Identification of Complex Ions of Nb(V)in FLINAK-O^(2-)System by Infrared Spectra

The FT-IR spectra for K_2NbF_7-FLINAK-O^(2-) solution were measured and compared with the spectra of crystalline K_2NbF_7 and K_2NbOF_6.The results show that the niobium fluoro-complex and/or oxyfluoro-complex ions are presented in these solutions.NbF_7^(2-) complex ion is the predominant species in Nb(V)-FLINAK solution(not considering oxide impurity).The influence of O^(2-) on the oxyfluoro-complex ions shows that NbOF_6^(3-) as a stable monooxyfluoro-complex anion presented in FLINAK-O^(2-) systems and the number of NbOF_6^(3-) species are increased with increasing of O^(2-) when molar ratio of O^(2-)/Nb(V) is less than 1.

Adsorption of uranyl complex ions on hydrous titanium oxide (HTO)——Ⅱ Infrared spectrum investigation

-The i. r. spectra of Na4 [UO2 (CO3)3], Na [UO2 (OH)3] and the surface species of uranium on HTO underthe condition of flowing natural seawater and concentrated seawater (NaCl-NaHCO3-U) were recorded, with the bands of urany! of surface species obtained and the finding that iigands of surface species besides HTO are mainly water and OH, and there are some CO32- groups under the condition of natural seawater. Some relations between the complex properties and the j. r. spectroscopic characters for uranyl complexes were studied, and the transferred change quantity of surface complex was calculated.Structure models for surface species of adsorption are herein presented and the mechanism for uranium adsorption is deduced.

Treatment of nickel-ammonia complex ion-containing ammonia nitrogen wastewater

Air stripping was adopted to treat nickel ammonia complex ion-containing wastewater in order to remove nickel and ammonia simultaneously in one technological process.The relationship among pH,the concentration of nickel ammonia complex ion and total ammonia concentration was analyzed theoretically.Influence of pH value,water temperature,airflow rate and time on air stripping was studied in detail by static experiment in laboratory.The results show that at pH 11,temperature of 60℃and airflow rate of 0.12 m3/h,NH3 and Ni 2+concentrations remained in wastewater are less than 2 and 0.2 mg/L,respectively,after blowing for 75 min,which reaches the standard of the state discharge.When the tail gas is absorbed by 0.5 mol/L H2SO4 in order to avoid the secondary pollution,the absorption rate can achieve 70%.

Gas Phase Activation of Methane Molecule with Lead Benzene Dication Complex Ion, [Pb(Benzene)₂]²⁺

Motivated by the search for ways of a more efficient usage of the ubiquitous, and unexploited resources of methane, recent progress in the gas-phase activation of methane by metal dication complex ion is discussed. The gas phase theoretical and experimental analysis on [Pb(Benzene)2]2+ was conducted. The [Pb(Benzene)2]2+ complex ions were prepared using a combination of the pick-up technique and high energy electron impact, and then held in a cold ion trap. Excitation with tuneable UV radiation resulted in the formation of [Pb(Benzene)2(H2O)]2+, [Pb(Benzene)2(H2O)2]2+, [Pb(Benzene)]+, Pb+ and Benzene+ ions when the experimental results were analysed. The two optimised geometries of [Pb(Benzene)2]2+ namely the C2V eclipse and C2 staggered were observed. Methane activation of [Pb(Benzene)2]2+ complex ion yielded [Pb(Benzene)2(Me)]2+. [Pb(Benzene)2(H2O)(Me)2]2+,? [Pb(Benzene)2(H2O)(Me)]2+, [PbBenzene(Me)3]2+ and [Pb(Benzene)(Me)]2+. The PEC calculated binding energy of methane to lead benzene dication complex ion was approximately 25.45% higher than the value recorded on DFT calculation. This difference was due to the charge differences on the lead metal centre. While the actual calculated charge on the Pb metal in the optimised geometry was 1.68 the charge of +2 on the Pb metal was considered in the PEC calculation.

