Preparation du complexe cationique [η5-cyclopentadienyl fer-η6-pentamethylaniline]+ et de quelques amides et sulfonamides derives

The [η⁵-cyclopentadienyl-η⁶-pentamethylanilineiron]⁺ cation has been prepared from ligand exchange between ferrocene and pentamethylaniline. Acidic chlorides (CH₃COCl, C₆H₅COCl) and sulfonyl chlorides (p-CH₃C₆H₄SO₂Cl, camphorsulfonyl-d₁₀ chloride) react in situ with deprotonated species after treatment of this cation with t-BuOK in THF. An acid—base reaction between amide or sulfonamide derivatives and deprotonated species takes place and can limit the yield; the mechanism is discussed. Amide derivatives also have been prepared by direct action of acidic chlorides with [η⁵-C₅H₅Fe-η⁶-C₆-(CH₃)₅NH₂]⁺ in acetone solution. An optically active sulfonamide has been prepared.     

A novel diphosphorus-molybdenum ring system

The reaction of ArPCl₂ (Ar = 2,4,6-t-Bu₃C₆H₂) with K[Mo(CO)₃(η-C₅H₅)] affords Ar(H)PP(Cl)Ar (1), ArP[Mo(CO)₂(η-C₅H₅)]₂ (2), ArPPAr, ArPH₂ and Ar(H)PP(H)Ar. By means of X-ray crystallography, it was established that the Mo₂P ring of 2 involves a planar phosphorus geometry, a slight degree of MoP multiple bonding, and a MoMo single bond. Thermolysis of the original reaction mixture produced the P₂Mo ring compound ArPP(H)(Ar)[μ²-Mo(CO)₂(η-C₅H₅)] (3). The structure of 3 was determined by X-ray diffraction.     

Optisch aktive übergangsmetall-komplexe: XXXIII. Substituenteneinfluss auf die racemisierungs geschwindigkeit von (+)579und(−)579−C5H5MN(COC6H5)(NO)P(pC6H4Y)3

In the reaction of [C₅H₅Mn(CO)₂(NO)] [X] ([X] = [BF₄], [PF₆]) with p-substituted triarylphosphines P(p-C₆H₄?Y)₃ [Y = CF₃, Cl, F, C₆H₅, CH₃, OCH₃, N(CH₃)₂] the asymmetric monosubstitution products [C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃] [X] are formed, which can be converted into the neutral esters C₅H₅Mn(COOC₁₀H₁₉)(NO)P(p-C₆H₄?Y)₃ by natrium menthoxide. The diastereoisomers (+)₅₇₉^? and (?)₅₇₉^?C₅H₅Mn(COOC₁₀H₁₉)(NO)P(p-C₆H₄?Y)₃ are separated by fractional crystallisation and transformed into the enantiomeric salts (+)₅₇₉^? and (?)₅₇₉-[C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃] [X] by cleavage with HCl and precipitation with NH₄PF₆. The (+)₅₇₉^? and (?)₅₇₉^? rotating salts in the reaction with LiC₆H₅ yield the carbonyl addition products (+)₅₇₉^? and (?)₅₇₉^? C₅H₅Mn(COC₆H₅)(NO)P(p-C₆H₄?Y)₃ and the ring addition products (+)₅₇₉^? and (?)₅₇₉^?(exo-C₆H₅)C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃, which can be separated by chromatography.The salts (+)₅₇₉^? and (?)₅₇₉^?[C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃] [X] and the cyclopentadiene complexes (+)₅₇₉^? and (?)₅₇₉-(exo-C₆H₅)C₅H₅Mn(CO)(NO)P(p-C₆H₄?Y)₃ are configurationally stable, whereas the esters (+)₅₇₉^? and (?)₅₇₉^?C₅H₅Mn(COOC₁₀H₁₉)(NO)P(p-C₆H₄?Y)₃ and the benzoyl complexes (+)₅₇₉^? and (?)₅₇₉^?C₅H₅Mn(COC₆H₅)(NO)P(p-C₆H₄?Y)₃ epimerise or racemise in solution.The rate of racemisation of the benzoyl compounds (+)₅₇₉^? and (?)₅₇₉C₅H₅Mn(COC₆H₅)(NO)P(p-C₆H₄?Y)₃ was measured polarimetrically in the temperature range 0–45° C. It turned out that electron-releasingsubstituents Y in the ligand P(p-C₆H₄?Y)₃ increase the half-lives, whereas electron-attracting substituents decrease the half-lives. There is a linear correlation between the σ-constants of the substituents and the rate constants of the racemisation (reaction constant p = +2.14).     

