Übergangsmetallphosphidokomplexe. VII. Ringgrößeneffekte bei den NMR-Daten von Übergangsmetallphosphor-Vier- und Sechsringkomplexen

Transition Metal Phosphido Complexes. VII. Ring Size Effects within the N.M.R. Data of Transition Metal Phosphorus Four- and Six-membered Ring Complexes Comparing the corresponding n.m.r. data of [cpNiPH₂]₂ 1 and [cpNiPH₂]₃ 2 , of [(CO)₄MnPH₂]₂ 3 and [(CO)₄MnPH₂]₃ 4 , and of [(CO)₄MnPF₂]₂ 5 and [(CO)₄MnPF₂]₃ 6 , respectively, it is shown that mainly the coupling constant between the phosphorus nuclei J_PMP (M = Ni, Mn) and all chemical shift values are strongly influenced by the ring size. The relevant coupling constants between the nuclei ¹H, ³¹P, and ¹⁹F have been obtained using computer simulations of the corresponding higher order spin systems.     

Übergangsmetallphosphidokomplexe. VIII. Strukturuntersuchungen an Übergangsmetallphosphor-Vier- und Sechsringkomplexen. Die Strukturen von [(CO)4MnPH2]2, [(CO)4MnPH2]3 und [cpNiPH2]3

Transition Metal Phosphido Complexes. VIII. X-Ray Diffraction Studies of Transition Metal Phosphorus Four- and Six-Membered Ring Complexes. Structures of [(CO)₄MnPH₂]₂, [(CO)₄MnPH₂]₃, and [cpNiPH₂]₃ [(CO)₄MnPH₂]₂ 1 crystallizes triclinic in the space group P1 with a = 680.4 pm, b = 706.4 pm, c = 919.1 pm, α 110.5°, β = 91.92°, γ 115.65°, and Z = 1 formula unit. The molecule exhibits a centrosymmetrical structure. The bond angles within the planar four-membered (Mn? P)₂-ring are 76.1° at the Mn atoms and 103.9° at the P atoms, respectively. The average Mn? P bond distance is found to be 235.1 pm. [(CO)₄MnPH₂]₃ 2 crystallizes monoclinic in the space group P2/n with a = 905.2 pm, b = 974.8 pm, c = 1264.2 pm, β = 109.1°, and Z = 2 formula units. The framework of the six-membered (Mn? P)₃-ring can be described as having a twist boat conformation. The average endocyclic bond angles are with 89.1° at the Mn atoms and 130.1° at the P atoms, respectively, largely widened compared to 1 . The average Mn? P bond distance, which is found to be 238.5 pm, is also slightly increased compared to 1 . [cpNiPH₂]₃ 3 crystallizes rhombohedral in the space group R3. The cell constants (hexagonal setting) are a = b = 1686.1 pm, c = 561.1 pm and Z = 3 formula units. The six-membered (Ni? P)₃-ring exhibits a chair conformation. The endocyclic bond angles are with 92.3° at the Ni atoms and 124.3° at the P atoms, respectively, comparable with those of the six-membered ring compound 2 . The Ni? P bond distance is found to be 215.2 pm. The eyclopentadienyl ligands are disordered and have been refined as rigid groups.     

Eisen- und Nickelcarbonylkomplexe mit substituierten Distiban- und Antimonido-Liganden

Iron and Nickel Carbonyl Complexes with Substituted Distibane and Antimonido Ligands The reactions of enneacarbonyldiiron with substituted distibanes yield mononuclear complexes [Fe(CO)₄SbR₂SbR₂] (R = C₂H₅, t-C₄H₉), a dinuclear complex [(CO)₄FeSbPh₂SbPh₂Fe(CO)₄] and antimonido-bridged compounds [(CO)₃Fe(SbR₂)₂-Fe(CO)₃] (R = C₂H₅, C₆H₅). Product of the reaction of tetramethyldistibane with tetracarbonylnickel is the binuclear complex [(CO)₃NiSbMe₂SbMe₂Ni(CO)₃]. The ¹H-n.m.r., i.r., and mass spectra of the new compounds are reported.     

Phosphite addition to organometallic cations to give phosphonium adducts

Addition of tri-n-butylphosphite to [(C₆H₇)Fe(CO)₃]BF₄, [(C₆H₆OMe)-Fe(CO)₃]BF₄, and [(C₇H₇)Cr(CO)₃]BF₄ has yielded novel phosphonium salts; which are remarkably stable.     

