄)Mn(CO)₃. Treatment of 2 b with Co₂(CO)₈ yielded trinuclear [(η⁵-1,3-tBu₂C₅H₃){η⁵-1,2-[Co₂(CO)₆]-3,4-(Me₃SiO)₂-5-(Me₃Si)P₂C₃}Fe] ( 11 ). Constitution and configuration of compounds 1 c, 2 c, 8 – 11 were determined by elemental analyses and spectra (IR, ¹H-, ¹³C-, ³¹P-NMR, MS). In addition the molecular structure of 11 was established by single crystal X-ray analysis.     

Ruthenium bis(phosphinite) pincer complexes

Resorcinol-based ruthenium bis(phosphinite) complexes were synthesized. Complexes RuCl(CO)[2,6-(Bu^t ₂PO)₂C₆H₃] (9) and RuH(CO)[2,6-(Bu^t ₂PO)₂C₆H₃] (10) were obtained by cyclometallation of 1,3-(Bu^t ₂PO)₂C₆H₃ with RuCl₂(DMSO)₄ in 2-methoxyethanol in the presence of Hünig’s base. The interconversion of complexes 9 and 10 was studied. The addition of carbon monoxide to complexes 9 and 10 yielded 18e adducts, RuCl(CO)₂[2,6-(Bu^t ₂PO)₂C₆H₃] (11) and RuH(CO)₂[2,6-(Bu^t ₂PO)₂C₆H₃] (12), respectively. In the case of complex 9, this reaction is reversible. Reaction of complex 10 with trifluoroacetic acid resulted in complex Ru(CF₃COO)(CO)[2,6-(Bu^t ₂PO)₂C₆H₃] (13), which reacted with carbon monoxide to give complex Ru(CF₃COO)(CO)₂[2,6-(Bu^t ₂PO)₂C₆H₃] (14). Based on the IR spectral data, the TFA ligand in complexes 13 and 14 is bound in a bi- and monodentate fashion, respectively. The structure of compound 9 was determined by X-ray diffraction analysis.     

Komplexchemie P‐reicher Phosphane und Silylphosphane. XXII. Die Bildung von [η2‐{tBu–P=P–SiMe3}Pt(PR3)2]aus (Me3Si)tBuP–P=P(Me)tBu2 und [η2‐{C2H4}Pt(PR3)2]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXII. The Formation of [η²‐{^tBu–P=P–SiMe₃}Pt(PR₃)₂] from (Me₃Si)^tBuP–P=P(Me)^tBu₂ and [η²‐{C₂H₄}Pt(PR₃)₂] (Me₃Si)^tBuP–P = P(Me)^tBu₂ reacts with [η²‐{C₂H₄}Pt(PR₃)₂] yielding [η²‐{^tBu–P=P–SiMe₃}Pt(PR₃)₂]. However, there is no indication for an isomer which would be the analogue to the well known [η²‐{^tBu₂P–P}Pt(PPh₃)₂]. The syntheses and NMR data of [η²‐{^tBu–P=P–SiMe₃}Pt(PPh₃)₂] and [η²‐{^tBu–P=P–SiMe₃}Pt(PMe₃)₂] as well as the results of the single crystal structure determination of [η²‐{^tBu–P=P–SiMe₃}Pt(PPh₃)₂] are reported.     

1‐Azaallyl Complexes of NiII,PdII, and TiIII

The metal complexes [Ni{N(Ar)C(R)C(H)Ph}₂) ( 2 ) (Ar = 2,6‐Me₂C₆H₃, R = SiMe₃), [Ti(Cp₂){N(R)C(Bu^t)C(H)R}] ( 3 ), M{N(R)C(Bu^t)C(H)R}I [M = Ni ( 4 a ) or Pd ( 4 b )] and [M{N(R)C(Bu^t)C(H)R}I(PPh₃)] [M = Ni ( 5 a ) or Pd ( 5 b )] have been prepared from a suitable metal halide and lithium precursor of ( 2 ) or ( 3 ) or, alternatively from [M(LL)₂] (M = Ni, LL = cod; M = Pd, LL = dba) and the ketimine RN = C(Bu^t)CH(I)R ( 1 ). All compounds, except 4 were fully characterised, including the provision of X‐ray crystallographic data for complex 5 a .     

