Synthesis and reactivity of functionalized rhenium germyl complexes (η5-C5H5)Re(NO)(PPh3)(GePh2X); dynamic equilibria with germylene complex [(η5-C5H5)Re(NO)(PPh3)(GePh2)]+X−

Reaction of Li⁺[(η⁵-C₅H₅)Re(NO)(PPh₃)]⁻ with Ph₃GeCl and Ph₂GeCl₂ (THF, −75°C) gives germyl complexes (η⁵-C₅H₅)Re(NO)(PPh₃)(GePh₃) (84%) and (η⁵-C₅H₅) Re(NO)(PPh₃)(GePh₂Cl) (3, 82%), respectively. Reaction of 3 and (CH₃)₃SiOTf gives (η⁵-C₅H₅)Re(NO)(PPh₃)(GePh₂OTf) (4, 82%). Several properties show the triflate substituent in 4 to be extremely labile. First, reaction of 4 and pyridine to give [(η⁵- C₅H₅)Re(NO)(PPh₃)(GePh₂NC₅H₅)]⁺TfO⁻ (5) is complete in < 5 min at −78°C; the pyridine in 5 rapidly exchanges with pyridine-d₅ (CD₂Cl₂, −80°C). Second, the ¹³C NMR resonances of the diastereotopic germanium phenyl substituents in 4 coalesce upon warming (ΔG3_268K (CD₂Cl₂) = 12.6±0.2 kcal mol⁻¹). The most likely mechanisms for this dynamic behaviour entail initial triflate dissociation to give the germylene complex [(η⁵-C₅H₅)Re(NO)(PPh₃)( GePh₂)]⁺TfO⁻.     

Synthesis,characterization, and reactivity of the neutral metal formyl (η5-C5Me5)(CO)2(PPh3)MoCHO. A new route to monocationic secondary alkoxycarbene complexes [(η5-C5Me5)(CO)2(PPh3)Mo(CHOE)]+ X− (E = H,Me)

(η⁵-C₅Me₅)(CO)₂(PPh₃)MoCHO (2) one of the few isolated neutral metal formyls, reacts with the electrophilic reagents (CF₃COOH and CH₃SO₃F without disproportionation to give the secondary carbene complexes [(η⁵-C₅Me₅)(CO)₂(PPh₃)Mo(CHOE)]⁺ X⁻ (E = H, X = CF₃COO (4); E = Me, X = PF₆ (5)).     

Self-recognition by the iron chiral auxiliary [(η5-C5H5)Fe(CO)(PPh3] in the formation of (RR,SS)-[(η5-C5H5)FE(CO)(PPh3)COCH2]2CH2

Complete self-recognition of chirality is observed in the Michael addition of the enolate derived from R,S-[η⁵-C₅H₅Fe(CO)(PPh₃-COCH₃] to the acryloyl complex R,S-[(η⁵-C₅H₅Fe(CO)(PPh₃)-COCHCH₂)] to generate exclusively the single diastereoisomer of the glutaroyl complex RR,SS-[(η⁵-C₅H₅)Fe(CO)(PPh₃)COCH₂]₂CH₂.     

Substituent Effect on the Thermodynamics and Kinetics of Carbyne Complex [(η5-C5H5)(CO)(COMe)Re≡CC6H4X] Isomerization to Carbene Complex [(η5-C5H5)(CO)2Re=C(Me)(para-C6H4X]: A Theoretical Study

Russian Journal of Physical Chemistry A - This study investigates the effect of different substituents on the isomerization reaction of the [(η5‑C5H5)(CO)(Me)Re≡CC6H5] carbyne...     

[2 + 2] Photodimerization of the acenaphthylene ruthenium complex [(C5Me4CH2OMe)Ru(η6-C12H8)]+

The [2 + 2] photodimerization of the complex [(C₅Me₄CH₂OMe)Ru(η⁶-C₁₂H₈)]⁺ under visible-light irradiation leads to a mixture of the head-to-head heptacyclene products [(μ-η⁶: η⁶-C₂₄H₁₆)Ru₂(C₅Me₄CH₂OMe)₂]²⁺ (syn- and anti-) with the predominant formation of the syn-isomer; the structures of both isomers were established by X-ray diffraction analysis.     

