Synthesis reactivity and electrochemical properties of substituted cyclopentadienyl cobalt (III) complexes

Cyclopentadienyl cobalt complexes (η⁵‐C₅H₄R) CoLI₂ [L = CO,R=‐COOCH₂CH=CH₂ (3); L=PPh₃, R=‐COOCH₂‐CH=CH₂ (6); L=P(p‐C₆H₄O₃)₃, R = ‐COOC(CH₃) = CH₂ (7), ‐COOCH₂C₆H₅ (8), ‐COOCH₂CH = CH₂ (9)] were prepared and characterized by elemental analyses, ¹H NMR, ER and UV‐vis spectra. The reaction of complexes (η⁵‐C₅H₄R)CoLI₂ [L= CO, R= ‐COOC(CH₃) = CH₂ (1), ‐COOCH₂C₆H₅(2); L=PPh₃, R=‐COOC (CH₃) = CH₂ (4), ‐COOCH₂C₆H₅ (5)] with Na‐Hg resulted in the formation of their corresponding substituted cobaltocene (η⁵‐C₅H₄R)₂ Co[R=‐COOC(CH₃) = CH₂ (10), ‐COOCH₂C₆H₅ (11)]. The electrochemical properties of these complexes 1–11 were studied by cyclic voltammetry. It was found that as the ligand (L) of the cobalt (III) complexes changing from CO to PPh₃ and P(p‐tolyl)₃, their oxidation potentials increased gradually. The cyclic voltammetry of α,α′‐substituted cobaltocene showed reversible oxidation of one electron process.     

Reaction of [Fe4(μ3-CCH3)(CO)12]− with alkynes: Ethylidyne-alkyne coupling on a tetranuclear iron cluster anion

The [Fe₄(μ₄-η³-C(CH₃)C(R)C(R′)(μ-CO)₂(CO)₉]⁻ cluster anions have been obtained by the reaction of the Fe₄(μ₃-CCH₃)(CO)₁₂⁻ anion with RCCR alkynes in boiling 3-pentanone. In the cases in which R = R′ = C₆H₅ or CH₃, and R = H, R′ = C₆H₅ or t-Bu, only one isomer has been detected. In the case in which R = CH₃, and R′ = C₆H₅, two isomers with the C(CH₃)C(C₆H₅)C(CH₃) and C(CH₃)C(CH₃)C(C₆H₅) fragments have been identified.     

Optisch aktive übergangsmetall-komplexe LXIV. Neue optisch aktive Cp(CO)Fe-acyl-komplexe mit

The novel complexes CpFe(CO)(COR)P(C₆H₅)₂NR'R^* with Cp = C₅H₅,C₉H₇ (indenyl); R = CH₃, C₂H₅, CH(CH₃)₂, CH₂C₆H₅;R` = H, CH<sub>3</sub>, C<sub>2</sub>H<sub>5</sub>, CH<sub>2</sub>C<sub>6</sub>H<sub>5</sub> and R<sup>*</sup> = (S)-CH(CH<sub>3</sub>)(C<sub>6</sub>H<sub>5</sub>), have been synthesized by reaction of CpFe(CO)<sub>2</sub>R wiht P(C<sub>6</sub>H<sub>5</sub>)<sub>2</sub>NR`R^* and characterized analytically as well as spectroscopically. The pairs of diastereoisomers RS/SS have been separated by preparative liquid chromatography and fractional crystallization, respectively. The optically pure complexes (+)₄₃₆- und ()₄₃₆-CpFe(CO)(COR)P(C₆H₅)₂NR`R^* are configurationally stable at room temperature. At higher temperatures they equilibrate with CpFe(CO)₂R and epimerize with respect to the Fe configuration.     