Reduction of (1,3-diformylindenyl)cyclopentadienylruthenium derivatives

The reduction of the (1,3-diformylindenyl)cyclopentadienylruthenium derivatives {η⁵-1,3-(CHO)₂C₉H₅}RuCp (Cp = C₅H₅), {η⁵-1,3-(CHO)₂C₉H₅}RuCp* (Cp* = C₅Me₅), and {η⁵-1,3-(CHO)₂C₉H₅}RuCpF (Cp^F = C₅Me₄CF₃) with NaBH₄ or LiAlH₄ under mild conditions affords the [1,3-bis(hydroxymethyl)indenyl]cyclopentadienylruthenium complexes {η⁵-1,3-(CH₂OH)₂C₉H₅}RuCp, {η⁵-1,3-(CH₂OH)₂C₉H₅}RuCp*, and {η⁵-1,3-(CH₂OH)₂C₉H₅}-RuCp^F, respectively, in good yields.     

Synthesis and comparative X-ray diffraction study of first ruthenocene-based pincer palladium complexes, PdCl[{2,5-(But 2PCH2)2C5H2}Ru(Cp′)] (Cp′ = C5H5 or C5Me5)

First ruthenocene-based palladium complexes PdCl[{2,5-(Bu^t ₂PCH₂)₂C₅H₂} Ru(Cp′)] (Cp′ = C₅H₅ (4) or C₅Me₅ (5)) were synthesized. Comparative single-crystal X-ray diffraction study of complexes 4 and 5 showed that the deviations of the cyclopentadienyl rings in these complexes from being parallel are 2.6 and 10.1°, respectively. In addition, the shift of the palladium atom relative to the plane of the metallated cyclopentadienyl ligand is 0.007 Å for 4 and 0.336 Å for 5. These differences in the structures of complexes 4 and 5 are due to close contacts between the pseudoequatorial tert-butyl groups at the phosphorus atoms and the unmetallated cyclopentadienyl ring. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1879–1884, November, 2006.     

Mono and dinuclear iridium, rhodium and ruthenium complexes containing chelating carboxylato pyrazine ligands: Synthesis, molecular structure and electrochemistry

The mononuclear complexes [(η⁵-C₅Me₅)IrCl(L¹)] (1), [(η⁵-C₅Me₅)RhCl(L¹)] (2), [(η⁶-p-PrⁱC₆H₄Me)RuCl(L¹)] (3) and [(η⁶-C₆Me₆)RuCl(L¹)] (4) have been synthesised from pyrazine-2-carboxylic acid (HL¹) and the corresponding complexes [{(η⁵-C₅Me₅)IrCl₂}₂], [{(η⁵-C₅Me₅)RhCl₂}₂], [{(η⁶-p-PrⁱC₆H₄Me)RuCl₂}₂], and [{(η⁶-C₆Me₆)RuCl₂}₂], respectively. The related dinuclear complexes [{(η⁵-C₅Me₅)IrCl}₂(μ-L²)] (5), [{(η⁵-C₅Me₅)RhCl}₂(μ-L²)] (6), [{(η⁶-p-PrⁱC₆H₄Me)RuCl}₂(μ-L²)] (7) and [{(η⁶-C₆Me₆)RuCl}₂(μ-L²)] (8) have been obtained in a similar manner from pyrazine-2,5-dicarboxylic acid (H₂L²). Compounds isomeric to the latter series, [{(η⁵-C₅Me₅)IrCl}₂(μ-L³)] (9), [{(η⁵-C₅Me₅)RhCl}₂(μ-L³)] (10), [{(p-PrⁱC₆H₄Me)RuCl}₂(μ-L³)] (11) and [{(η⁶-C₆Me₆)RuCl}₂(μ-L³)] (12), have been prepared by using pyrazine-2,3-dicarboxylic acid (H₂L³) instead of H₂L². The molecular structures of 2 and 3, determined by X-ray diffraction analysis, show the pyrazine-2-carboxylato moiety to act as an N,O-chelating ligand, while the structure analyses of 5-7, confirm that the pyrazine-2,5-dicarboxylato unit bridges two metal centres. The electrochemical behaviour of selected representatives has been studied by voltammetric techniques.     

