Non-transition Metal Research Articles

Physicochemical laws of the interaction of nickel aluminides with alloying elements: I. Formation of nickel aluminide-based solid solutions

Physicochemical interactions in Ni-Al-M, where M is an alloying element (metal or metalloid), have been systematically analyzed. In most cases, the order of the solubilities of alloying elements (AEs) in the nickel aluminides β-NiAl and γ′-Ni3Al (with an ordered crystal lattice) and the character of substitution of AEs for the positions of Ni (Group VIIIA electronegative transition metal with the valence-electron configuration d 8 s 2 and atomic radius r at = 0.124 nm) and/or Al (Group IIIA electropositive nontransition s 2 p 1 metal with atomic radius r at = 0.143 nm) in these aluminides can be satisfactorily explained using the positions of these elements in the periodic system, the atomic radii of the isolated elements, and their outer electron configurations. The study of β-NiAl-based solid solutions demonstrates that the transition of the sp electrons of Al to the d band of transition metals changes the effective atomic radii of both Al and the transition metals. As a result, the ratio of their atomic radii can change. A correlation has been established between the ability of AE atoms to substitute for Ni and Al atoms in the crystal lattice of the intermetallic compound β-NiAl or γ′-Ni3Al and the effective atomic radii of the components of solid solutions. The use of the effective atomic radii of the solution components to estimate the atomic-size misfit makes it possible to take into account the atomic radii of pure components and their changes as a result of chemical interaction in a solid solution caused by electron redistribution. These changes depend on the position of an AE in the periodic table. This approach explains some contradictions that appear when the shape of a homogeneity area and the solubility of the AE in β-NiAl or γ′-Ni3Al are related to the atomic radii of pure components.

Factors that affect Li mobility in layered lithium transition metal oxides

The diffusion constant of Li in electrode materials is a key aspect of the rate capability of rechargeable Li batteries. The factors that affect Li mobility in layered lithium transition metal oxides are systematically studied in this paper by means of first-principles calculations. In close packed oxides octahedral ions diffuse by migrating through intermediate tetrahedral sites. Our results indicate that the activation barrier for Li hopping is strongly affected by the size of the tetrahedral site and the electrostatic interaction between ${\mathrm{Li}}^{+}$ in that site and the cation in the octahedron that shares a face with it. The size of the tetrahedral site is determined by the $c$-lattice parameter which has a remarkably strong effect on the activation barrier for Li migration. The effect of other factors such as cation mixing and doping with nontransition metal ions can be interpreted quantitatively in terms of the size and electrostatic effect. A general strategy to design high rate electrode materials is discussed.

Oxidation energies of transition metal oxides within theGGA+Uframework

The energy of a large number of oxidation reactions of $3d$ transition metal oxides is computed using the generalized gradient approach (GGA) and $\mathrm{GGA}+\mathrm{U}$ methods. Two substantial contributions to the error in GGA oxidation energies are identified. The first contribution originates from the overbinding of GGA in the ${\mathrm{O}}_{2}$ molecule and only occurs when the oxidant is ${\mathrm{O}}_{2}$. The second error occurs in all oxidation reactions and is related to the correlation error in $3d$ orbitals in GGA. Strong self-interaction in GGA systematically penalizes a reduced state (with more $d$ electrons) over an oxidized state, resulting in an overestimation of oxidation energies. The constant error in the oxidation energy from the ${\mathrm{O}}_{2}$ binding error can be corrected by fitting the formation enthalpy of simple nontransition metal oxides. Removal of the ${\mathrm{O}}_{2}$ binding error makes it possible to address the correlation effects in $3d$ transition metal oxides with the $\mathrm{GGA}+\mathrm{U}$ method. Calculated oxidation energies agree well with experimental data for reasonable and consistent values of U.

Theory of Overlithiation Reaction in LiMO2 Battery Electrodes

Layered compounds with composition LixMO2 and structure R3m, in which M is a first-row transition metal or a combination of transition (and possibly nontransition) metals, are attractive materials for lithium-battery cathodes. For most choices of M, lithiation beyond x = 1 results in either decomposition or transformation to a nonlayered structure. In this article, we present first-principles calculations, on the basis of the GGA+U method, to compare addition, decomposition (with metal oxide and lithia as products), and displacement (with metal and lithia as products) reactions when an additional Li is added to LiMO2. We consider M = Mn, Co, and Ni, as well as equiatomic binary mixtures of these elements. Although the displacement reaction is energetically (or thermodynamically) favored, the addition and decomposition reactions are apparently more favored kinetically, as it is the latter that are observed experimentally. The ratio of the open-circuit cell voltage to the magnitude of the reaction energy, ...