Group 12 metal complexes of tetradentate N2O2–Schiff-base ligands incorporating pyrazole: Synthesis,characterisation and reactivity toward S-donors,N-donors,copper and tin acceptors

New [M(Q)₂(X)] derivatives (where M=Zn, Cd or Hg; Q=1-phenyl-3-methyl-4-R(C=O)-pyrazolon-5-ato; in detail: Q_L, R=C₆H₅; Q_B, R=CH₂C(CH₃)₃; Q_S, R=CH(C₆H₅)₂; X=EtOH or H₂O) have been synthesised and characterised. These compounds undergo a condensation reaction with the appropriate diamine in ethanol, affording novel Schiff-base metal derivatives [M(diaquo)bis(1-phenyl-3methyl-4-R(C=N)-pyrazolone)(CH₂)_ndiimmine] (LⁿH₂, R=C₆H₅, n=2, 3 or 4; BⁿH₂, R=CH₂C(CH₃)₃, n=2, 3 or 4; SⁿH₂, R=CH(C₆H₅)₂, n=2 or 3; M=Zn, Cd or Hg). These compounds possess a six-coordinate metal environment. A ¹¹³Cd NMR study has been carried out on cadmium derivatives. The derivative [Zn(L²)(H₂O)₂] reacted with CuCl₂ and with Cu(ClO₄)₂ affording [Cu(Q_L)₂] and [Cu(en)₂](ClO₄)₂ (en=ethylendiamine), respectively, upon breaking of the C=N bond in the Schiff-base donor. In addition [Zn(L²)(H₂O)₂] reacted with 1,10-phenanthroline (phen), yielding the derivative [Zn(Q_L)₂(phen)]. Whereas when [Zn(L²)(H₂O)₂] reacted with CdCl₂, formation of [Cd(L²)(H₂O)₂] due to exchange of the metal centre was observed. Finally the derivative [Zn(L²)(Hmimt)], likely containing a five-coordinate ZnN₂O₂S central core, has been obtained from the exchange reaction between [Zn(L²)(H₂O)₂] and 1-methylimidazolin-2-thione (Hmimt).     

Direktsynthese von orthometallierten Ketonen des Typs RCO (o-C6H4)Mn(CO)4−nLn (R = Alkyl- und Arylrest,n = 0, 1, 2, L = Ligand)

Direct Synthesis of Orthometallated Ketones of the Type RCO(o-C₆H₄)Mn(CO)_4?nL_n (R = Alkyl and Aryl Groups, n = 0, 1, 2, L = Ligand) The starting materials of the type RMn(CO)_5?nL_n und (C₆H₅)₂ Hg react to the products of the type RCO(o-C₆H₄)Mn(CO)_4?nL_n[n = 0, R = Ch₃, C₂H₅, C₃H₇, C₆H₅,CH₂; R = C₆H₅, n = 1, L = E(C₆H₅)₃, E = P, As, Sb; R = C₆H₅, n = 2, L = P(OR′)₃, R′ = C₆H₅, CH₃, C₂H₅, C₃H₇]. Steps of their complex reaction pathway are proposed. These orthometallated substances have been characterized by means of ¹H-n.m.r., i.r. and u.v. spectroscopic measurements. The determination of the molecular structure of the two compounds RCO(o-C₆H₄)Mn(CO)₃L [R = C₂H₅, L = CO; R = C₆H₅, L = As(C₆H₅)₃] show that both contain a planar heterocyclic five-membered ring of the type .     

Silicium-stickstoff-fluorverbidungen: V. Darstellung neuer silylaminofluorsilane

Compounds of the composition RR′SiFNR″Si(CH₃)₃ (R = H, F, CH₃, C₂H₅, C₃H₇, C₂H₃, C₆H₅, C(CH₃)₃; R = F, CH₃, C₆H₅; R″ = CH₃, C(CH₃)₃, Si(CH₃)₃) are obtained by the reaction of silicontetrafluoride or organo-substituted silicon-fluorides with the lithium salts of alkylsilylamines in a molar ratio of $\text{1}\text{1}$. The disubstituted compounds RSiF(NR′Si(CH₃)₃)₂ (R = H, F, CH₃, C₂H₃, C₆H₅; R′ = CH₃, C(CH₃)₃) result when the reactants are in a $\text{1}\text{2}$ molar-ratio. Likewise the unsymmetrical siliconfluorsilylamines of the formulae F₂Si(NRSi(CH₃)₃) (NR′Si(CH₃)₃) (R = CH₃, R′ = C(CH₃)₃), as well as the trisubstituted compounds FSi(NCH₃Si(CH₃)₃)₃ and FSi(NCH₃Si(CH₃)₃)₂(N(Si(CH₃)₃)₂) were made. By reacting phenyltrifluorsilane with dialkylamines ($\text{1}\text{2}$) C₆H₅SiF₂NR₂(R = CH₃, C₂H₅) was obtained. The IR-, mass-, ¹H and ¹⁹F NMR spectra of the above-mentioned compounds are reported.     

