New syntheses of platinum (IV) and platinum (VI) fluorides

γ-Ray and peroxide-initiated additions of dimethylether to F-cyclobutene, F-cyclopentene, and F-cyclohexene give mixtures of $\text{cis-}$ and $\text{trans-}$ adducts in each case, with a clear preference for $\text{trans}$-addition with F-cyclobutene. Selective bromination of the adducts occurs but the position of chlorination depends dramatically on solvent. Fluorination with cobalt trifluoride is very efficient.     

Synthesis, 13C NMR and IR spectroscopic studies of gold(I) complexes of imidazolidine-2-thione and its derivatives

The gold(I) complexes of imidazolidine-2-thione and its derivatives were synthesized and their ¹³C NMR and IR spectroscopic studies were carried out. When gold(III) was reacted with the ligands using a 1:4 metal to ligand ratio, gold(III) was reduced to gold(I), the bis complexes of the general formula AuL_nX (where n = 2) were formed. However, when gold(III) was reduced to gold(I) by a reducing agent followed by an addition of the ligand to an aqueous or methanolic solution of gold(I), only mono complexes of the type AuLX were obtained. The structures of the reported complexes are proposed on the basis of their spectroscopic measurements.     

Notable features in the molecular structure of W2(OCH2-t-Bu)6(NCNMe2)3: Three different modes of bonding for NCNMe2(2-) ligands

Hydrocarbon solutions of W₂(OCH₂-t-Bu)₆(HNMe₂)₂(MM) and Me₂NCN (?3 equiv) react at 0°C to give a compound of formula W₂(OCH₂-Bu-t)₆(NCNMe₂)₃. The crystal and molecular struture of the latter compound, deduced from an X-ray study, reveals the loss of the WW triple bond (WW = 3.85 Å) and the formal reduction of each Me₂NCN molecule to a 2- ligand for which three different modes of bonding are seen.     

3,6-bis(2′,-pyridyl)pyridazine dinuclear complexes: Palladium(II), platinum(II) and first row transition metal(II) mixed complexes

New Pd(II) and Pt(II) 3,6-bis(2′-pyridyl)pyridazine (dppn) mononuclear complexes of the type M(dppn)Cl₂ were prepared and characterized. From M(dppn)Cl₂, the bimetallic homonuclear complexes M(dppn)MCl₄ were prepared by reaction with Pd(PhCN)₂Cl₂ or K₂PtCl₄. Bimetallic heteronuclear species of the type M(dppn)M′Cl₄, were prepared reacting the mononuclear complexes with the stoichiometric amount of M′Cl₂ (M′ = Cu, Co, Ni). All the described reaction give product in high yield. The isolated compounds, almost completely insoluble in most organic solvents, were characterized by elemental analysis, IR, ESR, reflectance spectra, and magnetic moment measurements. On the basis of these data the geometries around the metals are discussed.     

Alkyl telluraalkanoates CnH2n+1Te(CH2)mCOOR (R = CH3, C2H5 OR H)

Methyl telluraalkanoates, C_nH_2n+1Te(CH₂)_mCOOR (n, m: 4, 7; 6, 4; 6, 7; 6, 9; 7, 4; 8, 7; 11, 2; 11, 5; 18, 11) were synthesized in yields ranging from 33 to 82 percent based on the quantities of the methyl ω-bromoalkanoates substrates. Disodium ditelluride was obtained from tellurium and sodium in ethylenediamine and was treated with alkyl bromides to give dialkyl ditellurides. The crude ditellurides were reduced with NaBH₄ to the alkane tellurolates which were coupled with methyl ω-bromoalkanoates to give the methyl telluraalkanoates. Ethyl 4-tellurapentadecanoate was prepared similarly from ethyl 3-bromopropanoate. The telluraalkanoates were characterized by elemental analyses, mass spectrometry, NMR spectrometry, and UV and IR spectrophotometry. Telluraalkanoates radiolabeled with ^123mTe or other radioisotopes have been reported elsewhere to be preferentially taken up by the heart and promise to be useful as myocardial imaging agents.     

Organometallic ligands : II. The coordination chemistry of 1-[(dimethylamino)-methyl]-2-(diphenylphosphino)ferrocene

