The reactions of AgI electrophile with [Fe2(η-C5H5)2(CO)2(L){CN(Me)H}]+ and [Fe2(η-C5H5)2(CO)2{CN(Me)H}2]2+ salts (L = CO or CNMe)

The protonated species [Fe₂(η-C₅H₅)₂(CO)₂(η-CO){μ-CN(Me)H}]X, [Fe₂(η-C₅H₅)₂(CO)(CNMe)(μ-CO){μ-CN(Me)H}][X], and [Fe₂(η-C₅H₅)₂(CO)₂{η-CN(Me)H}₂][X]₂ react with one equivalent of AgY. The Ag⁺ and one H⁺ act together as a two-electron oxidant. Silver metal is precipitated quantitatively and the substrates cleaved to give mono-nuclear products of the type (a) [Fe(η-C₅H₅)(CO)(L)X] and [Fe(η-C₅H₅(CO)(L)Y] or (b) Fe(η-C₅H₅(CO)(L)(CNMe)][X] (L = CO, CNMe). If X⁻ and Y⁻ are both coordinating anions such as NO₃⁻, I⁻, or Br⁻ or the solvent is MeCN products of type (a) are usually obtained with X = Y = MeCN⁺ if acetonitrile is used as the solvent. However, if either X⁻ or Y⁻ is a non-coordinating anion such as BF₄⁻ or PF₆⁻ and methanol is the solvent, the products are usually those of type (b). When X⁻ = [p-MeC₆H₄SO₃]⁻, both types of products are obtained in significant amounts. If two equivalents of Ph₃P are added to the methanol solution of [Fe₂(η-C₅H₅)₂(CO)₂{-CN(Me)H}₂[BF₆]₂, no reaction takes place until the third equivalent of AgNO₃ has been added. The products have been isolated and characterized by analysis and infrared spectroscopy. The previously unreported [Fe₂(η-C₅H₅)₂(CO)(CNMe)(η-CO){η-CN(Me)H}] X salts are described for X⁻ = BF₄⁻, PF₆⁻, Br⁻ · 2H₂O, I⁻ · H₂O, NO₃⁻ · 0.5H₂O, and p-MeC₆H⁴SO₃⁻.     

De-protonation of (η4-isoprene)Fe(CO)3; an isoprene anion equivalent

(η⁴-Isoprene)Fe(CO)₃ can be deprotonated with lithium diisopropylamide. The resulting coordinated isoprene anion reacts with electrophiles at low temperature, but rearranges to an isomeric (η⁴-trimethylenemethane)Fe(CO)₃ anion derivative at higher temperatures.     

Tetracarbonyliron adducts of Cp2Cr2(CO)4(μ-η2-P2). Syntheses and crystal structures of Cp2Cr2(CO)4P2[Fe(CO)4] m (m=1 and 2)

Cp₂Cr₂(CO)₄( - ² - P₂), 1, reacts with one molar equivalent of Fe₂(CO)₉ in THF to yield the mono- and di-iron complexes, Cp₂Cr₂(CO)₄P₂[Fe(CO)₄], 2, (16.5% yield) and Cp₂Cr₂(CO)₄P₂[Fe(CO)₄]₂, 3, (16.9% yield), as dark magenta brown and dark greenish brown crystals, respectively. Both complexes were characterized by single-crystal X-ray diffraction analysis. Crystal data –2: space group =P2₁/c,a=17.024(1) Å,b=8.180(1) Å,c=30.891(2) Å, =100.953(5)°,V=4223.4(7)ų,Z=8, 3743 observed reflections,R _F=0.033; 3: space group P1,a=10.209(2) Å,b=10.212(2) Å,c=15.989(3) Å, =106.93(1)°, =91.87(1)°, =119.50(1)°,V=1356.5(4) ų,Z=2, 3489 observed reflections,R _F=0.029.     