The rapid sub-picogram determination of volatile organo-mercury compounds by gas chromatography with a microwave emission spectrometric detector system.

The applicability of a gas Chromatograph with a microwave emission spcctrometric detector (g.c.-m.e.s.) to the determination of trace amounts of volatile organo-mercury compounds in environmental samples is described. The high selectivity of the detector to mercury compounds allows the procedures to be drastically simplified. Thus, the total analysis time for methylmercury in fish is less than 15 min and more than 30 samples of CH₃HgCl (benzene extracts) can be analyzed per hour. The detection limit is 0.5 pg for CH₃HgCl (or C₂H₅HgCl) and 2 pg for (CH₃)₂Hg. The relative sensitivity for CH₃HgCl in water samples is 1 ng l^?1 and for fish samples is 1 ng g^?1. Direct determinations of CH₃HgCl and (CH₃)₂Hg in aqueous solutions arc also discussed.     

Darstellung neuer Alkylaminofluorsilane

Preparation of New Alkylaminofluorosilanes Aminofluorosilanes of the composition RSiF₂NR′R″ (R = H, CH₃, C₂H₃, C₆H₅; R′ = Si(CH₃)₃; R″ = C(CH₃)₃; R′ = R″ = i-C₃H₇), as well as C₆H₅SiF₂N[C(CH₃)₂CH₂]₂CH₂ are obtained by the reaction of fluorosilanes with the lithium salts of the corresponding amines in a molar ratio 1:1. The further reaction of these compounds with the lithium salts of alkylamines and anilin leads to the formation of the diaminofluorosilanes RSiFNR′R″NHR? (R? = C(CH₃)₃, i-C₃H₇, C₆H₅). The ¹H, ¹⁹F, ²⁹Si n.m.r. and mass spectra of the above mentioned compounds are reported.     

Study on synthesis of lanthanide chelates of fluorochloroalkyl β-diketones useful as shift reagents

Several lanthanide chelates of the fluorochloroalkyl β-diketones Ln(CF₂ClCOCHCOR)₃ ·nH₂O were prepared (2, Ln=Eu; 2a, R=C(CH₃)₃, n=0; 2b, R=C₆F₅, n=0; 2c, R=CF₂Cl, n=2. 3, Ln=Pr; 3a, R=C (CH₃)₃, n=0; 3b, R=C₆F₅, n=l; 3c, R=CF₂Cl, n=2. 4, Ln=La, R=C₆H₅, n=0) and the NMR shift data of compounds 2 and 3 had been determined using alcohols, ether, ketones and amine as substrates. With alcohol, ether and ketone, compounds 2 induces shifts similar to that induced by Eu (fod)₃. However due to the high solubility of the chelates in non-polar organic solvents such as CHCl₃ and CCl₄ and the absence of ¹H signal from compounds 2b and 2c, their application as a series of new ¹H NMR shift reagents seems promising.     

Synthesis and helicity of optically active poly(N‐propargylphosphonamidates) having chiral phosphorus center

Novel chiral N‐propargylphosphonamidate monomers (HC?CCH₂NHP(?O)R? O? menthyl, 1 : R = CH₃, 2 : R = C₂H₅, 3 : R = n‐C₃H₇, 4 : R = Ph) were synthesized by the reaction of the corresponding phosphonic dichlorides with menthol and propargylamine. Pairs of diastereomeric monomers 1 – 4 with different ratios were obtained due to the chiral P‐center and menthyl group. One diastereomer could be separated from another one in the cases of monomers 1 and 2 . Polymerization of 1 – 4 with (nbd)Rh⁺[η⁶‐C₆H₅B^?(C₆H₅)₃] as a catalyst in CHCl₃ gave the polymers with number‐average molecular weights ranging from 5000 to 12,000 in 65–85%. Poly( 1 )–poly( 4 ) exhibited quantitative cis contents, and much larger specific rotations than 1 – 4 did in CHCl₃. The polymers showed an intense Cotton effect around 325 nm based on the conjugated polyacetylene backbone. It was indicated that the polymers took a helical structure with predominantly one‐handed screw sense, and intramolecular hydrogen bonding between P?O and N? H of the polymers contributed to the stability of the helical structure. Poly( 1a ) and poly( 2a ) decreased the CD intensity upon raising CH₃OH content in CHCl₃/CH₃OH. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1515–1524, 2007     

