This document describes a study investigating whether oxidation state 10 exists. Density functional theory calculations were performed on compounds containing palladium, platinum, and darmstadtium with formal oxidation states of 10. It was found that platinum tetroxide dication (PtO4
2+) is kinetically stable, with a barrier of 31 kcal/mol for decomposition. PtO4
2+ has a calculated lifetime of 0.9 years before decomposing. This provides evidence that oxidation state 10 can exist, represented by the metastable PtO4
2+ compound.
The document discusses chemical reactions and equations. It provides examples of writing balanced chemical equations, including combustion reactions. Key steps in writing equations are identifying reactants and products, determining the chemical formulas, counting atoms on each side, and adding coefficients to balance the equation. Examples show balancing equations for reactions of metals with oxygen and other common reactions like burning of fuels.
The document discusses chemical formulae including molecular, empirical and structural formulae. It provides examples of formulae for different types of compounds such as ionic compounds, molecular compounds and covalent compounds. It also gives examples of how to calculate empirical formulae from experimental data including mass of elements and relative atomic masses.
This document provides an overview of key concepts related to the mole concept in chemistry. It defines the mole as the number of atoms or molecules in 1 gram of hydrogen or 12 grams of carbon. The mole concept allows chemists to relate mass, number of particles, and volume of gases. It discusses how to calculate empirical and molecular formulas, Avogadro's constant, molar mass, limiting reactants, and other mole-related calculations and applications. Worked examples are provided to demonstrate how to use the mole concept to find formulas of compounds from percentage composition data and other information.
This document provides information on naming and writing formulas for various types of chemical compounds including:
1) Binary ionic compounds consisting of a metal and non-metal are named by writing the metal followed by the non-metal with "ide" ending. The chemical formula is written with the symbols.
2) Ionic compounds with multivalent metals or polyatomic ions are named using prefixes like "ous" and "ic". Formulas include charges in parentheses.
3) Molecular compounds of non-metals are named by writing the non-metals with the second element having an "ide" ending. Prefixes are converted to subscripts in formulas.
This document provides an overview of basic chemistry concepts related to naming and writing formulas for ionic compounds. It discusses:
1) How to name ionic compounds by writing the cation first followed by the anion with "-ide" ending, except for polyatomic ions.
2) How to write formulas for ionic compounds by ensuring charges are balanced between cations and anions using subscripts.
3) Special rules for writing formulas involving polyatomic ions and d-block metal cations, which can have multiple oxidation states requiring specifying the oxidation number.
4) How to calculate formula masses of compounds by multiplying the number of atoms of each element by the atomic mass and summing the products.
Chemical formulas represent compounds by showing the types and numbers of atoms present. There are two main types of chemical formulas: empirical formulas and molecular formulas. Empirical formulas show the simplest whole number ratio of atoms in a compound, such as CH2O for glucose. Molecular formulas show the actual number and types of atoms in a molecule, such as C6H12O6 for glucose. The molecular formula can be a multiple of the empirical formula, such as how C6H12O6 is a multiple of CH2O for glucose. Some compounds, like HCl and H2O, have the same empirical and molecular formulas.
The document provides information about chemical formulas and equations. It defines empirical and molecular formulas, and explains how to determine them through calculation of moles and mass ratios of elements in a compound. It also describes writing and balancing chemical equations, naming ionic compounds based on their constituent ions, and using formulas and equations to solve stoichiometric problems. Key topics covered include determining formulas from experimental data, relating formulas to molecular structure and mass, and representing chemical reactions systematically.
This document provides an overview of chemical reactions including:
1. Key vocabulary like reactants, products, and chemical equations.
2. How to write and balance chemical equations.
3. The five basic types of chemical reactions.
4. Factors that affect the rate of chemical reactions like temperature, concentration, and catalysts.
The document discusses chemical reactions and equations. It provides examples of writing balanced chemical equations, including combustion reactions. Key steps in writing equations are identifying reactants and products, determining the chemical formulas, counting atoms on each side, and adding coefficients to balance the equation. Examples show balancing equations for reactions of metals with oxygen and other common reactions like burning of fuels.
The document discusses chemical formulae including molecular, empirical and structural formulae. It provides examples of formulae for different types of compounds such as ionic compounds, molecular compounds and covalent compounds. It also gives examples of how to calculate empirical formulae from experimental data including mass of elements and relative atomic masses.
This document provides an overview of key concepts related to the mole concept in chemistry. It defines the mole as the number of atoms or molecules in 1 gram of hydrogen or 12 grams of carbon. The mole concept allows chemists to relate mass, number of particles, and volume of gases. It discusses how to calculate empirical and molecular formulas, Avogadro's constant, molar mass, limiting reactants, and other mole-related calculations and applications. Worked examples are provided to demonstrate how to use the mole concept to find formulas of compounds from percentage composition data and other information.
This document provides information on naming and writing formulas for various types of chemical compounds including:
1) Binary ionic compounds consisting of a metal and non-metal are named by writing the metal followed by the non-metal with "ide" ending. The chemical formula is written with the symbols.
2) Ionic compounds with multivalent metals or polyatomic ions are named using prefixes like "ous" and "ic". Formulas include charges in parentheses.
3) Molecular compounds of non-metals are named by writing the non-metals with the second element having an "ide" ending. Prefixes are converted to subscripts in formulas.
This document provides an overview of basic chemistry concepts related to naming and writing formulas for ionic compounds. It discusses:
1) How to name ionic compounds by writing the cation first followed by the anion with "-ide" ending, except for polyatomic ions.
2) How to write formulas for ionic compounds by ensuring charges are balanced between cations and anions using subscripts.
3) Special rules for writing formulas involving polyatomic ions and d-block metal cations, which can have multiple oxidation states requiring specifying the oxidation number.
4) How to calculate formula masses of compounds by multiplying the number of atoms of each element by the atomic mass and summing the products.
