| Journal Articles: 48 results |
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Orbital Exponent Optimization in Elementary VB Calculations of the Chemical Bond in the Ground State of Simple Molecular Systems Valerio Magnasco Orbital exponent optimization in the elementary ab-initio VB calculation of the ground states of H2+, H2, He2+, and He2 gives a fair description of the exchange-overlap component of the interatomic interaction that is important in the bond region. Magnasco, Valerio. J. Chem. Educ. 2008, 85, 1686.
Atomic Properties / Structure |
Computational Chemistry |
Covalent Bonding |
Molecular Properties / Structure |
Quantum Chemistry |
Theoretical Chemistry |
Valence Bond Theory
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Predicting the Stability of Hypervalent Molecules Tracy A. Mitchell, Debbie Finocchio, and Jeremy Kua In this exercise, students use concepts in thermochemistry such as bond energy, ionization potentials, and electron affinities to predict the relative stability of two hypervalent molecules (PF5 and PH5) relative to their respective non-hypervalent counterparts. Mitchell, Tracy A.; Finocchio, Debbie; Kua, Jeremy. J. Chem. Educ. 2007, 84, 629.
Computational Chemistry |
Covalent Bonding |
Ionic Bonding |
Lewis Structures |
Molecular Modeling |
Calorimetry / Thermochemistry |
Molecular Properties / Structure
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Entropy and the Shelf Model: A Quantum Physical Approach to a Physical Property Arnd H. Jungermann A quantum physical approach relying on energy quantization leads to three simple rules which are the key to understanding the physical property described by molar entropy values. Jungermann, Arnd H. J. Chem. Educ. 2006, 83, 1686.
Alcohols |
Alkanes / Cycloalkanes |
Carboxylic Acids |
Covalent Bonding |
Ionic Bonding |
Physical Properties |
Quantum Chemistry |
Thermodynamics
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Cis and Trans Isomerization in Cyclic Alkenes: A Topic for Discovery Using the Results of Molecular Modeling Susan E. Barrows and Thomas H. Eberlein This article describes an activity in which students are led to discover the fundamental reasons behind the unusual instability of the trans isomers in medium-sized cycloalkenes by using the results of molecular modeling. Notably, students will make the unexpected discovery that twisting about p bonds is perhaps more facile than they had been led to believe. Barrows, Susan E.; Eberlein, Thomas H. J. Chem. Educ. 2004, 81, 1529.
Covalent Bonding |
Computational Chemistry |
Molecular Modeling |
Alkenes |
Molecular Properties / Structure
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Effects of Exchange Energy and Spin-Orbit Coupling on Bond Energies Derek W. Smith It is shown that the ground states of atoms having pn configurations are stabilized by exchange energy (n = 2, 3, or 4) and/or spinorbit coupling (n = 1, 2, 4, or 5). Smith, Derek W. J. Chem. Educ. 2004, 81, 886.
Atomic Properties / Structure |
Main-Group Elements |
Molecular Properties / Structure |
Periodicity / Periodic Table |
Descriptive Chemistry |
Ionic Bonding |
Covalent Bonding |
Metallic Bonding
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The Noble Gas Configuration—Not the Driving Force but the Rule of the Game in Chemistry Roland Schmid Explains the covalent and ionic bonding behavior of main-group elements in terms of electromagnetic forces rather than the supposed "stability" of noble-gas configurations. Schmid, Roland. J. Chem. Educ. 2003, 80, 931.
Molecular Modeling |
Periodicity / Periodic Table |
Main-Group Elements |
Atomic Properties / Structure |
Reactions |
Covalent Bonding |
Ionic Bonding
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Understanding and Interpreting Molecular Electron Density Distributions C. F. Matta and R. J. Gillespie A simple introduction to the electron densities of molecules and how they can be analyzed to obtain information on bonding and geometry. Matta, C. F.; Gillespie, R. J. J. Chem. Educ. 2002, 79, 1141.
