Electrochemical synthesis of polypyrrole/poly-N-(p-nitrophenyl)pyrrole co-polymer

Copolymers of pyrrole and N-(p-nitrophenyl)pyrrole have been synthesized electrochemically. Cyclic voltammetric studies show that the electroactivities of both nitrobenzene and polypyrrole are apparent in the copolymer. Growth of poly-N-(p-nitrophenyl)pyrrole films is self-limiting an stops at 200 to 300 nm. Copolymerization allows thick and freestanding films incorporating the nitrophenyl moiety to be grown.     

pentahapto- UND trihapto- cycloheptadienylkobalt(I)-komplexe

Treatment of [CoH(N₂)(PPh₃)₃] with cycloheptatriene in diethyl ether affords [Co(1—5-η-C₇H₉)(PPh₃)₂] (I). An etherical solution of (I) reacts with CO at room temperature and under normal pressure to yield the carbonyl complex [Co(1—3-η-C₇H₉)(CO)₂(PPh₃)] (II). These compounds are characterized by their PMR and IR spectra.     

The mercuration of ortho- and meta-carboranes

The mercuration of ortho- and meta-carboranes is described. This mercuration proceeds at the boron atom of the icosahedral at position 9.     

Cyclopalladation compounds of the 2-pyridylhydrazone derivatives of p-substituted acetophenones and acetylthiophenes

Cyclopalladation occurs for 2-pyridylhydrazones(HL) of p-methyl-, p-methoxy-, p-chloro-, and p-nitro-acetophenone, and 3-acetyl- and 2-acetyl-thiophene with lithium tetrahalopalladate to give the complexes [PdXL] (X = Cl and Br) and some iodo complexes are prepared by metathesis of the chloro complexes with lithium iodide. These complexes are characterized spectroscopically. The hydrazones are coordinated to palladium through benzene or thiophene ortho-carbon, hydrazone-nitrogen, and pyridine ring-nitrogen atoms forming fused five-membered chelate rings.     

A new uninegative ligand, tris-(diphenylthiophosphinyl)methanide

The reaction of tris-(diphenylthiophosphinyl)methane, [(C₆H₅)₂P(S)]₃CH, with mercury(II) halides produces complexes of the type [(C₆H₅)₂P(S)]₃CHgX, where X is Cl, Br and I.     

The reaction of aqua-(ethylenediaminetetra-acetato)ruthenium(III) with o-phenylenediamine under aerobic conditions

An electron-transfer reaction between [Ru(III)(Hedta)(H₂O)] and o-phenylenediamine in the presence of O₂ takes place to give a Ru(II)-edta complex with coordinated (bidentate) o-benzoquinone diimine. The complex obtained has been characterized by analysis, magnetic measurements, electronic, IR, ¹H and ¹³C NMR spectral data.     

Solvolytic behaviour and the solubilities of various inorganic compounds, lewis acids and bases in fused monobromo acetic acid solvent system—II

Solubilities and the solvolytic behaviour of various inorganic compounds, Lewis acids and bases in fused monobromoacetic acid at 60 ± 0.5°C are discussed. Ionic compounds are fairly soluble, iodides and thiocyanates being comparatively more soluble than chlorides and bromides. Tetraalkyl ammonium halides are highly soluble in this solvent. Conductometric and spectroscopic studies of various Lewis acids and bases in fused monobromoacetic acid indicate their solvolytic behaviour and their subsequent ionization. The solvolyses products BBr₃·CH₂BrCOOH and SbCl₅·CH₂BrCOOH have been observed to be the strongest Bronsted acids. Auto-ionization of this solvent has been supported by acid/base titrations.     