Chemical formulas represent compounds by showing the types and numbers of atoms present. There are two main types of chemical formulas: empirical formulas and molecular formulas. Empirical formulas show the simplest whole number ratio of atoms in a compound, such as CH2O for glucose. Molecular formulas show the actual number and types of atoms in a molecule, such as C6H12O6 for glucose. The molecular formula can be a multiple of the empirical formula, such as how C6H12O6 is a multiple of CH2O for glucose. Some compounds, like HCl and H2O, have the same empirical and molecular formulas.
The document provides information about chemical formulas and equations. It defines empirical and molecular formulas, and explains how to determine them through calculation of moles and mass ratios of elements in a compound. It also describes writing and balancing chemical equations, naming ionic compounds based on their constituent ions, and using formulas and equations to solve stoichiometric problems. Key topics covered include determining formulas from experimental data, relating formulas to molecular structure and mass, and representing chemical reactions systematically.
This document provides an overview of chemical reactions including:
1. Key vocabulary like reactants, products, and chemical equations.
2. How to write and balance chemical equations.
3. The five basic types of chemical reactions.
4. Factors that affect the rate of chemical reactions like temperature, concentration, and catalysts.
Chapter 7.1 : Chemical Names and FormulasChris Foltz
Chemical formulas indicate the relative number and type of atoms in a chemical compound or molecule. A chemical formula for an ionic compound represents one formula unit and uses the simplest whole number ratio of ions present. Binary ionic compounds are composed of two elements and the total positive charges must equal the total negative charges. Molecular compounds use a prefix system to indicate the number of atoms of the less electronegative element present. Polyatomic ions are named as units within chemical formulas.
This document summarizes key concepts from Chapter 3 of a general chemistry textbook, including:
- Molecular and ionic compounds are composed of molecules and ions respectively. Ionic compounds form when atoms gain or lose electrons to become ions.
- The molecular mass and empirical formula of compounds can be determined from the relative abundances of elements in the compound.
- Common polyatomic ions and functional groups are important for naming organic and inorganic compounds systematically. Isomers have the same molecular formula but different structural arrangements.
The document discusses organic chemistry topics including:
- Classes of organic compounds such as aliphatic hydrocarbons, aromatic hydrocarbons, and functional groups.
- Alkanes have the general formula CnH2n+2 and contain only single bonds. Cycloalkanes contain carbon atoms joined in rings.
- Alkenes contain carbon-carbon double bonds and have the general formula CnH2n. Alkynes contain carbon-carbon triple bonds and have the formula CnH2n-2.
- Aromatic compounds contain benzene rings, and their naming involves indicating substituted groups on the ring.
The document describes the oxidation number method for balancing redox reactions. It provides two examples showing the steps:
1) Assign oxidation numbers and identify changes
2) Determine the ratio that balances the changes
3) Use the ratio to balance the reactants and products
4) Balance other elements by inspection
The first example balances the reaction of aluminum with manganese dioxide to form aluminum oxide and manganese. The second example balances the reaction of ammonia with oxygen to form nitrogen dioxide and water.
The document provides examples for calculating the Ksp (solubility product constant) of various ionic compounds given their molar solubility in water. It first explains the general process: writing the dissolution reaction, writing the Ksp expression, inserting concentrations based on molar ratios, and calculating the value. Several examples are then worked through step-by-step, calculating Ksp values from molar solubilities for compounds such as silver bromide, calcium fluoride, and mercury(I) bromide. The document also discusses calculating Ksp from solubilities provided in grams per 100mL by first converting to molar solubility. More examples demonstrate this process for nickel sulfide, magnesium fluoride, and manganese(II) i
This document contains 15 multiple choice questions related to chemistry concepts such as moles, empirical formulas, relative atomic mass, and chemical equations. Specifically:
- Questions 1-5 ask about calculating the number of molecules or mass of substances using values like the Avogadro constant and relative atomic masses.
- Questions 6-10 involve determining empirical formulas from the percentages or relative masses of elements in compounds.
- Questions 11-15 require balancing chemical equations or identifying products of reactions given word equations.
The questions cover a range of foundational chemistry topics and calculations involving moles, masses, empirical formulas and chemical equations.
This document discusses chemical formulas and nomenclature. It explains that chemical formulas indicate the relative number and ratio of atoms in a compound. It also describes systems for naming ionic compounds, acids, salts, and covalent network compounds. Oxidation numbers are introduced as a method for determining formulas based on the electronegativity of elements. Molar mass and formula mass are defined as ways to determine the mass of compounds from their chemical formulas.
Oxidation numbers describe the distribution of electrons between bonded atoms as if they were transferred, even though they are often shared in covalent bonds. Oxidation numbers are useful for understanding redox reactions where the oxidation states of atoms change, such as hydrogen being oxidized and fluorine being reduced when they react. The oxidation number of an atom is zero when it is alone in a neutral substance, and is calculated using rules such as hydrogen being +1 when bonded to nonmetals, and the sum of the oxidation numbers being zero in neutral compounds.
This document discusses chemical formulae and equations. It defines relative atomic mass and relative molecular mass, which are used to calculate the mass of elements and compounds from their chemical formulae. The mole concept is introduced, relating the Avogadro constant to the number of particles in a given number of moles. Relationships are shown between moles, mass, particles and volume. Empirical and molecular formulae are distinguished. Ionic compounds have formulae showing cation and anion combinations. Examples of writing and balancing chemical equations are provided.
The document discusses various chemistry concepts including:
1. Avogadro's number defines the number of particles in one mole of a substance as 6.02x1023.
2. Molar mass is the mass of one mole of a pure substance and is used to convert between grams and moles.
3. Empirical and molecular formulas can be determined from percent composition data using mole ratios and molar mass.
4. Chemical equations represent chemical reactions and must be balanced to satisfy the law of conservation of mass.
This document discusses stoichiometry, which includes naming chemical compounds and writing balanced chemical equations. It begins by explaining the systematic naming of elements based on their symbols. Rules are provided for naming binary compounds of nonmetals, compounds of metals and nonmetals, compounds of metal ions and polyatomic ions, and naming oxides, acids, and bases. Balanced chemical equations are described as representing chemical changes where reactants on the left produce products on the right while obeying the law of conservation of mass. Examples of several types of chemical names and balanced equations are also provided.