Complexes of the organometallic ligand (h⁵-C₅H₅)Fe[(h⁵-C₅H₃)(1-CH₂NMe₂)(2-PPh₂)] (FcCNP) have been prepared with the carbonyls of chromium, molybdenum, tungsten, iron, and cobalt and with borane. With the Group VIB metals, the ligand forms complexes of the type (FcCNP)M(CO)₄ in which the FcCNP ligand is chelating. However, in the case of (FcCNP)Fe(CO)₄ and [(FcCNP)₂Co(CO)₃]BPh₄ the ligand is monodentate, the phosphorus acting as the donor atom. Infrared and NMR data were used to establish the mode of coordination in each case. The electrochemistry of the Group VIB metal carbonyl complexes has been investigated, the chromium complex being of particular interest. The cyclic voltammogram of (FcCNP)Cr(CO)₄ consists of two, reversible, one electron redox waves at E_{peak, anodic} + 0.54 V and + 0.96 V (vs. SCE in CH₂Cl₂), and a third, irreversible wave at E_{peak, anodic} + 1.47 V. At + 0.54 V the solution color changed from yellow to orange and the v(CO) bands shifted from 2011 w, 1891 s, and 1831 s (cm^?1) in the neutral complex to 2080 m, 2000 s, and 1970 s (cm^?1) in the singly oxidized species. At + 0.96 V, the color changed further to blue-green, but no additional shift in v(CO) was observed. On the basis of this information, it is concluded that the first redox wave represents the process Cr⁰ → Cr⁺ and the second wave Fe²⁺ → Fe³⁺. Other aspects of the electrochemistry of the Group VIB metal carbonyl complexes are discussed.     

Studies on the reaction products of bis(2-furanthiocarboxyhydrazidato)m(II) with pyridine-2- and -4-carboxaldehydes

Condensation of bis(2-furanthiocarboxyhydradatometal(II), M(fth)₂; [M (II) = Mn, Fe, Co, Ni, Cu and Zn] with pyridine-2- and -4-carboxaldehydes gave complexes of the formula M(pfth)₂ [pfth? = pyridine-2-carboxaldehyde-2-furanthiocarboxyhydrazonato], Ni(Ifth)₂, Zn(Ifth)₂, Cu(Ifth) and Co(Ifth)₃, (Ifth? = pyridine-4-carboxaldehyde-2-furanthiocarboxyhydrazonato). The magnetic and electronic spectral studies coupled with photoacoustic or Mössbauer spectra suggested octahedral geometry for the M(II) complexes with low-spin states for Co(Ifth)₃ and Fe(pfth)₂. IR and ¹H NMR spectral studies of diamagnetic complexes suggested bonding through “azomethine” nitrogen and “thiolo” sulphur. IR spectra also showed the involvement of pyridine ring nitrogen in coordination in all the complexes except Cu(Itfh), Co(Ifth)₃, and Zn(Ifth)₂. Some of the compounds possessed antimicrobial activity.     

Rearrangement of 2-(2-thienyl)benzothiazoline in the presence of thiophilic metal ions

2-(2-thienyl)Benzothiazoline and 2-(2thienyl)benzothiazol have been synthesized and characterized by several techniques (IR, NMR, UV-VIS, MS) and elemental analysis. The reactions of a solution of 2-(2thienyl)benzothiazoline with Zn, Cd, Hg(II) and Pb(II) ions have been studied. The spectral studies of the isolated complexes showed that the arrangement of the benzothiazoline to the Schiff base, N-2-mercaptophenyl-2′-methyleneimine, had occurred. The factors influencing this arrangement are discussed. Several complexes of 2-(2-pyridyl)benzothiazoline with Cd and Pb(II) were synthesized for purposes of comparison.     

Synthesis and characterization of mixed ligand complexes of copper(II), nickel(II), cobalt(II) and zinc(II) with glycine and uracil or 2-thiouracil

Mixed ligand complexes of Cu(II), Ni(II), Co(II) and Zn(II) formed with glycine and uracil or 2-thiouracil have been synthesized and characterized by elemental analysis, conductance, spectral (IR and electronic spectra) and magnetochemical measurements. Results show that glycine is bidentate in all cases; uracil behaves as a bidentate ligand in Cu(II) complex, coordinating through its one carbonyl oxygen and nitrogen, whereas in other cases it is only monodentate, coordinating only through nitrogen. With thiouracil, coordination occurs from carbonyl oxygen and one nitrogen in Cu(II) and Ni(II) complexes, but in the Co(II) complex coordination occurs from thionyl sulphur and nitrogen. In the Zn(II) complex it shows tridentate behaviour, coordinating through oxygen, sulphur and one nitrogen. Mixed Cu(II), Co(II) and Zn(II) complexes of uracil and of Ni(II) and Zn(II) with thiouracil are octahedral, whereas the mixed Ni(II) complex with uracil shows distorted tetrahedral geometry, and the mixed Co(II)-thiouracil complex is square planar. The mixed Cu(II)-thiouracil complex has a binuclear structure, with square planar arrangement around each copper atom.     

