Chloro Complexes Research Articles

Synthesis and spectroscopic characterizations of Cu(II) complexes with novel 15‐membered N4 macrocyclic ligand and their utility to obtain CuO nanostructures for efficient degradation of dyes

This paper describes synthesis, characterization and application of a series of Cu(II) complexes with a novel 3‐thioxo‐[1,2,4,5]tetrazocane‐6,8‐dione (N4) macrocyclic ligand. The complexes were characterized by physicochemical and spectroscopic techniques, such as UV–visible and IR spectroscopies, molar conductance, magnetic susceptibility measurements, and elemental analysis. The data suggest that the mononuclear Cu(II) complexes have a metal‐to‐ligand mole ratio of 1:1 and that the Cu(II) ions are coordinated with the four nitrogen atoms inside the N4 macrocyclic ring. The experimental anisotropic g‐values indicate that the chloro, nitrato, acetate, and perchlorato complexes have six‐coordinate distorted octahedral behavior, whereas the sulfato complex has five‐coordinate square‐pyramidal geometry. A simple and nontoxic method for preparation of CuO nanoparticles based upon the thermal decomposition of the synthesized Cu(II) complexes has been explored. Finally, the degradation of Rhodamine 6G dye by the catalytic performance of nano‐sized CuO material has been evaluated.

Sugar-Incorporated Chelating Bis-N-Heterocyclic Carbene Palladium Complexes. Synthesis, Structures, and Catalytic Ability for Suzuki-Miyaura Cross-Coupling Reactions in Water

Abstract Sugar-incorporated chelating bis-N-heterocyclic carbene ligand precursors 1,1′-bis(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)-3,3′-ethylene-diimidazolyl ([(bisNHC-C2)H2]2+) and 1,1′-bis(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)-3,3′-propylene-diimidazolyl ([(bisNHC-C3)H2]2+) were synthesized and used to prepare palladium complexes [Pd(bisNHC-C2)Cl2] and [Pd(bisNHC-C3)Cl2], respectively, by direct metallation reaction using dichlorobis(acetonitrile)palladium as a metal source. Catalytic abilities of the complexes for Suzuki-Miyaura coupling in aqueous media were examined and moderate TON (85,000) and TOF (170,000 h−1) were obtained. Because the terminal chloro ligands in the complexes were substituted with solvent molecules or chloride anion and hence 1H NMR spectra of the chloro complexes were complicated, hydrosulfido complexes [Pd(bisNHC-Cn)(SH)2] (n = 2 and 3) were prepared to confirm structures in solution. Dynamic behavior of flapping-wing motion of the bisNHC ligand in [Pd(bisNHC-C3)(SH)2] in solution was evaluated using the signals of the SH protons, which are inequivalent in 1H NMR spectra attributed to the chirality of the glucopyranosyl units.

Production of synthetic rutile from ilmenite via anion-exchange

ABSTRACTThis investigation identified that ion-exchange chromatography can efficiently remove iron from the leaching of ilmenite by HCl. The strong basic anionic-exchange resin IRA 410 Cl is capable of retaining the negatively charged iron chloro complex from 20% HCl leachate of ilmenite. Oxidative conversion of Fe2+ to Fe3+ facilitates the iron exchange to the resin, resulting in an iron-free solution of titanium oxychloride (TiOCl2). This can be directly used to produce synthetic rutile. The procedure is relatively simple and generates little acid waste.