Reactions of xenon difluoride: Oxidative fluorination of methyl derivatives of the p-block elements

A survey has been carried out to determine how xenon difluoride reacts with methyl derivatives of p-block elements, Me_nX (n = 3, X = N, P, As, or Sb; n = 2, X = O, S, or Se; n = 1, X = Cl, Br, or I), on the basis of NMR measurements, tensimetric and IR analysis of the gaseous products, and mass balances. The reaction proceeds smoothly in most cases, although a Freon like CCl₃F may be needed as a moderator; the rate of the reaction seems to reflect the basicity of the substrate Me_nX. The difluoride Me_nXF₂ is formed in the cases where X = P, As, Sb, Se, or I. The scope of xenon difluoride in these conditions as a mild selective oxidative fluorinating agent is illustrated by the synthesis of the known compounds (CF₃)₂XF₂ (X = S or Se) and the novel compound Me(CF₃)SeF₂. By contrast, cleavage of CH bonds, with the formation of CH₂F derivatives, is the predominant path in the cases where X = N, O, or S, and cleavage of CX bonds, with the formation of MeF, occurs in the cases where X = Cl or Br.     

Magnetic and spectral studies on N-(thiophene-2-carboxamido)salicylaldimine complexes of some bivalent 3d metal ions

Metal(II) complexes of N-(thiophene-2-carboxamido)salicylaldimine (H₂TCS) of types M(H₂TCS)₂Cl₂ [M = Ni, Cu and Zn], M(HTCS)Cl [M = Co, Ni and Cu], M(HTCS)₂ [M = Mn, Fe, Co, Ni, Cu and Zn], M(TCS)·xH₂O [M = Mn, Co and Ni, x = 2; M = Cu, x = 0], Ni(TCS)py₂ and Cu(TCS)py have been prepared. Elemental analyses, molar conductance, magnetic moment, electronic, IR and ESR spectral studies have been used to characterize these complexes. The different modes of chelation of the ligand and the stereochemistry of the complexes are discussed.     

Infrared study of some specificities of the dπpπ interaction in organogermanium compounds

The analysis is presented for the frequencies of stretching modes ν(GeH) in the IR spectra of organogermanium compounds R₂XGeH, RX₂GeH, RXYGeH, X₂YGeH and XYGeH₂ (where R is a substituent which does not make a d_πp_π bond with germanium, and X and Y are groups capable of d_πp_π interaction with germanium). It is shown that ν(GeH) in these compounds is dependent on both the I effect of R, X and Y, and the d_πp_π interaction in GeX and GeY bonds. If only one substituent capable of d_πp_π interaction with germanium is present, the value of such an effect is determined by itsσo_Rconstant. However, when germanium is bound to several substituents capable of d_πp_π interaction its magnitude depends on the effective charge at germanium which is determined by the inductive and mesomeric effects of X and Y. The data obtained are compared to the dependences observed in the IR spectra of similar organosilicon compounds.     

The isomerization of cis,trans-1,5-cyclodecadiene by RhCl3 · 3H2O in ethanol

The isomerization of cis,cis-1,6-cyclodecadiene to cis,trans-1,5-; and cis,cis-1,5-cyclodecadiene in the presence of their rhodium complexes seems to indicate an isomerization for which no thermal conversion has been reported. Evidences are presented for the functioning of ethanol as a hydride source in these polymerizations.     

Reaction of trans-[Co(en)2(SO3)(H2O)]+ with imidazole and containing ligands

trans-[Co(en)₂(SO₃)(H₂O)]⁺ reacts with imidazole (ImH) and imidazole containing ligands (L) to form trans-[Co(en)₂(SO₃)L]⁺ in the pH range 6.0–9.0. The complex seems to react both in the hydroxy and in the aquo form. The rate constant for the reaction of imidazole with the aquo form is 6.0±0.7 and 4±1M^?1s^?1 for the reaction with the hydroxy form at 25°C. The apparent equilibrium constant for formation of the imidazole complex at pH 7 is consistent with the value of 3 x 10² measured previously. Appreciable amounts of complex form only in the pH 6–9 range. Above pH 9 NMR spectra show that even the immediate products are different. In aged solutions at all pHs other products form.     

