How to understand very weak Cr–Cr double bonds and negative spin populations in trinuclear Cr complexes: theoretical insight

Trinuclear Cr(ii) complex [Cr3(dpa)4Cl2] (Hdpa = dipyridylamine) has two Cr–Cr double bonds linked with each other but [Cr3(dpa)4(N3)2] has one Cr–Cr quadruple bond. CASCF/CASPT2 studies provide understanding of these Cr–Cr bonds and β-spin population on the center Cr.

Development of a joint refinement model for the spin-resolved one-electron reduced density matrix using different data sets

The paper describes a joint refinement model of the spin-resolved one-electron reduced density matrix using simultaneously magnetic structure factors and magnetic directional Compton profiles. The model is guided by two strategies: (i) variation of basis functions and (ii) variation of the spin population matrix. The implementation for a finite system is based on an expansion of the natural orbitals on basis sets. To show the potential benefits brought by the joint refinement model, the paper also presents the refinement results using magnetic structure factors only. The joint refinement model provides very satisfactory results reproducing the pseudo-data. In particular, magnetic Compton profiles have a strong effect not only on the off-diagonal elements of the spin-resolved one-electron reduced density matrix but also on its diagonal elements.

Reactions between hydroxyl-substituted alkylperoxy radicals and Criegee intermediates: correlations of the electronic characteristics of methyl substituents and the reactivity

Methyl substituents tune ΔE and ΔG, thereby exhibiting correlations with spin population, interatomic distance, E(2) and NPA charges in their transition states.