Half-sandwich hydrazine complexes of iridium: Preparation and reactivity

Chloro complexes IrCl2(η5-C5Me5)[P(OR)3] (1) (RMe, Et) were prepared by reacting dimer [IrCl2(η5-C5Me5)]2 with phosphites in alcohol. Treatment of 1 with R1NHNH2 gave monohydrazine complexes [IrCl(η5-C5Me5)(R1NHNH2){P(OR)3}]BPh4 (2, 3, 4) [R1H (2), Me (3), Ph (4)]. Bis(hydrazine) complexes [Ir(η5-C5Me5)(R1NHNH2)2{P(OR)3}](BPh4)2 (5, 6) were prepared by reacting chloro complexes first with AgOTf and then with an excess of hydrazine. Oxidation with Pb(OAc)4 at −40°C of both mono- and bis(hydrazine) complexes afforded phenyldiazene derivatives [IrCl(η5-C5Me5)(PhNNH){P(OR)3}]BPh4 (7) and [Ir(η5-C5Me5)(PhNNH)2{P(OR)3}](BPh4)2 (9). Bis(aryldiazene) [Ir(η5-C5Me5)(PhNNH)2{P(OR)3}](BPh4)2 (9, 10) were also prepared by allowing hydride IrH2(η5-C5Me5)[P(OR)3] (8) to react with aryldiazonium cations [ArN2]BF4. The complexes were characterised spectroscopically and by X-ray crystal structure determination of [IrCl(η5-C5Me5)(NH2NH2){P(OEt)3}]BPh4 (2b) and [IrCl(η5-C5Me5)(CH3NHNH2){P(OEt)3}]BPh4 (3b).

Removal of Cd(II) and Hg(II) from effluents by ionic solid impregnated chitosan

Ethylhexadecyldimethyl ammonium bromide impregnated chitosan (EHDAIC) was prepared to remove cadmium and mercury from synthetic effluent. The adsorbent was characterized by FTIR, XRD, SEM, EDX and TGA-DTA. Adsorption studies were carried out under different conditions of pH, adsorbent dose, temperature, and contact time. The results showed that the adsorption capacity of EHDAIC is a function of the solution pH and the optimum pH for these metal ions was found to be 3.0. The equilibrium data has been described using Langmuir and Freundlich isotherm models. The maximum adsorption capacity of 341.30mg/g was observed for Cd(II) and 43.43mg/g for Hg(II) in accordance with Langmuir adsorption isotherm in the form of their chloro complexes. The kinetic data fitted well with pseudo-second-order model, and equilibrium data was found to follow Freundlich isotherm model. The calculated thermodynamic parameters showed that the adsorption process was feasible, exothermic and spontaneous. Effect of common excipient ions was studied. Also the material was tested for large sample volumes using column extraction process. The adsorbent material could be regenerated for repetitive applications.

Influence of Hydrogen Adsorption on Electrodeposition of Platinum from Chloro Complex Solution

The influence of hydrogen adsorption on the electrodeposition of platinum was investigated using an electrochemical quartz crystal microbalance (EQCM) method and thermal desorption spectroscopy (TDS). Three types of hydrogen adsorption were observed in a tetrachloroplatinate(II) solution by the EQCM method: UPD-H1, UPD-H2, and OPD-H in order from positive to negative potential. Platinum films were electrodeposited potentiostatically at 0 for UPD-H1, -0.1 and -0.2 for UPD-H2, and -0.3 V vs. Ag/AgCl for OPD-H. The amount of hydrogen desorbed by TDS, that is, the hydrogen incorporated into the films by electrodeposition, depended on the deposition potential. At the potential for UPD-H1, no hydrogen was incorporated into the bulk of the platinum films. At the UPD-H2 potential, hydrogen was uniformly incorporated in the platinum films at the content of ca. 0.02 in an atomic ratio of H/Pt. At the OPD-H potential, a fairly large amount of hydrogen, 0.1 of content, was incorporated uniformly in the platinum films.

Speciation of indium(iii) chloro complexes in the solvent extraction process from chloride aqueous solutions to ionic liquids.