The stereoselective reaction of sodium cyanide with the cationic ruthenium vinylidene complex [(η5-C5H5)(PMe3)2RuCC(Me)Ph]+

The reaction of sodium cyanide with [(η⁵-C₅H₅)(PMe₃)₂RuCC(Me)Ph]PF₆ (1) proceeds with high stereoselectivity (> 95 : 5) to give (Z)-(η⁵-C₅H₅)(PMe₃)₂RuC(CN)C(Me)Ph, which under acid conditions isomerises (< 5 : 95) to the E isomer.     

Synthesis of alkene- and alkyne-pentamethylcyclopentadienyl dicarbonyliron complexes via the aquo derivative [Fe(η-C5Me5)(CO)2(OH2)]+BF4-; crystal structure of the ruthenium analogue

[Fe(η-C₅Me₅)(CO)₂(OH₂)]⁺ BF₄^- (2a) reacts with alkenes and alkynes to give the new complexes [Fe(η-C₅Me₅)(CO)₂(alkene)]⁺ BF₄^- and [Fe(η-C₅Me₅)(CO)₂(alkyne)]⁺ BF₄^-. The crystal structure of the ruthenium analogue [Ru(η-C₅Me₅)(CO)₂(OH₂)]⁺ CF₃SO₃^- (2b) is described.     

Dimeric uranium complexes with bridging phospholyl ligands. Crystal structure of [{U(η5-C4Me4P)(μ-η5-C4Me4P)(BH4)}2]

In the symmetrical crystal structure of [{U(η⁵-C₄Me₄P)(μ-η⁵,η¹-C₄Me₄P)(BH₄)}₂], the U-P bond distances for the terminal and bridging η⁵-phospholyl ligands are 2.945(3) and 2.995(3) Å respectively, and the U-P (η¹-phospholyl) bond length is equal to 2.996(3) Å; the tridentate borohydride ligands are cis to the (UP)₂ ring. The cis and trans isomers of [{U(Cp¹)(μ-η⁵,η¹C₄ Me₄P)(BH₄)}₂] (Cp¹ = η⁵-C₅Me₅) are in equilibrium in toluene.     

Conformational analysis and x-ray crystal structure of [(η5-C5H5)Fe(CO)(PPh3)CH2CH3]

The complex [(η⁵-C₅H₅)Fe(CO)(PPh₃)CH₂CH₃] is shown by ¹H NMR spectroscopy and an X-ray crystal structure analysis to adopt a single conformation with the methyl group residing between the cyclopentadienyl and carbon monoxide ligands.     

Synthesis and structures of the η5-C5H5Cl(CO)2W-η1,η5-(PPh2)C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)3 and MeSi[C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)2PPh3]3 complexes

The metallation of the η⁵-C₅H₅(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ complex with BuⁿLi (THF, ?78 °C) followed by the treatment of the lithium derivative with Ph₂PCl afforded the η⁵-Ph₂PC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ complex. The reaction of the latter with η⁵-C₅H₅(CO)₃WCl in the presence of Me₃NO produced the trinuclear complex η⁵-C₅H₅Cl(CO)₂W-η¹,η⁵-(Ph₂P)C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃. The structure of the latter complex was established by IR, UV, and 1H and ³¹P NMR spectroscopy and X-ray diffraction. The reaction of MeSiCl₃ with three equivalents of LiC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₂PPh₃ gave the hexanuclear complex MeSi[C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₂PPh₃]₃.     