Comparative efficiency of immobilized non-transition metal phthalocyanine photosensitizers for the visible light transformation of chlorophenols

Photolysis of aqueous solutions of chlorophenols (4-chlorophenol, 2,4-dichlorophenol, 2,4,5-trichlorophenol and pentachlorophenol) in the presence of immobilized non-transition metal phthalocyanine photosensitizers onto Amberlite ® is presented. The photosensitizers studied are: Al (AlOCPc) and Zn (ZnOCPc) octacarboxyphthalocyanines; Al (AlPcS 4) and Zn (ZnPcS 4) tetrasulfophthalocyanines; sulfonated phthalocyanine complexes (containing mixtures of differently substituted derivatives) of Al (AlPcS mix), Zn (ZnPcS mix), Ge (GePcS mix), Si (SiPcS mix) and Sn (SnPcS mix). Photolysis of the chlorophenols resulted mainly in the formation of chlorobenzoquinone derivatives. The complexes showed order of activity towards the transformation of pentachlorophenol as follows: ZnOCPc > SiPcS mix > SnPcS mix > ZnPcS mix > GePcS mix > ZnPcS 4 > AlPcS mix > AlOCPc > AlPcS 4. The generation of singlet oxygen ( 1O 2) by these immobilized MPc photosensitizers was found to play a major role in their photoactivities towards the transformation of these chlorophenols. Langmuir–Hinshelwood (L–H) kinetic model studies showed that the ZnOCPc, GePcS mix and ZnPcS mix photocatalysis occurred on the catalysts surface.

Coordination chemistry of anticrowns: Synthesis and X-ray crystal structure determination of the polydecker sandwich complexes of cyclic trimeric perfluoro- o-phenylenemercury with azulene and 6-( N, N-dimethylamino)pentafulvene

The interaction of cyclic trimeric perfluoro- o-phenylenemercury ( o-C 6F 4Hg) 3 ( 1) with azulene results in the formation of a complex, {[( o-C 6F 4Hg) 3](azulene)} ( 2), containing one molecule of azulene per one macrocycle molecule. The complex represents a polydecker sandwich wherein the azulene units alternate with the molecules of the mercury anticrown. The reaction of 1 with 6-( N, N-dimethylamino)pentafulvene (DMAPF) also gives a 1:1 complex, {[( o-C 6F 4Hg) 3](DMAPF)} ( 3), having a polydecker sandwich structure in the crystal. In complex 2, both the C 5 and C 7 rings of the azulene ligand are involved in the bonding to the Hg sites of 1. In complex 3, the C 5 ring of the fulvene ligand together with its exocyclic carbon atom take part in the coordination to the mercury centres. In both adducts, the negatively charged five-membered ring of the azulene and, correspondingly, the fulvene moieties is arranged in the space between the central Hg 3C 6 rings of the adjacent macrocycles while the remaining portion of these moieties is disposed outside this space. The molecules of azulene and DMAPF in 2 and 3 are bonded to 1 through donation of their π-electrons on vacant orbitals of the Hg atoms. The synthesized 2 and 3 are the first examples of structurally characterized complexes of azulene and DMAPF with a non-transition metal compound.

Mild Non‐Transition Metal Catalyzed Deprotection of N‐Allyloxycarbonyl Amines.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of New Visible Light Active Photocatalysts of Ba(In1/3Pb1/3M1/3‘ )O3 (M‘ = Nb, Ta): A Band Gap Engineering Strategy Based on Electronegativity of a Metal Component

