Synthesis of organoantimony(V) and μ-oxy-bis(triarylantimony) selenocyanates using a phase-transfer catalyst

Several new, pentacoordinated, triorganoantimony bis-selenocyanates [R₃Sb(SeCN)₂ (R = Me, Ph, p-CH₃C₆H₄, p-ClC₆H₄, p-F-C₆H₄ or C₆F₅)], tetraorganostibonium selenocyanates [R₃R′Sb(SeCN) (R = R′ = Ph; R = Ph, and R′ = CH₂CHCH₂)] and μ-oxy-bis(triarylantimony) bis-selenocyanates {[Ar₃SbOSbAr₃](SeCN)₂ (Ar = Ph, p-CH₃C₆H₄, p-ClC₆H₄ or p-FC₆H₄)} have been synthesized from potassium selenocyanate and the corresponding organoantimony halide (chloride and/or bromide) in the presence of the phase-transfer catalyst 18-crown-6, and characterized. Spectroscopic evidence suggested an iso structure (Sb—NCSe). The compounds were also obtained in the absence of 18-crown-6 but in lower yields. Some of these compounds were found to exhibit a significant biological activity.     

Carbamoyl and alkoxycarbonyl complexes of palladium(II) and platinum(II)

Carbamoyl and alkoxycarbonyl complexes of palladium(II) and platinum(II) of the type M(pnp)(CONHR)Cl (pnp = 2,6-bis(diphenylphosphinomethyl)pyridine; M Pd, R  C₆H₅, p-CH₃C₆H₄, p-CH₃OC₆H₄, C₆H₁₁, t-Bu; M  Pt, R  C₆H₅), Pd(pnp)[CON(Pr)₂]Cl (Pr = propyl), M(pnp)(COOR)Cl (M  Pd, R  C₆H₅, CH₃; M  Pt, R  CH₃), Pd(pnp)(COOCH₃)₂ result from reaction of M(pnp)Cl₂ with carbon monoxide and amines or alkoxides at room temperature and atmospheric pressure.The carbamoyl complexes react with bases to give urethane or diphenylurea depending upon the experimental conditions.     

Étude de l'oxydation de triphénylamines par voltammétrie à variation linéaire de tension en couche mince

The mechanism of the oxidation of substituted triphenylamines R₁R₂R₃N (R₂=R₃=C₆H₅, R₁=p-OCH₃C₆H₄ (1) or p-CH₃C₆H₄ (2); R₁=R₂=R₃=p-OCH₃C₆H₄ (3) or C₆H₅ (4)) has been investigated by using thin layer linear potential sweep voltammetry. The tetraphenylbenzidine which is formed during the oxidation results from a dimerization of two cation radicals. The rate constants are calculated for (1) and (2).     

(Chloromethyl)thallium(III) compounds

Aryl(chloromethyl)thallium chlorides, Ar(ClCH₂)TlCl (Ar=C₆H₅, p-CH₃C₆H₄) have been prepared by treatment of arylthallium dichlorides with diazomethane. The derived carboxylates, Ar(ClCH₂)TlX, react with HgX₂ to give the dicarboxylates, (ClCH₂)TlX₂ (X = OCOCH₃, OCOC₃H₇-i) and with tetramethyltin to give CH₃(ClCH₂)TlX compounds. R(ClCH₂)TIX compounds (R = CH₃, C₆H₅, p-CH₃C₆H₄) undergo disproportionation in methanol to R₂TlX and (ClCH₂)₂TlX compounds.     

Reactions of (η5-C5H5)2Tir compounds with organic cyanides

The syntheses and properties of the titanium(III) complexes Cp₂Tir · R′CN (R = C₆H₅, o-, m-, p-CH₃C₆H₄, CH₂C₆H₅, C₆F₅, Cl; R′ = CH₃, t-C₄H₉, C₆H₅, o-CH₃C₆H₄, 2,6-(CH₃)₂C₆H₃) are described. In the complexes the nitrogen atom of the cyanide ligands is coordinated to the metal. The thermal stabilities of the complexes depend markedly on R and R′; on heating they undergo a novel reaction in which two cyanide ligands are coupled by formation of a CC bond, while the metal is oxidized to titanium(IV).     