Thermal reaction of aquaammineruthenium(III) complex with amino acid or imidazole derivative in the solid state

Intermolecular thermal-substitution reaction between aquaammineruthenium(III) complex and amino acid or imidazole derivative has been investigated in the solid state by the TG-DTA method. Pentaammineruthenium(III) complexes containing amino acid or imidazole derivative have been obtained directly by the thermal reactions. Glycine, β-alanine, and γ-aminobutyric acid coordinate to Ru(III) through their carbonyl oxygen, and imidazole does through its N(3) atom. Distinct coordination site is provided in the complex with histidine and/or adenine: the bonding site depends on the outer-sphere anion of aquaammine complex. The N(3) atom of the histidine and N(7) atom of the adenine coordinate to Ru(III) taking the paratoluenesulphonate salt of aquaammineruthenium(III) into the reaction. When the methanesulphonate salt is used, the nitrogen atom in the side-chain amino-group participates in complexation. Direct chelation of the glycine, histidine, and adenine to the deaquated cis-diaquatetraammineruthenium(III) complex has been confirmed.     

Trans-bis(dimethylglyoximato) cobalt(III) complexes containing imidazole and thiocyanate as axial ligands

Imidazole(Im), benzimidazole(BzIm), morpholine (Morph) and their derivatives react with Co(CNS)₂ and dimethylglyoxime(DH₂) in ethanolic medium in presence of air to form a number of new cobalt(III) complexes of the type trans-[Co(DH)₂(L)(SCN)], which are characterised on the basis of electronic and IR spectra, NMR (¹H and ¹³C) and mass spectra as well as thermogravimetric (TG-DTA) and conductance measurements. The thiocyanate groups are S-bonded. The NMR observations suggest that in solution these compounds exist as mixtures of the neutral species [Co(DH)₂(L)(SCN)] and the salt [Co(DH)₂(SCN)₂]^? [Co(DH)₂(L)₂]⁺. The mass spectra does not show the molecular ion peak of the complex. The TG-DTA measurements show that the thermolysis of these complexes proceeds through polymeric intermediates giving CO₃O₄ as the end product.     

Spectroscopic investigation of adsorbed 7-(4-ethyl-1-methyloctyl)-8-quinolinol (kelex 100) and of its gallium(III) complex: Comparison with the behaviours observed in solvent extraction systems

The adsorption of a long hydrocarbon chain oxine derivative, 7-(4-ethyl-1-methyloctyl)-8-quinolinol, on the macromolecular Amberlite XAD-7 support is shown by FT-IR spectroscopy to be the result of only weak extractant-support interactions. It is also shown that the chelation ability of the extractant towards gallium(III) does not suffer from the presence of the solid support. Finally the stereochemistry (fac or mer configuration) of the tris-7-(4-ethyl-1 -methyloctyl)-8-quinolinato gallium(III) complex formed either in solution in an organic diluent or on the support is discussed on the basis of ¹H and ¹³C NMR and FIR data.     

Improved syntheses of chlorodicyclopentadienyl derivatives of scandium(III), titanium(III) and vanadium(III)

An improved synthesis of chlorodicyclopentadienyl derivatives of scandium(III), titanium(III) and vanadium(III) has been developed by the reaction of thallium cyclopentadienide with the appropriate anhydrous metal trihalides.     

Fragmentierung des schwefeldiimidsystems in tBu2PN=S=NPtBu2 an dreikernigen osmiumclustern. Synthese,feströrperstruktur und dynamische eigenschaften von Os3(CO)11[PtBu2(NH2)] und HOs3(CO)9PtBu2N(H)S]

The phosphino-substituted sulphur diimide, S(NP^tBu₂)₂, reacts with the trinuclear osmium clusters Os₃(CO)₁₁(NCMe) and H₂Os₃(CO)₁₀ with cleavage of one of the NS bonds to give the cluster compounds Os₃(CO)₁₁[P^tBu₂(NH₂)] (I) and HOs₃(CO)₉[P^tBu₂N(H)S] (II), respectively. In the solid state, I contains a closed Os₃ triangle with the phosphine ligand bonded equatorially to an osmium atom through the phosphorus. In solution intramolecular dynamic processes are observed which are explained by carbonyl migration and pseudoration mechanisms. The osmium cluster II, in the solid state, forms an irregular Os₃ triangle which is bridged by a [P^tBu₂N(H)S] system, and the longest edge of which is bridged by a μ₂-hydride. In contrast to I, molecule II is relatively rigid in solution; only pseudorotations are observed as dynamic phenomena.     

Carbonyl-organocobalt(I) and -(II) complexes

Passage of CO through solutions of complexes (C₆F₅)₂CoL₂ gives carbonyl derivatives (C₆F₅)₂CoL₂(CO) (L₂ = 2 PEt₃, 2 P-n-Bu₃, 2 PPh₃, Ph₂PCH₂CH₃PPh₂). The properties of these compounds are described.The compounds are also produced by treating solutions of (C₆F₅)₂Co-(dioxane)₂ with CO, but a simultaneous reduction to (C₆F₅)Co(CO)₄ takes place. Treatment of the latter complex with monodentate ligands gives substitution products (C₆F₅)Co(CO)₃L (L = PEt₃, P-n-Bu₃, PPh₃) all of which are monomeric, whereas the addition of Ph₂PCH₂CH₂PPh₂ gives the dimer (C₆F₅)(CO)₂CoLLCo(CO)₂(C₆F₅). The properties of these compounds are discussed.     