The document discusses a laboratory experiment to determine the empirical formula of metal oxide X. The procedure involves weighing a crucible before and after heating a sample of metal X inside it to form an oxide. The mass changes are used to calculate the empirical formula as XpOq by determining the ratio of metal X to oxygen in the oxide.
Oxidation numbers reflect the gain or loss of electrons by an atom in a compound. They are assigned according to a set of rules, such as hydrogen being +1, oxygen being -2, and the sum of oxidation numbers in a neutral compound being 0. Oxidation numbers track the change in electrons during oxidation-reduction reactions where oxidation is a loss of electrons and reduction is a gain.
The document discusses chemical formulas and how they are used to express information about the proportions of atoms in compounds. It covers:
- Chemical formulas for covalent molecular compounds, covalent networks, and ionic compounds show the number or ratio of elements present
- Formulas are written using element symbols and subscripts to indicate atom counts
- Valence and Roman numerals are used to indicate an element's bonding tendency which helps write formulas
- Prefixes like mono-, di-, tri- are also used to show atom ratios
- Polyatomic ions, ions formed of multiple elements, are also represented in formulas
- Ionic formulas show the charges of ions present in ionic substances
Chemical formula and equation, mol conceptRossita Radzak
1. This document provides information on chemical formulas, equations, mole concept and stoichiometry calculations. It includes examples of writing chemical formulas and balancing equations, as well as mole calculations to determine the number of particles, moles of substances, and masses involved in various chemical reactions.
2. Key concepts covered are the mole, molar mass, molar volume, empirical formulas, and stoichiometric calculations to determine limiting reactants, products formed and reaction yields. Sample problems demonstrate mole calculations for common reactions like metal-acid or carbonate reactions.
3. The document serves as a reference for students to learn essential concepts and skills in writing formulas, balancing equations, and solving a wide range of stoichiometric problems.
The document discusses balancing redox reactions using the half-reaction method. It provides several examples of writing and balancing half-reactions and using them to derive the overall balanced redox equation. Key steps include separating the reaction into oxidation and reduction half-reactions, balancing all elements except H and O, adding H2O to balance O, adding H+ or OH- to balance H, and adding electrons to balance charge.
1) The document discusses chemical formulas and equations, including relative atomic mass (RAM), relative molecular mass (RMM), moles, and molar mass.
2) RAM is the average mass of an atom of an element compared to 1/12 the mass of one carbon-12 atom. RMM is the average mass of a molecule compared to 1/12 the mass of one carbon-12 atom.
3) A mole is defined as the amount of substance containing as many elementary entities (atoms, molecules, ions, etc) as there are atoms in exactly 12 grams of carbon-12, which is a quantity known as Avogadro's number (6.02x1023).
The document provides information on chemical formulae, equations, calculations involving moles and molar mass/volume. It also covers the chemical properties and reactions of group 1 and 17 elements, as well as properties of salts such as solubility, color, and the effects of heating on different salts such as carbonates and nitrates.
This document discusses chemical concepts related to combustion analysis, oxidation states, assigning oxidation states, naming inorganic compounds, binary compounds, polyatomic ions, and oxoacids. It provides examples and rules for determining oxidation states, naming inorganic compounds based on their formulas, and identifying common polyatomic ions and their names. Key points include that combustion analysis can be used to analyze chemical substances, oxidation states are related to electrons gained or lost by atoms, and there are systematic rules for naming inorganic compounds and identifying polyatomic ions based on their structures and formulas.
This document discusses the kinetic study of the hydriding process of the TiFe0.5Co0.5 alloy. Experiments were conducted using thermogravimetric analysis to measure the absorption and desorption of hydrogen under various temperatures and pressures. Two kinetic models, the Johnson–Mehl–Avrami model and Jander diffusion model, were used to analyze the results. The activation energy and pre-exponential constants were estimated using the Arrhenius equation. The results provide insight into the absorption mechanism and rate-limiting step of the hydriding reaction for this alloy.
Chapter 7.1 : Chemical Names and FormulasChris Foltz
Chemical formulas indicate the relative number and type of atoms in a chemical compound or molecule. A chemical formula for an ionic compound represents one formula unit and uses the simplest whole number ratio of ions present. Binary ionic compounds are composed of two elements and the total positive charges must equal the total negative charges. Molecular compounds use a prefix system to indicate the number of atoms of the less electronegative element present. Polyatomic ions are named as units within chemical formulas.
This document summarizes key concepts from Chapter 3 of a general chemistry textbook, including:
- Molecular and ionic compounds are composed of molecules and ions respectively. Ionic compounds form when atoms gain or lose electrons to become ions.
- The molecular mass and empirical formula of compounds can be determined from the relative abundances of elements in the compound.
- Common polyatomic ions and functional groups are important for naming organic and inorganic compounds systematically. Isomers have the same molecular formula but different structural arrangements.
The document discusses organic chemistry topics including:
- Classes of organic compounds such as aliphatic hydrocarbons, aromatic hydrocarbons, and functional groups.
- Alkanes have the general formula CnH2n+2 and contain only single bonds. Cycloalkanes contain carbon atoms joined in rings.
- Alkenes contain carbon-carbon double bonds and have the general formula CnH2n. Alkynes contain carbon-carbon triple bonds and have the formula CnH2n-2.
- Aromatic compounds contain benzene rings, and their naming involves indicating substituted groups on the ring.