Covalent Bonding |
Molecular Properties / Structure |
Quantum Chemistry |
Theoretical Chemistry |
Atomic Properties / Structure |
Molecular Modeling |
VSEPR Theory
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Lewis Structures in General Chemistry: Agreement between Electron Density Calculations and Lewis Structures Gordon H. Purser The internuclear electron densities of a series of X-O bonds (where X = P, S, or Cl) are calculated using quantum mechanics and compared to Lewis structures for which the formal charges have been minimized; a direct relationship is found between the internuclear electron density and the bond order predicted from Lewis structures in which formal charges are minimized. Purser, Gordon H. J. Chem. Educ. 2001, 78, 981.
Covalent Bonding |
Computational Chemistry |
Molecular Properties / Structure |
Lewis Structures |
Quantum Chemistry
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The Use of Molecular Modeling and VSEPR Theory in the Undergraduate Curriculum to Predict the Three-Dimensional Structure of Molecules Brian W. Pfennig and Richard L. Frock Despite the simplicity and elegance of the VSEPR model, however, students often have difficulty visualizing the three-dimensional shapes of molecules and learning the more subtle features of the model, such as the bond length and bond angle deviations from ideal geometry that accompany the presence of lone pair or multiple bond domains or that result from differences in the electronegativity of the bonded atoms, partial charges and molecular dipole moments, and site preferences in the trigonal bipyramidal electron geometry. Pfennig, Brian W.; Frock, Richard L. J. Chem. Educ. 1999, 76, 1018.
Molecular Modeling |
Molecular Properties / Structure |
Covalent Bonding |
VSEPR Theory
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Lewis Structures Are Models for Predicting Molecular Structure, Not Electronic Structure Gordon H. Purser This article argues against a close relationship between Lewis dot structures and electron structure obtained from quantum mechanical calculations. Lewis structures are a powerful tool for structure prediction, though they are classical models of bonding and do not predict electronic structure. Purser, Gordon H. J. Chem. Educ. 1999, 76, 1013.
Molecular Properties / Structure |
Covalent Bonding |
Computational Chemistry |
Quantum Chemistry |
MO Theory |
Learning Theories |
Lewis Structures |
Molecular Modeling
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Covalent and Ionic Molecules: Why Are BeF2 and AlF3 High Melting Point Solids whereas BF3 and SiF4 Are Gases? Ronald J. Gillespie Calculated ionic charges show that BF3 and SiF4 are predominately ionic molecules yet in contrast to BeF2 and AlF3 they exist as gases at room temperature and form molecular solids rather than infinite three-dimensional "ionic" solids at low temperature. Whether or not ionic molecules form a three-dimensional infinite ionic lattice or a molecular solid depends more on relative atomic (ionic) sizes than on the nature of the bonding in the isolated molecule. Gillespie, Ronald J. J. Chem. Educ. 1998, 75, 923.
Covalent Bonding |
Molecular Properties / Structure |
Solids |
Gases |
Ionic Bonding
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The Mechanism of Covalent Bonding George B. Bacskay, Jeffrey R. Reimers, and Sture Nordholm In this paper we reexamine the mechanism of covalent bonding, specifically with a view to its teaching, that starts with quantum theory and the interpretation of its predictions, such as electronic delocalization and the concomitant lowering of the electronic energy as bonding occurs. Indeed, delocalization is shown to be the central mechanism of covalent bond formation. These ideas are discussed in detail in the context of the simplest molecules: H2+ and H2. Bacskay, George G.; Reimers, Jeffrey R.; Nordholm, Sture. J. Chem. Educ. 1997, 74, 1494.
Theoretical Chemistry |
Covalent Bonding
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Pi-Electron Delocatlization in Organic Molecules with C-N Bonds Vernon G. S. Box and Hing Wan Yu Molecular modeling can provide great stimulation to the pedagogical process if students and teachers use this tool to examine the structural aspects of organic molecules whose structures have been determined by X-ray crystallography. An example of this is provided by one of our undergraduate research projects that examined delocalization in p-systems. Box, Vernon G. S.; Yu, Hing Wan. J. Chem. Educ. 1997, 74, 1293.
Molecular Modeling |
Molecular Properties / Structure |
Covalent Bonding |
X-ray Crystallography
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The Role of Electrostatic Effects in Organic Chemistry Kenneth B. Wiberg Electrostatic effects on the properties of organic compounds are reviewed to demonstrate the importance of electronegativity differences between the atoms forming a bond. Bond dissociation energies are generally found to increase as the electronegativity difference increases, and the bonds have increased ionic character. Wiberg, Kenneth B. J. Chem. Educ. 1996, 73, 1089.