Synthesis of cationic indenyliron complexes: [η5-C9H7Fe(CO)2L]+ (L = phosphine,phosphite, CO)

Synthetic routes to the cationic complexes [η⁵-C₉H₇Fe(CO)[₂L]⁺, (L = CO, phosphine, phosphite, nitrile, pyridine) have been investigated. The most versatile method is oxidation of the dimer [η⁵-C₉h₇Fe(CO)₂]₂ with ferricinium ion. in the presence of the appropriate ligand. [η⁵-C₉H₇Fe(CO)₃]⁺ is best prepared by oxidation of the dimer with Ph₃CBF₄. This tricarbonyl cation readily loses one CO group on reactiom with phosphines and P(OCH₃). The acentonitrile ligand [η⁵-C₉H₇Fe(CO)₂CH₃CN]⁺ can also be replaced bny phosphines. Finally, reactions of η⁵-C₉H₇Fe(CO)₂X, (X = Br, I) with phosphines also yield cationic products isolatedas PF₆⁻ salts.     

Insertion reactions of t-Bu(η5-C5H5)Fe(CO)2

The complex t-Bu(η⁵-C₅H₅)FE(CO)₂ has been treated with triphenylphosphine in refluxing THF to produce t-BuCO(η⁵-C₅H₅)Fe(CO)(PPh₃). The large steric bulk of the t-butyl group suggests that this reaction should be faster than the reaction involving the methyl group, and a kinetic investigation illustrates this to be the case. The same steric bulk predicts that the reaction with SO₂ should be slow, and indeed we have been unable to effect the related SO₂ insertion reaction. Attempts to prepare the corresponding t-Bu(η⁵-C₅H₅)W(CO)₃ led to formation of the related isobutyl complex.     

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.     

The preparation of a series of ring-linked derivatives of [Fe2(η-C5H5)2(CO)2(μ-CO)2] starting from [Fe2η5,η5-C5H4CH(NMe3)CH(NMe2)C5H4}(CO)2(μ-CO)2]+ salts

The salts [Fe₂η⁵,η⁵-C₅H₄CH{NMe₃)CH(NMe₂)C₅H₄}(CO)₂(μ-CO)₂][X] (X = I or SO₃CF₃) are the synthetic precursors to a wide range of [Fe₂(η-C₅H₅)₂(CO)₂(μ-CO)₂] derivatives in which the two cyclopentadienyl ligands are joined by a two-carbon bridge.     

Organodiphosphines in cis-Pt(η2-P2L)(η2-S2L) derivatives – structural aspects

Abstract

In this review structural parameters of forty complexes with an inner coordination sphere of Pt(η²-P₂L)(η²-S₂L) are analyzed and classified These complexes crystallize in three crystal systems: orthorhombic (four examples), triclinic (six examples) and monoclinic (thirty examples). The organodiphosphines create four- (PCP), five- (PC₂P), six- (PC₃P) and seven- (PC₄P) membered metallocyclic rings with mean P-Pt-P bite angle values of 72.5° (PCP) < 85.3° (PC₂P) < 93.0° (PC₃P) < 97.4° (PC₄P). The dithiolates create four- (SCS), five- (SC₂S), six- (SC₃S; SCSCS; SPNPS; SPCPS) and seven- (SC₄S) membered metallocyclic rings with mean S-Pt-S bite angle values of 74.5° (SCS) < 85.8° (SCSCS) < 87.0° (SPNPS) < 89.0° (SC₂S) < 92.3° (SC₄S) < 93.5° (SC₃S) < 97.5° (SPCPS). The mean Pt-P and Pt-S bond distances are 2.257 and 2.328?Å, respectively. The data are compared with those found in complexes with inner coordination spheres of Pt(PL)₂(SL)₂, Pt(PL)₂(η²-S₂L) and Pt(η²-P₂L)(SL)₂.     

(Tetragermacyclobutadiene)ruthenium tricarbonyl [η4-(But 2MeSi)4Ge4]Ru(CO)3

Tetrakis(di-tert-butylmethylsilyl)tetragermacyclobutadiene]ruthenium tricarbonyl [η⁴-(Bu^t ₂MeSi)₄Ge₄]Ru(CO)₃ is synthesized. This analogue of well-known cyclobutadiene transition metal complexes bears a tetragermacyclobutadiene derivative as ligand. The structure and spectroscopic parameters of the complex are compared with those of its iron-containing analogue [η⁴-(Bu^t ₂MeSi)₄Ge₄]Fe(CO)₃. Based on experimental data and results of quantum chemical calculations, it is shown that the π-donating ability of ligands increases upon replacement of carbon atoms in the cyclobutadiene moiety by silicon or germanium atoms, tetrasilacyclobutadiene and tetragermacyclobutadiene being comparable in π-donating activity.     