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.     

Cobalt, nickel, and copper coordination compounds with 3-phenylpropenal benzoylhydrazone

3-Phenylpropenal benzoylhydrazone (HL) reacts with cobalt, nickel, and copper chlorides, nitrates, and acetates to give coordination compounds MX₂ · nH₂O [M = Co, Ni, Cu; X = Cl, NO₃, HL = C₆H₅CH=CHCH=NNHC(O)C₆H₅; n = 0, 2] and ML₂ · nH₂O (M = Co, Ni, Cu; n = 1–3). Complexes MALCI (M = Co, Ni, Cu) were obtained by these reactions in the presence of amines (A = C₅H₅N, 2-CH₃C₅H₄N, 3-CH₃C₅H₄N, 4-CH₃C₅H₄N). All the compounds have a monomeric structure. Azomethine (HL) in them behaves as a bidentate N,O-ligand. Thermolysis of the complexes involves the stages of dehydration (70–90°C), deaquation (145–155°C) or deamination (145–185°C), and complete thermal decomposition (330–490°C).     

Synthesis, structural characterization of some germanium substituted chiral diethyltin derivatives

Some new bimetallic carboxylates of tin and germanium with general formula where R¹ = m-CH₃C₆H₄, p-CH₃C₆H₄, C₆H₅, R² = o-CH₃C₆H₄, p-CH₃C₆H₄, o-CH₃OC₆H₄, C₆H₅, CH₃, have been prepared by the condensation reaction of diethyltin oxide and triarygermyl(substituted)propanoic acid in 1:2 mole ratio, respectively, and characterized by multinuclear (¹H, ¹³C, ¹¹⁹Sn) NMR, ^119mSn Mössbauer and IR spectroscopy. The X-ray crystal structure of the ligand I₄ [(C₆H₅)₃GeCH(o-CH₃OC₆H₄)CH₂COOH] delineate four coordinated germanium atom with a peculiarity of having a molecule of solvent (CHCl₃). The chiral center in the synthesized compounds was identified on the basis of ¹H NMR data and measurements of angle of rotations.     

Alkaline hydrolysis of diaryl ditellurides under phase transfer conditions; synthesis of alkyl aryl tellurides

The disproportionation reaction of diaryl ditellurides [(C₆H₅Te)₂, (p-CH₃C₆H₄Te)₂, (p-CH₃OC₆H₄Te)₂, (p-C₂H₅OC₄Te)₂, (2-naphthyl-Te)₂] with sodium hydroxide under phase transfer conditions at room temperature is described for the first time. The phase transfer catalyst used is 2HT-75, a trade name for a mixture of dialkyldimethylammonium chlorides. The intermediates aryl tellurolates react “in situ” with alkyl halides to give the corresponding alkyl aryl tellurides (ArTeR) in 52–72% yield. The following compounds were prepared: Ar  C₆H₅, R=CH₃(CH₂)₃CH₂, (CH₃)₂CHCH₂CH₂, (CH₃)₂CHCH₂, CH₃CHBrCH₂CH₂, CH₃(CH₂)₈CH₂, C₆H₅CH₂, ClCH₂, C₆H₅CH₂CH₂, CH₂CHCH₂, C₆H₅CHCHCH₂, C₆H₅SeCH₂, $\text{CH}{}_2\text{CH}{}_2\text{CH}{}_2\text{CHCHC}$H; Ar=p-CH₃C₆H₄, R = CH₃(CH₂)₂CH₂; Ar=p-CH₃OC₆H₄, R = CH₃(CH₂)₂CH₂; Ar = p-CH₂H₅OC₆H₄, R= CH₃(CH₂)₂CH₂; Ar = 2-naphthyl, R = CH₃(CH42)₂CH₂.     

