First-row Transition Elements Research Articles

Determination of Chemical Valence State by X-ray Emission Analysis Using Electron Beam Instruments: Pitfalls and Promises

The use of X-ray emission spectroscopy to determine the valence states of first-row transition elements is evaluated using measurements of X-ray wavelength shifts, line shapes, and relative X-ray line intensities (Lβ/Lα and Kβ/ Kα). X-ray wavelength (or energy) centroids and line shapes are shown to vary not only with oxidation state but also with chemical bonding for the same oxidation state. In many of the cases studied, the ratio of Kβ to Ka is shown to vary depending upon the differential absorption at a similar level to what is cited in the literature as due to the valence state. Similarly, in a number of cases studied, the ratio of Lβ to Lα is shown to vary by differences in self-absorption (and at low electron beam energies, differences in overvoltage) by levels comparable to what is ascribed in the literature as due to valence state. Differences were found among compounds with different oxidation states that exceeded the magnitude predicted by absorption or overvoltage effects; however, no systematic variations were found that were dependent only on the valence state of the element (as opposed to which other elements it was bonded). The results show that oxidation state cannot be simply and unambiguously determined by X-ray emission spectroscopy at the resolution obtainable with conventional wavelength-dispersive detectors on electron microscopes or microprobes. Of the various techniques employed in X-ray emission spectroscopy, the most promising for oxidation-state determination appears to be measurement of the wavelength shift and/or satellite line shape variation, but then only when comparing compounds in which the cation has the same bonding environment. It is critically important to correct for self-absorption effects when attempting to relate variations in Lβ/Lα to differences in oxidation state or bonding environment, regardless of the electron beam energy used in analysis. Specifically, Lβ/Lα measurements cannot be used to determine the oxidation state of Cu in high-temperature superconductors.

Chemical Effects on the Kβ/KαIntensity Ratios in First-Row Transition Element Compounds

Chemical Effects on the K_β/K_αIntensity Ratios in First-Row Transition Element Compounds

Structure, Bonding, and Heats of Formation of Silatitanacyclobutanes

The MP2/TZVP geometries and the standard heats of formation at 0 and 298.15 K of 1,2- and 1,3-silatitanacyclobutanes and a number of smaller Ti- and/or Si-containing alkanes are calculated using the G2 model. The G2 procedure was suitably modified to allow for treatment of first-row transition elements and was directly applied to the reference compounds, which were subsequently connected to the two rings via the appropriate homodesmic reactions. The expected accuracy should be on the order of 3 kcal mol-1. Bonding and structural characteristics are discussed in terms of Boys localized orbitals and Bader density analysis.

Performance of inductively coupled plasma mass spectrometric methods used in the determination of trace elements in surface waters in hydrogeochemical surveys

The capability of ICP-MS in determining trace and ultra-trace elements at their natural concentrations in stream and lake waters is evaluated. The need to preconcentrate trace elements such as the first-row transition elements and REEs is demonstrated and figures of merit given for the chelation method employing the iminodiacetate resin, MetPac CC-1. For example, chelaton results in method detection limits of 0.1–1 ng l–1 for Cd, U and REEs, and improves precision of their measurement 2–5 fold at low ng ml–1 levels. Long-term quality control data for in-house and international standard water samples (SLRS-2, SLEW-1, CASS-2, NASS-3 and 1643C) are presented for both direct and chelation ICP-MS. Detection limits of 2–3 ng l–1 are achieved for Bi, Sb, Se and Te by HG-ICP-MS and field duplicate data show precision generally of the order of 10–20% RSD at levels below 100 ng l–1. Considerations with respect to filtration and preservation protocols for hydrogeochemical surveys are discussed. Field and laboratory (i.e., analytical) duplicate data indicate good precision for trace and ultra-trace elements, averaging 13% RSD across all the elements determined.