Heterobimetallische phosphanido-verbrückte Zweikern-Komplexe - Synthese von cis-rac-[(η-C5H4R)2Zr{μ-PH(2,4,6−iPr3C6H2)}2M(CO)4] (RMe,MCr,Mo; RH,MMo)

Heterobimetallic Phosphanido-bridged Dinuclear Complexes - Syntheses of cis-rac-[(η-C₅H₄R)₂Zr{μ-PH(2,4,6-ⁱPr₃C₆H₂)}₂M(CO)₄] (R?Me, M?Cr, Mo; R?H, M?Mo) The zirconocene bisphosphanido complexes [(η-C₅H₄R)₂Zr{PH(2,4,6-ⁱPr₃C₆H₂)}₂] (R?Me, H) react with [(NBD)M(CO)₄] (NBD?norbornadiene, M?Cr, Mo) to give only one diastereomer of the phosphanido-bridged heterobimetallic dinuclear complexes cis-rac-[(η-C₅H₄R)₂Zr{μ-PH(2,4,6-ⁱPr₃C₆H₂)}₂M(CO)₄] [R?Me, M?Cr ( 1 ), Mo ( 2 ); R?H, M?Mo ( 3 )]. However, no reaction was observed between [(η-C₅H₅)₂Zr{PH(2,4,6-^tBu₃ C₆H₂)}₂] and [Pt(PPh₃)₄]. 1—3 were characterised spectroscopically. For 1—3 , the presence of the racemic isomer was shown by NMR spectroscopy. No reaction was observed at room temperature for 3 and CS₂, (NO)BF₄, Me₃NO or PH(2,4,6-Me₃C₆H₂)₂. With Et₂AlH or PhC?CH decomposition of 3 was observed.     

Strukturen von SF5-substituierten Metallkomplexen

Structures of SF₅-substituted Metal Complexes Crystal and molecular structure of [(CO)₆Co₂(F₅S? C?C? SF₅)], [(CO)₄Co? CH₂? SF₅] and [(CO)₅Mn? S? CF?N? SF₅] are reported. Whereas the first two complexes are formed as expected, the latter one is the product of an unclear reaction pathway. In decomposition reactions of [(CO)₄Co? CH₂? SF₅] and [(CO)₅Mn? CH₂? SF₅] H₂C?SF₄ is produced. This allows a one step preparation of this elusive, simplest alkylidine sulfur tetrafluoride.     

Metallkomplexe mit biologisch wichtigen Liganden. CLVII [1] Halbsandwich‐Komplexe mit Isocyanoacetylaminosäureestern und Isocyanoacetyldi‐ und tripeptidestern („Isocyano‐Peptide”︁)

Metal Complexes of Biologically Important Ligands, CLVII [1] Halfsandwich Complexes of Isocyanoacetylamino acid esters and of Isocyanoacetyldi‐ and tripeptide esters (?Isocyanopeptides”?) N‐Isocyanoacetyl‐amino acid esters CNCH₂C(O) NHCH(R)CO₂CH₃ (R = CH₃, CH(CH₃)₂, CH₂CH(CH₃)₂, CH₂C₆H₅) and N‐isocyanoacetyl‐di‐ and tripeptide esters CNCH₂C(O)NHCH(R¹)C(O)NHCH(R²)CO₂C₂H₅ and CNCH₂C(O)NHCH(R¹)C(O)NHCH (R²)C(O)NHCH(R³)CO₂CH₃ (R¹ = R² = R³ = CH₂C₆H₅, R² = H, CH₂C₆H₅) are available by condensation of potassium isocyanoacetate with amino acid esters or peptide esters. These isocyanides form with chloro‐bridged complexes [(arene)M(Cl)(μ‐Cl)]₂ (arene = Cp*, p‐cymene, M = Ir, Rh, Ru) in the presence of Ag[BF₄] or Ag[CF₃SO₃] the cationic halfsandwich complexes [(arene)M(isocyanide)₃]⁺X^? (X = BF₄, CF₃SO₃).     

Molybdenum complexes containing substituted cyclopenta[l]phenanthrenyl ligand

The synthesis of new cyclopenta[l]phenanthrenyl complexes [(η⁵-C₁₇H₁₀Me)(η³-C₃H₅)Mo(CO)₂] and [(η⁵-C₁₇H₉(COOMe)N(CH₂)₄)(η³-C₃H₅)Mo(CO)₂] is described. Although these compounds are structural analogues their reactivity is different. Protonation of [(η⁵-C₁₇H₁₀Me)(η³-C₃H₅)Mo(CO)₂] gives a stable ionic compound [(η⁵-C₁₇H₁₀Me)Mo(CO)₂(NCMe)₂][BF₄] while its analogue containing both tertiary amino and carboxylic ester groups [(η⁵-C₁₇H₉(COOMe)N(CH₂)₄)(η³-C₃H₅)Mo(CO)₂] decomposes under the same conditions. [(η⁵-C₁₇H₁₀Me)Mo(CO)₂(NCMe)₂][BF₄] reacts with cyclopentadiene to give a stable η⁴-complex [(η⁴-C₅H₆)(η⁵-C₁₇H₁₀Me)Mo(CO)₂][BF₄] that was successfully oxidized to the Mo(IV) dicationic compound [(η⁵-C₅H₅)(η⁵-C₁₇H₁₀Me)Mo(CO)₂][Br][BF₄].     