Dicationic surfactant based catalytic systems for alkaline hydrolysis of phosphonic acid esters

Use of aqueous micellar solutions of dicationic surfactants with the general formula [R(CH₃)₂N(CH₂)₆N(CH₃)₂R]²⁺2Br⁻ (R = n-C₁₀H₂₁ to n-C₁₆H₃₃) as the reaction medium for the alkaline hydrolysis of phosphonic acid esters has revealed a strong catalytic effect of the surfactants, which can increase the reaction rate by two orders of magnitude. This effect depends on the surfactant structure, shows itself at low surfactant concentrations, and is substrate-specific. The effect of the micelles on the phosphonate hydrolysis rate is largely determined by the hydrophobicity factor.     

Synthesis and structural characterisation of redox-responsive N-ferrocenoyl amino acid esters; the X-ray crystal structure of N-ferrocenoyl alanine methyl ester; electrochemical anion recognition and H NMR complexation studies

The N-ferrocenoyl amino acid ester derivatives FcCOR {Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄)} where R=Gly(OMe) 1, Gly(OEt) 2, Gly(OBn) 3, l-Ala(OMe) 4, l-Ala(OEt) 5, l-Leu(OMe) 6, l-Leu(OEt) 7, l-Leu(OBn) 8, l-Phe(OMe) 9 and l-Phe(OEt) 10, were prepared by coupling ferrocene carboxylic acid with the appropriate amino acid ester starting materials using the 1,3-dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBt) protocol and these have been characterised by spectroscopic techniques. The electrochemical anion sensing behaviour of compounds 1-10 with several anions using a platinum microdisk working electrode is described, together with ¹H NMR anion complexation studies. The X-ray single crystal structure of N-ferrocenoyl-l-alanine methyl ester 4 has been determined and contains two molecules which differ slightly in conformation in the asymmetric unit of space group P2₁ (No. 4); principal dimensions are amide N(H)CO 1.224(6) and 1.231(6) Å, ester CO 1.220(10) and 1.190(7) Å, with N-H?OC(amide) as the primary intermolecular hydrogen bond, N?O 2.992(6) and 2.971(6) Å and with graph set C(4).     

The preparation of polysiloxane xerogels containing amide derivatives of phosphonic and thiophosphonic acids in the surface layer

Xerogels containing residues of amide derivatives of phosphonic and thiophosphonic acids, ≡Si(CH₂)₃NHP(S, O)(OC₂H₅)₂ (functional group concentration of 1.3–2.2 mmol/g) have been prepared by a sol-gel method. It has been shown that xerogels having a developed porous structure (with specific surface areas of 240–485 m²/g, pore volumes of 0.20–0.50 cm³/g, and pore diameters of 3.6–6.5 nm) are formed at tetraethoxysilane-to-trifunctional silane ratios of 4: 1 (and above) and 6: 1 (and above) for the derivatives of phosphonic and thiophosphonic acids, respectively. The IR and ¹³C CP/MAS NMR spectroscopy data have demonstrated that the surface layer of the xerogels contains not only (thio)phosphonic acid residues, but also silanol groups and water molecules participating in hydrogen bonding. The ²⁹Si CP/MAS NMR spectroscopy data have indicated that structural groups are, for the most part, contained in structural units T³ [(≡SiO)₃Si(CH₂)₃NHP(O, S)(OC₂H₅)₂] and T² [(≡SiO)₂Si(OR)[(CH₂)₃NHP(O, S)(OC₂H₅)₂] (R = H or C₂H₅).     