Sulfenamides as ligands in transition metal chemistry Pentacarbonyl(Sulfenamide)Chromium(0) Complexes

The complexes Cr(CO)₅(R′SNR₂) [R′ = CH₃; NR₂ = N(CH₃)₂, N(C₄H₈)O. R′ = C₆H₅; NR₂ = N(CH₃)₂, N(C₄H₄)O, N(CH₂? C₆H₅)₂, N(C₆H₁₁)₂] have been prepared by reaction of the sulfenamides with Cr(CO)₅ · THF and characterized by analytical and spectroscopic methods. The IR, ¹H-NMR, UV-VIS, and mass spectra of the complexes support the coordination of the sulfenamide via the sulfur atom. π-acceptor abilities of sulfenamides in the prepared coordination compounds, determined from IR and UV-VIS data, were compared with those of other divalent sulfur conpounds.     

Mono‐ and heterodi‐nuclear complexes of aluminium: synthesis,characterization and antifungal activity

Some new types of mononuclear derivatives, AlL(1–4)L(1–4)H ( 1a–1d ) of aluminium were synthesized by the reaction of Al(OPrⁱ)₃ and LH₂ [XC(NYOH)CHC(R)OH], X = CH₃, Y = (CH₂)₂, R = CH₃(L1H₂); X = C₆H₅, Y = (CH₂)₂, R = CH₃(L2H₂); X = CH₃, Y = (CH₂)₃, R = CH₃(L3H₂); X = C₆H₅, Y = (CH₂)₃, R = CH₃(L4H₂) in 1:2 molar ratio in refluxing benzene. Reactions of AlL(1–4)L(1–4)H with hexamethyldisilazane in 2:1 molar ratio yielded some new ligand bridged heterodinuclear derivatives AlL(1–4)L(1–4)SiMe₃ ( 2a – 2d ). All these newly synthesized derivatives were characterized by elemental analysis and molecular weight measurements. Tentative structures were proposed on the basis of IR and NMR spectra (¹H, ¹³C, 27 Al and ²⁹Si) and FAB‐mass studies. Schiff base ligands and their mono‐ and heterodi‐nuclear derivatives with aluminium have been screened for fungicidal activities. These compounds showed significant antifungal activity against Aspergillus niger and A. flavus. Copyright © 2007 John Wiley & Sons, Ltd.     

Homo- and hetero-dinuclear derivatives of aluminium containing Schiff-base ligands: synthesis,characterization and antibacterial activity of mononuclear derivative of aluminium

Reactions of Al(OPrⁱ)₃ with LH₂ =?[R′C(NYOH)CHC(R)OH] R=R′=CH₃, Y =?(CH₂)₂ (L¹H₂); R =?CH₃, R′ =?C₆H₅, Y =?(CH₂)₂ (L²H₂); R =?R′ =?CH₃, Y =?(CH₂)₃ (L³H₂); R =?CH₃, R′ =?C₆H₅, Y =?(CH₂)₃ (L⁴H₂), in 1 : 2 molar ratio give mononuclear derivatives of aluminium AlLLH (1a–1d). Equimolar reactions of AlLLH with M(OPrⁱ)₃ (M =?Al and B) yield homo- and hetero-dinuclear derivatives AlLLM(OPrⁱ)₂ (M=Al=2a–2d M=B=3a–3d). Reaction of 2a with L¹H₂ affords AlL¹L¹AlL¹ (4). All these derivatives have been characterized by elemental analysis, molecular weight measurements and plausible structures have been suggested on the basis of IR, NMR [¹H, ¹³C, ²⁷Al and ¹¹B] spectral data and FAB-mass studies of 2b and 3b. Schiff base L¹H₂ and its mononuclear derivative with aluminium (AlL¹L¹H) have been screened for their antibacterial activity against Escherischia coli and Bacillus subtilis.     