The document describes the oxidation number method for balancing redox reactions. It provides two examples showing the steps:
1) Assign oxidation numbers and identify changes
2) Determine the ratio that balances the changes
3) Use the ratio to balance the reactants and products
4) Balance other elements by inspection
The first example balances the reaction of aluminum with manganese dioxide to form aluminum oxide and manganese. The second example balances the reaction of ammonia with oxygen to form nitrogen dioxide and water.
The document provides examples for calculating the Ksp (solubility product constant) of various ionic compounds given their molar solubility in water. It first explains the general process: writing the dissolution reaction, writing the Ksp expression, inserting concentrations based on molar ratios, and calculating the value. Several examples are then worked through step-by-step, calculating Ksp values from molar solubilities for compounds such as silver bromide, calcium fluoride, and mercury(I) bromide. The document also discusses calculating Ksp from solubilities provided in grams per 100mL by first converting to molar solubility. More examples demonstrate this process for nickel sulfide, magnesium fluoride, and manganese(II) i
This document contains 15 multiple choice questions related to chemistry concepts such as moles, empirical formulas, relative atomic mass, and chemical equations. Specifically:
- Questions 1-5 ask about calculating the number of molecules or mass of substances using values like the Avogadro constant and relative atomic masses.
- Questions 6-10 involve determining empirical formulas from the percentages or relative masses of elements in compounds.
- Questions 11-15 require balancing chemical equations or identifying products of reactions given word equations.
The questions cover a range of foundational chemistry topics and calculations involving moles, masses, empirical formulas and chemical equations.
This document discusses chemical formulas and nomenclature. It explains that chemical formulas indicate the relative number and ratio of atoms in a compound. It also describes systems for naming ionic compounds, acids, salts, and covalent network compounds. Oxidation numbers are introduced as a method for determining formulas based on the electronegativity of elements. Molar mass and formula mass are defined as ways to determine the mass of compounds from their chemical formulas.
Oxidation numbers describe the distribution of electrons between bonded atoms as if they were transferred, even though they are often shared in covalent bonds. Oxidation numbers are useful for understanding redox reactions where the oxidation states of atoms change, such as hydrogen being oxidized and fluorine being reduced when they react. The oxidation number of an atom is zero when it is alone in a neutral substance, and is calculated using rules such as hydrogen being +1 when bonded to nonmetals, and the sum of the oxidation numbers being zero in neutral compounds.
This document discusses chemical formulae and equations. It defines relative atomic mass and relative molecular mass, which are used to calculate the mass of elements and compounds from their chemical formulae. The mole concept is introduced, relating the Avogadro constant to the number of particles in a given number of moles. Relationships are shown between moles, mass, particles and volume. Empirical and molecular formulae are distinguished. Ionic compounds have formulae showing cation and anion combinations. Examples of writing and balancing chemical equations are provided.
The document discusses various chemistry concepts including:
1. Avogadro's number defines the number of particles in one mole of a substance as 6.02x1023.
2. Molar mass is the mass of one mole of a pure substance and is used to convert between grams and moles.
3. Empirical and molecular formulas can be determined from percent composition data using mole ratios and molar mass.
4. Chemical equations represent chemical reactions and must be balanced to satisfy the law of conservation of mass.
This document discusses stoichiometry, which includes naming chemical compounds and writing balanced chemical equations. It begins by explaining the systematic naming of elements based on their symbols. Rules are provided for naming binary compounds of nonmetals, compounds of metals and nonmetals, compounds of metal ions and polyatomic ions, and naming oxides, acids, and bases. Balanced chemical equations are described as representing chemical changes where reactants on the left produce products on the right while obeying the law of conservation of mass. Examples of several types of chemical names and balanced equations are also provided.
The document discusses a laboratory experiment to determine the empirical formula of metal oxide X. The procedure involves weighing a crucible before and after heating a sample of metal X inside it to form an oxide. The mass changes are used to calculate the empirical formula as XpOq by determining the ratio of metal X to oxygen in the oxide.
Oxidation numbers reflect the gain or loss of electrons by an atom in a compound. They are assigned according to a set of rules, such as hydrogen being +1, oxygen being -2, and the sum of oxidation numbers in a neutral compound being 0. Oxidation numbers track the change in electrons during oxidation-reduction reactions where oxidation is a loss of electrons and reduction is a gain.
The document discusses chemical formulas and how they are used to express information about the proportions of atoms in compounds. It covers:
- Chemical formulas for covalent molecular compounds, covalent networks, and ionic compounds show the number or ratio of elements present
- Formulas are written using element symbols and subscripts to indicate atom counts
- Valence and Roman numerals are used to indicate an element's bonding tendency which helps write formulas
- Prefixes like mono-, di-, tri- are also used to show atom ratios
- Polyatomic ions, ions formed of multiple elements, are also represented in formulas
- Ionic formulas show the charges of ions present in ionic substances
Chemical formula and equation, mol conceptRossita Radzak
1. This document provides information on chemical formulas, equations, mole concept and stoichiometry calculations. It includes examples of writing chemical formulas and balancing equations, as well as mole calculations to determine the number of particles, moles of substances, and masses involved in various chemical reactions.
2. Key concepts covered are the mole, molar mass, molar volume, empirical formulas, and stoichiometric calculations to determine limiting reactants, products formed and reaction yields. Sample problems demonstrate mole calculations for common reactions like metal-acid or carbonate reactions.
3. The document serves as a reference for students to learn essential concepts and skills in writing formulas, balancing equations, and solving a wide range of stoichiometric problems.
The document discusses balancing redox reactions using the half-reaction method. It provides several examples of writing and balancing half-reactions and using them to derive the overall balanced redox equation. Key steps include separating the reaction into oxidation and reduction half-reactions, balancing all elements except H and O, adding H2O to balance O, adding H+ or OH- to balance H, and adding electrons to balance charge.
1) The document discusses chemical formulas and equations, including relative atomic mass (RAM), relative molecular mass (RMM), moles, and molar mass.
2) RAM is the average mass of an atom of an element compared to 1/12 the mass of one carbon-12 atom. RMM is the average mass of a molecule compared to 1/12 the mass of one carbon-12 atom.