The synthesis and characterization of metal-containing vinylic monomers of iron and tungsten

A series of metal-containing vinylic monomers of the type L_nM(COC₆H₄CH=CH₂) and L_nM (COCH=CHC₆H₅) [L_nM = (η⁵-C₅H₅)Fe(CO)₂, (η⁵-C₅Me₅)Fe(CO)₂ and (η⁵-C₅H₅)W(CO)₃] were prepared by the reaction of the appropriate metal anion with either 4-vinylbenzoyl chloride or cinnamoyl chloride. (η⁵-C₅H₅)(CO)₂FeCOCH=CH₂ was prepared by the reaction of Na[(η⁵-C₅H₅)Fe(CO)₂] and acryloyl chloride, whereas the compound (η⁵-C₅H₅)(CO)₂Fe(C₆H₄CH=CH₂) was prepared via a transmetallation reaction using a palladium catalyst. All compounds were fully characterized using FTIR, ¹H and ¹³C NMR spectroscopy and mass spectrometry. Copyright © 1998 John Wiley & Sons, Ltd.     

Darstellung und chemie von Me2TlN(SiMe3)2 und Tl[N(SiMe3)2]3

The complexes [Rh(η³-C₃H₄R)(η⁵-C₅R′₅)L]⁺BF₄^- (R  1-Me, R′  H, Me; R  2-Me, R′  H) (L  C₅H₅N, Ph₃P, Ph₃As) have been prepared from Rh(η³-C₃H₄R)(η⁵-C₅R′₅)Cl and AGBF₄ in acetone, followed by reaction with the stoicheiometric quantity of L. The ¹H and ¹³C NMR spectra of the salts are reported and discussed.     

Synthesis and characterization of MH···HOR dihydrogen bonded ruthenium and osmium complexes(η~5-C_5H_4CH_2OH)MH(PPh_3)_2(M = Ru,Os)

Treatment of RuCl2(PPh3)3 with 6-dimethylaminopentafulvene in THF in the presence of water produced(η5-C5H4CHO) RuCl(PPh3)2, which was reduced by NaBH4 to give the Ru–H···HO dihydrogen bonded complex(η5-C5H4CH2OH) RuH(PPh3)2. The dihydrogen bonded complex(η5-C5H4CH2OH)RuH(PPh3)2 could also be synthesized by the reduction of complex(η5-C5H4CHO)RuH(PPh3)2, which was obtained by the reaction of RuHCl(PPh3)3 with 6-dimethylaminopentafulvene in the presence of water. The analogous dihydrogen bonded osmium complex(η5-C5H4CH2OH)OsH(PPh3)2 was similarly prepared. Single crystal structures and DFT calculations support the presence of intra-molecular H···H interaction, with separations of around 1.9 to 2.0 .     

Übergangsmetallketen-verbindungen: XXXVIII. Synthese wolframhaltiger fünfringheterocyclen durch addition von trimethylphosphin an phosphino- und arsinoketenkomplexe

The reaction of phosphino- and arsino-ketene complexes of tungsten η⁵-C₅H₅(CO[P(CH₃)₃] XW[η¹-R₂Y(C₆H₄CH₃)CCO] (X = Cl, I; Y = P, As) with trialkylphosphines does not lead to a substitution of the phosphino- and arsinoketene ligands but to a nucleophilic attack of the phosphine at the central ketene carbon and a concomitant substitution of the halogene ligand via the former ketene oxygen, affording the cationic compelex η⁵-C₅H₅(CO)[P(CH₃)₃]W[η²-R₂YC-(C₆H₄CH₃C(PR′₃)O]X and P,O and As,O chelate ligands. The substitution products R₂Y(C₆H₄CH₃)CCO and η⁵-C₅H₅(CO)[P(CH₃)₃]XW(PR′₃) initially expected could only be obtained as a result of a selective rearrangement/elimination reaction as shown in the case of the arsenic substituted complex η⁵-C₅H₅(CO)(PMe₃)IWAs(CH₃)₂C(C₆H₄CH₃)C=O.     

