Synthesis and properties of monocyclopentadienyltitanium compounds

The pentacoordinated complexes (RCp)TiCl₂(acac) (R = H, Me, Ph₂CH) have been prepared by photolysis of (RCp)₂TiCl₂ and acetylacetone in THF and the hexacoordinated compounds (RCp)TiCl(acac)₂ by the reaction of (RCp)₂TiCl₂ and acetylacetone in the presence of triethylamine in isobutyronitrile. The hexacoordinated complexes (RCp)TiCl(oq)₂ (R = H, Me, Ph₂CH; oq = 8-oxyquinolate) have been prepared by the direct interaction of (RCp)₂TiCl₂ and 8-hydroxyquinoline in isobutyronitrile; these compounds can be obtained more quickly by photolysis of the same starting materials in THF solution.     

The structure and magnetic properties of chromium(III) molybdate

Magnetic susceptibility measurements have shown that Cr₂(MoO₄)₃ orders magnetically at 42 K. Powder neutron diffraction experiments at 295 and 5 K indicate that Cr₂(MoO₄)₃ is chemically and magnetically isostructural with the L-type ferrimagnet Fe₂(MoO₄)₃, and has a magnetic moment of 2.5 ± 0.2 μ_B per cation at 5 K. The limitations imposed on powder neutron diffraction methods by particle-size effects are discussed.     

Stability and thermodynamics of La(III)-, Pr(III)-, Nd(III)-, Gd(III)- and Eu(III)-p-nitrobenzaldehyde thiosemicarbazone systems

Three complexes containing bidentate N-2,3-dimethylphenylglycine, (2,3-HDPG), N-2,4-dimethylphenylglycine, (2,4-HDPG) and N-2-ethylphenylglycine, (2-HEPG) acids have been prepared and characterized. These compounds have the general formula Zn(2,3-DPG)₂·2 H₂O, Zn(2,4-DPG)₂ and Zn(2-EPG)₂·2 H₂O, respectively. The structure of the complexes as inferred from their chemistries have been found to be compatible with the infrared spectral data. The thermal behaviour of these complexes has been studied from their TG, DTG and DSC diagrams obtained in a dynamic atmosphere of pure air. Heats of dehydration have been calculated from DSC curves.     

The thermal properties of inorganic compounds: II. Evolved gas studies of some mercury(I) and (II) compounds

The combined thermal analysis techniques of thermogravimetry, evolved gas analysis and mass spectrometry were used to investigate the thermal decomposition of several selected mercury(I), (II) compounds. Although TG curves are presented, the analysis of the evolved gases formed during the thermal decomposition processes was of greater interest. Gaseous products detected included: HgSO₄SO, SO₂ and O₂; Hg(SCN)₂CS₂, (CN)₂ and N₂; Hg(NO₃)₂NO, N₂O, NO₂ and O₂; HgNO₃ H₂ONO, NO₂ and N₂O; and Hg(C₂H₃O₂)₂—organic fragments. The evolved gas analysis was complicated by sublimation of the compounds at low pressures.     

Thermal studies on oxalate complexes. II. Complexes of iron (III) and chromium (III)

The decomposition of solid K₃[Fe(C₂O₄)₃] · 2 H₂O and K₃[Cr(C₂O₄)₃] · 3 H₂O has been studied using TGA and DSC. After dehydration, the chromium compound was found to decompose by the loss of CO in two steps, the loss of CO₂ and additional CO, and finally the loss of CO₂. The final product appears to be either K₃CrO₃ or the mixed oxides of chromium and potassium. Kinetic parameters and enthalpy data are presented for these reactions. In the case of K₃[Fe(C₂O₄)₃] · 2 H₂O, dehydration is followed by the loss of CO₂ and CO, CO₂ alone, and finally CO. The final product appears to be a basic carbonate of the type K₃[FE(O)₂(CO₃)]. Kinetic and thermal data are presented for most of these decomposition reactions.     