We have synthesized new, efficient, visible light active photocatalysts through the incorporation of highly electronegative non-transition metal Pb or Sn ions into the perovskite lattice of Ba(In(1/3)Pb(1/3)M'(1/3))O3 (M = Sn, Pb; M' = Nb, Ta). X-ray diffraction, X-ray absorption spectroscopic, and energy dispersive spectroscopic microprobe analyses reveal that tetravalent Pb or Sn ions exist in the B-site of the perovskite lattice, along with In and Nb/Ta ions. According to diffuse UV-vis spectroscopic analysis, the Pb-containing quaternary metal oxides Ba(In(1/3)Pb(1/3)M'(1/3))O3 possess a much narrower band gap (E(g) approximately 1.48-1.50 eV) when compared to the ternary oxides Ba(In(1/2)M'(1/2))O3 (E(g) approximately 2.97-3.30 eV) and the Sn-containing Ba(In(1/3)Sn(1/3)M'(1/3))O3 derivatives (E(g) approximately 2.85-3.00 eV). Such a variation of band gap energy upon the substitution is attributable to the broadening of the conduction band caused by the dissimilar electronegativities of the B-site cations. In contrast to the ternary or the Sn-substituted quaternary compounds showing photocatalytic activity under UV-vis irradiation, the Ba(In(1/3)Pb(1/3)M'(1/3))O3 compounds induce an efficient photodegradation of 4-chlorophenol under visible light irradiation (lambda > 420 nm). The present results highlight that the substitution of electronegative non-transition metal cations can provide a very powerful way of developing efficient visible light harvesting photocatalysts through tuning of the band structure of a semiconductive metal oxide.

Heavy metal precipitation by polycation–polyanion complex of PEI and its phosphonomethylated derivative

The removal of various heavy metal ions such as Cu 2+, Co 2+, Zn 2+, Ni 2+ and Pb 2+ from aqueous solutions by precipitation with polyelectrolyte complex of PPEI and PEI was conducted. Heavy metal binding with PPEI was initially allowed to occur and then upon equilibration, PEI was added to initiate precipitation of the polyelectrolyte complex together with the heavy metal ion. The PPEI–PEI system was found effective for heavy metal scavenging purposes even in the presence of high concentrations of non-transition metal ions like Na +. Heavy metal concentration may be reduced beyond emission standards for industrial wastewaters. The PPEI–PEI polyelectrolyte complex was found to be more effective than traditional precipitation methods for the treatment of a representative electroless Ni plating waste solution.

Mild non-transition metal catalyzed deprotection of N-allyloxycarbonyl amines

A synthesis of methyl (2 S)-2-amino-4-oxo-2,4-diphenylbutanoate has been achieved via a novel one-pot non-transition metal mediated deprotection of the N-allyloxycarbonyl amine using iodine in wet acetonitrile. The applicability of this transformation has been demonstrated by deprotecting a variety of N-allyloxycarbonyl amines, α-aminomethyl esters and simple N-allyloxycarbonyl alkyl amines. Deprotection occurs in high yield (82–93%) without erosion of the optical purity of the chiral substrates.

Effect of co-existing biologically relevant molecules and ions on DNA photocleavage caused by pyrene and its derivatives.

Inorganic ions, coenzymes, amino acids, and saccharides could co-exist with toxic environmental chemicals, such as polycyclic aromatic hydrocarbons (PAHs), in the cell. The presence of these co-existing chemicals can modulate the toxicity of the PAHs. One of the genotoxic effects by PAHs is light-induced cleavage, or photocleavage, of DNA. The effect of inorganic ions I-, Na+, Ca2+, Mg2+, Fe3+, Mn2+, Cu2+, and Zn2+ and biological molecules riboflavin, histidine, mannitol, nicotinamide adenine dinucleotide (NAD), glutathione, and glutamic acid on the DNA photocleavage by pyrene, 1-hydroxypyrene (1-HP), and 1-aminopyrene (1-AP), is studied. The non-transition metal ions Na+, Ca2+, and Mg2+, usually have very little inhibitory effects, while the transition metal ions Fe3+, Cu2+, and Zn2+ enhance, Mn2+ inhibits the DNA photocleavage. The effect by biological molecules is complex, depending on the photochemical reaction mechanisms of the compounds tested (1-AP, 1-HP and pyrene) and on the chemical nature of the added biological molecules. Riboflavin, histidine, and mannitol enhance DNA photocleavage by all three compounds, except that mannitol has no effect on the photocleavage of DNA by pyrene. Glutathione inhibits the DNA photocleavage by 1-AP and 1-HP, but has no effect on that by pyrene. NAD enhances the DNA photocleavage by 1-AP, but has no effect on that by 1-HP and pyrene. Glutamic acid enhances the DNA photocleavage by 1-AP and pyrene, but inhibits that by 1-HP. These results show that the co-existing chemicals may have a profound effect on the toxicity of PAHs, or possibly on the toxicity of many other chemicals. Therefore, if one studies the toxic effects of PAHs or other toxic chemicals, the effect of the co-existing chemicals or ions needs to be considered.