Development and application of a sensitive and rapid analytical method to determine the rare-earth elements in surface waters

A new cost-effective method to determine the 14 rare-earth elements (REE's) in waters to levels as low as 0.2–1.0 ng l −1 (ppt) has been established. Inductively coupled plasma mass spectrometry (ICP-MS) is used for measurement following automated preconcentration using the Dionex® MetPac CC-1 resin of iminodiacetate functionality. The free REE ion is chelated onto the resin while alkali and alkaline-earth elements are washed through and separated, enabling the method to be applied to seawater as well as fresh water. The eluant, 0.8 M HNO 3, provides an ideal medium for analysis by ICP-MS and the suite of elements determined can be expanded to include first-row transition elements, Cd, Pb and U. Based on replicate analyses of control samples and data for field and laboratory duplicate samples (lakes and streams), relative standard deviations are better than ±10% except where concentrations are below 5 ng l −1. Application of this method to 135 lake waters in the Baie d'Espoir region of Newfoundland indicates: (a) contamination is not introduced from sampling bottles (Nalgene®, LPE) or during the filtering and acidification process, even at low ng l −1 levels; (b) there is a high degree of correlation in element distribution patterns between lake waters and their corresponding centre-lake sediments for Yb and Tb; (c) the chondrite-normalized plots for water and sediment are similar in shape and show consistent patterns within geological units but are distinct between such units; and (d) the powerful potential of REE concentrations in surface water for geochemical mapping.

Solid solution limits and selected mechanical properties of the quaternary L1 2 trialuminide AlTiMnMo

Intermetallics based on the trialuminide Al[sub 3]Ti, or on Al[sub 11]Ti[sub 5], have been extensively researched in recent years. Alloying with approximately 10 at.% of first-row transition elements, such as Cr or Mn, converts the DO[sub 22] structure of Al[sub 3]Ti to L1[sub 2]. Although this transition to the L1[sub 2] structure increases the number of independent slip systems to five and causes substantial softening, room-temperature tensile ductilities and fracture toughnesses remain low. Typical values for the room-temperature ductilities of Al-25Ti-8Cr and Al-25Ti-9Mn are 0.2% and room-temperature fracture toughnesses of trialuminides range from 2 to 5 MPa m[sup 1/2]. Reasons for the low fracture toughness of trialuminides have been discussed by Turner et al. and George et al. On a phenomenological basis, it appears that fracture toughnesses might improve, if either Poisson's ratio or the ratio of the bulk and shear moduli can be increased. In principle, this might be achieved by macroalloying ternary L1[sub 2] trialuminides, while at the same time maintaining the L1[sub 2] crystal structure. Focusing on first-row transition elements, Kumar and Brown investigated a range of such quaternary compounds. They did not observe any improvement in ductility, as compared to the ternary compounds. In the presentmore » work, it was decided to focus on a second-row transition element, namely, 2 molybdenum. As compared to Cr and Mn, which are only slightly soluble in Al[sub 3]Ti, up to 20 at. % Mo dissolves in Al[sub 3]Ti at 1,198 K. This raises the question whether substantial amounts of Mo also dissolve in the cubic ternary trialuminides such as Al-Ti-Mn. In order to verify this possibility, the extent of the single-phase region of cubic Al-Ti-Mn-Mo intermetallic was mapped out at 1,473 K. In addition, a limited characterization of room-temperature mechanical properties was carried out.« less

Ligand Interchange Controls Many Oxidations of Divalent First-Row Transition Metal Ions by Free Radicals