Most metal extraction studies focus on the kinetics, the maximum loading and the extraction equilibrium, while structural information on the extracted complexes has been limited. This paper concerns the nature of the indium(iii) chloride complexes, present in the organic and aqueous phase during the solvent extraction of indium(iii) from an aqueous HCl solution by undiluted ionic liquids Cyphos® IL 101 and Aliquat® 336. In an aqueous HCl solution (0-12 M), indium(iii) exists as octahedral mixed complexes, [In(H2O)6-nCln]3-n (0 ≤ n ≤ 6). EXAFS and 115In NMR were used to characterize these species. The stoichiometric composition of the extracted complexes, which is estimated from viscosity and maximum loading studies and confirmed by EXAFS, is unaffected by the HCl concentration in the aqueous phase. Indium(iii) is present in the ionic liquid phase as the tetrahedral [InCl4]- complex. Based on the speciation results an extraction mechanism is proposed.

Schiff base thorium(iv) and uranium(iv) chloro complexes: synthesis, substitution and oxidation chemistry.

New tetradentate Schiff base chloro complexes of U(iv) and Th(iv) are prepared by salt metathesis approaches. These compounds undergo clean salt metathesis with NaN3 to generate stable pseudo-trans azide compounds. The uranium dichloro complex also undergoes 2 e- oxidation with excess NaNO2 to generate the uranyl derivative. All classes of complexes are characterized by single crystal X-ray diffraction and NMR spectroscopy.

Growth mechanisms of zinc oxide and zinc sulfide films by mist chemical vapor deposition

The growth mechanisms of zinc oxide and zinc sulfide films by mist chemical vapor deposition (mist-CVD) were experimentally investigated from the viewpoint of mist behaviors and chemical reactions. The proper growth model, either vaporization or the Leidenfrost model, was studied by supplying two kinds of mists with different kinds of sources, such as H216O and H218O for ZnO growth and ZnCl2 and thiourea for ZnS growth. Moreover, the origin of the oxygen atoms of ZnO was investigated using a quantitative analysis. The role of chloro complex of zinc in the growth of ZnS from aqueous solutions was also examined by systematic studies.

Platinum(II) and platinum(IV) chloro complexes with (RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1Н-1,2,4-triazol-1-ylmethyl)pentan-3-ol

Platinum(II) and platinum(IV) chloro complexes with (RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1Н-1,2,4-triazol-1-ylmethyl)pentan-3-ol (L), namely, cis-[PtCl2L2], trans-[PtCl2L2], and trans-[PtCl4L2], were synthesized. The structures of their coordination cores and the coordination mode of the reagent to the metal ions via the N(4) atom of the triazole ring were determined by electronic, IR, and NMR 1H and 13C spectroscopy. The ratio between treo and erythro diastereomers and the conformation of reagent L in the complexes were established from the complete assignment of signals in their NMR spectra.

Influence of Hydrogen Adsorption on Electrodeposition of Platinum from Chloro Complex Solution