3) A mole is defined as the amount of substance containing as many elementary entities (atoms, molecules, ions, etc) as there are atoms in exactly 12 grams of carbon-12, which is a quantity known as Avogadro's number (6.02x1023).
The document provides information on chemical formulae, equations, calculations involving moles and molar mass/volume. It also covers the chemical properties and reactions of group 1 and 17 elements, as well as properties of salts such as solubility, color, and the effects of heating on different salts such as carbonates and nitrates.
This document discusses chemical concepts related to combustion analysis, oxidation states, assigning oxidation states, naming inorganic compounds, binary compounds, polyatomic ions, and oxoacids. It provides examples and rules for determining oxidation states, naming inorganic compounds based on their formulas, and identifying common polyatomic ions and their names. Key points include that combustion analysis can be used to analyze chemical substances, oxidation states are related to electrons gained or lost by atoms, and there are systematic rules for naming inorganic compounds and identifying polyatomic ions based on their structures and formulas.
This document discusses the kinetic study of the hydriding process of the TiFe0.5Co0.5 alloy. Experiments were conducted using thermogravimetric analysis to measure the absorption and desorption of hydrogen under various temperatures and pressures. Two kinetic models, the Johnson–Mehl–Avrami model and Jander diffusion model, were used to analyze the results. The activation energy and pre-exponential constants were estimated using the Arrhenius equation. The results provide insight into the absorption mechanism and rate-limiting step of the hydriding reaction for this alloy.
Basic inorganic chemistry part 2 organometallic chemistryssuser50a397
The document provides an overview of organometallic chemistry including:
- Key concepts such as the 18 electron rule, metal carbonyls, and sandwich compounds.
- Important discoveries such as Zeise's salt (first transition metal organometallic compound) and ferrocene (first sandwich compound).
- Industrial applications of organometallic catalysts in homogeneous catalysis including hydroformylation and hydrocarbon conversions.
- Methods for counting electrons in organometallic complexes using the neutral atom and oxidation state methods.
This document discusses the nature and properties of complex compounds. It defines complex compounds as those containing a central atom surrounded by ligands. Coordination compounds are complex compounds that exist in both crystalline and solution states. The document outlines the early history of complex compound discovery and theories. It provides examples of different types of complex compounds and rules governing their behavior, such as Peyrone's rule regarding the cis orientation of products from acid complex reactions with ammonia.
This document discusses the nature and properties of complex compounds. It defines complex compounds as those containing a central atom surrounded by ligands. Coordination compounds are complex compounds that exist in both crystalline and solution states. The document outlines the early history of complex compound discovery and theories. It provides examples of different types of complex compounds and rules governing their formation, naming conventions, and isomerism.
This document provides study material for class 12 on p-block elements. It includes 16 questions with answers on topics like why pentahalides are more covalent than trihalides, the conditions required to maximize ammonia yield in the Haber process, and the nature of the bonds in SO2. It also lists important oxides, oxyacids, and properties of elements in the oxygen family and provides information on interhalogens, hydrogen halides, and xenon compounds.
The document summarizes key concepts about coordination compounds. It defines coordination compounds as complex inorganic substances where a central metal ion is surrounded by surrounding ligand molecules or ions. The coordination theory proposed by Alfred Werner explains that the central ion occupies a central position and is bonded to surrounding ligand ions or molecules. Properties such as coordination number, isomerism, stability constants, and chemical reactions are also discussed.
H2 OXIDATION AT Pd100 A FIRST-PRINCIPLES CONSTRAINED THERMODYNAMICS STUDYNi Zhenjuan
This document summarizes a first-principles constrained thermodynamics study of H2 oxidation at Pd(100). It examines various surface structures and compositions using DFT calculations linked to ab initio thermodynamics to build a thermodynamic map of surface termination under different O2 and H2 partial pressures. Key findings include:
1) For O adsorption on Pd(100), binding energy decreases with increasing coverage from 0.25 to 1 ML due to repulsive interactions between adsorbed O atoms. Above 0.5 ML coverage, surface oxide formation is favored.
2) For H adsorption, maximum binding energy occurs at 0.5 ML coverage in a c(2×2) structure
Density functional theory calculations were performed to investigate the structural, electronic, and CO2 adsorption properties of 55-atom bimetallic CuNi nanoparticles. The calculations revealed that decorated Cu12Ni43 and core-shell Cu42Ni13 configurations were more energetically favorable than the monometallic Cu55 and Ni55 nanoparticles. CO2 was found to chemisorb on Ni55, Cu13Ni42, Cu12Ni43, and Cu43Ni12 by undergoing a transition from linear to bent geometry and elongating the C=O bonds, while it only physisorbed on Cu55 and Cu42Ni13. The presence of surface Ni atoms played a key role in strongly adsorbing and activating CO
This document discusses bioinorganic chemistry and the roles of metal ions in biological systems. It begins by noting that the key elements that make up biomolecules are carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur, with phosphorus playing a role in ATP and DNA and sulfur enabling cysteine coordination in proteins. Other essential elements include sodium, potassium, magnesium, and calcium which are involved in osmotic control, nerve action, chlorophyll, and structural functions. Trace metals like iron, cobalt, copper, zinc, and molybdenum are also required in small amounts. The document classifies the essential chemical elements into bulk elements, macrominerals and ions, and trace elements.
The document discusses the Ellingham diagram, which plots the standard free energy of formation (ΔG0) of various oxides and sulfides as a function of temperature. The diagram shows that below a critical temperature, oxides are more stable than metals, while above this temperature metals become more stable. Lines on the diagram represent oxidation/reduction reactions, with their intersection indicating the equilibrium temperature. Additional scales were later added to allow reading the equilibrium oxygen partial pressure directly from the diagram. The Ellingham diagram is a useful tool for predicting spontaneity and equilibrium in metallurgical oxidation/reduction reactions.