Synthesis and structural characterization of ruthenium(II) and iron(II) complexes containing 1,2-di-(2-thienyl)-ethene derived ligands as chromophores

A new family of three-legged piano stool structured organometallic compounds containing the η⁵-cyclopentadienylruthenium(II)/iron(II) fragments {M(η⁵-C₅H₅) (DPPE)}⁺, {Ru(η⁵-C₅H₅)(PPh₃)₂}⁺ and {Ru(η⁵-C₅H₅)(TMEDA)}⁺ with coordinated thiophene based chromophores, namely 5-(2-thiophen-2-yl-vinyl)-thiophene-2-carbonitrile (L1) and 5-[2-(5-Nitro-thiophen-2-yl)-vinyl]-thiophene-2-carbonitrile (L2) has been synthesized and fully characterized by ¹H, ¹³C, ³¹P NMR, IR and UV-Vis spectroscopies. Also, electrochemical studies were carried out by cyclic voltammetry and all experimental data are interpreted and compared with related compounds under the scope of NLO properties. Compounds [Ru(η⁵-C₅H₅)(DPPE)(NC(C₄H₂S)C(H)C(H)(C₄H₃S))][CF₃SO₃] (1′Ru) [Fe(η⁵-C₅H₅)(DPPE)(NC(C₄H₂S)C(H)C(H)(C₄H₃S))] [PF₆] (1Fe) and [Ru(η⁵-C₅H₅)(DPPE)(NC(C₄H₂S)C(H)C(H)(C₄H₂S)NO₂)][CF₃SO₃] (4′Ru) were also crystallographically characterized.     

Intermediates in associative phosphine substitution reactions of (η5-C5H5)W(CO)2(NO)

The reaction of (η⁵-C₅H₅)W(CO)₂(NO), 6W, with P(CH₃)₃ proceeds rapidly at 25°C to give (η⁵-C₅H₅)W(CO)(NO)[P(CH₃)₃], 7W. The rate of formation of 7W was found to be 4.48 × 10^?2M^?1 [6W] [P(CH₃)₃] at 25.0°c in THF. In neat P(CH₃)₃ at ?23°C, 6W is converted to (η¹-C₅H₅)W(CO)₂(NO)[P(CH₃)₃]₂, 8W. In dilute solution, 8W decomposes to initially give a 2:1 mixture of 6W and 7W. The mixture is then converted to 7W. The reaction of (η⁵-C₅H₅)Mo(CO)(NO), 6Mo, with P(CH₃)₃ is 6.1 times faster than that of the tungsten analog.     

Reactions of metal carbonyl derivatives X. The synthesis and reactivity of some dinuclear derivatives of iron containing both bridging carbonyls and bridging phosphido or sulphido groups

The tertiary phosphine π-C₅H₅Fe(CO)₂P(C₆H₅)₂ reacts with a suspension of Fe₂(CO)₉ in benzene to give the dinuclear complex π-C₅H₅Fe₂P(C₆H₅)₂(CO)₆. This compound is also obtained by nucleophilic attack of [π-C₅H₅Fe(CO)₂]⁻ on Fe(CO)₄-[P(C₆H₅)₂Cl] in tetrahydrofuran. Irradiation of a benzene solution of π-C₅H₅Fe₂-P(C₆H₅)₂(CO)₆ with ultraviolet light affords π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅ which contains both a bridging carbonyl and a bridging phosphido group. The unstable bridged sulphido derivatives π-C₅H₅Fe₂SR(CO)₆ (R = CH₃ and C₆H₅) and π-C₅H₅Fe₂(t-C₄H₉S)(CO)₅ are similarly obtained employing π-C₅H₅Fe(CO)₂SR as ligand. The reactions of π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅ with tertiary phosphines and phosphites yield three types of products depending on the reaction conditions and the ligand involved. Examples include π-C₅H₅Fe₂P(C₆H₅)₂(CO)₄P(C₆H₅)₃, a mono-substituted derivative of π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅, and π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅P(C₂H₅)₃ and π-C₅H₅Fe₂P(C₆H₅)₂(CO)₄[P(OCH)₃)₃]₂, mono- and bis-substituted derivatives of π-C₅H₅Fe₂P(C₆H₅)₂(CO)₆, respectively. The reaction of π-C₅H₅Fe₂P(C₆H₅₂(CO)₅ with (C₆H₅)₂PCH₂P(C₆H₅)₂ in benzene under reflux affords [π-C₅H₅Fe₂P(C₆H₅)₂(CO)₄](C₆H₅)₂PCH₂P(C₆H₅)₂ in which the ditertiary phosphine bridges two iron atoms.     