Platinum (Pt) is widely used as insoluble and catalytic electrodes for electrolysis, automotive catalytic converters, and fuel cells. We have been investigating hydrogen incorporation in electrodeposited metal films and its influence on crystal structure of metals (1-3). It was reported that large amount of hydrogen (content in atomic ratio: x = H/Pt = 0.1) is incorporated in the Pt films electrodeposited from a solution including dinitrosulfatoplatinate(II) (H2Pt(NO2)2SO4, DNS) as a metal source. In this study, an electrochemical quartz crystal microbalance (EQCM) method (4) is used to examine influence of hydrogen adsorption on the electrodeposition and hydrogen incorporation into deposited films of Pt from a chloro complex solution. The current-potential and mass increase (Pt deposition rate)-potential curves in 0.024 mol dm-3 K2PtCl4solution adjusted at pH of 0.8 with HCl were measured using an EQCM system (Hokuto Denko, HQ-101D and HZ-5000). A quartz electrode coated with Au, an Ag/AgCl electrode, and a Pt wire were used as the working, reference, and counter electrodes, respectively. The hydrogen content of samples was measured by thermal desorption spectroscopy (TDS). Figure 1 shows the current density and mass increase rate versus electrode potential curves for the chloro complex solution. In the first forward potential sweep toward negative potentials of Fig. 1(a), the cathode current and deposition rate of Pt started increasing at +0.3 V vs. Ag/AgCl. Peaks for cathode current and deposition rate appeared at -0.19 V. The current efficiency was 74% at this peak. Then, as the potential was swept to lower potentials, the deposition rate and current efficiency decreased. This decrease in the current efficiency of Pt deposition is caused by hydrogen adsorption. In the return potential sweep (Fig.1 (b)), the cathode current and Pt deposition steeply increased by hydrogen desorption from the Pt surface, and the current efficiency was 113% at the potential of -0.25 V. The hydrogen content of Pt-electrodeposited Au foil (Pt: 1 μm and Au: 20 μm in thickness) increased as the deposition potential of Pt decreased from 0 to -0.3 V, and was much lower than that deposited from the DNS solution. Acknowledgements The present work was partly supported by JSPS KAKENHI (26289276). References N. Fukumuro, M. Yokota, S. Yae, H. Matsuda, Y. Fukai, J. Alloys Compd., 580, S55 (2013). N. Fukumuro, S. Kojima, M. Fujino, Y. Mizuta, T. Maruo, S. Yae, Y. Fukai, J. Alloys Compd., 645, S404 (2015). N. Hisanaga, N. Fukumuro, S. Yae, H. Matsuda, ECS Trans., 50, 77 (2013). T. Hagihara, K. Yaori, K. Iwakura, N, Fukumuro, S. Yae, Electrochim. Acta, 176, 65 (2015). Figure 1

Ruthenium Complexes of Substituted Terpyridine and Pyridyl-quinoline Based Ligands with Ancillary Ligands: Synthesis, Characterization, Electrochemical Study and DFT Calculation

Herein we report three novel ruthenium(II) complexes of general formula [Ru(LL′L“)](PF6)n (where L= 4’-(9-Anthryl)-2,2’:6’,2”-terpyridine, L′=2-(2-pyridyl)-4-carboxyquinoline (pcqH) and L”=Cl, n=1 (for 1), L“=SCN, n=1 (for 2) and L”=H2O, n=2 (for 3)). All the complexes were characterized by routine spectroscopic techniques e. g., FTIR, UV-Vis, mass and NMR. A detailed pH based spectroscopic and electrochemical analysis for the complexes 1,2 and 3 were carried out to determine the pka of carboxyl and aqua moiety coordinated to ruthenium centre. The COOH group in complex 2 (pkCOOH=3.13) is slightly more acidic than in complex 3 (pkCOOH=3.98). Whereas pkH2O for complex 1 (12.33) and 3 (12.27) are comparable as expected. A Pourbaix diagram for the aqua complex has been reported. The lability of the Chloro moiety in aqueous medium has been corroborated with D2O exchange 1H-NMR study. Photovoltaic measurements for the Chloro and thiocyanato complex are also carried out. During the pH based spectrochemical and electrochemical study we find in-situ conversion of the aqua complex into hydroxo complex. A detailed TDDFT analysis of all the three synthesized complexes and in-situ generated hydroxo complex in the aqueous medium at higher pH has been performed to explain the various experimental findings. In the electronic spectrum all the molecules show a MLCT transition in the visible region (1: 529 nm, 2: 511 nm, 3: 488 nm). The remarkable blue shift on going from 1 to 2 to 3 is because of the decreasing stabilizing effect of the dπ (Ru) orbital (H2O > SCN > Cl). All the electronic transitions have been nicely correlated with the TDDFT analysis. Preliminary electrochemical experiment indicates that the aqua complex 3, may act as a promising catalyst for light driven water oxidation.