Application of electron-transfer chain catalysis: preparation of bridged 〚{(η5-C5H5)Fe(CO)2}2(μ-diphosphine)2+〛 complexes without chelated 〚(η5-C5H5)Fe(CO)(η2-diphosphine)+〛 byproducts

The ligand substitution by diphosphine L–L on (η⁵-C₅H₅)Fe(CO)₂I usually results in the chelated 〚(η⁵-C₅H₅)Fe(CO)(η²-L–L)⁺〛〚I^–〛 product exclusively. One could suppress the chelated complexes and selectively prepare the bridged 〚{(η⁵-C₅H₅)Fe(CO)₂}₂(μ-L–L)²⁺〛 complexes by application of the electron-transfer chain catalysis with a chemical initiation. Introducing a catalytic amount of reductant at low temperature to the mixture of 2:1 (η⁵-C₅H₅)Fe(CO)₂I/L–L in THF selectively produces the bridged complexes in 78–93% isolated yields where L–L is Ph₂P(CH₂)_nPPh₂, n = 1–4, or (η⁵-C₅H₄PPh₂)₂Fe.     

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.     

Reactions of (η6-diphenylacetylene) chromiumtricarbonyl complexes with polynuclear carbonyls I. Synthesis of Cr(CO)3(η6-diphenylacetylene) complex and its reaction with Co2(CO)8. Crystal and molecular structure of Cr(CO)3(η6:η2-diphenylacetylene)Co2(CO)6

The reaction of Cr(CO)₃(NH₃)₃ with diphenylacetylene affords as a main product the complex with Cr(CO)₃ moiety bound to a phenyl ring of diphenylacetylene; Cr(CO)₃(η⁶-PhC₂Ph) (I). Complex I readily reacts with Co₂(CO)₈ yielding the mixed metal complex Cr(CO)₃(η⁶:η²-PhC₂Ph)Co₂(CO)₆ (II). The reaction proceeds with retention of the Cr(CO)₃ (η⁶-arene) structural unit, the Co₂(CO)₆ fragment being bound to the triple bond of diphenylacetylene in μ₂,η²-mode. The structure of II was determined by single crystal X-ray analysis. The complex crystallizes in space group P2₁/c with unit cell parameters a 8.666(3) Å, b 18.046(3) Å, c 15.155(6) Å. β 97.57(3)°, V 2349(2) ų, Z = 4, D_x = 1.70 g/cm³. The structure was solved by direct methods and refined by full-matrix least-squares technique to R and R_w values of 0.032 and 0.034, respectively, for 3655 observed reflections. The data obtained show that two structural units in II, Cr(CO)₃(η⁶-Ph-) and Co₂(CO)₆(μ₂,η²-CC), are distorted due to steric repulsion between these metal carbonyl moieties. The Cr(CO)₃ fragment is shifted from the centre of the phenyl ring and slightly tilted with respect to the phenyl ring plane. The Co₂C₂ tetrahedron in the Co₂(CO)₆(μ₂,η²-CC) moiety is distorted in such a way that two of the four Co_iC_j bonds are elongated.     

Reactions of 1,4-difeffocenylbuta-1,3-diyne and 1,4-diphenylbut-l-en-3-yne with Ru3(CO)12. Crystal structure of Ru3(CO)8(μ3-η-1-η1-η4-η2-C4Ph2(CH=CHPh)2)

Diyne FcCmCC.CFc (Fc is ferrocenyl) reacts with Ru₃(CO)₁₂ in boiling hexane to yield binuclear complexes Ru₂ and Ru₂(CO)₆(C₄Fc₂(C=CFc)₂C=O) containing ruthenacyclopentadiene and diruthenacycloheptadienone rings, respectively. The isomerism of the complexes is due to the different ways of coupling of the alkyne fragments of the diyne, namely, head-to-head, head-to-tail or tail-to-tail. The reaction of enyne PhC=CCH=CHPh with Ru₃(CO)₁₂ under similar conditions gives isomeric binuclear complexes Ru₂(CO)₆(C₄Ph₂(CH=CHPh)₂) and trinuclear clusters Ru₃(CO)₆(w-CO)₂(C₄Ph₂(CH=CHPh)₂) and Ru₃(CO)₈(₃-,¹-¹-⁴-² C₄Ph₂(CH=CHPh)₂). The structure of the latter was determined by X-ray diffraction analysis. The Ru₃ triangle coordinates eight terminal CO groups and the organic ligand resulting from the head-to-head dimerization of enyne molecules; the ruthenacyclopentadiene moiety is ⁴-coordinated to the Ru(CO)₂ group, and the third ruthenium atom is 2-bound to one of the PhCH=CH groups.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1261–1267, May, 1996.     