Metal dimers as catalysts : III. The reaction between Fe(CO)5, and group V donor ligands in the presence of [(η5-C5H4R)Fe(CO)222]2 (R  H,Me) and [(η5-C5Me5)Fe(CO)2]2 as catalyst

The reaction between Fe(CO)₅, and group V donor ligands L, (L  PPh₃, AsPh₃, SbPh₃, PMePh₂, PMe₂Ph, Asme₂Ph, P(C₆H₁₁)₃, P(n-Bu)₃, P(i-Bu)₃, P(OPh)₃, P(OEt)₃, P(OMe)₃) in the presence of [(η⁵-C₅Me₅Fe(CO)₂]₂ (R  H, Me) or [(η⁵-C₅Me₅)Fe(CO)₂]₂ as catalyst in refluxing toluene, rapidly gives the complexes Fe(CO)₄L in yields > 85%. The reaction rate is essentially independent of the nature of L for [(η₅-C₅Me₅)Fe(CO)₂]₂ as catalyst. For the other catalysts, the rate is influenced predominantly by the steric properties of L. These results are interpreted in terms of the interaction between the catalyst and the ligand L to give derivatives of the type (η⁵-C₅H₄R)₂Fe₂,(CO)₃,(L). These derivatives were also found to catalyse the reaction between Fe(CO)₅, and L. The complexes [(η-C₅H₄R)Fe(CO)₂]₂ (R  H, Me) and [(η⁵-C₅Me₅)Fe(CO)₂]₂ also catalyse the reaction between Mn₂(CO)₁₀ and PPh₃ to give Mn₂(CO)₈- PPh₃)₂ in > 80% yield.     

Reactions of metal carbonyl derivatives : XIV. Bridged phosphido derivatives of iron and ruthenium

The tertiary phosphines P(C₆H₅)₂R [RM π-C₅H₅)(CO)₂ M(π-C₅H₅(CO)₂ (M = Fe or Ru)] readily effect the displacement of the chloro group in [M′(φ-C₅H₅)(CO)₂Cl] (M′ = Fe or Ru) to give bridged cationic species of the type [MM′(φ-C₅H₅)₂(CO)₄P(C₆H₅)]⁺. Treatment of [Fe₂(CO)₉] with P(C₆H₅)₂R [RRu(φ-C₅H₅)(CO)₂] leads to the formation of the neutral mixed-metal derivatives [FeRu(φ-C₅H₅)(CO)₆P(C₆H₅)₂] and [FeRu(φ-C₅H₅)(CO)₅P(C₆H₅)₂].     

The stereospecificity at the iron center of the decarbonylation of an ironacetyl complex

The dinuclear complex [(h⁵-1-CH₃-3-C₆H₅C₅H₃)Fe(CO)₂]₂ was synthesized by reaction of Fe₂(CO)9 with 1-methyl-3-phenylcyclopentadiene; it was converted to (h⁵-1-CH₃-3-C₆H₅C₅H₃)Fe(CO)₂CH₃ by reduction with sodium amalgam and addition of CH₃l, and thence to (h⁵-1-CH₃-3-C₆H₅C₅H₃)Fe(CO)[P(C₆H₅)₃] (COCH₃) (I) by reaction with P(C₆H₅)₃. The acetyl I was separated into two diastereomerically related pairs of enantiomers. Ia and Ib, by a combination of column chromatography on alumina and crystallization from benzene/pentane. The photochemical decarbonylation of Ia and Ib in benzene or THF solution was examined by ¹H NMR spectroscopy. This reaction proceeds with high stereospecificity (>84% retention or inversion) at the iron center to yield (h⁵-1-CH₃-3-C₆H₈C₅H₃)Fe(CO)[P(C₆H₅)₃]CH₃(II), enriched in the diastereomerically related pairs of enantiomers, IIa and IIb, respectively. Since IIa and IIb epimerize under the photolytic conditions of decarbonylation, the actual stereospecificity of the conversion of I to II is higher than 84%, and likely 100%. This is supported by the data from kinetic studies of the decarbonylation of I and the epimerization of II, carried out under identical photolytic conditions. The implications of the foregoing results to the mechanism of the decarbonylation are considered. Also described herein is the synthesis of other complexes with two asymmetric centers of the general formula (h⁵-cyclopentadienyl)Fe(CO)(L)(COR) and (h⁵-cyclopentadienyl)Fe(CO)(L)R that contain either an unsymmetrically substituted h⁵-cyclopentadienyl ring or a chiral tertiary phosphine.     

