Follow-Up Study of -C to -C Thermally or Photochemically Induced Isomerization of Terpyridine Adducts of Cycloruthenated 2-Aryl-2'-pyridine Compounds.

The mechanism of isomerization of the known 2-phenyl,pyridine () derivatives [Ru(-κC,N) (MeCNN)()]PF, , to [Ru(-κC,N)(MeCNC)()]PF ( = 2,2';6',2″-terpyridine), , at temperatures >50 °C has been investigated both by H NMR spectroscopy and by DFT calculations. The photoisomerization of to by UV light occurred also quantitatively in MeCN after 20 h at room temperature. A similar behavior to that of could be established for the related compound [Ru(3-acridine-2'-CHN-κC,N)(MeCNN)(2,2';6',2″-terpyridine)]PF, (acridine = dibenzo[,]pyridine or 2,3-benzoquinoline), that was obtained from the reaction between [Ru(3-acridine-2'-CHN-κC,N) (MeCN)]PF, , and in MeOH/MeCN at 60 °C for 24 h.

Affinity of Telluronium Chalcogen Bond Donors for Lewis Bases in Solution: A Critical Experimental-Theoretical Joint Study.

Telluronium salts [Ar MeTe]X were synthesized, and their Lewis acidic properties towards a number of Lewis bases were addressed in solution by physical and theoretical means. Structural X-ray diffraction analysis of 21 different salts revealed the electrophilicity of the Te centers in their interactions with anions. Telluroniums' propensity to form Lewis pairs was investigated with OPPh .

Electrophilic Si-H Activation by Acetonitrilo Benzo[h]quinoline Iridacycles: Influence of Electronic Effects in Catalysis.

The performance of six newly synthesized benzo[h]quinoline-derived acetonitrilo pentamethylcyclopentadienyl iridium(III) tetrakis(3,5-bis-trifluoromethylphenyl)borate salts bearing different substituents -X (-OMe, -H, -Cl, -Br, -NO and -(NO ) ) on the heterochelating ligand were evaluated in the dehydro-O-silylation of benzyl alcohol and the monohydrosilylation of 4-methoxybenzonitrile by Et SiH, two reactions involving the electrophilic activation of the Si-H bond. The benchmark shows a direct dependence of the catalytic efficiency with the electronic effect of -X, which is confirmed by theoretical assessment of the intrinsic silylicities Π of hydridoiridium(III)-silylium adducts and by the theoretical evaluation of the propensity of hydridospecies to transfer the hydrido ligand to the activated substrate. The revisited analysis of the Ir-Si-H interactions shows that the most cohesive bond in hydridoiridium(III)-silylium adducts is the Ir-H one, while the Ir-Si is a weak donor-acceptor dative bond.

An Iridium-Stabilized Borenium Intermediate.

Exploration of new organometallic systems based on polyhedral boron clusters has the potential to solve challenging chemical problems such as the stabilization of reactive intermediates and transition-state-like species postulated for E-H (E = H, B, C, Si) bond activation reactions. We report on facile and clean B-H activation of a hydroborane by a new iridium boron cluster complex. The product of this reaction is an unprecedented and fully characterized transition metal-stabilized boron cation or borenium.

Temperature dependence of the Kirkwood correlation factor and linear dielectric constant of simple isotropic polar fluids.

The theory developed in an accompanying paper [Déjardin, Phys. Rev. E 105, 024109 (2022)10.

Deciphering the Role of Noncovalent Interactions in the Conformations of Dibenzo-1,5-dichalcogenocines.

This work reports a combined experimental and theoretical study on the new dibenzo-1,5-ditellurocine 2-Te in order to get an overview on the parameters controlling conformational change and to explain the differences with sulfur and selenium analogues. The preference of the boat conformer over the chair one is revealed by DFT calculations. For 2-Te, a ΔG value of about 3 kJ/mol was calculated, close to the value measured by NMR (5 kJ/mol).

Noncovalent Interactions in Organometallic Chemistry: From Cohesion to Reactivity, a New Chapter.

Noncovalent interactions (NCIs) have long interested a vast community of chemists who investigated their "canonical categories" derived from descriptive crystallography, e.g., H-bonds, π-π interactions, halogen/chalcogen/tetrel bonds, cation-π and C-H-π interactions, metallophilic interactions in the broad sense, etc.

Hydroboration of Alkenes Catalysed by a Nickel N-Heterocyclic Carbene Complex: Reaction and Mechanistic Aspects.

The pentamethylcyclopentadienyl N-heterocyclic carbene nickel complex [Ni(η -C Me )Cl(IMes)] (IMes=1,3-dimesitylimidazol-2-ylidene) efficiently catalyses the anti-Markovnikov hydroboration of alkenes with catecholborane in the presence of a catalytic amount of potassium tert-butoxide, and joins the very exclusive club of nickel catalysts for this important transformation. Interestingly, the regioselectivity can be reversed in some cases by using pinacolborane instead of catecholborane. Mechanistic investigations involving control experiments, H and B NMR spectroscopy, cyclic voltammetry, piezometric measurements and DFT calculations suggest an initial reduction of the Ni precursor to a Ni active species with the concomitant release of H .

A noncovalent interaction insight onto the concerted metallation deprotonation mechanism.

The CMD/AMLA mechanisms of cyclopalladation and the parent fictitious but challenging cyclonickelation of N,N-dimethylbenzylamine have been investigated by joint DFT-D and DLPNO-CCSD(T) methods assisted by QTAIM-based noncovalent interaction plots (NCI plots) and interacting quantum atoms (IQA) analyses, and the local energy decomposition (LED) procedure. Bader charges, NCI plots, IQA and the LED analyses clearly suggest that coulombic interactions play an important role and somewhat govern the whole process that is sensitive to the charge borne by the metal centre. It is found that replacement of acetate by acetamidate used as a ligand and a base significantly lowers the barrier to the formation of the key agostic intermediate.

Open-ended formulation of self-consistent field response theory with the polarizable continuum model for solvation.

The study of high-order absorption properties of molecules is a field of growing importance. Quantum-chemical studies can help design chromophores with desirable characteristics. Given that most experiments are performed in solution, it is important to devise a cost-effective strategy to include solvation effects in quantum-chemical studies of these properties.

Complete analytic anharmonic hyper-Raman scattering spectra.

We present the first computational treatment of the complete second-order vibrational perturbation theory applied to hyper-Raman scattering spectroscopy. The required molecular properties are calculated in a fully analytic manner using a recently developed program [Ringholm, Jonsson and Ruud, J. Comp.

A Global Analytical Representation of the Potential Energy Surface of the FHF(-) Anion.

A global analytical representation of the potential energy hypersurface of the lowest adiabatic electronic state of the FHF(-) anion is derived from ab initio calculations at the coupled cluster level of theory with full single and double and perturbative triple excitations using explicitly correlated atomic basis functions. The new compact function of interatomic distances combines covalent short-range and long-range electrostatic interaction forms and assesses accurately both the lowest reaction channels between the F(-) and HF fragments, with reaction enthalpies to within 1 kJ mol(-1), as well as vibrational terms to within 1.5 cm(-1) deviation from experimental values.

Analytic calculations of anharmonic infrared and Raman vibrational spectra.

Using a recently developed recursive scheme for the calculation of high-order geometric derivatives of frequency-dependent molecular properties [Ringholm et al., J. Comp.