Catalytic etherification of alcohols in Shilov system: C[sbnd]O versus C[sbnd]H bond activation

A novel catalytic reaction of alcohol etherification in the system ROH − PtCl42− ‐ PtCl62− was found. Methanol easily transforms into dimethyl ether in the presence of catalytic amounts of PtII chloro complexes at 70°C. Under the same conditions reaction of ethanol affords diethyl ether (catalytic) and π-ethylene PtII complex (stoichiometric). The reactions are accompanied by multiple H/D exchange, which is indicative of intermediacy of corresponding alkyl platinum derivatives. The plausible reaction mechanism involves oxidative addition of alcohol forming intermediate alkyl platinum(IV) derivative followed by decomposition of it via reductive elimination step under the action of alcohol giving the ether and regenerating catalyst. In the case of ethyl alcohol reaction, β-hydrogen abstraction from the intermediate Pt-ethyl species yields π-ethylene platinum(II) complex. Although it seems that the reaction does not involve the initial breaking of CH bonds of an alcohol, this system can be regarded as a model for studying of some peculiarities of Shilov chemistry, in particular, of isotope scrambling mechanisms in Shilov alkane activation.In contrast to reactions of dimethyl and diethyl ethers formation, tert-butyl ethers formation in CD3OH/t-BuOH medium is catalyzed by PtIV chloro complexes also and is not accompanied by isotope scrambling. These observations argue against intermediacy of alkyl platinum derivatives suggesting that acid-catalyzed mechanism operates in tert-butyl alcohol etherification.

Spin Modulation in Highly Distorted FeIII Porphyrinates by Using Axial Coordination and Their π‐Cation Radicals

A series of five‐coordinate FeIII octaaryltetraphenylporphyrins [FeIII(por)(X)] (X = Cl, I, I3, ClO4, or SO3CF3) and their 1 e–‐oxidized complexes [FeIII(por·)(X)(Y)] (X = Cl, I, ClO4, or SO3CF3; Y = SbCl6, I3, ClO4, or SO3CF3) have been synthesized and characterized. The electronic structures have been confirmed by using UV/Vis, IR, 1H NMR, EPR, and Mössbauer spectroscopy as well as signal‐crystal X‐ray diffraction studies. The neutral five‐coordinate complexes exhibit spin states ranging from essentially pure high spin (S = 5/2 with X = Cl), admixed intermediate spin (S = 5/2, 3/2 with X = I) to an essentially pure intermediate spin (S = 3/2 with X = I3, ClO4, and SO3CF3) depending upon the axial ligand field strength. The average Fe–Np length decreases with decreasing axial ligand strengths, Cl < I < ClO4 < I3 ≈ SO3CF3, which happens to be the order of increasing contributions of the intermediate‐spin state to the complexes. DFT calculations demonstrate a dramatic change in the orbital energy levels upon changing the axial ligand strength. Upon 1 e– oxidation, the high‐spin chloro complex forms the five‐coordinate high‐spin FeIII porphyrin π‐cation radical, whereas the essentially pure intermediate perchlorato, triflato, triiodo iron(III) porphyrinates produce the corresponding six‐coordinate high‐spin iron(III) porphyrin π‐cation radicals. The oxidation also induces larger separation between the up‐ and down‐field shifted methylene resonances in the 1H NMR spectra owing to the presence of the π‐cation radical.

(β‐Diketiminato)cadmium Bis(trimethylsilyl)amide: Facile Access to Low‐Coordinate Cadmium Complexes

A new route to access low‐coordinate (β‐diketiminato)cadmium complexes has been developed. Treatment of [Cd(HMDS)2] with BDI‐H (HMDS = [N(SiMe3)2]; BDI = [{N(2,6‐iPr2C6H3)C(Me)}2CH]) forms [(BDI)Cd(HMDS)], which is a useful synthon for the generation of other low‐coordinate cadmium complexes such as anilido complex [(BDI)Cd(NH{N(2,6‐iPr2C6H3})(THF)], aryloxo complex [(BDI)Cd(O‐2,6‐tBu2C6H3)], as well as chloro complex [{(BDI)CdCl}2]. [(BDI)Cd(HMDS)] is extremely sensitive to hydrolysis, generating [{(BDI)Cd(OH)}2] upon exposure to “dry” tert‐butyl alcohol.