Atomic Properties / Structure |
Covalent Bonding |
Ionic Bonding
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Lewis Structures of Oxygen Compounds of 3p-5p Nonmetals Darel K. Straub Procedure for writing Lewis structures of oxygen compounds of 3p-5p nonmetals. Straub, Darel K. J. Chem. Educ. 1995, 72, 889.
Lewis Structures |
Molecular Properties / Structure |
Covalent Bonding |
Main-Group Elements
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Lewis Structures of Boron Compounds Involving Multiple Bonding Straub, Darel K. Considers evidence for multiple bonding in boron compounds and supposed exceptions to the octet rule. Straub, Darel K. J. Chem. Educ. 1995, 72, 494.
Lewis Structures |
Covalent Bonding
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Bond Energy Data Summarized Kildahl, Nicholas K. A periodic table that summarizes a variety of bond energy information. Kildahl, Nicholas K. J. Chem. Educ. 1995, 72, 423.
Periodicity / Periodic Table |
Covalent Bonding |
Ionic Bonding
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The significance of the bond angle in sulfur dioxide Purser, Gordon H. Discussion of the bonding in and structure of SO2. Purser, Gordon H. J. Chem. Educ. 1989, 66, 710.
Molecular Properties / Structure |
Covalent Bonding
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The arsenic-arsenic double bond revisited Levinson, Alfred S. Arsenic-arsenic double bonds are stabilized by bulky substituents. Levinson, Alfred S. J. Chem. Educ. 1987, 64, 407.
Covalent Bonding
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Coulombic models in chemical bonding. II. Dipole moments of binary hydrides Sacks, Lawrence J. A discussion of Coulumbic models and their aid in understanding chemical bonding. Sacks, Lawrence J. J. Chem. Educ. 1986, 63, 373.
Electrochemistry |
Molecular Properties / Structure |
Covalent Bonding |
Noncovalent Interactions
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The Pauling 3-electron bond: A recommendation for the use of the Linnett structure Harcourt, Richard D. Recommends the Linnett structure IV for future use when a valence-bond structure for a Pauling 3-electron bond is required. Harcourt, Richard D. J. Chem. Educ. 1985, 62, 99.
Covalent Bonding
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Structural parameters of methyl iodide by infrared spectroscopy McNaught, Ian J. A study of the rotation-vibration spectrum of methyl chloride permits calculation of band origins of the fundamentals, Coriolis coupling constants of the degenerate modes, rotation constants, and bond lengths and force constants. McNaught, Ian J. J. Chem. Educ. 1982, 59, 879.
IR Spectroscopy |
Spectroscopy |
Molecular Properties / Structure |
Covalent Bonding
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A needed replacement for the customary description of chemical bonding Sanderson, R. T. Description of and encouragement to use an alternative to the covalent / ionic model for chemical bonding. Sanderson, R. T. J. Chem. Educ. 1982, 59, 376.
Covalent Bonding |
Ionic Bonding
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Bent bonds and multiple bonds Robinson, Edward A.; Gillespie, Ronald J. Considers carbon-carbon multiple bonds in terms of the bent bond model first proposed by Pauling in 1931. Robinson, Edward A.; Gillespie, Ronald J. J. Chem. Educ. 1980, 57, 329.
Covalent Bonding |
Molecular Properties / Structure |
Molecular Modeling |
Alkenes |
Alkynes
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The valence bond interpretation of molecular geometry Smith, Derek W. Shows that the valence bond theory not only provides an attractive means of describing the bonding in a molecule but can also explain its geometry. Smith, Derek W. J. Chem. Educ. 1980, 57, 106.
Covalent Bonding |
Molecular Properties / Structure |
VSEPR Theory
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Loosely-bound diatomic molecules Balfour, W. J. Over the past decade, careful spectroscopic studies have established the existence of bound rare gas and alkaline earth diatomic molecules. Balfour, W. J. J. Chem. Educ. 1979, 56, 452.