Synthesis and characterization of some novel triphenylarsenic(V) derivatives of monofunctional bidentate 2,2‐disubstituted benzothiazoline ligands

A series of triphenylarsenic(V) derivatives Ph₃As(OPrⁱ)[SC₆H₄N:C(R)CH₂C(O)R′] have been synthesized by the reactions of triphenylarsenic(V)‐ isoproproxide, Ph₃As(OPrⁱ)₂ with the corresponding 2,2‐disubstituted benzothiazolines of the type (where R = CH₃, R′ = CH₃( 1 ); R = CH₃, R′ = C₆H₅( 2 ); R = CH₃, R′ = 4‐CH₃C₆H₄( 3 ); R = CH₃, R′ = 4‐ClC₆H₄( 4 ); and R = CF₃, R′ = C₆H₅( 5 )) in equimolar ratio in refluxing benzene solution. Molecular weight measurements of these complexes show their monomeric nature in solution. Characterization of these compounds using elemental analyses, molecular weight measurements, and spectral studies (IR as well as NMR (¹H and ¹³C)) shows the monofunctional bidentate nature of the ligands and a hexacoordination around the central arsenic atom in these organoarsenic(V) derivatives. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:76–80, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20233     

Some novel triorganotin(IV) derivatives of β, δ-triketones

Thirty triorganotin(IV) derivatives of the type R₃Sn(R′COCHCOCH₂COR″) and [R₃Sn]₂ (R′COCHCOCHCOR″) (where R = CH₃, C₂H₅, nC₃H₇, nC₄H₉ and C₆H₅ and R′ = R″ = CH₃, C₆H₅ or R′ = C₆H₅, R″ = CH₃) have been synthesised by the interaction of R₃SnCl with mono- or disodium salt of 2, 4, 6-heptanetrione, 1-phenyl-1, 3, 5-hexanetrione and 1, 5-diphenyl-1, 3, 5-pentanetrione in 1:1 and 2:1 molar ratios, respectively. The complexes have been examined by their molecular weight, IR, PMR and elemental analyses and their tentative structures assigned. Both “Z” and “E” forms have been identified in the 1:1 complexes in equilibrium with the enol form containing five coordinate tin. The 2:1 derivatives contain one five- and other four coordinated tin(IV) except the phenyl analogue where both the tins are five coordinated.     

Heat capacities and densities of mixtures of very polar substances. 3. Mixtures containing either trichloromethane or 1,4-dioxane or diisopropylether

Excess molar heat capacities C _P ^E at constant pressure and excess molar volumes V ^E have been determined, as a function of mole fraction x₁ at 25°C and atmospheric pressure, for 10 binary liquid mixtures containing either trichloromethane (series I) with C₆H₅CH₃, or C₆H₅Cl, or C₅H₅N, or CH₃COCH₃, or C₆H₅NO₂; 1,4-dioxane (series II) with (C₂H₅)₃N, or (CH₃)₂CHOCH(CH₃)₂, or (CH_{3 2}SO); or diisopropyl ether (di-1-methylethyl ether) (series III) with (C₂H₅)₃N, or CHCl₃. The dipole momentsp (10^–30C-m) of the substances range from nearly 0 to 14.1 for nitrobenzene. The C _P ^E of series I and III are all positive, with C _P ^E (x₁=0.5) (J-K^–1-mol^–1) ranging from 1.04 for {x₁CHCl₃+x₂C₆H₅Cl} to 16.66 for {x₁(CH₃)₂CHOCH(CH₃)₂+x₂CHCl₃}. In series II, the C _P ^E are positive and small for {x₁1,4-C₄H₈O₂+x₂(CH₃)₂CHOCH(CH₃)₂}, S-shaped and small for {x₁1,4-C₄H₈O₂+x₂(C₂H₅)₃N}, and negative and small for {x₁1,4-C₄H₈O₂+x₂(CH₃)₂SO}. The excess volumes are small and positive for {x₁CHCl₃+x₂C₆H₅CH₃}, S-shaped for {x₁CHCl₃+x₂CH₃COCH₃}, {x₁1,4-C₄H₈O₂+x₂(C₂H₅)₃N} and {x₁(CH₃)₂CHOCH(CH₃)₂+x₂(C₂H₅)₃N}, and negative for the other systems.Presented at the Symposium, 76^th CSC Congress, Sherbrooke, Quebec, May 30–June 3, 1993, honoring Professor Donald Patterson on the occasion of his 65^th birthday     