Reactions of palladium(II) cyclometallated benzylideneaniline Schiff's bases. Some relative rates for the synthesis of ortho-substituted carbomethoxy derivatives via CO insertion

The synthesis and characterisation of the complexes [(p-CH₃C₆H₄NCH($\text{C}{}_6\text{H}{}_3\text{Y))P}$d(OAc)]₂ (II) are reported. These complexes react at very different rates with carbon monoxide in methanol to give the ortho-substituted esters, p-CH₃C₆H₄NCHC₆H₃Y - 2R, R = CO₂CH₃, with electron withdrawing Y substituents slowing the reaction. The ¹³C{¹H} data for II show a linear correlation of δ(C(2)) in the 5′-complexes (Y trans to PdC) with δ(C(4)) of monosubstituted benzene compounds. For Y = 5′-NO₂, 4′-NO₂ and 4′-Cl, the bis complex [{p-CH₃C₆H₄NCH(

is formed in a secondary reaction.     

Regioselective anion generation and alkylation at carbon α to nitrogen in (CO)5WC[N(CH3)2]C6H4-p-CH3

Treatment of (CO)₅WC[N(CH₃)₂]C₆H₄-p-CH₃ (1) with lithium diisopropylamide (LDA) in THF at −78°C followed by quenching with D₂O leads to incorporation of deuterium into the (E)-N-methyl group only. Reaction of the anion of 1 with benzyl bromide at −78°C followed by quenching with water gave the E-isomer of (CO)₅WC[N(CH₃)CH₂CH₂C₆H₅]C₆H₄-p-CH₃ (2E, 26%) and recovered 1. When a mixture of the anion of 1 and benzyl bromide was warmed from −78°C to ambient temperature, a mixture of the E-isomer of the dibenzylated product (CO)₅WC[N(CH₃)CH(CH₂C₆H₅)₂]C₆H₄-p-CH was obtained. Reaction of the anion of 1 with allyl bromide gave (CO)₅WC[N(CH₃)CH₂CH₂CHCH₂]C₆H₄-p-CH₃ (5, 38%) and with methyl iodide gave a mixture of (CO)₅WC[N(CH₃)CH₂CH₃]C₆H₄-p-CH₃ (6, 7%) and (CO)₅W C[N(CH₃)CH(CH₃)₂]C₆H₄-p-CH₃ (7, 16%).     

Synthesis, crystal structures and in vitro antitumor activities of some arylantimony derivatives of analogues of demethylcantharimide

A series of novel arylantimony derivatives of analogues of demethylcantharimide with the formulae Ar_nSbL_(5−n) and Ar_nSbL^′_(5−n)(LH=N-hydroxy-demethyldehydrogencantharimide, L^′H=N-hydroxy-demethylcantharimide, n=3, 4; ArC₆H₅, 4-CH₃C₆H₄, 3-CH₃C₆H₄, 2-CH₃C₆H₄, 4-ClC₆H₄, 4-FC₆H₄) were synthesized and characterized by elemental analysis, IR, ¹H NMR and mass spectroscopy. The crystal structures of (C₆H₅)₄SbL, (4-CH₃C₆H₄)₃SbL₂ and (3-CH₃C₆H₄)₃SbL^′₂ were determined by X-ray diffraction. The in vitro antitumor activities of all compounds against six cancer cells are reported.     

Reactions of iridium and platinum complexes with N-sulfinyl compounds

The reactions of substituted N-sulfinylanilines with the complexes {Pt[P(C₆H₅₃]₂O₂} and {IrClCO[P(C₆H₅)₃]₂} have been reinvestigated. The former complex yields {Pt[P(C₆H₅)₃]₂SO₄} as the only isolable product in reactions with N-sulfinylaniline. In contrast to a previous report, Vaska's complex has been found not to react with C₆H₅NSO under anhydrous conditions. {Pt[P(C₆H₅)₃]₂-(C₂H₄)} reacts with N-sulfinyl compounds to give complexes of formula {Pt[P(C₆H₅)₃]₂-(RNSO)} where R = C₆H₅, p-O₂NC₆H₄, p-CH₃C₆H₄, or p-CH₃C₆H₄SO₂. {Pt[P(C₆H₅)₃]₃} reacts with C₆H₅NSO to give the same product obtained from reaction with the ethylene complex. Vaska's complex and its bromo analog form 1:1 adducts with p-O₂NC₆H₄NSO.     