Covalent Bonding |
Molecular Properties / Structure
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Assigning oxidation states to some metal dioxygen complexes of biological interest Summerville, David A.; Jones, Robert D.; Hoffman, Brian M.; Basolo, Fred Considers the bonding of dioxygen in metal-dioxygen complexes, paying particular attention to the problems encountered in assigning conventional oxidation numbers to both the metal center and coordinated dioxygen. Summerville, David A.; Jones, Robert D.; Hoffman, Brian M.; Basolo, Fred J. Chem. Educ. 1979, 56, 157.
Oxidation State |
Metals |
Covalent Bonding |
MO Theory
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Strength of chemical bonds Christian, Jerry D. Demonstrating the strength of chemical bonds by scaling a molecule up to a macroscopic size. Christian, Jerry D. J. Chem. Educ. 1973, 50, 176.
Covalent Bonding |
Molecular Properties / Structure |
Metallic Bonding
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The electron-pair repulsion model for molecular geometry Gmespie, R. J. Reviews the electron-pair repulsion model for molecular geometry and examines three-centered bonds, cluster compounds, bonding among the transition elements, and exceptions to VSEPR rules. Gmespie, R. J. J. Chem. Educ. 1970, 47, 18.
Molecular Properties / Structure |
Covalent Bonding |
MO Theory |
VSEPR Theory |
Transition Elements
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Molecular geometry: Bonded versus nonbonded interactions Bartell, L. S. Proposes simplified computational models to facilitate a comparison between the relative roles of bonded and nonbonded interactions in directed valence. Bartell, L. S. J. Chem. Educ. 1968, 45, 754.
Molecular Properties / Structure |
VSEPR Theory |
Molecular Modeling |
Covalent Bonding |
Noncovalent Interactions |
Valence Bond Theory |
MO Theory
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Why does methane burn? Sanderson, R. T. A thermodynamic explanation for why methane burns. Sanderson, R. T. J. Chem. Educ. 1968, 45, 423.
Thermodynamics |
Reactions |
Oxidation / Reduction |
Calorimetry / Thermochemistry |
Covalent Bonding |
Ionic Bonding
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The electron repulsion theory of the chemical bond. II. An alternative to resonance hybrids Luder, W. F. The author proposes the electron repulsion theory of the chemical bond as an alternative to resonance hybrids. Luder, W. F. J. Chem. Educ. 1967, 44, 269.
Covalent Bonding |
Resonance Theory
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The chemistry of tetrasulfur tetranitride Allen, Christopher W. The chemistry of sulfur-nitrogen compounds has several features of interest and importance: stability of the sulfur-nitrogen bond, tendency to form six- and eight-membered rings, ring contraction, polymerization, and negative ion formation. Allen, Christopher W. J. Chem. Educ. 1967, 44, 38.
Covalent Bonding |
Polymerization
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A unified theory of bonding for cyclopropanes Bernett, William A. Examines various models for bonding in cyclopropanes. Bernett, William A. J. Chem. Educ. 1967, 44, 17.
Covalent Bonding |
Molecular Properties / Structure |
Alkanes / Cycloalkanes |
MO Theory |
Molecular Modeling
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IV - Isoelectronic systems Bent, Henry A. A detailed consideration of the principles of isoelectric systems. Bent, Henry A. J. Chem. Educ. 1966, 43, 170.
Gases |
Nonmetals |
Covalent Bonding
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III - Bond energies Benson, Sidney W. Examines bond dissociation energies , methods for measuring such energies, some representative values of such energies, structural aspects of bond dissociation energies, and bond energies in ionized species. Benson, Sidney W. J. Chem. Educ. 1965, 42, 502.
Covalent Bonding
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Tangent-sphere models of molecules. III. Chemical implications of inner-shell electrons Bent, Henry A. While a study of atomic core sizes might seem to hold little promise of offering interesting insights into the main body of chemical theory, it is demonstrated here that from such a study emerges a picture of chemical bonding that encompasses as particular cases covalent, ionic, and metallic bonds. Bent, Henry A. J. Chem. Educ. 1965, 42, 302.