Organometallic compounds contain direct bonds between carbon atoms from organic groups and transition metals. The document discusses several key aspects of organometallic chemistry including:
1) Important early organometallic compounds like Grignard reagents and definitions of terms like hapticity and denticity used to describe ligand bonding.
2) The 18-electron rule which states that transition metal complexes are most stable when the metal has 18 electrons, and examples of applying this rule to determine stability.
3) Characteristics of important classes of organometallics like metal carbonyls and ferrocene, including their structures, bonding models and methods of synthesis.
Computer-assisted study on the reaction between pyruvate and ylide in the pat...Omar Alvarardo
n this study the formation of the lactyl–thia-
min diphosphate intermediate (L–ThDP) is addressed using
density functional theory calculations at X3LYP/6-
31??G(d,p) level of theory. The study includes potential
energy surface scans, transition state search, and intrinsic
reaction coordinate calculations. Reactivity is analyzed in
terms of Fukui functions. The results allow to conclude that
the reaction leading to the formation of L–ThDP occurs via
a concerted mechanism, and during the nucleophilic attack
on the pyruvate molecule, the ylide is in its AP form. The
calculated activation barrier for the reaction is 19.2 kcal/
mol, in agreement with the experimental reported value.
This document reports on a study of the photochemistry and thermal decomposition of glyoxylic acid vapor. The key points are:
1) The absorption spectrum of glyoxylic acid vapor was measured, showing three distinct absorption systems attributed to different electronic excited states.
2) Photolysis of glyoxylic acid produced primarily CO2 and formaldehyde (CH2O) initially, with minor CO and H2. Secondary photolysis of CH2O occurred at most wavelengths.
3) Thermal decomposition from 470-710 K primarily produced CO2 and CH2O, but CH2O was always less than stoichiometric. Rate constants for CO2 formation followed Arrhenius behavior.
The document summarizes a study on the kinetic analysis of the oxidation of 2-mercaptoethanol (2-ME) catalyzed by various cobalt phthalocyanine derivatives to understand the effects of perfluorinated groups on the catalysts. Experiments were conducted in a semi-batch reactor under isothermal conditions, and 2-ME conversions over 90% were achieved with 2-hydroxyethyl disulfide being the sole product. Kinetic analyses found that substrate binding is the rate-determining step for the unmodified H16PcCo catalyst, while expulsion of the thiyl radical is rate-determining for the fluorinated F16PcCo and F64PcCo catalysts. Substitution
A STUDY OF MOLYBDENUM CARBIDE CATALYST FOR FISCHER-TROPSCH SYNTHESIS-MEngSc P...Farhan Munir
This document is a thesis submitted by Farhan Munir for the degree of Master of Engineering Science in Process Engineering at the University of New South Wales in November 2001. The thesis studies molybdenum carbide catalyst for Fischer-Tropsch synthesis. It begins with acknowledgments and a table of contents. Chapter 1 provides an introduction on Fischer-Tropsch synthesis and motivation for studying Mo2C catalyst. Chapter 2 discusses Fischer-Tropsch synthesis background including reactions, thermodynamics, kinetics and mechanisms. Chapter 3 discusses Fischer-Tropsch catalysts including active metals, supports, and preparation methods. Chapter 4 focuses specifically on molybdenum carbide catalyst. The objectives, experimental details, results
A kinetic study is reported for the homologation of methanol to give ethanol. Cobalt carbonyl and iodine or cobalt iodide were used as catalyst systems with tri-n-butylphosphine as ligand. The reaction was investigated in 1,4-dioxane in a batch unit at (CO + H2) pressures between 3 and 15 MPa, with H2/CO ratios in the range of 0.33
to 3. The temperature was varied over the range of 150 to 210°C. The reaction rate was found to be first order with respect to methanol and cobalt concentrations and CO partial pressure. A rate expression is derived. A reaction mechanism is proposed in which the rate-determining step is suggested to be the reaction of methanol with a CO-rich cobalt complex existing in low concentration with regard to cobalt used.
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hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
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With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
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among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
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The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
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the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
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photon flux threshold of approximately 2 × 10−8 photons cm−2
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The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
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1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
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Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
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Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
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Exposé invité Journées Nationales du GDR GPL 2024
Deep Software Variability and Frictionless Reproducibility
Oxidation state 10 exists
1. German Edition: DOI: 10.1002/ange.201604670Inorganic Chemistry Hot Paper
International Edition: DOI: 10.1002/anie.201604670
Oxidation State 10 Exists
Haoyu S. Yu and Donald G. Truhlar*
Abstract: In a recent paper, Wang et al. found an iridium-
containing compound with a formal oxidation state of 9.[5]
This
is the highest oxidation state ever found in a stable compound.
To learn if this is the highest chemical oxidation state possible,
Kohn–Sham density functional theory was used to study
various compounds, including PdO4
2+
, PtO4
2+
, PtO3F2
2+
,
PtO4OH+
, PtO5, and PtO4SH+
, in which the metal has an
oxidation state of 10. It was found that PtO4
2+
has a metastable
state that is kinetically stable with a barrier height for
decomposition of 31 kcalmolÀ1
and a calculated lifetime of
0.9 years. All other compounds studied would readily
decompose to lower oxidation states.
The chemical physicist and spectroscopist, C. K. Jørgensen,
famously declared, “One of the major goals of inorganic
chemistry is to prepare compounds of elements in unusual
oxidation states.”[1]
As of 2009, the range of known oxidation
states produced by chemical means was À4 to + 8.[2,3]
In 2010,
Himmel et al. showed the existence of IrO4
+
by electronic
structure calculations;[4]
they studied the stability of cationic
species [MO4]+
(M = rhodium, iridium, meitneurium) and
showed that IrO4
+
is the only species that is stable to
decomposition into MO2
+
and O2, or MO2 and O2
+
. The
existence of IrO4
+
shows that oxidation state 9 exists. This was
confirmed in 2014 by Wang et al. by matrix-isolation experi-
ments.[5]
(As discussed previously,[2,4,6]
good experimental
Mçssbauer isomer shift evidence already existed[7]
for IrIX
in
1969; Ref. [5] was the first to produce IrIX
by chemical, as
opposed to nuclear, means.) Pyykkç and Xu[8]
reviewed the
formal oxidation states of iridium and noted, “…for many
new exotic species, prediction precedes production.” Herein,
we pose the question: does oxidation state 10 exist? We
predict that it does—in the species PtO4
2+
.