Zur oxidativen Addition von komplexierten Phosphanen bzw. Arsanen an Platin(0)‐Komplexen

Oxidative Addition Reactions of Complexed Phosphine and Arsine at Platinum(0) Complexes The reactions of E(SiMe₃)₃ with [W(CO)₅thf] yield after alcoholysis in a one‐pot reaction the complexes [(CO)₅WEH₃] ( 1 ) (E = P( a ), As( b )). This procedure circumvents the direct use of gaseous phosphine and arsine, respectively. Complexes 1 react with [(C₂H₄)Pt(PPh₃)₂] in an oxidative addition type reaction to form the heterometallic complexes [(PPh₃)₂Pt(H){(μ‐EH₂)W(CO)₅}] (E = P( 2 ), As( 3 )). Complexes 2 and 3 were obtained as mixtures of their cis‐ and trans‐isomers, in which the contents of the trans‐isomer dominates. The products were comprehensively spectroscopically characterised, and the structures of the trans‐complexes 2 and 3 were determined by X‐ray crystal structure analysis.     

Synthesis and x-ray crystal structure of [{(C5H4Me)Fe(CO)2}2BiCl]3: A compound containing a planar six-membered Bi3Cl3 ring

The reaction between BiCl₃ and two equivalents of Na[(C₅H₄Me)Fe(CO)₂] affords the title complex, [{(C₅H₄Me)Fe(CO)₂}₂BiCl]₃, containing a planar six-membered Bi₃Cl₃ ring in which each bismuth is bonded to two chlorine atoms and two (C₅H₄Me) Fe(CO)₂ fragments.     

Heteronukleare Komplexverbindungen mit Metall—Metall-Bindungen. VIII. Neue heterodinukleare Komplexe mit Bindungen zwischen Kupfer(I) und Mangan(–I), Eisen(–I) oder Cobalt(–I)

Heteronuclear Coordination Compounds with Metal—Metal Bonds. VIII. New Heterodinuclear Complexes with Bonds between Copper(I) and Manganese(?I), Iron(?I), or Cobalt(?I) [(en)Cu? Mn(CO)₅] ( 1a ), [(dien)Cu? Mn(CO)₅] ( 1b ), [(en)Cu? Fe(CO)₃(NO)] ( 2a ), [(dien)Cu? Fe(CO)₃(NO)] ( 2b ), [(en)Cu? Co(CO)₄] ( 3a ), and [(dien)Cu? Co(CO)₄] ( 3b ) are new heterobinuclear metal—metal bonded complexes. The geometry of the [Mn(CO)₅]^?, [Fe(CO)₃(NO)]^?, and [Co(CO)₄]^? ions is distorted only to a less extend in accord with a heteropolar bond to copper.     

Kinetics of nucleophilic attack on coordinated organic moieties : VI. Mechanism of addition of tri-n-butylphosphine to [(C7H7)M(CO)3]BF4 (M = Cr, Mo, W) and related cations

Phosphonium adduct formation via attack of tri-n-butylphosphine on the cations [(C₇H₇)M(CO)₃]⁺ (M = Cr, Mo, W) obeys the rate law, Rate = k [complex] [PBu₃]. The very similar rate constants for the Cr, Mo and W complexes confirm the similar electrophilicities of the tropylium rings in these cations, and also support the view that there is direct addition to the rings. The related complexes [(C₆H₇)Fe(CO)₃]BF₄ and [(C₆H₆)Mn(CO)₃]BF₄ also form adducts with PBu₃, and the quantitative reactivity order [(C₆H₇)Fe(CO)₃]⁺ > [(C₇H₇)Cr(CO)₃]⁺ » [(C₆H₆)Mn(CO)₃]⁺ (160:60:1) has been established.     