Synthesis, characterization, and stability of iron (III) complex ions possessing phenanthroline-based ligands

It has previously been demonstrated that phenanthroline-based ligands used to make gold metallotherapuetics have the ability to exhibit cytotoxicity when not coordinated to the metal center. In an effort to help assess the mechanism by which these ligands may cause tumor cell death, iron binding and removal experiments have been considered. The close linkage between cell proliferation and intracellular iron concentrations suggest that iron deprivation strategies may be a mechanism involved in inhibiting tumor cell growth. With the creation of iron (III) phen complexes, the iron binding abilities of three polypyridal ligands [1,10-phenanthroline (phen), 2,9-dimethyl-1, 10-phenanthroline (methylphen), and 2,9-di-sec-butyl-1, 10-phenanthroline (sec-butylphen)] can be tested via a competition reaction with a known iron chelator. Therefore, iron (III) complexes possessing all three ligands were synthesized. Initial mass spectrometric and infrared absorption data indicate that iron (III) tetrachloride complex ions with protonated phen ligands (RphenH+) were formed: [phenH][FeCl4], [methylphenH][FeCl4], [sec-butylphenH][FeCl4]. UV-vis spectroscopy was used to monitor the stability of the complex ions, and it was found that the sec-butylpheniron complex was more stable than the phen and methylphen analogues. This was based on the observation that free ligand was observed immediately upon the addition of EDTA to the [phenH][FeCl4] and [methylphenH] [FeCl4] complex ions.

Lithium ion conductivity of complex hydrides incorporating multiple closo–type complex anions

We report the lithium ionic conductivities of closo –type complex hydrides synthesized from various molar ratios of lithium borohydride(LiBH4) and decaborane(B10H14) as starting materials. The prepared closo –type complex hydrides comprised [B12H12]^2-, [B11H11]^2-, and [B10H10]^2- complex anions. In addition, increasing the LiBH4 content in the starting materials increased the amounts of [B11H11]^2- and [B10H10]^2-, leading to an improved ion conductivity of the prepared sample. The present study offers useful insights into strategies for controlling the complex anion composition in emerging solid electrolytes of closo-type complex hydrides at the molecular level, and improving their ionic conductivities.

Determination of Boron Trifluoride in Boron Trifluoride Complex by Fluoride Ion Selective Electrode

A method was proposed to determine boron trifluoride in boron trifluoride complex using fluoride ion selective electrode(ISE). Hydroxide was chosen to mask aluminum for the determination of 0.01—0.1 mol/L of fluoride. The simulation indicated that the permissible aluminum masked at a certain p H value was limited and hardly related to F-concentration and boric acid. It is better to control p H value below 11.5 and the aluminum concentration within 0.025 mol/L to minimize the interference of hydroxide to the fluoride ISE. The decomposition conditions of boron trifluoride by aluminum chloride were investigated. It is found that the F-detection ratio will approach 1.0 if the Al/F molar ratio is 0.3—0.7 and aluminum concentration is no more than 0.02 mol/L when heated at 80 ℃ for 10 min. In one word, hydroxide is quite fit to mask aluminum for samples which contain high content of fluoride and aluminum and the BF3 content can be successfully determined by this method.

Thiocyanate Ion Selective Solid Contact Electrode Based on Mn Complex of N,N'-BIs-(4-Phenylazosalicylidene)-O-Phenylene Diamine Ionophore

A thiocyanate ion selective poly(aniline) solid contact electrode based on manganese complex of N,N’-bis-(4-phenylazosalicylidene)-o-phenylene diamine ionophore was successfully developed. The electrode exhibits a good linear response of 58.1 mV/decade (at 20?C ± 0.2?C, r2 = 0.998) with in the concentration range of 1 × 10–1.0 ~ 1 × 10–5.8 M thiocyanate solution. The composition of this electrode was: ionophore 0.040, polyvinylchloride 0.300, dibutylphthalate 0.660 (mass). This dibutylphthalate plasticizer provides the best response characteristics. The electrode shows good selectivity for thiocyanate ion in comparison with any other anions and is suitable for use with aqueous solutions of pH 4.0 ~ 6.0. The standard deviations of the measured emf difference were ±1.70 and ±2.01 mV for thiocyanate sample solutions of 1.0 × 10–2 M and 1.0 × 10–3 M, respectively. The stabilization time was less than 170 sec. and response time was less than 17 sec.