To answer the question posed in the first paragraph, we
studied compounds containing palladium, platinum, and
darmstadtium, which are located in the tenth column of the
periodic table. We found that platinum is the element most
likely to have an oxidation state of 10. In 2014, Srivastava and
Misra studied compounds with the formula PdOn (n = 1–5).[9]
One of their conclusions is that palladium can bind stably to
four oxygen atoms, indicating an oxidation state of palladium
as high as 8. In the present paper, we studied the stability of
six transition metal compounds (PdO4
2+
, PtO4
2+
, PtO3F2
2+
,
PtO4OH+
, PtO5, and PtO4SH+
) of palladium and platinum
that have a formal oxidation state of 10.
Reaction energies, enthalpies, and free energies were
calculated (see methods in the Experimental Section) for the
following reactions:
PdO4
2þ
! PdO2
2þ
þ O2 DH ¼ À68:4 kcal molÀ1
ð1Þ
PtO4
2þ
! PtO2
2þ
þ O2 DH ¼ 28:7 kcal molÀ1
ð2Þ
PtO4
2þ
! PtO2
þ
þ O2
þ
DH ¼ À124:6 kcal molÀ1
ð3Þ
PtO4
2þ
! PtO3
þ
þ Oþ
DH ¼ 55:6 kcal molÀ1
ð4Þ
PtO4
2þ
! PtO3
2þ
þ O DH ¼ 83:2 kcal molÀ1
ð5Þ
PtO4
2þ
! PtO3 þ O2þ
DH ¼ 627:5 kcal molÀ1
ð6Þ
PtO3F2
2þ
! PtOF2
þ
þ O2
þ
DH ¼ À217:4 kcal molÀ1
ð7Þ
PtO4OHþ
! PtO2OHþ
þ O2 DH ¼ À94:8 kcal molÀ1
ð8Þ
PtO4OHþ
! PtO2OH þ O2
þ
DH ¼ À41:6 kcal molÀ1
ð9Þ
ðPtO4OHÞþ
! PtO5 þ Hþ
DH ¼ 184:4 kcal molÀ1
ð10Þ
PtO5 ! PtO4 þ O DH ¼ À9:2 kcal molÀ1
ð11Þ
PtO5 ! PtO3 þ O2 DH ¼ À93:7 kcal molÀ1
ð12Þ
PtO4SHþ
! PtO2SHþ
þ O2 DH ¼ À99:6 kcal molÀ1
ð13Þ
The reaction enthalpies shown above were determined at
298.15 K; the reaction energies and Gibbs free energies are
shown in Table S1 (Supporting Information). These results
show that none of the six compounds is thermodynamically
stable because they all have at least one decomposition
reaction that gives negative DE, DH, and DG. In particular,
PtO4
2+
can decompose into PtO2
+
and O2
+
, PtO3F2
2+
can
decompose into PtOF2
+
and O2
+
, PtO4OH+
can decompose
into PtO2OH+
and O2, PtO5 can decompose into PtO3 and O2,
and PtO4SH+
can decompose into PtO2SH+
and O2.
However, for PtO4
2+
all the possible reactions give
positive reaction energies, enthalpies, and free energies
except for reaction (3): PtO4
2+
!PtO2
+
+ O2
+
. The energy
profile and optimized structure of stationary points for
reaction (3) are shown in Figure 1, which starts with the Td
structure. IrO4
+
also has a Td structure, for which the bond
length is 1.689 Š and the PtO4
2+
bond length is 1.712 Š. These
may be compared to standard values (all in Š):[10,11]
IrÀO,
1.85; PtÀO, 1.86; Ir=O, 1.72; Pt=O, 1.69. On this basis, all the
metal-oxo bonds in the Td structures are double bonds. The Td
structure of PtO4
2+
decomposes through transition state TS1
into the C2v structure; the OÀO distance in the C2v structure is
1.21 Š, essentially the same as the 1.21 Š distance in diatomic
[*] H. S. Yu, Prof. D. G. Truhlar
Department of Chemistry, Chemical Theory Center, and Super-
computing Institute, University of Minnesota
207 Pleasant St. SE, Minneapolis, MN 55455-0431 (USA)
E-mail: truhlar@umn.edu
Supporting information and the ORCID identification number(s) for
the author(s) of this article can be found under http://dx.doi.org/10.
1002/anie.201604670.
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2. oxygen. The C2v structure goes to the Cs structure through
transition state TS2 and then through TS3 to the products
PtO2
+
and O2
+
. The PtO4
2+
species is kinetically stable
because it needs to go through a 30.7 kcalmolÀ1
energy
barrier in the first step. We calculated an enthalpy of
activation for this step of 29.2 kcalmolÀ1
and a free energy
of activation of 27.6 kcalmolÀ1
. The transition state theory
rate constant is 3.7 ” 10À8
sÀ1
. This gives a unimolecular
lifetime of 2.7 ” 107
seconds, which is 0.86 years. We conclude
that PtO4
2+
is kinetically stable to decomposition.
We note that PtO4
2+
is isoelectronic with IrO4
+
and the
commodity chemical OsO4. The orbitals of PtO4
2+
are very
similar to those of IrO4
+
, as illustrated in Figure 2 for the
highest occupied molecular orbital (HOMO) and in the
Supporting Information for additional orbitals. However, the
orbital energies are quite different, as would be expected
from the differing net charges. For example, the HOMO
orbital energy of IrO4
+
is À16.3 eV, whereas that of PtO4
2+
is
À23.6 eV.