Transition Metal Complexes with Bidentate Ligands Spanning trans-Positions. VIII. The reactions of the nucleophile trans-[RuCl(NO)(1)] (1 = 2,11-bis(diphenylphosphinomethyl)benzo[c]-phenanthrene) with carbon monoxide and the phosphite ligand (2) (2 = 1-ethyl-3,5,8-trioxa-4-phosphabicyclo (2.2.2)octane)

The preparation of the nucleophile trans-[RuCl(NO)( 1 )], where 1 is the bidentate ligand Ph₂PCH₂C₁₈CH₂PPh₂, and of the five-coordinate species [RuCl(CO)(NO)( 1 )], [RuCl(CO)(NO)(Ph₂PCH₂Ph)₂] and [RuCl(NO)( 2 )( 1 )] are reported. The crystal structure of [RuCl(CO)(NO)( 1 )] shows that the coordination around the metal atom is distorted trigonal bipyramidal with the phosphorus atoms in axial positions. The Ru? N? O bond angle is 142.8°. ¹H- and ³¹P-NMR. and \documentclass{article}\pagestyle{empty}\begin{document}$ \tilde \nu $\end{document}_NO IR.-data for the above complexes are reported and related to the coordination geometry.     

Flexidentate Coordination Behavior and Chemical Non-Innocence of a Bis(1,3-Diphosphacyclobutadiene) Sandwich Anion

The homoleptic 1,3-diphosphacyclobutadiene sandwich complex [Co(η⁴-1,3-P₂C₂tBu₂)₂]⁻ behaved as a versatile and highly flexible metalloligand toward Ni²⁺, Ru²⁺, Rh⁺, and Pd²⁺ cations, forming a range of unusual oligonuclear compounds. The reaction of [K(thf)₂{Co(η⁴-1,3-P₂C₂tBu₂)₂}] with [Ni₂Cp₃]BF₄ initially afforded the σ-complex [CpNi{Co(η⁴-1,3-P₂C₂tBu₂)₂}(thf)] ( 2 ), which converted into [Co(η⁴-CpNi{1,3-P₂C₂tBu₂-κP,κC})(η⁴-1,3-P₂C₂tBu₂)] ( 3 ) below room temperature. The structure of 3 contains an unprecedented 1,4-diphospha-2-nickelacyclopentadiene moiety formed by an oxidative addition of a ligand P−C bond onto nickel. At elevated temperatures, 3 isomerized to [Co(η⁴-CpNi{1,4-P₂C₂tBu₂-κ²P,P})(η⁴-1,3-P₂C₂tBu₂)] ( 4 ), which features a 1,3-diphospha-2-nickelacyclopentadiene unit. Transmetalation of [K(thf)₂{Co(η⁴-1,3-P₂C₂tBu₂)₂}] with [Cp*RuCl]₄ (Cp*=C₅Me₅) afforded tetranuclear [(Cp*Ru)₃(μ-Cl)₂{Co(η⁴-1,3-P₂C₂tBu₂)₂}] ( 5 ), in which the [Co(η⁴-1,3-P₂C₂tBu₂]⁻ anion acts as a chelate ligand toward Ru²⁺. The diphosphido complex [(Cp*Ru)₂(μ,η²-P₂)(μ,η²-C₂tBu₂)] ( 6 ) was formed as a byproduct. Pure compound 6 was isolated after prolonged heating of the reaction mixture. The reaction of [K(thf)₂{Co(η⁴-1,3-P₂C₂R₂)₂}] (R=tBu; adamantyl, Ad) with [RhCl(cod)]₂ (cod=1,5-cyclooctadiene) afforded unprecedented π-complexes [Rh(cod){Co(η⁴-1,3-P₂C₂R₂)₂}] ( 7 : R=tBu; 8 : R=Ad), in which one μ:η⁴:η⁴-P₂C₂R₂ ligand bridges two metal atoms. The pentanuclear complex [Pd₃(PPh₃)₂{Co(η⁴-1,3-P₂C₂tBu₂)₂}₂] ( 10 ), featuring a Pd₃ chain and a rare 1,4-diphospha-2-butene ligand, was synthesized by reacting [K(thf)₂{Co(η⁴-1,3-P₂C₂tBu₂)₂}] with cis-PdCl₂(PPh₃)₂. The redox properties of selected compounds were analyzed by cyclic voltammetry, whereas DFT calculations gave additional insight into the electronic structures. The results of this study revealed several remarkable and previously unrecognized properties of the [Co(P₂C₂tBu₂)₂]⁻ anion.     