These studies suggest that the rate-determining step in the oxidation of a large variety of transition metal complexes by free radicals is the ligand exchange step. In other words it is proposed that free radicals behave in many reactions with transition metal complexes as incoming nucleophilic ligands. It seemed of interest to investigate this speculative statement in more detail. It was decided therefore to study the interaction of various Mn(II), Fe(II), and Co(II) complexes with a variety of free radicals. These ions were selected as it was shown that Mn(II) ligand exchange processes processed usually via the I[sub a] mechanism, whereas those of Fe(II) and Co(II) proceed usually via the I[sub d] mechanism. The selected reactions are such that they were all suggested to proceed via the inner-sphere mechanism as their rates of reaction are nearly independent of the nature of the free radical and can therefore be considered as typical complex formation reactions as shown earlier. The pressure dependence of the studied reactions enables a detailed comparison with the volumes of activation for solvent exchange and complex formation reactions of these divalent first-row transition elements. Futhermore, it allows the authors to comment on the general behavior of free radicalsmore » during complex formation reactions with different metal centers.« less

Solution thermodynamics of first-row transition elements. 4. Apparent molal volumes of aqueous ZnSO4 and CuSO4 solutions from 15 to 55�C

The apparent molal volumes of ZnSO4 and CuSO4 have been determined from density data over the temperature range 15–55°C and concentration range 0–15 molal. The volume data have been fitted to the Pitzer formalism over the entire temperature and concentration range. The volume changes for the formation of ZnSO4 and CuSO4 ion pairs have been estimated over the temperature range covered and the partial molal volumes of ZnSO4 and CuSO4 ion pairs have been derived. The results were used to explain the hydration structure of the ion pair. UV spectral effects accompanying a change of temperature in the 15–65°C range in CuSO4 solution indicate direct coordination of sulfate anion to the cupric cation. The process is favored by an increase in temperature.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS): a rapid technique for the direct, quantitative determination of major, trace and rare-earth elements in geological samples

A Nd:YAG laser in fixed- Q (free-running) mode coupled to an inductively coupled plasma mass spectrometer was used to directly analyse pressed powder pellets of seven well-characterised silicate rock reference materials (AGV- 1, BIR- 1, DNC- 1, G- 2, NIST 2704, SCo- 1 and W- 2). The multielement limits of detection (LOD) were in the range 0.05–13 μ g −1 but with a majority of values better than 0.1 μ g −1. Using a narrow range scan LOD for the rare-earth elements (REE's) were between 11–84 ng g −1. Relative responses for the major elements indicate that the chemistry and mineralogy of individual rock samples influence the ablation behaviour, and that samples with very similar chemical and mineralogical compositions exhibit similar elemental responses. The accuracy of major-element determinations, for the materials studied, was generally better than ± 5% with a precision of 10% RSD. First-row transition elements, incompatible elements and, in particular, REE's displayed a high degree of accuracy, with precision of generally < 10% RSD. Providing that samples and standards are matched both in terms of bulk chemistry and mineralogical composition, fully quantitative determination of major and trace elements is possible. Laser ablation ICP-MS is therefore not only a rapid alternative method of elemental determination, but is also particularly applicable for a number of elemental groups whose quantitative determination may be complicated if it is necessary to dissolve samples prior to analysis.

The systematics of trace-element partitioning between coexisting muscovite and biotite in metamorphic rocks from the Black Hills, South Dakota, USA