Quantitative analysis of cefixime via complexation with palladium(Ⅱ) in pharmaceutical formulations by spectrophotometry

An optimized and validated spectrophotometric method has been developed for the determination of cefixime in pharmaceutical formulations. The method is based on the complexa- tion reaction between cefixime and palladium ion in the presence of acidic buffer solution （pH 3） in ethanol-distilled water medium at room temperature. The complex absorbed maximally at 352 nm. Beer＇s law is obeyed in the working concentration range of 2.5-35 μg/mL with apparent molar absorptivity of 1.015×104 L/mol cm and Sandell＇s sensitivity of 0.001 μg/cm2/0.001 absorbance unit. The limits of detection and quantitation for the proposed method are 0.175 and 0.583μg/mL, respectively. The effect of common excipients used as additives has been studied in the determination of cefixime. The proposed method has been successfully applied for the determina- tion of cefixime in pharmaceutical formulations. The results obtained by the proposed method were statistically compared with the reference method using t and F values and found no significant difference between the two methods.

Preparation and Characterization of Hydroxyiron-Montmorillonite Complexes

Hydroxy Fe ions react slowly with montmorillonite by intercalation into their interlayer space and adsorption on their surface to form various hydroxyiron montmorillonite complexes. Hydroxyiron montmorillonite complexes are assumed to have the ability to adsorb anions such as H 2PO - 4, HPO 2- 4, CrO 2- 4, CrO - 2, H 2AsO - 4, HAsO 2- 4 , AsO 3- 4 and F -, which may come from weathered rocks or waste industrial water, and result in concentration of P, Cr, As and F in soil. In this paper, hydroxy Fe ions including Fe(OH) 2+ , Fe(OH) + 2 and Fe 2(OH) 2+ 2 are prepared through hydrolysis of iron in acid solutions with different pH values. Corresponding hydroxyiron montmorillonite complexes are obtained by intercalation and adsorption of these hydroxy Fe ions into the interlayer space and on the surface of montmorillonite. The obtained hydroxyiron montmorillonite complexes are characterized with XRD and DTA, showing that they have similar basal space and thermal stability with Fe montmorillonite.

Novel Properties of Supramolecular Complexes Formed by Pairing Cationic Porphyrin and Anionic Metal-Oxo Cluster

MTBPyP (meso-tetrakis(4-N-benzylpyridyl)porphyrin, M=H-2, Zn) bearing positive charge has been shown to associate with SiW12O404- in water solution. The spectral evolution and Job's plots analyses reveal that the relatively stable aggregates contain equal numbers of MTBPyP4(+) and SiW12O404-.

EARLY PALEOZOIC SUBDUCTION-RELATED ACCRETIONARY COMPLEX IN WESTERN KUNLUN

Previous studies on ophiolite and granite revealed that a paleo\|ocean which was referred to as “Proto\|Tethys" developed in north part of western Kunlun in Pt 3～Pz 1.The geotectonic unit in Kuda, western Kunlun is composed of early Paleozoic accretionary complexes and the metamorphic equivalents due to subduction of Proto\|Tethys: Along the Xinzang highway (from Yecheng, Xinjiang to Shiquanhe, Tibet), about 30km north of Kuda, a schistose granodiorite intrudes a thick unit of deformed mafic rocks; Non to weakly metamorphosed early Paleozoic fore\|arc turbidite exposed in Yixiekegou; A set of metamorphic rocks about 20km wide in Kuda which was thought of the Precambrian basement is a large\|scale ductile shear zone determined by detailed field observation and laboratory research; About 10km north of Kuda, there is an undeformed potassic granite batholith intrudes the shear zone.The shear zone mainly consists of parametamorphic rocks and orthometamorphte rocks. Moreover, it contains various kinds of oceanic materials of different origins including fragments of seamounts, oceanic reef limestone and dismembered ophiolite suite, such as dunite, peridotite, gabbro and anorthisite with high number up to 91. The dismembered ophiolite suite may probably represents a remnant oceanic crust that related to the breakup of Rodinia. The parametamorphite rocks is composed of mica\|schist, quartzite and gamete\|mica schist,etc., of which protoliths are sedimentary rocks such as mudstone, sandstone, siliciclastic rocks and impure carbonates that most likely accumulated along the passive continental margin of pelagic sedimentary materials. The orthometamorphic rocks is composed of granitic gneiss and amphibolite,etc. The protoliths of amphibolite is oceanic island basalt of MORB basalt that was accretioned in accretionary complex. The accretionary wedge complex suffers intense ductile strain and metamorphism due to the subduction of Proto\|Tethys with the metamorphic grade reaching the greenschist facies to amphibolite facies. The 40 Ar/ 39 Ar age 451Ma of metamorphic homoblende in amphibolite is interpreted to closely date attainment of maximum metamorphic conditions representing the age of initial subduction at the latest, while the 40 Ar/ 39 Ar age 425Ma of biotite is interpreted as dating the post metamorphic cooling through temperatures required for intracrystalline retention of argon representing the cease of subduction. These data provide significant information on the timing of accretion and the age of the subducted Proto\|Tethys. The whole rock Sm\|Nd isochronal age of amphibolite is problematic 737Ma that maybe represent the rifting age of the Rodinia.