Oxidative Addition of the N–H Bond of Ammonia to Iridium Bis(phosphane) Complexes: A Combined Experimental and Theoretical Study

The chloro complex [IrCl(cod)(dppe)] (dppe = bis(diphenylphosphane)ethane; cod = 1,5-cyclooctadiene) was found to react with gaseous ammonia, affording the amido-bridged diiridium complex [{Ir(μ-NH2)H(dppe)(NH3)}2][Cl]2 (1), whose molecular structure has been solved by X-ray methods. The related cationic complexes [{Ir(μ-NH2)H(dppp)(NH3)}2][BF4]2 (3) and [{Ir(μ-NH2)H(dppb)(NH3)}2][BF4]2 (4) (dppp = bis(diphenylphosphane)propane; dppb = bis(diphenylphosphane)butane) are only accessible from the reactions of NH3(g) with the cationic starting materials [Ir(cod)(dppp)][BF4] and [Ir(cod)(dppb)][BF4], respectively. The formation of these species comes from an oxidative addition of an N–H bond of ammonia to the metals. The main structural difference between complex 2 and 3/4 relies on the relative stereochemistry of both ammonia and hydrido ligands; their cisoidal disposition in dppe complex [{Ir(μ-NH2)H(dppe)(NH3)}2][BF4]2 (2) directed the reactivity toward dppm (dppm = bis(diphenylphosphane)methane), generatin...

ChemInform Abstract: Ruthenium(II) Complexes Derived from C2‐Symmetric Ferrocene‐Based Chiral Bis(phosphinite) Ligands: Synthesis and Catalytic Activity Towards the Asymmetric Reduction of Acetophenones.

Chiral secondary alcohols are very important building blocks and valuable synthetic intermediates both in organic synthesis and in the pharmaceutical industry for producing biologically active complex molecules. A series of new chiral Ru–phosphinite complexes (1, 2, 3, 4, 5, 6, 7, 8) were prepared from chiral C2-symmetric ferrocenyl phosphinites and corresponding chloro complex, [Ru(η6-p-cymene)(μ-Cl)Cl]2. The complexes were characterized using conventional spectroscopic methods. The binuclear complexes were tested as pre-catalysts and were found to be good pre-catalysts for the asymmetric transfer hydrogenation of substituted acetophenones in basic 2-propanol at 82°C, providing the corresponding optically active alcohols with almost quantitative conversion and modest to high enantioselectivities (46–97%). Amongst the all complexes, complex 6 gave the highest ee of 97% in the reduction of 2-methoxyacetophenone to (S)-1-(2-methoxyphenyl)ethanol at 82°C. Copyright © 2015 John Wiley & Sons, Ltd.

Np(V) solubility, speciation and solid phase formation in alkaline CaCl2 solutions. Part I: Experimental results