Coexisting muscovite and biotite in forty-nine staurolite- and sillimanite-zone schists from the southern Black Hills, South Dakota, USA, have been analyzed by ICP spectrometry for major and selected trace elements. This study represents the first comprehensive effort to document and explain trace-element partitioning behavior between coexisting micas in metamorphic rocks. Overall, the data reveal systematic element distributions across a wide thermal-compositional range. Mean Henry's Law partition coefficients [ K ∗ D (bio/mus)] are as follows: Mn (14 ± 6 (1 σ)), Ni (14 ± 6), Zn (13 ± 8), Li (4.0 ± 1.1), Ti(2.9 ± 0.7), Co (2.6 ± 1.6), Yb (2.0 ± 1.7), Cu (1.9 ± 1.2), Y (1.5 ± 1.5), Be (1.1 ± 1.5), Cr (1.0 ± 0.2), La (0.8 ± 0.7), V (0.7 ± 0.1), Zr (0.6 ± 0.2), Ba (0.5 ± 0.3), Sc (0.4 ± 0.1), Sr (0.4 ± 0.4), and Na (0.2 ± 0.1). This sequence is governed largely by the crystal structure of the micas and their major-element compositions. Several structural effects on K ∗ D have been identified. First, the observed K ast; D sequences Cr 3+ > V 3+ > Sc 3+ and Ni 2+ > Co 2+ > Cu 2+ are just as predicted from relative octahedral site preference energies, indicating that crystal-field effects influence the partitioning behavior of transition-metal cations. Second, the presence of smaller (i.e., more collapsed) interlayer sites in muscovite (relative to biotite) favors substitution in muscovite of cations smaller than K +, namely, Na +, Sr 2+, Ba 2+, and La 3+. Likewise, interlayer cations larger than K + (e.g., H 3O +, Rb +, and Cs +) are predicted to substitute preferentially into biotite. Third, tetrahedral Fe 3+ is predicted to favor biotite over muscovite because of larger tetrahedral sheets in biotite (due, in turn, to more Al and less Si). Fourth, the occurrence of heterovalent interlayer cations in micas suggests that their partitioning behavior is partly governed by charge-balance reactions. As a general compositional effect on K ∗ D , the preferences exhibited by biotite for Li + and divalent cations of first-row transition elements reflect its high abundance of comparably sized vi(Mg, Fe 2+) relative to coexisting muscovite. Likewise, relatively strong affinities of muscovite for Cr 3+, V 3+, and Sc 3+ reflect its high stoichiometric vi(Al, Fe 3+) abundance. Element-specific compositional effects on K ∗ D are less evident; but there are indications that Mg 2+ partitioning affects that of Li +, Ni 2+, and Mn 2+. Temperatures inferred from Mg-Tschermak (MgSiAL 2) exchange between coexisting muscovite and biotite ( Hoisch, 1989) provide a convenient datum by which to evaluate the thermal behavior of analogous vector components involving trace elements. Several of these components appear to possess exchange potentials ( ΔG rxn ) sufficiently large so that respective equilibrium constants approach unity with temperature increase. These components include the following: NiSiAl −2, MgSiCr −1Al −1, MgSiV −1Al −1, MgSiSc −1Al −1, CrAl −1, VAl −1, and Li 2 Si viAl −1, vi□ −1, ivAl −1. In contrast, any thermal sensitivity of other such components is masked by analytical scatter.

Thia crown ether complexes as catalyst precursors for direct liquefaction

The paper reports the use of thia crown ether complexes of some first-row transition elements as catalyst precursors for direct liquefaction of coal

ChemInform Abstract: Electrostatic Bonding of CO to the Monocations of the First‐Row Transition Elements

ChemInformVolume 20, Issue 27 Physical Organic Chemistry ChemInform Abstract: Electrostatic Bonding of CO to the Monocations of the First-Row Transition Elements A. MAVRIDIS, A. MAVRIDIS Dep. Chem., Mich. State Univ., East Lansing, MI 48824, USASearch for more papers by this authorJ. F. HARRISON, J. F. HARRISON Dep. Chem., Mich. State Univ., East Lansing, MI 48824, USASearch for more papers by this authorJ. ALLISON, J. ALLISON Dep. Chem., Mich. State Univ., East Lansing, MI 48824, USASearch for more papers by this author A. MAVRIDIS, A. MAVRIDIS Dep. Chem., Mich. State Univ., East Lansing, MI 48824, USASearch for more papers by this authorJ. F. HARRISON, J. F. HARRISON Dep. Chem., Mich. State Univ., East Lansing, MI 48824, USASearch for more papers by this authorJ. ALLISON, J. ALLISON Dep. Chem., Mich. State Univ., East Lansing, MI 48824, USASearch for more papers by this author First published: July 4, 1989 https://doi.org/10.1002/chin.198927050Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume20, Issue27July 4, 1989 RelatedInformation