Preparation and characterization of complexes of RE^(3+) with furfural modified water-soluble chitosan

Degraded chitosan, with highly water-solubility, was obtained by the oxidation of chitosan with H2O2, and then reacted with furrural. The final product coordinated with the rare earth ions （RE^3＋ = Sm^3＋, Eu^3＋）, which led to the formation of the complexes. The prepared complexes were characterized with Infrared Spectroscopy （IR）, Ultra Violet （UV）, fluorescence, X-Ray Diffraction （XRD）, and Thermogravimetric-Differential Scanning Calorimetry （TG-DSC） measurements.

Studies on Electrophilic Substitution of Quasi-Aromatic Metal Ion Complexes

The electrophilic substitution reaction occurring to the chelate ring of the complexes could be regarded as an indication of quasi-aromaticity of the ring systems, no catalyst was used and only triethylamine was employed, implying that the aroylating agents with different p-substituents are polarized enough to be effective electrophiles to attack the methine carbon of the electron-rich substrate 1. This property is probably the clue to polarization of the ligand electrons by the nickel( Ⅱ ) ion and to the participation of the nickel( Ⅱ ) in the π-bond systems of the two coordinated conjugated rings. The linearity relationship between vd-d maxima, E1/2OX(1) and σp are obtained, respectively. The electronic environment of central metal ion as well as the aromaticity of the ring system are affected by the electronic properties of the p-substituents. A comparison of the electrochemical results with each other showed .that when the electronegativity of the substituent was higher, the oxidation(Ni2+/Ni3+) becomes more difficult.

REPLACED SITE OF Eu^(2+) ION IN THE COMPLEX FLUORIDES WITH THE PEROVSKITE CRYSTAL STRUCTURE

The replaced site of Eu^(2+) ion is dependent on the electronegativity difference of the cations in complex fluorides.In the mixed fluoride KMgF_3:Eu^(2+),Eu^(2+) ion occupies K^+ site,its emission spectrum is a sharp line and its valence-state is stable.

Ion Nonthermality Induced Nonlinear Dust Acoustic Wave Propagation in a Complex Plasma in Presence of Weak Secondary Electron Emission from Dust Grains

In this paper we have investigated the effect of ion nonthermality on nonlinear dust acoustic wave propagation in a complex plasma in presence of weak secondary electron emission from dust grains. Equilibrium dust charge in this case is negative. Dusty plasma under our consideration consists of inertialess nonthermal ions, Boltzman distributed primary and secondary electrons and negatively charged inertial dust grains. Both adiabatic and nonadiabatic dust charge variations have been taken into account. Our analysis shows that in case of adiabatic dust charge variation, at a fixed non-zero ion nonthermality increasing secondary electron emission decreases amplitude and increases width of the rarefied dust acoustic soliton whereas for a fixed secondary electron yield increasing ion nonthermality increases amplitude and decreases width of such rarefied dust acoustic soliton. Thus shape of the soliton may be retained if strength of both the secondary electron yield and the ion nonthermality are increased. Nonadiabatic dust charge variation shows that, at fixed non-zero ion nonthermality, increasing secondary electron emission suppresses oscillation of oscillatory dust acoustic shock at weak nonadiabaticity and pronounces monotonicity of monotonic dust acoustic shock at strong nonadiabaticity. On the other hand at a fixed value of the secondary electron yield, increasing ion nonthermality enhances oscillation of oscillatory dust acoustic shock at weak nonadiabaticity and reduces monotonicity of monotonic dust acoustic shock at strong nonadiabaticity. Thus nature of dust acoustic shock may also remain unchanged if both secondary electron yield and ion nonthermality are increased.