The preparation and X-ray crystal and molecular structure of (α,1,2-η-6-methylbenzyl) bis(triphenylphosphine)rhodium(I)

Reaction of [RhCl(PPh₃)₃] with [o-MeC₆H₄CH₂MgBr] affords high yields of the non-fluxional complex, [Rh(CH₂C₆H₄Me)(PPh₃)₂] which has been shown crystallographically to contain a 1-3-η-benzyl group bound through the phenyl carbon atom that is not substituted with the methyl group. Crystals of this compound are triclinic, space group P$\text{1}$, with a = 10.561(6). b = 17.705(3), c = 10.934(4) Å, α = 80.69(3), β = 116.86(4), γ = 102.30(4)° and Z = 2. The structure was solved via the heavy-atom method and refined to R = 0.032 using 5379 diffractometer data with I > 1.56(I). Attempts to prepare π-bonded xylylene complexes from this compound by reaction with base have been unsuccessful, but protonation followed by recrystallisation from acetone gives [Rh{(CH₃)₂CO}₂(PPh₃)₂]BF₄.     

New chemical reactivity in aromatic dithiocarbamate and monothiocarbamate ligands: syntheses of Mo2L4·2THF (L = Pyrrole or indole monothiocarbamate or pyrrole dithiocarbamate) and Mo2L4 (L = indoline monothiocarbamate)

The reactions between Mo₂(C₂H₃O₂)₄ and several new dithio- and monothiocarbamates have been studied. The first example of a dimolybdenum compound of a dithiocarbamate with the “molybdenum acetate” structure is reported (Mo₂L₄·2THF; L = pyrrole dithiocarbamate). In addition, the synthesis of Mo₂L′₄·2THF (L′ = pyrrole monothiocarbamate, indole monothiocarbamate, indole dithiocarbamate) and Mo₂L″₄ (L″ = indoline monothiocarbamate) are reported. A discussion of the unique stabilization of the dithiocarbamate bridge by “aromatic” dithio- and monothiocarbamates is presented.     

Organometallic and organobimetallic complexes of platinum(II) containing 2,2′-bipyrimidyl: syntheses and spectroscopic characteristics

Preparations are described of several monometallic complexes (bipym)PtR₂ [bipym = 2,2′-bipyrimidyl; R = Me, CF₃, Ph, 1-adamantylmethyl (adme); R₂ = (CH₂)₄] and bimetallic analogues R₂Pt(μ-bipym)PtR′₂ [R = R′ = CH₃, C₆H₅, adme; R = CH₃, R′ = Ph, adme, CF₃]. IR, ¹H NMR and UV/visible spectroscopic characteristics of the two modes of bipyrimidyl coordination are discussed.     

X-ray diffraction study of the bonding between sulphur and the elements of group IVB. The crystal and molecular structures of methylthiotriphenyl-methane, -silicon, -germanium, -tin and -lead

The X-ray analyses of the compounds methylthiotriphenyl-methane, -silicon, -germanium, -tin, and -lead were undertaken to see if the electronic interactions which affect the X-S bond could influence the molecular geometries. The five structures were solved or by direct methods or by Patterson and Fourier techniques and refined anisotropically to R = 0.053, 0.036, 0.031, 0.041, and 0.070 respectively. The central atom exhibits a distorted tetrahedral coordination; only the propeller shape orientation of the phenyl rings seems to be determined by differences in the electronic nature of the central atoms as well as by steric effects.     

Metal complexes of 2-(2′-carboxymethylthio-phenylazo)-5-nitrotoluene—II. Complex formation equilibria with copper(II) ion in several dioxane—water solvent mixtures

Stability constants of copper(II) complexes formed by 2-(2′-carboxymethyl-thiophenylazo)-5-nitrotoluene in dioxane—water solvent mixtures of several different compositions [50, 60 and 75% dioxane (v/v)] were determined from EMF measurements, at 25°C and 0.1 mol dm^?3 NAClO₄ ionic medium. Graphical treatment of experimental data gives for the equilibria nA^?+Cu²⁺ = CuA_n^(2-n)+ (n = 1 or 2), in a solvent with X% (v/v) dioxane, the following values of log β₁, and log β₂ (given here successively). X = 50:2.41, 6.77; X = 60:3.36, 7.45; X = 75:4.33, 7.64. The relation between solvent composition and the values found for the stability constants is discussed. From EMF measurements made with the copper(II) ion-selective electrode, at constant pH, the nature of the effective donor groups in this potentially terdentate ligand is inferred.