Photophysical and photochemical studies of sulphonated non-transition metal phthalocyanines in aqueous and non-aqueous media

The photophysical and photochemical parameters for mixed sulphonated metallophthalocyanine complexes (AlPcS mix, SiPcS mix, GePcS mix, SnPcS mix, and ZnPcS mix) are reported in phosphate buffer saline (PBS, pH 7.4), PBS containing the surfactant Triton X-100, and in dimethylsulphoxide (DMSO). The ground state spectra of SiPcS mix, GePcS mix and SnPcS mix show splitting of the Q-band in DMSO, but the fluorescence spectra have only one band, suggesting that only some components of the mixed complexes fluoresce. In general the quantum yields of fluorescence ( Φ F) were smaller in DMSO compared to the aqueous solvents, while quantum yields of triplet state ( Φ T) were larger in DMSO. Triplet lifetimes were much lower in aqueous solutions (compared to DMSO) due to the fact that water absorbs strongly around 1108 nm, which corresponds to the triplet energy of a metallophthalocyanine complex. The MPcS mix complexes quenched hydroquinone, and the Stern–Volmer constants follow the order: AlPcS mix > SiPcS mix > GePcS mix > ZnPcS mix > SnPcS mix which is the order of the extinction coefficients (of the low energy band for complexes with split Q-band) of these molecules. The rate constants for fluorescence, intersystem crossing, internal conversion, and photodegradation were determined from the hydroquinone quenching data.

Instant Notes in Inorganic Chemistry, Second Edition (P. A. Cox)

Instant Notes is divided by the major sections of inorganic chemistry (atomic structure; introduction to inorganic substances; structure and bonding in molecules; structure and bonding in solids; chemistry in solution; chemistry of nonmetals, non-transition metals, and transition metals; lanthanides and actinides; and environmental, biological and industrial aspects).

Effects of central metal on the photophysical and photochemical properties of non-transition metal sulfophthalocyanine

The photophysical and photochemical properties and quenching (by 1,4-benzoquinone) of metallophthalocyanine sulfonates of aluminium ( AlPcSmix), zinc ( ZnPcSmix), silicon ( SiPcSmix), germanium ( GePcSmix) and tin ( SnPcSmix) are presented. The quantum yield values of fluorescence (ΦF), triplet state (ΦT), singlet oxygen (ΦΔ) and photodegradation (Φd) were determined and the observed trends in their variation among the complexes discussed in terms of aggregation and the heavy atom effect. 1,4-benzoquinone effectively quenched the fluorescence of the complexes. Quenching analyses gave positive deviations from Stern-Volmer behavior, suggesting the existence of static quenching in addition to dynamic quenching. The static and dynamic components of the quenching were separated using a modified Stern-Volmer equation and the “sphere of action quenching model”. The quenching constant was found to be a function of the radius of the central metal ion.

Adsorption behaviour of non-transition metal ions on a synthetic chelating resin bearing iminoacetate functions

Glycidyl methacrylate–divinylbenzene (GMA/DVB) resin bearing iminoacetate function was prepared through subsequent treatment of (GMA/DVB) resin by ethylenediamine and potassium chloroacetate, respectively. The chelating resin obtained showed a powerful adsorption character towards non-transition metal ions (Zn 2+, Cd 2+ and Pb 2+) as well as alkaline earth metal ions (Ca 2+ and Mg 2+). The sodium form of the resin gave a slightly higher uptake capacity towards metal ions compared to the hydrogen form. The resin sample loaded with metal ions was regenerated using HCl (0.5–2.0 M) without activity loss.

Structural and physical properties of spinel-type NiMn2–xCoxO4 oxides

Spinel-type oxides of general formula NiMn2–xMexO4 (Me = transition or non-transition metal) have been synthesized and characterized through their magnetic behavior. In this work we present the case of Me = Co, since, because of its high magnetic transition temperature, it is a potential candidate for technological applications. Two magnetic transitions are observed: a paramagnetic-to-ferrimagnetic transition at Tc, which depends on the overall composition and a second transition at lower temperatures, towards a specific ordering or a collinear Néel state. This second transition takes place at about 50 K, increasing with the cobalt content up to about 160 K. Under moderate applied fields, the ferrimagnetic state transforms into a ferromagnetic one. The electrical resistance shows three different regimes: semi conducting behavior at high temperatures, slight temperature dependence at the highest magnetic transition, and constant value at low temperatures. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Spectroscopic and structural study of metal-metal bonded metalloporphyrinic derivatives: the case of rhodium-indium.