Modified cyclopentadienyl molybdenum compounds with enhanced cytotoxic activity towards MOLT‐4 leukaemia cells

A series of new cyclopentadienyl molybdenum compounds bearing substituted phenanthroline ligands [(η⁵‐C₅H₄CH₂C₆H₄X‐4)Mo(CO)₂(^N,NL)][BF₄] (X = F, Cl, Br; ^N,NL = phen, 5‐NH₂‐phen, 4,7‐Ph₂‐phen) was prepared and characterized using infrared and NMR spectroscopies. Crystal structures of [(η⁵‐C₅H₄CH₂C₆H₄F‐4)Mo(CO)₂(NCMe)₂][BF₄], [(η⁵‐C₅H₄CH₂C₆H₄X‐4)Mo(CO)₂(phen)][BF₄] (X = F, Cl, Br) and [(η⁵‐C₅H₄CH₂C₆H₄Cl‐4)Mo(CO)₂(4,7‐Ph₂‐phen)][BF₄]⋅(4,7‐Ph₂‐phen)⋅HBF₄ were determined using X‐ray diffraction analysis. Biological studies revealed a strong cytotoxic effect of the chelating ligands. Although the cytostatic effect of the halogen in the side chain of the cyclopentadienyl ring is negligible, it could be used for future post‐modification of these types of cytotoxic active molybdenum‐based compounds.     

Mehrfachbindungen zwischen hauptgruppenelementen und übergangsmetallen: XVII. Selen- und tellur-brücken in organometallkomplexen: AUFBAU,protonierung und methylierung

Selenium acts as a bridging ligand between two iron atoms in the novel complex (μ-Se)(η⁵-C₅H₅)Fe(CO)₂]₂ (1), obtained in 60% yield from Na⁺[(η⁵-C₅H₅)Fe(CO)₂] and Se₂Cl₂. 1 displays nucleophilic reactivity towards protic acids (e.g., HBF₄·OEt₂) and methyl triflate, CF₃SO₃CH₃, thus giving the protonated and methylated ionic species [(μ-SeR)(η⁵-C₅H₅)Fe(CO)₂₂]⁺ (R = H: 2a, BF₄ salt; R = CH₃: 2b, PF₆ salt) in quantitative yields. Rapid deprotonation of 2a occurs in the presence of bases such as diethylamine. Analogous protonation and methylation reactions have been observed with the tellurium complex (μ-Te)[(η⁵-C₅H₅)Cr(CO)₃]₂ (3); the ionic compounds [(μ-TeH)(η⁵-C₅H₅)Cr(CO)₃₂]BF₄ (4a) and [(μ-TeCH₃) (η⁵-C₅H₅)Cr(CO)₃₂]PF₆(4a), respectively, are obtained. In contrast, the electron-deficient tellurium ligand of the manganese complex (μ₃-Te)[(η⁵-C₅H₅)Mn(CO)₂]₃ (5) is neither attacked by Brønsted acids nor by electrophilic methylating agents (e.g., CF₃SO₃CH₃) but is rather methylated by methyllithium to give the anionic species [(μ₃-TeCH₃)η⁵-C₅H₅)Mn(CO)₂₃]^? that can be isolated pure as the PPN⁺ salt 6.     

Chirale Halbsandwich‐Pentamethylcyclopentadienyl‐Rhodium(III)‐ und Iridium(III)‐Komplexe mit Schiff‐Basen aus Salicylaldehyd und α‐Aminosäureestern [1]

Chiral Half‐sandwich Pentamethylcyclopentadienyl Rhodium(III) and Iridium(III) Complexes with Schiff Bases from Salicylaldehyde and α‐Amino Acid Esters [1] A series of diastereoisomeric half‐sandwich complexes with Schiff bases from salicylaldehyde and L‐α‐amino acid esters including chiral metal atoms, [(η⁵‐C₅H₅)(Cl)M(N,O‐Schiff base)], has been obtained from chloro bridged complexes [(η⁵‐C₅Me₅)(Cl)M(μ‐Cl)]₂ (M = Rh, Ir). Abstraction of chloride from these complexes with Ag[BF₄] or Ag[SO₃CF₃] affords the highly sensitive compounds [(η⁵‐C₅Me₅)M(N,O‐Schiff base]⁺X^? (M = Rh, Ir; X = BF₄, CF₃SO₃) to which PPh₃ can be added under formation of [(η⁵‐C₅Me₅)M(PPh₃)(N,O‐Schiff base)]⁺X^?. The diastereoisomeric ratio of the complexes ( 1 ‐ 7 and 11 ‐ 12 ) has been determined from NMR spectra.     