SPECTRAL VARIATION AND CHARACTERISTICS OF LOW VALENCY RARE EARTH IONS IN COMPLEX OXIDESⅢ.EFFECT OF THE CRYSTAL ENVIRONMENT AND CHEMICAL FACTORS ON LUMINESCENCE PROPERTIES OF EUROPIUM (Ⅱ) ION

In this paper,the influence of crystal-field on the Luminescence properties of Eu^(2+) in complex oxides are studied theoretically by using purely electrostatic model,the dependence of the 4f^65d levels on Eu-O bond distance is given.Quantum chemistry calculation shows that the splitting extent of 4f^65d energy band in cubic or in octahedral fields will be inversely proportional to R^5,where R is the distance of Eu^(2+) to oxygen ligand.The value of R affects slightly the location of the centre of 4f^65d energy band.According to the exper- imental spectrum data,we have discussed the influence of the host chemical composition,the replaced sites of Eu^(2+) and degree of covalency of Eu-O bond on luminescence properties of Eu^(2+).Some regularity of fluorescence spectrum was observed. In alkali-alkaline earth-phosphates,the splitting extent of 4f^65d band (△E) becomes smaller as the Eu-O bond distance (R) increases.In Na_(3-x)(PO_4)_(1-x)(SO_4)_x and Na_(2-x)CaSi_(1-x)P_xO_4 hosts,d-d emission peak of Eu^(2+) will shift to shorter wavelength with the increase of x's value. The crystal structure data show that Eu^(2+) in K_2Mg_2(SO_4)_3 is affected more strongly by crystal-field and covalancy than in KMgF_3,so K_2Mg_2(SO_4)_3:Eu^(2+) emits blue light (E_(em)~m=400nm) and KMgF_3:Eu^(2+) produces ultraviolet fluorescence.

Crystal Structure of the Addition Compound of N,N′-Bi(2-pyridylmethyl)-Oxamide and the Complex of Copper with 1,10-Phenanthroline

The structure of addition compound Cu(phen)3(PMoxdH)(CO4)2 was establish ed by means of X-ray crystallography,where PMoxdH is N,N-Bi(2-pyridyl-methyl)-oxamide,in which six nitrogen atoms of the three 1,10,-phen-anthroline bind to the copper ion and the oxygen atom of PMoxdH is uncoordinated.

Some Hybrid Systems of Chiral Schiff Base Zn(II) Complexes and Photochromic Spiropyrans for Environmental Ion Sensing

This is a review article including our recent results and some previous photo functional hybrid system having potential applications for environmental ion sensing. We have prepared several new and known chiral Schiff base Zn(II) complexes and measured (and also calculated) absorption and fluorescence spectra for sole complexes. After assembling hybrid systems with 1,3,3-trime- thylindolino-6’-nitrobenzopyrylospiran (SP) in methanol solutions, we measured spectral changes before and after alternate irradiation of UV and visible light. Intensity of fluorescence spectra for pale yellow Zn(II) complexes (λem = 450 nm, λex = 270 and 360 nm) was quenched by colorless SP (λem = 533 nm, λex = 612 nm). After UV light irradiation to form purple merocyanine (MC), photoisomerization resulted in changes of the intensity of absorption spectra as well as fluorescence spectra. Thus the hybrid systems could successfully act as molecular logic circuit by input (excitation by light) and output (intensity of fluorescence peaks). Moreover, we investigated concentration dependence of doped Zn(II) and Cu(II) ions to confirm quenching of intensity of fluorescence peaks by Zn(II) and Cu(II) MC complexes for metal ion sensing in solutions.