The preparation of cis- and trans-[PtH(C6Cl5)(PEt3)2 and a study of the “hydride-donor capacity” of the complexes trans- [PtH(C6X5(PEt3)2] (X = F and Cl)

The preparations of cis- and trans-[PtH(C₆Cl₅)(PEt₃)₂] by thermal decomposition of cis- and trans-[Pt(OCHO)(C₆Cl₅)(PEt₃)₂], respectively, are reported. Also described are cis- and trans-[Pt(SnCl₃)(C₆Cl₅)(PEt₃)₂], obtained by treating SnCl₂ with cis- and trans-[PtCl(C₆,Cl₅)(PEt₃)₂], respectively. It is shown that while trans- [PtH(C₆Cl₅)(PEt₃)₂] does not form hydride-bridged complexes in the presence of trans-(PtH(MeOH)(PEt₃)₂]⁺, the corresponding complex trans-[PtH(C₆)(PEt₃)₂] reacts with the same solvento complex, in methanol, giving labile [(PEt₃)₂HPt(-μH)Pt(C₆F₅)(PEt₃)₂]⁺.     

Kinetic study of the reaction of meso-tetrakis (p-trimethylammoniumphenyl)porphinatodiaquorhodate(II) with chloride,bromide, iodide,hexacyanocobaltate(III) and thiocyanate ions in aqueous solution

The reaction of Cl^?, Br^?, I^?, Co(CN)₆^3? and NCS^? with meso-tetrakis (p-trimethylammoniumphenyl)porphinatodiaquorhodate(III), [RhTAPP(H₂O)₂]⁵⁺, has been studied at 15, 25 and 35°C in 0.1 M [H⁺] with μ = 1.00 M (NaNO₃). The value of the acidity constant, K_al, at 25°C is 4.39 × 10^?9 M. The reactions are first order in anion concentration up to 0.9 M. The values of the stability constants, K₁, and the second order rate constants, k₁, for the reaction with Cl^?, Br^?, I^?, Co(CN)₆^3? and NCS^? are respectively 0.23 M^?1 and 2.5 × 10^?3 M^?1 s^?1, 1.1 M^?1 and 6.92 × 10^?3 M^?1 s^?1, 40.0 M^?1 and 17.0 × 10^?3 M^?1 s^?1, 550 M^?1 and 20.0 × 10^?3 M^?1 s^?1, 3400 M^?1 and 20.9 × 10^?3 M^?1 s^?1. The porphine greatly labilizes the Rh(III). There has been about a 500-fold increase in the rate constant for substitution compared to that of [Rh(NH₃)₅H₂O]³⁺. The substitution rates are however about the same as for [Rh(TPPS)(H₂O)₂]^3?, indicating that the overall charge on the complex plays only a minor role. The kinetic results indicate that dissociative activation is occurring in these reactions.     

Stabilisation of copper(II) tertiary-phosphine or -arsine complexes—II. Role of inductive effect and reaction conditions in stabilising copper(II)-arsine complexes of hybrid oxygen-arsenic ligands from o-R2AsC6H4CO2H

The characterization of the products of reactions between anhydrous/hydrated copper(II) acetate and the title acids having R = Me, C₆H₁₁, Ph and p-tolyl in different solvents and at different temperatures with the help of elemental analysis, TGA, DTA, room temperature magnetic susceptibility, IR, and UV-VIS and EPR spectral data reveal that a competition exists between the chelation of arsine to copper(II) on one side and the reduction of copper(II) to copper(I) and the subsequent chelation of the arsine to copper(I) and/or that of the arsine oxide to copper(II) on the other. This competition which is expected to be normally governed by the inductive effect of group R is disturbed by the change in reaction conditions leading to the conclusion that the reaction conditions rather than the inductive effect of the group R control the mode of reaction.     