Synthesis and reactivity of [(η-[32](1,3)Cyclophane)Mn(CO)3][BF4]

The manganese cyclophane complex, [(η⁶-[3₂](1,3)cyclophane)Mn(CO)₃][BF₄] 2, was prepared by the reaction of [[3₂](1,3)cyclophane] 1 with Mn(CO)₅FBF₃. Reaction of 2 with NaBH₃CN yielded the cyclohexadienyl manganese complex [(η⁵-6H-[3₂](1,3)cyclophane)Mn(CO)₃] 3. Interestingly, treatment of 3 with Mn(CO)₅FBF₃ gave the bis-manganese complex (η⁶,η⁵-6H-[3₂](1,3)cyclophane)[Mn(CO)₃]₂[BF₄] 4. When NaBH₃CN was treated with 4, [(η⁵,η⁵-6H,6^′H-[3₂](1,3)cyclophane)Mn(CO)₃] 5 was isolated as yellow crystals. The structure of compounds 2 and 3 were determined by single-crystal X-ray crystallography.     

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.     

Organometallchemie binuclearer 1-Azadien-nickel(0)-Komplexe Bimetallverbindungen mit Ni?Fe-Bindung durch Addition von Pentacarbonyleisen(0) und Nickelalactone durch Ringöffnung cyclischer Anhydride

Organometallic Chemistry of Binuclear 1-Azadiene-Nickel(0) Complexes: Bimetallic Compounds with a Ni? Fe Bond by Addition of Pentacarbonyl-iron(0) and Nickelalactons by Ring Opening Reaction of Cyclic Anhydrides The binuclear nickel(0) complexes 1–3 , which contain as well bridging 1-azadienes ligands as five or six-membered (N∩N)-chelate rings react at ?30°C with Fe(CO)₅ to form the bimetallic compounds 4–6 , containing a Ni? Fe bond and two carbonyl groups as bridging ligands. The coordination of the [(bpy)Ni(0)] fragment to the olefin part of the 1-azadiene chain in 6 leads to the formation of the trinuclear complex 7 , which can storage CO₂ at the peripheral position. Succinic acid anhydride or glutaric acid anhydrid undergo a ring opening reaction by reacting with 3 yield nickelalactones upon elimination of CO.     

Reaktionen von Cyclostibanen (RSb)n [R = (Me3Si)2CH,n = 3; Me3CCH2, n = 4, 5] mit den Übergangsmetallcarbonyl‐Komplexen [W(CO)5(thf)], [CpxMn(CO)2(thf)], [CpxCr(CO)3]2 und [Co2(CO)8]; Cpx = MeC5H4

Reactions of Cyclostibanes, (RSb)_n [R = (Me₃Si)₂CH, n = 3; Me₃CCH₂, n = 4, 5] with the Transition Metal Carbonyl Complexes [W(CO)₅(thf)], [Cp^xMn(CO)₂(thf)], [Cp^xCr(CO)₃]₂, and [Co₂(CO)₈]; Cp^x = MeC₅H₄ (RSb)₃ [R = (Me₃Si)₂CH] reacts with [W(CO)₅(thf)], [Cp^xMn(CO)₂(thf)], or [Co₂(CO)₈] to give [(RSb)₃W(CO)₅] ( 1 ), [RSb{Mn(CO)₂Cp^x}₂] ( 2 ) or [RSbCo(CO)₃]₂ ( 3 ). The reaction of (R′Sb)_n (n = 4, 5; R′ = Me₃CCH₂) with [Cp^xCr(CO)₃]₂ leads to [(R′Sb)₄{Cr(CO)₂Cp^x}₂] ( 4 ); Cp^x = MeC₅H₄, thf = Tetrahydrofuran.     

Metallkomplexe des Hexamethyl-trisila-tetraphospha-nortricyclen P4 (Sime2)3

Transition Metal Complexes of the Hexamethyl-trisila-tetraphospha-nortricyclene P₄ (Sime ₂) ₃ P₄(Sime₂)₃ 1 reacts with Mo(CO)₆, Cr(CO)₅THF, and Mn(η-C₅H₅)(CO)₂THF to give crystalline complexes in which 1 functions as a monodentate ligand. In each compound one phophorus atom of the cyclotriphosphane ring coordinates to the metal atom. Using Mn(η-C₅H₅)(CO)₂THF, two different P atoms of the P₃ Cr(CO)₄ norbornadiene and 1 react, yielding the dimeric, red, crystalline compound (CO) ₄Cr[μ-P₄(Sime₂)₃]₂Cr(CO)₄. In this complex the two molecules of 1 are both bonded by two P atoms of the P ₃ ring to the two Cr(CO)₄ Units, forming a six-memered (CrP₂)₂ring.