The synthesis and spectroscopic characterization of heterometallic porphyrinate derivatives containing rhodium-indium metal-metal bonds are reported. The investigated compounds are represented by the formula [(Porph)RhIn(Porph')], where Porph and Porph' are OEP, TPP, beta-Cl(4)TPP, beta-Cl(8)TPP, or TPyP. UV-Visible spectroscopy of the title complexes confirms the presence of a strong pi-pi interaction between the macrocycles in each derivative and denotes the effect of the nontransition metal in their optical features. For comparison purposes, a new bimetallic complex with a rhodium-thallium metal-metal bond is also presented. According to (1)H and (13)C NMR data, we were able to distinguish two major NMR regions: the endo- between the metal-metal bonded macrocycles and the exo-, which are characteristic features of porphyrinic complexes at very close proximity. X-ray absorption spectroscopy (XAS) structural characterization of Rh-In bond was performed on the [(OEP)RhIn(OEP)] complex, in the fluorescence mode, and we essentially focused on the metal-metal distance determination. Finally, the distance of 2.543(3) A was deduced from the X-ray structure of a new [(TPP)RhIn(TPyP)] derivative.

NOx reduction from diesel emissions over a non-transition metal zeolite catalyst: Effect of water in the feed

NO reduction activity with acetaldehyde over BaY is low in a dry feed, but significantly higher in the presence of water vapor. Aldol condensation of acetaldehyde takes place, polymerization of the resulting crotonaldehyde deactivates the catalyst. Water vapor prevents the formation of large amounts of carbonaceous deposits, either by suppressing the dehydration of aldol to crotonadehyde or by interacting with carbonaceous deposits or their precursors, transforming them to CO, CO2 and H2. Temperature-programmed oxidation (TPO) shows much lower coke formation after tests in the presence of water vapor. TPD–MS data show that nitromethane, a possible intermediate in the NOx reduction process, reacts with water on BaY forming NH3, COx and isocyanic acid HNCO. NOx conversion over BaY reaches values near 90% at 200°C and a GHSV of 30,000h−1 if the NOx initially contains both NO and NO2. No transition metal is involved in the reduction of NOx to NH3 and N2 over BaY.

Static Influence of Ligands: Comparison of DFT Calculations with Experimental Data

The possibility of reproducing regularities of static mutual influence of ligands in complexes of Period V and VI elements of the Periodic Table (Pd, Sn, Sb, Pt, Pb) using the density functional theory (DFT) calculations is studied. Relativistic effects are taken into account by means of the Dirac equation approximation (zero-order regular approximation, ZORA). The calculations reproduced trans-influence in Pt complexes and trans-shortening and cis-elongation in the nontransition metal complexes. At the same time, Pb chloride complexes and Sn iodide complexes exhibit substantial differences between experimental and calculation bond lengths. When solvation was accounted for by COSMO method, DFT calculations reproduce the relative stability of the cis- and trans-Pt(NH3)2X2 complexes (X is halogen) and of the sulfur-containing Ni and Pd chelate complexes. The calculated geometry of the cis-Pt(NH3)2X2 molecule noticeably differs from the experimental geometry due to the overestimated strength of intramolecular N-H···X hydrogen bonds.

One novel polynuclear complex [Cu 2(bpc) 2(N 3) 4Ca(H 2O) 2Na 2(H 2O) 2] n having three different transition and non-transition metal centres

The complex [Cu 2(bpc) 2(N 3) 4Ca(H 2O) 2Na 2(H 2O) 2] n ( 1) (bpc 2−=2,2 ′-bipyridyl-3,3 ′-dicarboxylate) has been prepared and characterised by elemental analyses, spectroscopic and single crystal X-ray diffraction study. Single crystal X-ray analysis revealed a novel polynuclear complex containing three different metal centres such as an alkali metal (sodium), an alkaline earth metal (calcium) and a transition metal atom (copper) connected together by azide and carboxylato groups.