Triphospha-Ferrocenes as Ligands. Crystal Structures of [Fe(η5-C5Me5)(η5-C2 TBu2P3)M(CO)5)], (M= Cr,MO, W) and the Novel ruthenium and Nickel Complexes [Fe(η5-C5Me5) (η5-C2 TBu2P3)Ru3(CO)9] and [Fe(η5-C5Me5)(η5-C2 tBu2P3)Ni(Co)2]2

Abstract

Syntheses and structures of penta- and hexaphosphorus analogues of ferrocene have been described recently¹. Unlike their simple ferrocene analogues, these complexes have further ligating potential towards other transition metal centres by virtue of the availability of the ring phosphorus lone-pair electrons that are not involved in the η⁵-coordination. We now describe the first examples of coordination compounds of the triphospha-ferrocene [Fe(η⁵-C₅Me₅) (η⁵-C₂ ^tBu₂P₃]. In the ruthenium complex [Fe(η⁵-C₅Me₅)(η⁵-C₂ ^tBu₂P₃) Ru₃(CO)₉] ² two adjacent phosphorus atoms of the η⁵-C₂ ^tBu₂P₃ ring are interlinked by a ruthenium carbonyl cluster in which all three ruthenium atoms interact with the phosphorus atoms. The tetrametallic nickel complex [Fe(η⁵-C₅Me₅)(η⁵-C₂ ^tBu₂P₃)Ni(CO)₂]₂ ³ represents the first example of intermolecular interlinkage of two phospha-ferrocene systems by two metal centres.     

Structure and bonding analysis of dimethylgallyl complexes of iron, ruthenium, and osmium [(η5-C5H5)(CO)2M(GaMe2)] and [(η5-C5H5)(Me3P)2M(GaMe2)

Density functional theory calculations have been performed for the dimethylgallyl complexes of iron, ruthenium, and osmium [(η(5)-C(5)H(5))(L)(2)M(GaMe(2)] (M = Fe, Ru, Os; L = CO, PMe(3)) at the DFT/BP86/TZ2P/ZORA level of theory. The calculated geometry of the iron complex [(η(5)-C(5)H(5))(CO)(2)Fe(GaMe(2))] is in excellent agreement with structurally characterized complex [(η(5)-C(5)H(5))(CO)(2)Fe(Ga(t)Bu(2))]. The Pauling bond order of the optimized structures shows that the M-Ga bonds in these complexes are nearly M-Ga single bond. Upon going from M = Fe to M = Os, the calculated M-Ga bond distance increases, while on substitution of the CO ligand by PMe(3), the calculated M-Ga bond distances decrease. The π-bonding component of the total orbital contribution is significantly smaller than that of σ-bonding. Thus, in these complexes the GaX(2) ligand behaves predominantly as a σ-donor. The contributions of the electrostatic interaction terms ΔE(elstat) are significantly smaller in all gallyl complexes than the covalent bonding ΔE(orb) term. The absolute values of the ΔE(Pauli), ΔE(int), and ΔE(elstat) contributions to the M-Ga bonds increases in both sets of complexes via the order Fe < Ru < Os. The Ga-C(CO) and Ga-P bond distances are smaller than the sum of van der Waal radii and, thus, suggest the presence of weak intermolecular Ga-C(CO) and Ga-P interactions.     

The reductive dimerization of [W(NCMe)(MeC2Me)2(η-C5H5)]+: Synthesis and X-ray structure of the novel bis(metallacyclopentadiene) complex [W2(μ-σ,σ,η2,η2-C4Me4)2(η-C5H5)2]

Treatment of [W(CO)(MeC₂Me)₂(-C₅H₅)][PF₆] with ONMe₃ in acetonitrile yields [W(NCMe)(MeC₂Me)₂(-C₅H₅)][PF₆] which undergoes irreversible reduction at a Pt electrode in THF. Sodium amalgam reduction of [W(NCMe) (MeC₂Me)₂(-C₅H₅)][PF₆] gives orange crystals of [W₂(µ-,, ², ²-C₄Me₄)₂ (-C₅H₅)₂] X-ray studies on which reveal pairwise alkyne coupling and a novel bis(metallacyclopentadiene) structure.Dedicated to Professor L. F. Dahl on the occasion of his 65th birthday.     

