We present two new hybrid meta exchange- correlation functionals, called M06 and M06-2X. The M06 functional is parametrized including both transition metals and nonmetals, whereas the M06-2X functional is a high-nonlocality functional with double the amount of nonlocal exchange (2X), and it is parametrized only for nonmetals.The functionals, along with the previously published M06-L local functional and the M06-HF full-Hartree–Fock functionals, constitute the M06 suite of complementary functionals. We assess these four functionals by comparing their performance to that of 12 other functionals and Hartree–Fock theory for 403 energetic data in 29 diverse databases, including ten databases for thermochemistry, four databases for kinetics, eight databases for noncovalent interactions, three databases for transition metal bonding, one database for metal atom excitation energies, and three databases for molecular excitation energies. We also illustrate the performance of these 17 methods for three databases containing 40 bond lengths and for databases containing 38 vibrational frequencies and 15 vibrational zero point energies. We recommend the M06-2X functional for applications involving main-group thermochemistry, kinetics, noncovalent interactions, and electronic excitation energies to valence and Rydberg states. We recommend the M06 functional for application in organometallic and inorganometallic chemistry and for noncovalent interactions.

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The M06 suite of density functionals for main group thermochemistry, thermochemical kinetics, noncovalent interactions, excited states, and transition elements: two new functionals and systematic testing of four M06-class functionals and 12 other functionals

: 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

We introduce density functional theory and review recent progress in its application to transition metal chemistry. Topics covered include local, meta, hybrid, hybrid meta, and range-separated functionals, band theory, software, validation tests, and applications to spin states, magnetic exchange coupling, spectra, structure, reactivity, and catalysis, including molecules, clusters, nanoparticles, surfaces, and solids.

Density functional theory for transition metals and transition metal chemistry

Recent Developments in the Preparation and Chemistry of Metallacycles and Metallacages via Coordination

A study is conducted to demonstrate catalytic dehydrogenation of light alkanes on metals and metal oxides. The study provides a complete overview of the materials used to catalyze this reaction, as dehydrogenation for the production of light olefins has become extremely relevant. Relevant factors, such as the specific nature of the active sites, as well as the effect of support, promoters, and reaction feed on catalyst performance and lifetime, are discussed for each catalytic Material. The study compares different catalysts in terms of the reaction mechanism and deactivation pathways and catalytic performance. The duration of the dehydrogenation step depends on the heat content of the catalyst bed, which decreases rapidly due to the endothermic nature of the reaction. Part of the heat required for the reaction is introduced to the reactors by preheating the reaction feed, additional heat being provided by adjacent reactors that are regenerating the coked catalysts.

Catalytic dehydrogenation of light alkanes on metals and metal oxides.

Uncatalyzed coupling of aryldiazonium tetrafluoroborates with N,N-disubstituted hydrazines and the DABCO bis-SO2-adduct offers a smooth and rapid synthesis of arylsulfonium hydrazides.

Metal-Free Aminosulfonylation of Aryldiazonium Tetrafluoroborates with DABCO·(SO2)2 and Hydrazines.

Various theoretical methods (HF, MP2, B3-LYP, QCSD, CCSD(T)) in combination with a hierarchy of basis sets have been used to determine the ground state conformations of B2F4 and B2F4+. It was found that the ground state of B2F4 has an eclipsed conformation (in D2h symmetry), while that of B2F4+ has a staggered conformation (in D2d symmetry). The experimental value for the ionization potential (IP) of B2F4 was found to have a far larger error than believed. The theoretical value of IP obtained by extrapolating the calculated energies to complete basis set limit, corrected for zero-point vibrational energy, spin−orbit and core−valence effects, is 271.70 kcal mol-1. Our best atomization energy and heats of formation at 0 and 298 K for the neutral B2F4 (D2h) are 685.64 kcal mol-1, −339.34 kcal mol-1, and −339.82 kcal mol-1, respectively, and those for the radical cation B2F4+ (D2d) are 413.94 kcal mol-1, −67.64 kcal mol-1, and −67.72 kcal mol-1, respectively.

B2F4 Molecule: A Challenge for Theoretical Calculations.

Under 1—4 bar ammonia, H3NBH3 (AB) reversibly absorbs up to 6 equivalents of NH3 forming liquid AB(NH3)n (n = 1—6) complexes at 0 °C.

Liquefaction of Solid-State BH3NH3 by Gaseous NH3.

N2 fixation is very difficult because of the nonpolarity and high stability of N2. Traditionally, it is achieved by transition metal (TM) systems utilizing the back donation from the d orbitals of the TM to the antibonding π* orbitals of N2 to activate N2. This back donation is rare for main group compounds due to the lack of high-lying valence d orbitals. In the present study, we show that borane compounds with weak B-X (X = H, Si, Ge, and Sb) bonds can mimic TM systems and be used to fix and activate N2. This is achieved by the back donation from the σ bonding orbitals of the B-X bonds to the antibonding π* and σ* orbitals of N2. There is even a linear relationship between the number of B-X bonds and the binding potential energy of N2 with BR1R2R3 (R1, R2, R3 = H, CH3, SiH3, GeH3, and SbH2). Based on these findings, we designed several stable silylborane compounds that are feasible for N2 fixation and activation under mild reaction conditions, i.e., room temperature and 1 atm. In some sandwich-like complexes formed between N2 and silylborane compounds, N2 is even activated from the triple bond to double bond.

Theoretical investigation of borane compounds mimicking transition metals for N2 fixation and activation.

A method for preparing a multi-ion embedded supercapacitor with electrochemical alkaline activation. A simple and rapid electrochemical alkaline activation method is employed to perform activation or deactivation processing on a transition metal hydroxide containing cobalt or nickel to realize intelligent regulation and control of the hydroxide electrode materials to storage capacity of various metal cations, and is applied to an ion embedded supercapacitor. Provided is a universal method capable of improving storage capacity of electrode materials of an ion embedded supercapacitor, and the range of application of the transition metal hydroxide electrode materials is further widened in the field of energy storage.

Zhen Hua Li

Papers

Metal-Free Aminosulfonylation of Aryldiazonium Tetrafluoroborates with DABCO·(SO2)2 and Hydrazines.

B2F4 Molecule: A Challenge for Theoretical Calculations.

Liquefaction of Solid-State BH3NH3 by Gaseous NH3.

Theoretical investigation of borane compounds mimicking transition metals for N2 fixation and activation.

Method for preparing multi-ion embedded supercapacitor with electrochemical alkaline activation