Di-tert-butylcyclopentadienyl complexes of europium and ytterbium: synthesis and crystal structures of (1,3-But 2C5H3)2 Eu·THF, (1,3-But 2C5H3)(C5Me5)Yb·THF, and\left( {1,3 - Bu^t _2 C_5 H_3 } \right)_2 Yb(\mu _2 - Cl)_2 Li(THF)_2

The (1,3-Bu^t ₂C₅H₃)₂Eu·THF complex was prepared by the reaction of 1,3-Bu^t ₂C₅H₃Na with Eul₂ in tetrahydrofuran. The mixed-ligand (1,3-Bu^t ₂C₅H₃)(C₅Me₅)Yb·THF complex was obtained by the reaction of YbI₂ with C₅Me₅Na and 1,3-Bu^t ₂C₅H₃Na. The reaction of 1,3-Bu^t ₂C₅H₃Li with YbCl₃ afforded the ( $\left( {1,3 - Bu^t _2 C_5 H_3 } \right)_2 Yb(\mu _2 - Cl)_2 Li(THF)_2 $ )ate-complex. The structures of the title compounds were established by X-ray diffraction analysis.     

Komplexchemie P-reicher Phosphane und Silylphosphane. XIV. Phosphinophosphiniden tBu2P?P als Ligand in den Pt-Komplexen [η2-{tBu2P?P}Pt(PPh3)2] und [η2-{tBu2P?P}Pt(PEtPh2)2]

Coordination Chemistry of P-rich Phosphanes and Silylphasphanes. XIV. The Phosphinophosphinidene ^tBu₂P? P as a Ligand in the Pt Complexes [η²-{^tBu₂P? P}Pt(PPh₃)₂] and [η²-{^tBu₂P? P}Pt(PEtPh₂)₂] [η²-{^tBu₂P? P}Pt(PPh₃)₂ 1 and [η²-{^tBu₂P? P}Pt(PEtPh₂)₂] 2 are the first complex compounds of ^tBu₂P? P 5 . They are formed in the reaction of ^tBu₂P? P ? P(Me)^tBu₂ 3 with [η²-{H₂C ? CH₂}Pt(PPh₃)₂] 6 or [η²-{H₂C ? CH₂}Pt(PEtPh₂)₂] 7 , respectively. Compound 1 is less stable than 2 and reacts on to [η²-{^tBu₂P? P} Pt(PPh₃)(P^tBu₂Me)] 10 with the coincidently formed ^tBu₂PMe. The molecular structures of 1 and 2 were derived from their ¹H and ³¹P-NMR spectra, 2 was additionally characterized by a X ray structure determination. 2 crystallizes in the monoclinic space group P2₁/n with a = 1222.36(7) pm, b = 1770.7(1) pm, c = 1729.7(1) pm, β = 108.653(6)°.     