The first ruthenium carbonyl derivative of fullerene: (η2-C60)Ru(CO)4

Buckminsterfullerene, C₆₀, reacts with Ru(CO)₅ to give a 1:1 adduct (η²-C₆₀)Ru(CO)₄. The synthesis and spectroscopic (IR and ¹³C NMR) characterization of this compound are described.     

The reactions of [Fe2(η-C5H5)2(CO)4−n(CNMe)n] (n = 0–4) complexes with halogens and mercury(II) salts

Halogens, X₂, and HgY₂ (X = Cl, Br, I; Y = X, F, NO₃, BF₄) cleave the metalmetal bonds in [Fe₂(η-C₅H₅)₂(CO)_4−n(CNMe)_n] complexes (n = 0–4). Typically, e.g., when n = 2, X₂ electrophiles give [Fe(η-C₅H₅)(CO)(CNMe)X] (a) and [Fe(η-C₅H₅)(CO)(CNMe)₂]X (b) in relative yields which depend on X, the reaction solvent and n, but HgY₂ give equimolar amounts of [Fe(η-C₅H₅)(CNMe)₂Y] (c and [Fe(η-C₅H₅)(CO)₂HgY] only. Hg(CN)₂ reacts more slowly than other HgY₂, and [Hg(PPh₃)₂I₂] does not react at all. It is suggested that the reactions which give rise to products of type (a), (b) or (c) are all two-electron oxidation which proceed by way of adducts containing μ-CA → X₂ or μ-CA → HgX₂ groups (Ca = CO or CNMe). One of these adducts has been isolated, namely [Fe₂(η-C₅H₅)₂(CNMe)₂{μ-CN(Me)HgCl₂}₂] · CHCl₃.     

Rh2(CO)4(μ-Cl)2和Rh4(μ-CO)3(CO)4的简正振动分析

金属簇合物具有独特的结构和成键方式。本文对铑簇合物的简正振动分析进行了研究。通过红外光谱用石蜡油糊涂KBr和聚乙烯窗口, 在Nicolet 200SXV FT-IR光谱上测定了Rh2(CO)4(μ-Cl)2的构型, 并使用分子振动全分析程序MVTA(Basic语言), 在PC机上进行计算。     

The chemistry of hydridocarbonylferrates revisited: syntheses and structures of the new [H2Fe4(CO)12]2- and [HFe5(CO)14]3- anions, and the [Fe(DMF)4][Fe4(CO)12(μ5-η2-CO)(μ-H)]2 adduct containing an unprecedented isocarbonyl

The di-hydride di-anion [H(2)Fe(4)(CO)(12)](2-) has been quantitatively obtained by protonation of the previously reported mono-hydride tri-anion [HFe(4)(CO)(12)](3-) in DMSO and structurally characterised in its [NEt(4)](2)[H(2)Fe(4)(CO)(12)] salt. It shows some subtle but yet significant differences in the stereochemistry of the ligands in comparison to the heavier Ru(4) and Os(4) congeners. The study of the reactivity of these [H(4 -n)Fe(4)(CO)(12)](n-) (n = 2,3) species allowed the serendipitous isolation and structural characterization of the new pentanuclear [HFe(5)(CO)(14)](3-) mono-hydride tri-anion. Attempts to obtain the latter in better yields led to the discovery of intermolecular CO/H(-) mutual exchange reactions and isolation and structural characterization of the [Fe(DMF)(4)][Fe(4)(CO)(12)(μ(5)-η(2)-CO)(μ-H)](2)·0.5CH(2)Cl(2) and [M(+)][Fe(4)(CO)(12)(μ(4)-η(2)-CO)(μ-H)](-) (M = K, Cs) adducts, the former containing an unprecedented isocarbonyl group. The isolation of new tetranuclear and, above all, pentanuclear hydridocarbonylferrates indicates that it is possible to further expand the chemistry of homoleptic Fe carbonyl species.