SYNTHESIS AND CHARACTERISATION OF DIORGANOANTIMONY(III) COMPLEXES OF THIOSEMICARBAZONES

Abstract

The interaction of the sodium salts of thiosemicarbazones with diphenylantimony chloride in 1:1 molar ratio in benzene solution lead to the formation of derivatives, Ph₂Sb[SC(NH₂)NN: C(R)R′] where R = H; R′ [dbnd] C₆H₅, CH₃OC₆H₄, C₆H₅CH[dbnd]CH, and R′ [dbnd] CH₃; R′[dbnd]C₆H₅, CH₃OC₆H₄, C₆H₄CH₃, respectively. The resulting complexes have been characterised on the basis of elemental analyses and molecular weight determination. The mode of bonding of the ligands with the metal atom has been proposed on the basis of I.R., ¹H and ¹³C NMR studies. All these ligands are found to behave as monofunctional bidentate moiety in these complexes.     

Derivate des borabenzols: XVI. (Borinato)(cyclobutadien)cobalt-komplexe mit tetramethyl- und tetraphenylcyclobutadien-liganden. Synthese,elektrophile aromatische substitution und ringgliedsubstitution am borinato-liganden

The preparation of (borinato)(cyclobutadiene)cobalt complexes from the reactions of Co(C₅H₅BR)(1,5-C₈H₁₂) with acetylenes C₂R′₂ and of [C₄(CH₃)₄]Co(CO)₂I with Tl(C₅H₅BR) (R,R′ = CH₃, C₆H₅) is described.In electrophilic substitution reactions Co(C₅H₅BCH₃)[C₄(CH₃)₄] (IVa) is more reactive than ferrocene. CF₃CO₂D effects H/D-exchange in the α-position of the borabenzene ring within a few minutes at ambient temperature and in the γ-position within less than four hours Friedel-Crafts acetylation with CH₃COCl/AsCl₃ in CH₂Cl₂ affords the 2-acetyl and the 2,6-diacetyl derivative of IVa. With the more active catalyst AlCl₃, ring-member substitution is effected to give cations [Co(arene)C₄(CH₃)₄]⁺ (arene = C₆H₅CH₃, 2-CH₃C₆H₄COCH₃). Vilsmeier formylation gives the 2-formyl derivative of IVa. The acyl derivatives Co(2-R¹CO-6-R²C₅H₃BCH₃)[C₄(CH₃)₄] (R¹ = CH₃, R² = H, CH₃CO and R¹ = R² = H) transform to the corresponding cations [Co(ortho-R¹R²C₆H₄)C₄(CH₃)₄]⁺ in superacidic media. The mechanistic relationship between acylation and ring-member substitution is discussed in detail.     

Darstellung und eigenschaften von diorganogermaniumdisulfinsäureestern

Diorganogermaniumdisulfinic esters of the type R₂Ge(O₂SR′)₂ (R = CH₃, R′ = CH₃, C₆H₅, p-CH₃C₆H₄; R = C₆H₅, R′ = CH₃, p-CH₃C₆H₄) which are sensitive to hydrolysis are obtained by reaction of the corresponding diorganogermanium dichlorides with anhydrous silver sulfinates. The newly prepared compounds are thoroughly investigated on the basis of their ¹H NMR, mass, IR and Raman spectra. The methyl ester (CH₃)₂Ge(O₂SCH₃)₂ is compared with the already known sulfinato complex of tin with the same formal composition.     

Effets electroniques en stereochimie—III : Réduction asymétrique de phénylalkylcétones diversement substituées par des organomagnésiens aromatiques chiraux

The asymmetric reduction of phenylalkylketones p-X-C₆H₄COR (X = H, R = C₂H₅, ¹C₃H₇, ¹C₄H₉ and R = C₂H₅, X = CH₃, OCH₃, Cl, CF₃) with chiral aromatic Grignard reagents p-YC₆H₄-CH(C₂H₅) CH₂MgCl (Y = H, OCH₃, CF₃) give optically active phenylalkylcarbinols. The absolute configuration and the enantiomeric excess depends on electronic effects of substituents carried by the organomagnesium reagent and/or ketone.