Diorganostyrylzinndiorganophosphine und ihre tricarbonylnickel-komplexe

Diorganostyryltin chlorides R₂StySnCl (R = C₄H₉, p-CH₃C₆H₄, R₂ = (CH₂)₅) react with trimethylsilyl di-t-butylphosphine or trimethylsilyl diphenylphosphine to form trimethylchlorosilane and the corresponding diorganostyryltin-diorganophosphines, which can be separated and characterized by IR, NMR, Mössbauer and mass spectroscopy. With Ni(CO)₄ the tin—phosphorus derivatives give diorganostyryltin diorganophosphinetricarbonylnickel complexes.     

Coordination chemistry of sulfines : I. Synthesis and characterization of the complexes Pt(PPh3)2(XYCSO) (X,Y = aryl,S-aryl,S-alkyl,Cl). Coordination via the CS-π-bond

Reactions of Pt(PPh₃)₄ with the sulfines, XYCSO, (X, Y = aryl, S-aryl, S-alkyl, Cl) yield coordination compounds of the type Pt(PPh₃)₂(XYCSO). Infrared, ³¹P and ¹H NMR spectra reveal that in all cases the sulfine ligand is coordinated side-on via the CS π-bond (Pt—η²-CS). Reactions of Pt(PPh₃)₄ with either the E- or Z-isomer of (p-CH₃C₆H₄)(CH₃S)CSO yields the corresponding E- or Z-coordination compound, Pt(PPh₃)₂[E-(p-CH₃C₆H₄)(CH₃S)CSO] or Pt(PPh₃)₂[Z-(p-CH₃C₆H₄)(CH₃S)CSO], indicating that the configuration of the sulfine ligand is retained upon coordination to the Pt(PPh₃)₂ unit. The compounds Pt(PPh₃)₂(XYCSO), containing reactive CX and/or CY bonds (X, Y = S-aryl, S-alkyl, Cl), undergo a rearrangement in solution to give complexes of the type PtX(PPh₃)₂(YCSO).     

C-S bond formation catalyzed by N-heterocylic carbene palladium phosphine complexes

N-Heterocyclic carbenes (NHCs) are known to be useful ligands for palladium-complex catalysis. It was found that [(NHC)Pd(PPh₃)Cl₂] is an effective pre-catalyst in Pd-catalyzed C-S cross coupling reactions to produce the functionalized sulfides in excellent yields. The turn over frequency (TOF) for the coupling of p-CH₃C₆H₄Br with p-CH₃C₆H₄SH reaches to 6.25 (mol of product) (mole of catalyst)⁻¹ h⁻¹.     

Binuclear dinitrogen complexe of aryl- and benzyldicyclopentadienyltitanium(III) compounds

The preparation of the deep-blue diamagnetic dinitrogen complexes (Cp₂TiR)₂N₂ with R=C₆H₅, o-, m-, p-CH₃C₆H₄, C₆F₅, CH₂C₆H₅ is described. Their chemical and physcial properties confirm the formulation in which the R groups are σ-bonded to the Cp₂Ti moiety, and the two nitrogen atoms are equivalent. The heats of formation of the complexes from Cp₂TiR and N₂ in toluene have been determined from spectrophotometric data; for R=C₆H₅, o-, m-, p-CH₃C₆H₄, C₆F₅, CH₂C₆H₅, the values are ?18, ?9, ?17, ?20, ?17 and ?14 kcal·mol^?1, respectively. The solid complexes vary markedly in thermal stability, and are extremely air sensitive. The complexed nitrogen can be completely reduced with sodium naphthalene; after hydrolysis of the products, NH₃ and N₂H₄ are obtained. In the thermolysis of the solids, some of the nitrogen is reduced.     