Abstract The aqueous chemistry of Np(V) in alkaline 0.01 to 5.5 M CaCl2 solutions at T = 23 ± 2 ℃ was thoroughly studied by long-term batch solubility experiments from both over- and undersaturation. Applying a comprehensive set of experimental and spectroscopic techniques including Vis/NIR and Np L3-edge EXAFS, the solubility controlling Np(V) solid phases and the predominant aqueous Np(V) species were identified. The results demonstrate that the solubility behavior of Np(V) in alkaline CaCl2 solutions differs completely from the one reported for alkaline NaCl and NaClO4 solutions: as solubility limiting solid phases, three so far not considered Ca-Np(V)-OH compounds were identified and their solubility and stability in CaCl2 solutions analyzed: CaNpO2(OH)2.6Cl0.4 · 2H2O(s) (I) (metastable), Ca0.5NpO2(OH)2 · 1.3H2O(s) (II) (long-term metastable) and Ca0.5NpO2(OH)2(s) (III) (stable). The considerably higher stability of these (qua)ternary phases which readily form in alkaline CaCl2 solutions from oversaturation (addition of NpO2 +) and undersaturation (addition of binary NpO2OH(am)) limit the Np(V) equilibrium concentrations to values that are up to 3 log-units lower compared to those for NpO2OH(am) in NaCl and NaClO4 systems. Based on systematic evaluation of the pH dependence (solubility curve slopes), Vis/NIR and EXAFS spectroscopic information, unhydrolysed NpO2 + and innersphere chloro complexes, NpO2Cl(aq) and Ca z [NpO2Cl]2z+ with z = 1 (EXAFS, Vis/NIR), were identified as prevailing Np(V) species in less alkaline solutions with pHm < 10.5 for [CaCl2] ≤ 2.0 M and [CaCl2] > 2.0 M, respectively. The steep increase of the Np(V) solubility for pHm > 11 with slopes of approximately + 2.5 (for solid phase (I)) and + 3 (for solids (II) and (III)) as well as the Np L3-edge EXAFS results for the aqueous Np(V) species in 4.5 M CaCl2/pHm ≈ 12 confirm the presence of ternary Ca-Np(V)-OH complexes Ca x [NpO2(OH)2]2x–1 (x ≈ 1 is estimated within the thermodynamic evaluation in a subsequent paper (Fellhauer, D., Altmaier, M., Gaona, X., Lützenkirchen, J., Fanghänel, Th., Np(V) solubility, speciation and solid phase formation in alkaline CaCl2 solutions. Part II: Thermodynamics and implications for source term estimations of nuclear waste disposal (Radiochim. Acta, DOI 10.1515/ract-2015-2490), in the following referred to as “Part II” [1]) and Ca y [NpO2(OH)5]2y–4 with y ≈ 2.4 ± 1.5 (EXAFS result) as predominant Np(V) hydrolysis species in solution for [CaCl2] ≥ 0.25 and pHm > 10.5. The thermodynamic evaluation and implications of the new findings with respect to source term estimations for nuclear waste disposal scenarios are discussed in “Part II” [1]).

Ditopic N-Heterocyclic Pincer Carbene Complexes Containing a Perylene Backbone

A new class of ditopic perylene-based N-heterocyclic pincer ligands, tetrakis(phosphinomethyl)-1,2,3,8,9,10-hexahydrobenzo[1,2,3-gh:4,5,6-g′h′]diperimidine derivatives (TPHDP), were synthesized via a one-pot reaction from 3,4,9,10-tetraaminoperylene either directly with the corresponding phosphine and paraformaldehyde or with the phosphonium salt and triethylamine as base. In this way the diphenyl-, dicyclohexyl-, and isopropylphosphinomethyl-functionalized protioligands were obtained (1a–1c). Reaction of 1a–1c with [RhCl(PPh3)3] led to a double geminal C–H activation and coordination of the ditopic PCP pincer to the rhodium centers, yielding the rhodium(I)chloro complexes (2a–2c) of all three ligands. These were found to be suitable starting materials for further ligand exchange of the chloride. Reaction with lithium phenylacetylide or the abstraction of the chloride ligand with thallium(I) hexafluorophosphate in the presence of neutral donors gave the corresponding alkynyl complexes 3a and 3b or the ion...

THE METHOD OF REMOVAL YTTRIUM (III) AND YTTERBIUM (III) FROM DILUTE AQUEOUS SOLUTIONS

Yttrium (III) and ytterbium (III) cations ion flotation from diluted aqueous solutions in the presence of chloride ions using sodium dodecyl sulfate as collector agent were studied. Y (III) and Yb (III) distribution and recovery coefficients as a function of aqueous phase рН value at different sodium chloride concentrations were received. Yttrium (III) and ytterbium (III) chloro and hydroxo complexes instability constants were calculated. The calculation of separation coefficient at рН specified values depending on chloride ion concentration was conducted. Maximum separation coefficient was observed when chloride concentration of 0.01 M is 50 at рН 7.8. Ksep is minimal in nitrate medium ans is 3 at рН 7.0. At sodium chloride concentration of 0.05 М Ksep is 9 at рН 7.8.