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Other Resources: 17 results
Interactive Molecular Orbitals  William F. Coleman
The majority of Introductory Chemistry texts provide students with an adequate introduction to the visual aspects of the molecular orbital model for homonuclear diatomic molecules. The treatment of heteronuclear diatomic and polyatomic molecules is less uniform. Heteronuclear diatomics, when mentioned, are invariably treated as being derived from homonuclear diatomics. While the atomic orbital energy level differences in heteronuclear diatomics is sometimes pictured, the consequences of those differences for the resultant molecular orbitals are rarely discussed. The discussion of polyatomic molecular orbitals in these texts is limited to showing that parallel p-orbitals produce delocalized pi molecular orbitals. The molecules typically mentioned in this context are benzene, nitrate ion and carbonate ion. However, It is rarely pointed out that the six p-orbitals in benzene would form 6 pi molecular orbitals, and that only one of these orbitals would look like the picture in the text.These interactive modules are designed to clarify this subject.
MO Theory
Aldehydes and Ketones  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Aldehydes / Ketones
Aldehydes and Ketones in the Cinnamon Trade  Garrett Schwarzman
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Aldehydes / Ketones
Molecular Orbitals  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
MO Theory |
Magnetic Properties
Delocalized Electrons  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Resonance Theory |
MO Theory
Aromatic Hydrocarbons  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Aromatic Compounds
Conjugated Systems  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Aromatic Compounds
Hybrid Orbitals  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Molecular Properties / Structure |
MO Theory
Ketosis in Biology  Robert Hetue
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Aldehydes / Ketones |
Metabolism |
Bioorganic Chemistry
Interactive Molecular Orbital Diagrams  William F. Coleman
Here is an application for constructing the molecular orbital electron configurations of heteronuclear diatomic molecules. Energy level diagrams are given for the two different cases encountered in heteronuclear diatomics of the first short period (Li2 - Ne2). This is a useful tool for having students explore questions of bond order, magnetic properties and numbers of unpaired electrons.
Covalent Bonding |
MO Theory |
Enrichment / Review Materials
Heteronuclear Diatomic Molecular Orbital Formation  William F. Coleman
Here is a set of movies that demonstrates heteronuclear diatomic molecular orbital formation. The orbitals start at a distance where there is little or no interatomic interaction and move to the appropriate bond distance. Orbital phase is shown by the different colors.
Covalent Bonding |
MO Theory |
Enrichment / Review Materials
Molecular Models of Ruthenium(II) Organometallic Complexes  William F. Coleman
The featured molecules for this month come from the paper "Experiments in Thermodynamics and Kinetics of Phosphine Substitution in (p-Cymene)RuCl2(PR3)" by Ozerov, Moura, and Hoffman in which they study the reactions of a number of "piano stool" complexes of ruthenium(II). The synthesis of compound 2a offers students an alternative to the preparation of ferrocene if they are only preparing one metal-arene complex, and the use of the (p-cymene)RuCl2 dimer as a starting material introduces them to a compound that has become important for the synthesis of a number of ruthenium catalysts. Two structures are found for the dimer in the gas phase, one with the chlorides cis to one another and a more stable form with the chlorides trans. DFT calculations using the LanL2MB basis set and the B3LYP functional in Gaussian 03 (1) show the trans form to be about 90 kJ/mol more stable than the cis form. The structures of the trans form of the dimer and of compound 2a are presented in 2 formats with bonds from the ruthenium ion to all of the carbons in the aryl ring and with a single line to a ghost atom in the center of the ring. These are the two common ways of representing such structures but students should be made aware that the overall coordination about the ruthenium in both the dimer and in compound 2a is octahedral, and should look at the structures to convince themselves of that fact. It is also instructive to look at compound 2a, and the other piano stool complexes that are made in the paper, to see how deceptive representation of the triphenylphosphine moiety as PR3 is in terms of the stereochemical bulk of that group.
Organometallics
Hückel Determinant Solver  Robert M. Hanson
Generates energy diagrams for simple Hückel molecular orbital systems using JavaScript. You can specify the determinant or select one for a specific compound from a list.
Computational Chemistry |
MO Theory |
Theoretical Chemistry |
Enrichment / Review Materials
Inorganic Molecules; A Visual Database  Charles E. Ophardt, Evan M. Davis, Dustin Underwood
Inorganic Molecules: A Visual Data Base contains text and graphics describing 66 molecules and ions commonly used as examples in general chemistry courses. For each molecule, fifteen molecular properties are presented visually by eight or nine different molecular models created by the CAChe Scientific Molecular Modeling program.
Atomic Properties / Structure |
MO Theory |
Molecular Properties / Structure
ChemPaths 104 M Jan 24  John W. Moore
Today in Chem 104: * Lecture: Organic Chemistry * Reading: Kotz: Ch. 10, Sec. 3-4 Moore: Ch. 12: Sec. 1, 3-4 * Practice Quiz, Homework #1 due by 11:55pm Today! * Also, Safety Quiz is due before lab this week.
Alcohols |
Ethers |
Aldehydes / Ketones |
Carboxylic Acids |
Amines / Ammonium Compounds
Coumarin, Naphthalene, and Additional Polycyclic Aromatic Hydrocarbons  William F. Coleman
The featured molecules this month are drawn from two papers. The first, "One-Pot Synthesis of 7-Hydroxy-3-carboxycoumarin in Water", is a Green Chemistry feature by Fringuelli, Piermatti, and Pizzo. The three-dimensional versions of the molecules in the synthesis of the coumarin derivative are directly tied to the reaction scheme included in the paper, opening the possibility of showing large numbers of complex synthetic pathways in this manner.The second paper is "Determining the Carbon-Carbon Distance in an Organic Molecule with a Ruler" by Simoni, Tubino, and Ricchi. This article describes an experiment to determine the size of a naphthalene molecule, using an extension of classic experiments for determining molecular size and Avogadro's number. While the structure of naphthalene will come as no surprise to most students, the molecule collection also includes additional polycyclic aromatic hydrocarbons (PAHs) that can be used to introduce students to the environmental and health issues related to these molecules.
Molecular Modeling |
Molecular Properties / Structure |
Aromatic Compounds
Restricted Hartree-Fock SCF Calculations Using Microsoft Excel  Mark A. Freitag, Cortney A. Boots, Taylor R. Page
Courses in computational chemistry are increasingly common at the undergraduate level. Excellent user-friendly programs, which make the execution of ab initio calculations quite simple, are available. However, there is a danger that the underlying SCF procedure (usually coupled with contracted Gaussian atomic orbital basis sets) can become a ?black box? for the student. This Microsoft Excel spreadsheet contains all the essential elements of far more complicated ab initio calculations, but on the simplest possible molecular system.
Computational Chemistry |
Mathematics / Symbolic Mathematics |
MO Theory |
Quantum Chemistry |
Theoretical Chemistry