Thermal and X-ray diffraction investigations of some lanthanum(III) and neodymium(III) oxide-alkali persulfate binary systems

Different molar ratios of La₂O₃ or Nd₂O₃:Na₂/K₂S₂O₈ have been prepared, and the results of their TG and DTA investigations, under an atmosphere of static air, are reported. The effects of either La₂O₃ or Nd₂O₃ on the thermal decomposition of the persulfates from ambient to 1050°C, using a derivatograph, have been studied. It has been found that La₂O₃ lowers the initial decomposition temperatures of these alkali persulfates through catalytic activity. Nd₂O₃ shows little or no catalytic effect and therefore it acts as an insulator. Intermediate and final products are identified by X-ray diffraction analysis. The stoichiometric molar ratios of the solid state reactions are 1:3::R₂O₃:M₂S₂O₈. (R = La or Nd. M = Na or K), which give double salts of formulae: NaLa(So₄)₂, KLa(SO₄)₂, NaNd(SO₄)₂, and KNd(SO₄)₂. No sulfates or oxysulfates of lanthanum or neodymium have been identified.     

Reactions of metal carbonyl complexes III. Synthesis and reactions of Mn(CO)3(Triphos)X(X = Cl,Br, I)

The halopentacarbonylmanganese(I) complexes, Mn(CO)₅X(X = Cl, Br, I), react with PPh(CH₂CH₂PPh₂)₂(Triphos) to give two isomers of fac-Mn(CO)₃(Triphos)X in which the Triphos ligand is only coordinated to the manganese atom through two of its three phosphorus atoms. The fac-Mn(CO)₃(Triphos)X complexes may be considered as “monodentate ligands” in that the free phosphorus atoms readily displace CO and other groups in a variety of metal carbonyls to give a series of novel bimetallic complexes, e.g. Br(CO)₃Mn(Triphos)Cr(CO)₅ and I(CO)₃Mn(Triphos)Mn(CO)₄I. The reactions of Mn(CO)₂[P(OMe)₃](Triphos)Br with Cr(CO)₅THF and Mn(CO)₃(Triphos)X(X = Br, I) with O₂ (and O₃) to produce Br(CO)₂[P(OMe)₃]Mn(Triphos)Cr(CO)₅ and fac-Mn(CO)₃(Triphos=O)X, respectively, are also described. The IR-active COstretching absorptions exhibited by the new complexes are discussed.     

Separation of trans-1,2-cyclohexanediaminetetra-acetic acid chelates of bismuth(III), iron(III) and copper(II) by reversed-phase paired-ion chromatography

Trans-1,2-cyclohexanediaminetetra-acetic acid (DCTA) chelates of bismuth(III), iron(III) and copper(II) have been separated by two techniques using reversed-phase paired-ion chromatography. In one, the chelates in aqueous solution were separated within 20 min on a 6.0 × 300 mm ERC-ODS column with 10⁻²M tetrabutylammonium ion (TBA⁺) in methanoi-water mixture (45:55 v/v) as eluent. In the other, the metal ions in aqueous solution were separated within 10 min by direct injection into an ERC-ODS column with 10⁻²M TBA⁺/10⁻³M DCTA in methanoi-water mixture (40:60 v/v) as eluent.     

Reactivity of cyclopalladated compounds: VIII. Synthesis of cyclometallated compounds with an oxygen as the donor atom. Crystal and molecular structure of (8-methylquinoline-C,N)-(1-methoxynaphthalene-8-C,O)palladium(II)