Solution thermodynamics of first-row transition elements. 2. Apparent molal volumes of aqueous manganese dichloride, manganese diperchlorate, cobalt dichloride, cobalt diperchlorate, iron dichloride, and iron, diperchlorate from 15 to 55.degree.C

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolution thermodynamics of first-row transition elements. 2. Apparent molal volumes of aqueous manganese dichloride, manganese diperchlorate, cobalt dichloride, cobalt diperchlorate, iron dichloride, and iron, diperchlorate from 15 to 55.degree.CRandall F. Pogue and Gordon AtkinsonCite this: J. Chem. Eng. Data 1989, 34, 2, 227–232Publication Date (Print):April 1, 1989Publication History Published online1 May 2002Published inissue 1 April 1989https://doi.org/10.1021/je00056a024RIGHTS & PERMISSIONSArticle Views66Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (461 KB) Get e-Alerts Get e-Alerts

On the electrostatic bonding of carbonyl to the monocations of the first-row transition elements

On the electrostatic bonding of carbonyl to the monocations of the first-row transition elements

Solution thermodynamics of first-row transition elements. 1. Apparent molal volumes of aqueous nickel dichloride nickel diperchlorate cupric chloride and cupric perchlorate from 15 to 55.degree.C

The authors have used a flow densimeter to measure the densities of aqueous solutions of NiCl/sub 2/, Ni(ClO/sub /)/sub 2/, CuCl/sub 2/, and Cu(ClO/sub 4/)/sub 2/ at 10/sup 0/C intervals from 15 to 55/sup 0/C. Infinite dilution apparent molal volumes are determined at each temperature by using the Redlich-Meyer equation. These values are fitted to the polynomial Phi/sub upsilon/ = a + bt + ct/sup 2/. The Pitzer formalism has been used to fit the volume data over the entire concentration range (0-3.5 m).

Comparative metallaborane chemistry: preparation and nuclear magnetic resonance studies of some nido-5-metalladecaboranes of rhodium, iridium, ruthenium, and osmium

The isolation, and characterisation by n.m.r. spectroscopy, of the new ten-vertex nido-metalladecaboranes [5-(η5-C5Me5)-nido-5-RhB9H13], [5-(η5-C5Me5)-nido-5-IrB9H13], [6-(η5-C5Me5)-nido-6-IrB9H13], [5-(η6-C6Me6)-nido-5-RuB9H13], and [5-(η6-C6Me6)-nido-5-OsB9H13] are described. The n.m.r. data of the nido-5-metalladecaboranes, together with those of the previously reported first-row transition element compounds [5-(η5-C5Me5)-nido-5-CoB9H13] and [5-(η6-C6H3Me3-1,3,5)-nido-FeB9H13] permit an examination of n.m.r. shielding trends for this compound type across two columns and down three rows of the periodic Table. Similarities within the periods are more marked than those within the groups. [6-(OH)-5-(η6-C6Me6)-nido-5-OsB9H12] was also tentatively identified during this work.

Investigations of ion-Size-Selective Synergism in Solvent Extraction

Abstract Organophilic crown ethers and other similar macrocyclic compounds produce a synergistic enhancement of the extraction of several metal ions by organic-phase—soluble carboxylic, phosphoric, and sulfonic acids. Ions examined include the alkali metals, the alkaline earths, and some first-row transition elements. In many cases, the synergistic effects are clearly related to the correspondence of the ion size to the macrocycle cavity diameter. In other cases this is less true, and occasionally, complete lack of syner-gism or even antagonism is observed. These phenomena have been investigated by systematic studies of the systems involved, by equilibrium studies of selected extraction systems, and by vapor-pressure osmometric studies of the iritermolecular bonding between the organic-phase macrocycles and acids. Lack of synergism (when it is expected from size correspondence) does not appear to be due to bonding interactions between the macrocycle and the extractant acid, Other considerations suggest th...