Preparation and properties of monoorganoantimony tetrachloride adducts

Several adducts of monoorganoantimony tetrachlorides, RSbCl₄L (R = CH₃, C₆H₅, p-CH₃C₆H₄; L = HMPT, PyO, 4-CH₃PyO, DMSO), were prepared. In the solid state all of these adducts are stable at room temperature. They are monomeric in solution, and the existence of hexacoordinate antimony is indicated. CH₃SbCl₄L (L = PyO, 4-CH₃PyO) exists in two isomeric forms in solution and decomposes above 70° into CH₃Cl and SbCl₃L. CH₃SbCl₄(HMPT) decomposes in a similar manner even at room temperature.     

Synthesis and reactivity of some isocyanide complexes of iridium(I)

Several isocyanide complexes [Ir(RNC)₄]X (I) (R = p-CH₃C₆H₄, X = I; R = p-CH₃OC₆H₄, X = I and PF₆) and [Ir(RNC)₂(PPh₃)₃] ClO₄(II) (R = p-CH₃C₆H₄ and p-CH₃OC₆H₄) have been prepared by the reactions of [Ir(COD)Cl]₂ and [Ir(COD)(PPh₃)₂]ClO₄ (COD = l,5-cyclooctadiene) with aryIisocyanides, respectively. Oxidative addition reactions of I and II with halogens, and II with π-acids such as tetracyanoethylene(TCNE), fumaronitrile, maleic anhydride, dimethyl fumarate, acrylonitrile, and dimethyl acetylenedicarboxylate are described. The structures of I, II and the π-acid addition products of II, [Ir(p-CH₃C₆H₄NC)₂ (PPh₃)₂ (π-acid)]ClO₄ (IV) (π-acid = TCNE, fumaronitrile, maleic anhydride, and acetylene dicarboxylate), are discussed on the basis of their electronic, IR, and NMR spectra. Especially, I is suggested to have an unusual layer structure involving Ir to Ir interaction, the result of which is relatively low reactivity in oxidative addition reactions. Trigonal bipyramidal configurations are suggested for IV with the two isocyanides in the trans and cis positions for the olefin and acetylene adducts, respectively.     

Dirhodium(II) dicarboxylato complexes containing carbonyl and C-bonded methoxycarbonyl ligands

Oxidation of rhodium(I) carbonyl chloride, [Rh(CO)₂Cl]₂, with copper(II) acetate or isobutyrate in methanol solutions yields binuclear double carboxylato bridged rhodium(II) complexes with RhRh bonds, [Rh(μ-OOCRκO)(COOMeκC)(CO)(MeOH)]₂, where R=CH₃ or i-C₃H₇. According to X-ray data, surrounding of each rhodium atom in these complexes is close to octahedral and consists of another rhodium atom, two oxygens of carboxylato ligands, terminal carbonyl group, C-bonded methoxycarbonyl ligand, and axial CH₃OH. Methoxycarbonyl ligand is shown to originate from CO group of the parent [Rh(CO)₂Cl]₂ and OCH₃ group of solvent. N- and P-donor ligands L (p-CH₃C₆H₄NH₂, P(OPh)₃, PPh₃, PCy₃) readily replace the axial MeOH yielding [Rh(μ-OOCRκO)(COOMeκC)(CO)(L)]₂. The X-ray data for the complex with R=i-C₃H₇, L=PPh₃ showed the same molecular outline as with L=MeOH. Electronic effects of axial ligands L on the spectral parameters of terminal carbonyl group are essentially the same as in the known series of rhodium(I) complexes (an increase of δ¹³C and a decrease of ν(CO) with strengthening of σ-donor and weakening of π-acceptor ability of L).