To understand the charge
distribution in the compounds
with a high oxidation state, we
calculated partial atomic charges
on the metal by both CM5[12]
and
Hirshfeld[13,14]
charge analysis.
The results for the Td structure
are in Table 1. For both IrO4
+
and
PtO4
2+
, the Td structure gives the
highest positive charge on the
metal. The CM5 charge of the
metal is higher than the Hirshfeld
charge for all three structures
(Td, C2v, and Cs). The charge
difference between PtO4
2+
and
IrO4
+
is significant in that
platinum has a charge about 0.2
atomic units higher than iridium.
In Table 2 we also compared the
dipole moments of the polar
structures, as calculated by CM5
charges, Hirshfeld charges, and
the DFT density. As we can see,
the Hirshfeld dipole moment is
closer to the DFT dipole moment
than the CM5 dipole moment.
Thus, the Hirshfeld charges give
the best estimate of the partial atomic charges in these
molecules.
In summary, we predict that oxidation state 10 exists in the
Td structure of PtO4
2+
. The energy profile shows that in order
to decompose, PtO4
2+
needs to pass a high barrier—so high
that the lifetime is calculated to be 0.86 years. Compared to
the previously found highest oxidation state (oxidation
number 9 in IrO4
+
), PtO4
2+
shows a similar charge distribution
and electron densities, but the partial atomic charge on the
metal is about 0.2 units higher.
Figure 1. Enthalpy profile of reaction (3): PtO4
2+
!PtO2
+
+O2
+
. The spin states for Td, TS1, C2v, TS2, Cs,
and TS are all singlet. The spin states for O2
+
and PtO2
+
are doublet. P=products.
Figure 2. HOMO of IrO4
+
(left) and PtO4
2+
(right).
Table 1: Hirshfeld Charges and CM5 Charges of Td structures of IrO4
+
and PtO4
2+
.
IrO4
+
PtO4
2+
Metal center CM5 Hirshfeld CM5 Hirshfeld
Platinum/iridium 1.63 1.01 1.85 1.28
Oxygen À0.16 0.00 0.04 0.18
Table 2: Hirshfeld, CM5, and density dipole moments (in Debye units)
of the polar structures of PtO4
2+
and IrO4
+
.
Dipole moment CM5 Hirshfeld Density
IrO4
+
(C2v) 2.16 1.95 2.00
PtO4
2+
(C2v) 1.55 1.56 1.98
IrO4
+
(Cs) 0.38 0.65 0.71
PtO4
2+
(Cs) 8.19 7.82 7.57
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3. Experimental Section
Methods
The method employed involves electronic structure calculations by
Kohn–Sham density functional theory (DFT) with the M06-L
exchange-correlation functional,[15]
the aug-cc-pVTZ basis set[16]
for
H, O, and F, the aug-cc-pV(T+ d)Z basis set[17]
for S, and the
aug-cc-pVTZ-PP basis set[18,19]
for palladium, iridium, and platinum.
The M06-L functional has been well-validated for transition-metal
energetics.[20]
Calculated Born–Oppenheimer energies of reactions
(DE) were converted into enthalpies of reaction (DH) and free
energies of reaction (DG) by the rigid-rotator, quasiharmonic-
oscillator-approximation with a vibrational scale factor[21]
of 0.980.
We used the same functional, basis sets, and vibrational approxima-
tion to calculate the enthalpy of activation, and we used conventional
transition state theory[22]
to calculate the unimolecular rate constant k
for one reaction; the unimolecular lifetime is 1/k. All calculations are
for thermally equilibrated gas-phase species at 298.15 K and 1 bar.
Gaussian 09[23]
software was used for all the electronic structure
calculations.
Acknowledgements
We thank C. Cramer, W. Gladfelter, D. Leopold, and I. Tonks
for feedback on the manuscript. This work was supported as
part of the Inorganometallic Catalyst Design Center, an
Energy Frontier Research Center funded by the U.S. Depart-
ment of Energy, Office of Science, Basic Energy Sciences
under Award DE-SC0012702.
Keywords: density functional calculation ·
formal oxidation state · oxidation state ·
platinum tetroxide dication
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[14] J. P. Ritchie, S. M. Bachrach, J. Comput. Chem. 1987, 8, 499.
[15] Y. Zhao, D. G. Truhlar, J. Chem. Phys. 2006, 125, 194101.
[16] T. H. Dunning, Jr., J. Chem. Phys. 1989, 90, 1007.
[17] T. H. Dunning, Jr., K. A. Peterson, A. K. Wilson, J. Chem. Phys.
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[20] R. Peverati, D. G. Truhlar, Philos. Trans. R. Soc. London Ser. A
2014, 372, 20120476.
[21] I. M. Alecu, J. Zheng, Y. Zhao, D. G. Truhlar, J. Chem. Theory
Comput. 2010, 6, 2872.
[22] M. M. Kreevoy, D. G. Truhlar, Investigation of Rates and
Mechanisms of Reactions, 4th ed. (Ed.: C. F. Bernasconi), John
Wiley and Sons, New York, 1986, pp. 13 – 95.
[23] Gaussian 09 (Revision C01), M. J. Frisch, et al., (Gaussian, Inc.,
Wallingford CT, 2009).
Received: May 13, 2016
Published online: ,
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4. Communications
Inorganic Chemistry
H. S. Yu, D. G. Truhlar* —
Oxidation State 10 Exists
An existential conundrum: The stability of
transition metal compounds with a metal
formal oxidation state of 10 was deter-
mined with Kohn–Sham density func-
tional theory, and PtO4
2+
was found to be
stable. PtO4
2+
reveals a similar electron
density but a larger partial atomic charge
on the metal when compared to IrO4
+
, for
which the highest oxidation state of 9 was
previously found.
Angewandte
ChemieCommunications
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