Certain relationships in predicting the activity of oxide catalysts

1. In the model reactions of low-temperature hydrogenation of ethylene and double-bond migration in butenes, we have carried out a systematic investigation of the catalytic properties of the rare earths and the oxides of first-row and second-row transition elements and subgroups I and IIIb of the periodic table, as well as type Y zeolite in the Na, Cr, Nd, and La forms, and CeO2-Nd2O3 solid solutions. The data available in the literature on these reactions have been analyzed critically and refined, as well as data on the ortho-para conversion and homomolecular exchange of hydrogen and isotope deuterium exchange in hydrocarbons. 2. For the first time, we have established experimentally and justified theoretically the extremal dependence of specific catalytic activity of oxides on the calcination temperature. Activity of oxide systems is manifested only after partial dehydroxylation and desorption of acidic impurities (CO2, NO2, etc.). At the Tamman temperature, deactivation is observed. 3. In the reactions investigated, the low-temperature activity of oxides with a valence of the element equal to the number of the group increases from top to bottom and from right to left in the groups and periods of the periodic table. For oxides of a given element, the activity decreases with increasing degree of oxidation of the metal. It is suggested that the active centers are of a basic nature. 4. All oxide catalysts for low-temperature hydrogenation are also active, under similar conditions, in double-bond migration in olefins, homomolecular exchange and ortho-para conversion of hydrogen, and isotope deuterium exchange in hydrocarbons; the mechanism of catalyst action is similar in all of these reactions.

ChemInform Abstract: THERMAL PROPERTIES OF HYDRAZINIUM FLUOROMETALLATES OF THE FIRST ROW TRANSITION ELEMENTS

Chemischer InformationsdienstVolume 11, Issue 37 Physical Inorganic Chemistry ChemInform Abstract: THERMAL PROPERTIES OF HYDRAZINIUM FLUOROMETALLATES OF THE FIRST ROW TRANSITION ELEMENTS J. SLIVNIK, J. SLIVNIKSearch for more papers by this authorJ. MACEK, J. MACEKSearch for more papers by this authorA. RAHTEN, A. RAHTENSearch for more papers by this authorB. SEDEJ, B. SEDEJSearch for more papers by this author J. SLIVNIK, J. SLIVNIKSearch for more papers by this authorJ. MACEK, J. MACEKSearch for more papers by this authorA. RAHTEN, A. RAHTENSearch for more papers by this authorB. SEDEJ, B. SEDEJSearch for more papers by this author First published: September 16, 1980 https://doi.org/10.1002/chin.198037022Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume11, Issue37September 16, 1980 RelatedInformation

Characterization of inner- and outer-sphere complexes by thermodynamics and absorption spectra. Part 1. Sulphato-complexes of the first-row transition elements

The sulphato-complexes of the transition-metal ions MnII, FeII, CoII, NiII, and CuII have been shown to be predominantly outer sphere, and [Fe(SO4)]+ has been classified as inner sphere, for I= 0 and 5 mol dm–3 at 25 °C. At I= 0, a linear free-energy relatron (I.f.e.r.) between log K1for the formation of the sulphato- and for the mono-hydroxo-complexes allows the classifications to be rationalised. The I.f.e.r. also allows the sulphate ligand to be tentatively identrfied as unidentate in the inner-sphere complexes from comparisons with n-dentate ligands (n= 1–3 ). The Fuoss equation adequately describes the K1 values for those complexes of sulphate and other ligands that are predominantly outer sphere in character. The inner- and outer-sphere character of the species at I= 5 mol dm–3, deduced from spectrophotometric measurement of the formation constants, is similar to the pattern at I= 0. Large decreases in the entropy of formation of both inner- and outer-sphere species are attributed mainly to the reduced influence of the sulphate ligand on the structure of the medium.