Zweikernige silylenverbrückte Cyclopentadienylrhodiumbis(ethen)-Komplexe,photochemische Reaktion mit Benzolderivaten und selektiver Einschluß von Methylcyclopentan in das Kristallgitter von [Me2Si{3-But-C5H3Rh(C2H4)2}2]

Dinuclear Silylene Bridged Cyclopentadienylrhodiumbis(ethene) Complexes, Photochemical Reaction with Benzene Derivatives, and Selective Inclusion of Methylcyclopentane into the Crystal Lattice of [Me₂Si{3-Bu^t-C₅H₃Rh(C₂H₄)₂}₂] By reaction of [{(C₂H₄)₂RhCl}₂] with Na₂[Me₂Si(C₅H₄)₂] or with Li₂[Me₂Si(3-Bu^t-C₅H₃)₂] in THF the dinuclear silylene bridged complexes [Me₂Si{C₅H₄Rh(C₂H₄)₂}₂] 1 and [Me₂Si{3-Bu^t-C₅H₃Rh(C₂H₄)₂}₂] 2 , respectively, were synthesized. Due to the asymmetric substitution of the five-membered rings and their hindered rotation around the Si? C axes, 2 is formed as three isomers. The X-ray structure analysis of 2 obtained from hexane reveals the selective inclusion of methylcyclopentane, the content of which in the solvent is about 17%, into the crystal lattice. UV irradiation of 1 in hexane in the presence of benzene causes elimination of the ethene ligands yielding the μ-η³:η³ benzene complex [Me₂Si(C₅H₄Rh₂)₂C₆H₆] which cannot be separated from unreacted 1 . However, separation is possible in case of the hexamethylbenzene compound 4 analogous with 3 .     

Einfluß der Chelatbildner dppe und dppp auf die Bildung und die Eigenschaften der Pt-Komplexe des tBu2P–P

Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XV. Influence of the Chelate Compounds dppe and dppp on Formation and Properties of the Pt Complexes of ^tBu₂P–P The chelating ligands dppe and dppp replace the PPh₃ groups in [η²-{^tBu₂P–P}Pt(PPh₃)₂] 1 yielding [η²-{^tBu₂P–P}Pt(dppe)] 2 and [η²-{^tBu₂P–P}Pt(dppp)] 8 . However, they don't replace the phosphinophosphinidene ligand ^tBu₂P–P. dppm does not react at all with 1 . [η²-{H₂C=CH₂}Pt(dppe)] 3 yields in the presence of ^tBu₂P–P=P(Me)^tBu₂ 4 exclusively Pt(dppe)₂ 5 and elemental Pt; no 2 could be detected. Similarly, [η²-{H₂C=CH₂}Pt(dppp)] 7 reacts with 4 to give mainly Pt(dppp)₂ 9 and Pt; [η²-{tBu₂PP}Pt(PPh₃)₂] 8 is present only as a minor product. [η²-{^tBu₂P–P}Pt(dppe)] 2 crystallizes in the monoclinic space group P2₁/c (no. 14) with a = 1834.40(10) pm, b = 1679.70(10) pm, c = 1125.79(6) pm, β = 103.963(5)°.     

Reaktionen des [η2-{P–PtBu2}Pt(PPh3)2] und [η2-{P–PtBu2}Pt(dppe)] mit Metallcarbonylen. Bildung von [η2-{(CO)5M · PPtBu2}Pt(PPh3)2] (M = Cr,W) und [η2-{(CO)5Cr · PPtBu2}Pt(dppe)]

Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XVI [1] Reactions of [g²-{P–P^tBu₂}Pt(PPh₃)₂] and [g²-{P–P^tBu₂}Pt(dppe)] with Metal Carbonyls. Formation of [g²-{(CO)₅M · PP^tBu₂}Pt(PPh₃)₂] (M = Cr, W) and [g²-{(CO)₅Cr · PP^tBu₂}Pt(dppe)] [η²-{P–P^tBu₂}Pt(PPh₃)₂] 4 reacts with M(CO)₅ · THF (M = Cr, W) by adding the M(CO)₅ group to the phosphinophosphinidene ligand yielding [η²-{(CO)₅Cr · PP^tBu₂}Pt(PPh₃)₂] 1 , or [η²-{(CO)₅W · PP^tBu₂}Pt(PPh₃)₂] 2 , respectively. Similarly, [η²-{P–P^tBu₂}Pt(dppe)] 5 yields [η²-{(CO)₅Cr · PP^tBu₂}Pt(dppe)] 3 . Compounds 1 , 2 and 3 are characterized by their ¹H- and ³¹P-NMR spectra, for 2 and 3 also crystal structure determinations were performed. 2 crystallizes in the monoclinic space group P2₁/n (no. 14) with a = 1422.7(1) pm, b = 1509.3(1) pm, c = 2262.4(2) pm, β = 103.669(9)°. 3 crystallizes in the triclinic space group P1 (no. 2) with a = 1064.55(9) pm, b = 1149.9(1) pm, c = 1693.2(1) pm, α = 88.020(8)°, β = 72.524(7)°, γ = 85.850(8)°.     

A Nickel Complex Containing a Pyramidalized,Ambiphilic Pincer Germylene Ligand

Reaction of N-heterocyclic carbene (NHC)-stabilized PGeP-type germylene Ge{o-(PiPr₂)C₆H₄}₂⋅^MeIiPr ( 1 ) (^MeIiPr=1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) with Ni(cod)₂ gave pincer germylene complex Ni[Ge{o-(PiPr₂)C₆H₄}₂](^MeIiPr) ( 2 ), in which the Ge center of 2 is significantly pyramidalized. Theoretical calculation on 2 predicted the ambiphilicity of the germanium center, which was confirmed by reactivity studies. Thus, complex 2 reacted with both Lewis base ^MeIMe (^MeIMe=1,3,4,5-tetramethylimidazol-2-ylidene) and Lewis acid BH₃⋅SMe₂ at the germanium center to afford the adducts Ni[Ge{o-(PiPr₂)C₆H₄}₂⋅^MeIMe](^MeIiPr) ( 3 ) and Ni[Ge{o-(PiPr₂)C₆H₄}₂⋅BH₃](^MeIiPr) ( 4 ), respectively. Furthermore, the former was slowly converted to dinuclear complex Ni₂[Ge{o-(PiPr₂)C₆H₄}₂]₂(^MeIMe)₂ ( 5 ) at room temperature. Complex 5 can be regarded as a dimer of the ^MeIMe analog of 2 with a Ni-Ge-Ge-Ni linkage.     

Reactions of 2-arsa- and 2-stiba-1,3-dionato lithium complexes with group 4-7 metal halides

The reactions of a range of 2-arsa- and 2-stiba-1,3-dionato lithium complexes with group 4-7 metals have been investigated. These have given rise to several complexes in which an arsadionate acts as a chelating ligand; [V{η²-O,O-OC(Bu^t)AsC(Bu^t)O}₃], [M{η²-O,O-OC(Bu^t)AsC(Bu^t)O}₂(DME)], M=Cr or Mn; or as an η¹-As-diacylarsenide, [MnBr(CO)₄{As[C(O)Bu^t]₂Li(DME)}]₂. In addition, reactions of lithium arsadionates with TaCl₅ have led to metal mediated arsadionate decomposition reactions and arsadionate oxidative coupling reactions to give the known arsaalkyne tetramer, As₄C₄Bu^t₄, and the new tetraacyldiarsane, [{As[C(O)Mes]₂}₂] Mes=mesityl, respectively. The treatment of several lithium arsadionates with [MoBr₂(CO)₂(PPh₃)₂] has also initiated arsadionate decomposition reactions and the formation of the metal carboxylate complexes, [MoBr(CO)₂{η²-O₂C(R)}(PPh₃)₂] R=Bu^t, Ph, Mes. The X-ray crystal structures of six of the prepared complexes are discussed.