Covalent modification of calcium hydroxyapatite surface by grafting phenyl phosphonate moieties

The reaction between phenyl phosphonic dichloride (C₆H₅P(O)Cl₂) and synthetic calcium hydroxy- and fluorapatite has been investigated. The presence of mono- or polymeric (C₆H₅PO) fragment bound to hydroxyapatite was evidenced by IR, and solid-state ³¹P NMR spectroscopy. X-ray powder analysis has shown that the apatitic structure remains unchanged during the reaction. In contrast, no reaction was found using fluorapatite. According to the results found for these two different apatites a mechanism was proposed for the formation of covalent P-O-P bonds as the result of a reaction between the C₆H₅P(O)Cl₂ organic reagent and (HPO₄)⁻ and/or OH⁻ ions of the hydroxyapatite.     

Reactions of π-benzeneruthenium(II) complexes with alkylating reagents

The compounds (π-C₆H₆)Ru(R)Cl(PPh₃) (RCH₃, C₆H₅), (π-C₆H₆)RuCl(π-C₃H₅) and [(π-C₆H₆)Ru(π-C₅H₅)]Cl are described. The ³¹P NMR spectra of a series of tertiary phosphine complexes of the π-benzeneruthenium system are also reported.     

Oxidation of (η5-6-exo-cyclopentadienylcyclohexadienyl)- (η5-cyclopentadienyl) iron by trityl hexafluorophosphateby trityl hexafluorophosphate

Oxidation of the cyclohexadienyl complex Fe(η⁵-C₅H₅)(1-5-7⁵-6-exo-C₅H₅-C₆H₆) (2) by (Ph₃C)PF₆ (CH₂Cl₂, from −30 to +20 °C) occurs as two concurrent processes: elimination of an H atom from the cyclohexadienyl ligand and replacement of an H atom in the cyclopentadienyl ring by a CPh₃ fragment. A mixture of cationic complexes [Fe(η⁵-C₅H₅) (η⁶-Ph-C₅H₅]⁺ (1⁺) and [Fe(η⁵-C₅H₄CPh₃) (η⁶-Ph-C₅H₅]⁺ (4⁺) (4 ⁺) with PF₆ ⁻ anions is obtained. Deprotonation of the mixture of 1⁺ and 4⁺ complexes under the action of Bu ^t OK inm-xylene followed by boiling of the reaction mixture gives phenylferrocene (7) as the product of η⁶:η⁶ haptotropic rearrangement. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, NO. 5, pp. 1045–1047, May, 1997.     

Synthesis and spectroscopic investigation of adducts of diorgano tin(IV) dichloride

Adducts of bis-p-biphenyl tin(IV) dichloride of types (p-C₆H₅-C₆H₄)₂SnCl₂·2L and (p-C₆H₅-C₆H₄)₂SnCl₂·L₁ (where 2L = pyridine, piperidine, α-, β- or γ-picolines, isoquinoline or morpholine and L₁ = 2,2′-bipyridine or 1,10 phenanthroline) have been prepared by the reaction of bis-p-biphenyl tin(IV) dichloride with the corresponding ligand in 1:2 and 1:1 molar ratios in acetone. IR, ¹H NMR and Mössbauer studies indicate that the biphenyl group occupies in the trans position, except in morpholine, where it is in the cis position.