Preparation,crystal and molecular structure of,and NMR parameters for,the exopolyhedral heterocyclic platinaundecaborane [μ-2,7-(SCSNEt2)-7-(PMe2Ph)-NIDO-7-PtB10H11]

The compound [μ-2,7-(SCSNEt₂)-7-(PMe₂Ph)-nido-7-PtB₁₀H₁₁] has been obtained in a yield of 52% from the reaction of [7,7-(PMe₂Ph)-nido-7-PtB₁₀H₁₂] and [AuBr₂(S₂CNEt₂)], and identified by single crystal X-ray diffraction analysis and multi-element single and double resonance NMR spectroscopy. The yellow-orange compound crystallizes in the monoclinic space group P2₁/n with a 1179.2(2), b = 1244.9(5), c = 1641.4(2) pm, β = 95.45(1)°, Z = 4, and the structure (R 0.0209, R_w = 0.0211 for 3719 observed reflections) is that of a nido-7-platinaundecaborane with an exopolyhedral N,N-diethyldithiocarbamate ligand bridging the Pt(7) and B(2) positions to give a $\text{-Pt-B-C-S-}$ five-membered ring. The tetrahapto platinum-to-borane bonding has a considerable twist distortion relative to other nido-7-platinaundecaboranes which do not possess this cyclic feature. The NMR parameters exhibit no anomalies and are consistent with the crystal molecular structure. A plot of δ(¹¹B) vs δ(¹H) for directly bound exo-terminal hydrogen atoms shows good correlation with the slope 16 : 1.     

Crystal and molecular structure of the tetrachloropalladate of the dication meso-3,7-diazonia tricyclo[4.2.2.22,5]dodeca-3,7,9,11-tetraen-4,8 diamine obtained by coupling reaction of 2-aminopyridines

A solution of trans-bis(2-aminopyridine)dichloropalladium(II) in DMF and HCl 2 N was left for several weeks. The compound isolated from this solution was identified by X-ray structural analysis as the tetrachloropalladate of meso-3,7-diazonia tricyclo[4.2.2.2^2,5] dodeca-3,7,9,11-tetraen-4,8 diamine, which contains a dication not previously described in literature. The organic dication is formed by two aminopyridine rings linked by CC bonds whose length is greater (1.61 Å) than a normal single CC bond.     

The preparation and synthetic value of fac-[M(CO)3(NCR)3]+ cations (M  Mn or Re; R  Et,Pr OR PhCH2)

Treatment of MBr(CO)₅ (M = Mn or Re) with AgClO₄ and an organonitrile in a suitable solvents affords the complexes fac-[M(CO)₃(NCR)₃][ClO₄], (R = Et, Pr or PhCH₂). The use of these complexes as synthetic precursors has been illustrated by the preparation of fac-[M(CO)₃L₃][ClO₄], (M = Mn, L = NH₃ or L₃ = dien; M = Re, L₃ = triphos). Pure fac-[Re(CO)₃(NH₃)₃][ClO₄] could not be prepared using this nitrile displacement route, but may be isolated, as the PF₆^? salt, from the reaction of [Re(CO)₃(toluene)][PF₆] and ammonia in chloroform.     

Cyclobutadieneiron tricarbonyl carboxylic acids: Synthesis and acidity

Two carboxylic acid derivatives of the cyclobutadieneiron tricarbonyl (I) system have been synthesized and their pK_a values determined. It appears that I tends to be electron withdrawing by induction and electron releasing by resonance.     

Far-IR spectra of charge-transfer complexes between IX (X = Cl,Br or I) and trans-1,2-bis(4-pyridyl)ethylene, 1,2-bis(4-pyridyl)ethane and 4,4′-

Far-IR spectra of charge-transfer complexes of trans-1,2-bis(4-pyridyl)ethylene (Bpe), 1,2-bis(4-pyridyl)ethane (Bpa) and 4,4′-bipyridyl (4,4′-