Treatment of 1-methoxynaphthalene (MXNH) with n-butyllithium in a diethyl ether/n-hexane solution gives 1-methoxynaphthalene-8-lithium (MXNLi) in 30% yield as an insoluble material. This compound reacts with PdCl₂(SEt₂)₂ to give bis(1-methoxynaphthalene-8-C,O)palladium(II) (I)_and with PtCl₂(SEt₂)₂ to give cis- and trans-(1-methoxynaphthalene-8-C,O)(1-methoxynaphthalene-8-C)(diethylsulfide)platinum(II) (II), which are non-rigid molecules in solution. With the cyclopalladated dimers [{$\text{Pd(CN}$)Cl₂}₂], MXNLi gives the palladobicyclic compounds: ($\text{N∩C)P}$$\text{d(C∩O}$) (III). An X-ray diffraction study of compound IIIa where N∩N = 8-methylquinoline-C,N reveals the planarity of the molecule, shows that it has a cis configuration with respect to the PdC bonds, and confirms that the oxygen atom of MXN is bonded to palladium: PdO 2.236(4) Å. The geometry of IIIa is maintained in solution, whereas the corresponding compounds IIIb and IIIc in which N∩C is benzo[h]quinoline-9-C,N and N,N-dimethyl-1-naphthylamine-8-C,N, respectively, appear to be mixtures of cis and trans isomers in solution. With PMe₂Ph I and II give trans-Pd(MXN)₂(PMe₂Ph)₂ and cis-Pt(MNX)₂(PMe₂Ph)₂, respectively, in which the methoxynaphthalene is bound to the metals via the 8-carbon of the naphthalene ring. Only one phosphine ligand adds to compounds IIIb and IIIc with displacement of the O → Pd bond. One carbon monoxide ligand can be added to the platinum compound II to give Pt(MXN)₂(SEt₂)CO which in solution exists as two isomers in equilibrium.     

Darstellung und charkterisierung von pentahalogenomonocarbonylosmaten(III)

By decarbonylation of trans-[OsBr₄(CO)₂]^- and exchange of the pure halogen monocarbonyls [OsX₅(CO)]^2? (X Cl, Br, I) can be prepared and isolated as stable salts with various cations. The complexes are characterized by UV-VIS and vibrational spectra and the observed bands are assigned. The stability and behaviour in solution are comparable with similar hexahalo- or pentahalo-nitrosyl compounds.     

Cleavage by halogens of carboncobalt bonds in organometallic complexes of cobalt(III) : II. Organobis(dimethylglyoximato)cobalt(III) complexes

The reaction between organocobaloximes and ICl in chloroform has been studied. In absence of an excess of added chloride ion the reaction is electrophilic in character; in presence of an excess of chloride ion both oxidative dealkylation and radical attack can occur.     

Thermal decomposition of some dihalotetramminecobalt(III) nitrates

The thermal decomposition of some dihalotetramminecobalt(III) nitrates [tetrammire =(NH₃)₄, (NH₃)₂(en), (NH₃)(dien), (en)₂, (pn)₂, (trien), etc.] with different degrees of chelation was studied by various thermoanalytical techniques. A partial oxidation—reduction was observed for these complexes above 200°C which was indicated by a rapid TG mass-loss and a large exothermic DTA peak. A relative order thermal stability is reported.     

Synthesis of new layered-type and new mixed-layered-type bismuth compounds

Four new compounds, PbBi₂TiTaO₈F, PbBi₂TiNbO₈F, Bi₅Ti₂WO₁₄F, and Bi₇Ti₅O₂₀F, were prepared and identified by X-ray diffraction analysis. Two of them are new members of a family called layered bismuth compounds. The other two are new members of a family called mixed-layered bismuth compounds. Thermal properties of the new compounds were studied. Moreover, the possibility of the existence of other new members belonging to the family called mixed-layered bismuth compounds is discussed.     

Spectrophotometric determination of microamounts of gold(III) with propericiazine

Propericiazine is proposed as a new reagent for the spectrophotometric determination of gold(III). The reagent forms an orange-red-colored species with gold(III) instantaneously in 4–8 M phosphoric acid. The orange-red species exhibits maximum absorbance at 511 nm. Beer's law is valid over the concentration range 0.1–7.0 μg/ml. The molar absorptivity is found to be 3.85 × 10⁴ liter mol⁻¹ cm⁻¹. The effects of acidity, time, order of addition of reagents, temperature, reagent concentration, and diverse ions are investigated.     

Structural researches on organotin(iv) compounds. synthesis and structure of nitratotriphenyl(triphenylphosphine oxide)tin(iv)

A nitrato-complex of organotin(IV) containing triphenylphosphine oxide, Sn(C₆H₅)₃(NO₃) [(C₆H₅)₃PO], has been synthesized and characterized by infrared spectroscopy and X-ray structural analysis. The compound crystallizes in space group P 1¯, with a = 11.817(6), b = 11.086(6), c = 12.471(6), α = 99.6(1),β = 90.8(1), γ = 97.8(1), Z = 2. The structure has been solved from X-ray diffractometer data by Patterson and Fourier methods and refined by least-squares calculations to R = 6.4% for 4301 independent reflections. The structure consists of discrete monomer units in which tin shows trigonal bipyramidal geometry.     

