"Chemists familiar with conventional quantum mechanics will applaud and benefit greatly from this particularly instructive, thorough and clearly written exposition of density functional theory: its basis, concepts, terms, implementation, and performance in diverse applications. Users of DFT for structure, energy, and molecular property computations, as well as reaction mechanism studies, are guided to the optimum choices of the most effective methods. Well done!" Paul von RaguE Schleyer "A conspicuous hole in the computational chemist's library is nicely filled by this book, which provides a wide-ranging and pragmatic view of the subject.[...It] should justifiably become the favorite text on the subject for practioneers who aim to use DFT to solve chemical problems." J. F. Stanton, J. Am. Chem. Soc. "The authors' aim is to guide the chemist through basic theoretical and related technical aspects of DFT at an easy-to-understand theoretical level. They succeed admirably." P. C. H. Mitchell, Appl. Organomet. Chem. "The authors have done an excellent service to the chemical community. [...] A Chemist's Guide to Density Functional Theory is exactly what the title suggests. It should be an invaluable source of insight and knowledge for many chemists using DFT approaches to solve chemical problems." M. Kaupp, Angew. Chem.

A Chemist's Guide to Density Functional Theory

A scheme that reduces the calculations of ground-state properties of systems of interacting particles exactly to the solution of single-particle Hartree-type equations has obvious advantages. It is not surprising, then, that the density functional formalism, which provides a way of doing this, has received much attention in the past two decades. The quality of the energy surfaces calculated using a simple local-density approximation for exchange and correlation exceeds by far the original expectations. In this work, the authors survey the formalism and some of its applications (in particular to atoms and small molecules) and discuss the reasons for the successes and failures of the local-density approximation and some of its modifications.

The density functional formalism, its applications and prospects

The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

The Halogen Bond

The detection methods and generation mechanisms of the intrinsic reactive oxygen species (ROS), i.e., superoxide anion radical (•O2–), hydrogen peroxide (H2O2), singlet oxygen (1O2), and hydroxyl radical (•OH) in photocatalysis, were surveyed comprehensively. Consequently, the major photocatalyst used in heterogeneous photocatalytic systems was found to be TiO2. However, besides TiO2 some representative photocatalysts were also involved in the discussion. Among the various issues we focused on the detection methods and generation reactions of ROS in the aqueous suspensions of photocatalysts. On the careful account of the experimental results presented so far, we proposed the following apprehension: adsorbed •OH could be regarded as trapped holes, which are involved in a rapid adsorption–desorption equilibrium at the TiO2–solution interface. Because the equilibrium shifts to the adsorption side, trapped holes must be actually the dominant oxidation species whereas •OH in solution would exert the reactivity...

Generation and Detection of Reactive Oxygen Species in Photocatalysis

: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

A simple synthesis for carbon-13 enriched fluorochloromethanes and fluoromethanes.

Simultaneous matrix deposition of Li atoms and N2O at high dilution in nitrogen has produced new infrared absorptions which show appropriate lithium and oxygen isotopic shifts for vibrational assignment to the high temperature molecules LiO and LiOLi, which were observed in earlier evaporative studies. The identification of LiO and LiOLi was confirmed in mixed isotopic experiments. Isotopic assignments to ν3 of Li2O in nitrogen matrices provide data for calculations of the Li–O–Li bond angle which are consistent with a linear molecule, in agreement with the electric deflection and earlier infrared work on Li2O.

Matrix reactions of lithium atoms with N2O: Infrared spectra of LiO and Li2O

The first bands in the photoelectron spectra of the CH2Br, CD2Br, CHBr2, and CH2I free radicals

Codeposition of argon-diluted samples of O{sub 3} and HCN produced a unique 1:1 O{sub 3}-HCN complex where the C{sub 2v} symmetry of O{sub 3} is retained and HCN appears to form weak hydrogen bonding interactions with both terminal atoms of O{sub 3}. Complexes with isotopic substitution at all atomic positions were studied. Photolysis of Ar/HCN/O{sub 3} samples with the full mercury arc produced the O-HCN hydrogen-bonded complex and HNCO as primary products and (HNCO){sub 2} as a secondary product.

Matrix infrared studies of the hydrogen cyanide + ozone and hydrogen cyanide + oxygen atom systems

Magnesium atoms generated by laser ablation were reacted with methyl halides diluted (0.5% to 0.1%) in argon. Reaction products were trapped in a cryogenic argon matrix and analyzed by infrared spectroscopy. The primary reaction product, isolated Grignard molecule CH3MgX, and the secondary reaction products MgX, MgX2, MgH, MgH2, CH4, C2H6, CH2X, CH3MgCH3, XMgCH2, HMgCH3, and HMgCH2X were identified by isotopic (13C, D, and 26Mg) substitution and by correlation with B3LYP and BP86 isotopic frequency calculations. This investigation reports the first experimental evidence for the fluoride Grignard species, CH3MgF. Infrared absorptions were also observed for associated Grignard species.

Formation of Grignard Species from the Reaction of Methyl Halides with Laser-Ablated Magnesium Atoms. A Matrix Infrared Study of CH3MgF, CH3MgCl, CH3MgBr, and CH3MgI

Lester Andrews

Papers

A simple synthesis for carbon-13 enriched fluorochloromethanes and fluoromethanes.

Matrix reactions of lithium atoms with N2O: Infrared spectra of LiO and Li2O

The first bands in the photoelectron spectra of the CH2Br, CD2Br, CHBr2, and CH2I free radicals

Matrix infrared studies of the hydrogen cyanide + ozone and hydrogen cyanide + oxygen atom systems

Formation of Grignard Species from the Reaction of Methyl Halides with Laser-Ablated Magnesium Atoms. A Matrix Infrared Study of CH3MgF, CH3MgCl, CH3MgBr, and CH3MgI