Atomic Properties / Structure |
Molecular Properties / Structure |
Molecular Modeling |
Covalent Bonding |
Ionic Bonding |
Metallic Bonding
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Principles of chemical reaction Sanderson, R. T. The purpose of this paper is to examine the nature of chemical change in the hope of recognizing and setting forth the basic principles that help us to understand why they occur. Sanderson, R. T. J. Chem. Educ. 1964, 41, 13.
Reactions |
Thermodynamics |
Mechanisms of Reactions |
Kinetics |
Synthesis |
Covalent Bonding |
Ionic Bonding |
Metallic Bonding
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Tangent-sphere models of molecules. II. Uses in Teaching Bent, Henry A. Tangent-sphere models can be used to represent highly strained bonds and multicentered bonds, atoms with expanded and contracted octets, inter- and intramolecular interactions, and the effects of electronegative groups, lone pairs, and multiple bonds on molecular geometry, bond properties, and chemical reactivity. Bent, Henry A. J. Chem. Educ. 1963, 40, 523.
Molecular Properties / Structure |
Covalent Bonding
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Relationship of exothermicities of compounds to chemical bonding Siegel, Bernard The sign and magnitude of the standard heat of formation of a chemical compound is often used incorrectly to characterize its relative stability compared to other compounds. Siegel, Bernard J. Chem. Educ. 1963, 40, 308.
Calorimetry / Thermochemistry |
Covalent Bonding
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Stable gaseous species at high temperatures Siegel, Bernard Presents a systematic correlation of the bonding in the gaseous elements with the strengths of their respective bonds. Siegel, Bernard J. Chem. Educ. 1963, 40, 304.
Gases |
Carbocations |
Covalent Bonding
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Chemistry of diphosphorus compounds Huheey, James E. Examines diphosphorus chemistry, including tri- and tetra- covalent diphosphorus compounds; optical activity in diphosphines; unsaturated diphosphorus compounds, cyclic compounds, and higher phosphines; reactions producing and destroying P-P bonds; and diphosphorus compounds as ligands. Huheey, James E. J. Chem. Educ. 1963, 40, 153.
Molecular Properties / Structure |
Reactions |
Covalent Bonding |
Coordination Compounds
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Intrinsic bond energies Siegel, S.; Siegel, B. Examines intrinsic bond energies drawn from spectroscopic data and focusses on beryllium hydride as an example. Siegel, S.; Siegel, B. J. Chem. Educ. 1963, 40, 143.
Covalent Bonding |
Molecular Properties / Structure
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The uses and abuses of bond energies Knox, Bruce E.; Palmer, Howard B. The author argues that the concepts of bond energy and bond-dissociation energy be presented to undergraduate physical and organic chemistry students in enough detail that some real understanding results. Knox, Bruce E.; Palmer, Howard B. J. Chem. Educ. 1961, 38, 292.
Calorimetry / Thermochemistry |
Covalent Bonding
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Distribution of atomic s character in molecules and its chemical implications Bent, Henry A. Explains the shape of simple molecules using the distribution of atomic s character. Bent, Henry A. J. Chem. Educ. 1960, 37, 616.
Atomic Properties / Structure |
Molecular Properties / Structure |
Covalent Bonding
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On the origin of characteristic group frequencies in infrared spectra Dows, David A. Examines the mechanics and energetics of vibrations in small and large molecules. Dows, David A. J. Chem. Educ. 1958, 35, 629.
IR Spectroscopy |
Molecular Properties / Structure |
Covalent Bonding
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The coordinate bond and the nature of complex inorganic compounds. I. The formation of single covalent bonds Busch, Daryle H. The factors determining the stabilities of complex inorganic compounds are considered in terms of thermochemical cycle; it is pointed out that the stabilities of complexes increase as the percent covalent character in their bonds increases, and weak covalent bonds will occur in any given instance. Busch, Daryle H. J. Chem. Educ. 1956, 33, 376.
Coordination Compounds |
Covalent Bonding |
Metals |
Atomic Properties / Structure
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Nature of adhesion Reinhart, Frank W. Examines the theory of adhesion and the variety of attractive forces involved. Reinhart, Frank W. J. Chem. Educ. 1954, 31, 128.
Surface Science |
Covalent Bonding |
Metallic Bonding |
Noncovalent Interactions
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