富勒烯配合物η2-C60[Ru(NO)(PPh3)]2的合成与表征

从1985年Kroto等[1]发现富勒烯至今, 其在化学、材料和物理等领域已有较多的研究[2～8]. 目前有关C60取代的金属小分子配合物(如羰基、亚硝酰基等)的研究方兴未艾. 而以NO为配体的亚硝酰基金属富勒烯配合物仅有数例[2,3], Green等[3]在研究以CO和NO为配体的金属富勒烯系列化合物的合成中, 认为C60不能与Ru(NO)2(PPh3)2发生反应. 本文利用Ru(NO)2(PPh3)2与C60反应首次合成出η2-C60[Ru(NO)(PPh3)]2配合物, 并对其进行了表征.     

Copper-tungsten complexes with bridging tolylmethylidyne ligands: Crystal structure of the compound [CuW2(μ3-CC6H4Me-4)(CO)4(PPh3)(η-C5H5)2]·CH2Cl2

The complexes [W(CC₆H₄Me-4)(CO)₂(η-C₅H₅)] and [Cu(NCMe)₄][PF₆] in dichloromethane combine to form the salt [Cu&W(CC₆H₄Me-4)(CO)₂(η-C₅H₅)&₂][PF₆], but the latter very readily dissociates in solution releasing the tolylmethylidynetungsten compound. The more stable salt [CuW(μ-CC₆H₄Me-4)(CO)₂(NCMe)(PPh₃) (η-C₅H₅)][PF₆] is obtained by addition of [W(CC₆H₄Me-4)(CO)₂(η-C₅H₅)] to a dichloromethane solution of [Cu(NCMe)₄][PF₆] previously treated with 1 mol equivalent of PPh₃. In the presence of additional PPh₃, however, no copper-tungsten complex is formed. Several reactions of [CuW(μ-CC₆H₄Me-4)(CO)₂(NCMe)(PPh₃)(η-C₅H₅)][PF₆] have been studied, but these led only to release of [W(CC₆H₄Me-4)(CO)₂(η-C₅H₅)]. The compounds [&CuH(PPh₃)&₆] and [W(CC₆H₄Me-4)(CO)₂(η-C₅H₅)] react in toluene at room temperature to give [W(CO)₂(η³-CH₂C₆H₄Me-4)(η-C₅H₅)] and the new cluster compound [CuW₂(μ₃-CC₆H₄Me-4)(CO)₄(PPh₃)(η-C₅H₅)₂]. The structure of the latter species has been established by X-ray diffraction. A CuW₂ metal triangle [CuW 2.640(2) and 2.610(2), and WW 3.064(1) Å] is asymmetrically capped by a CC₆H₄Me-4 group [μ₃-CCu 2.130(9), μ₃-CW 2.035(9) and 2.122(9) Å]. The copper atom is ligated by a PPh₃ molecule, and each tungsten by an η⁵-cyclopentadienyl and two carbonyl groups. The copper atom is weakly coordinated in a semi-bridging manner by two of the CO ligands, one on each tungsten, and is also very weakly bound to a third. The molecule undergoes dynamic behaviour in solution.     

π-complexes of monoanionic carborane ligand [9-(Me2S)-7,8-C2B9H10]− with [η-C5R5Fe]+ (R=H, Me) and [η-C4Me4Co]+ cationic fragments

Compounds (η-C₅R₅)Fe[η-9-(Me₂S)-7,8-C₂B₉H₁₀] (R=H, Me) and (η-C₄Me₄)Co[η-9-(Me₂S)-7,8-C₂B₉H₁₀] were synthesized by the reactions of Na[9-(Me₂S)-7,8-C₂B₉H₁₀] with complexes [(η-C₅H₅)Fe(MeCN)₃]PF₆, [(η-C₅Me₅)Fe(MeCN)₃]BF₄, and [(η-C₄Me₄)Co(MeCN)₃]PF₆, respectively. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 177–179, January, 1999.