Synthetic studies of organodi-π-cyclopentadienyl- titanium (III) derivatives

Two synthetic routes to compounds of the type π-Cp₂Ti^IIIR (R=CH₃, CH₂Si(CH₃)₃, C₆F₅) have been investigated: (a) chemical reduction of π-Cp₂Ti^IV(R)Cl by zinc or aluminum metal in tetrahydrofuran, and (b) conventional organometallic syntheses using organo-lithium or -magnesium reagents and [π-Cp₂Ti^IIICl]₂. The preferred route is via an organolithium reagent, since chemical reduction gives a mixture of products. Green, monomeric complexes (R = CH₂Si(CH₃)₃, C₆F₅) were isolated and characterised. From the reaction of π-Cp₂Ti^IVCl₂ and trimethylsilylmethyllithium in a 1/1 ratio, π-CpTi^IV [CH₂Si(CH₃)₃]₃ was obtained. Unlike π-Cp₂Ti^IIIC₆F₅, π-Cp₂Ti^IIICH₂Si(CH₃)₃ does not form a blue complex with molecular nitrogen.     

Cobalt(I) and cobalt(III) derivatives from the reactions of phosphine ligands with cobalt(II) salts containing low-coordinating anions

Complexes of the type [Co(CO)_n(P)_5?n]ClO₄, [CoH₂(P)₄]ClO₄, [CoH(P)₅](ClO₄)₂ and [CoHX(F)₄]ClO₄ (P = secondary or tertiary phosphine) have been prepared from Co(ClO₄)₂·6 H₂O and phosphine in isopropyl alcohol.     

Polarographic analytical determination of Hg(II), Cu(II), Cd(II), As(III), Sb(III), Ti(IV) and U(VI) in the presence of Fe(III)

The analytical determination of Hg(II), Cu(II), Cd(II), As(III), Sb(III), Ti(IV) and U(VI) in the presence of Fe(III) and 1 M H₂SO₄ are investigated using the polarographic technique. The wave corresponding to the reduction of Fe(III) to Fe(II) was found to be completely suppressed by the addition of 1% pyrogallol. Thus, different mixtures of these elements, viz. Hg(II), Cu(II), Cd(II), As(III) and Fe(III)-mixture (A), Cu(II), Cd(II), Sb(III), As(III) and Fe(III)-mixture (B), and Cu(II), Cd(II), Ti(IV), U(VI) and Fe(III)-mixture (C), were quantitatively determined using 1% pyrogallol and 1 M H₂SO₄ as supporting electrolyte. The i₁/c results give excellent correlations in each case, as indicated from the results of leastsquares regression analysis.     

Synthesis and molecular structure of hydrido(tetrahydroborato)(1,1,1-tris(diphenylphosphinomethyl)ethane)-iron(II)

Sodium tetrahydroborate reacts with iron(II) tetrafluoroborate and 1,1,1-tris(diphenylphosphinomethyl)ethane (triphos) to give the complex (triphos)-FeH(BH₄) whose molecular structure, determined from X-ray data consists of monomolecular units in which the iron atom is six-coordinated by the three phosphorus atoms of the ligand, two hydrogen atoms of the BH₄ group, and a hydridic hydrogen atom. Variable temperature ³¹P NMR spectra reveal stereochemical non-rigidity of the complex in solution.     

Interactions between europium(III) ion and methyl glycofuranosides in aqueous solution

The interactions between Eu(III) ion and some methyl glycofuranosides have been studied luminometrically in aqueous solution. The measurements were based on the delayed fluorescence of the Eu(III) ion known to be environmentally sensitive. The reciprocal lifetimes, i.e., the decay constants of this fluorescence, depend on the number of OH bonds in the primary hydration sphere of the ion. These were determined in aqueous glycofuranoside solutions of various concentrations. These data enable us to discuss the effect of ligand configuration on the binding sites in the formed complexes. The formation constants for these complexes have been evaluated with the aid of decay rate equations.