A feasibility study on obtaining d-orbital populations from aspherical-atom refinements on three spin crossover compounds

The Electron Density Distribution in Crystals of η6–[1,4–dihydrospiro(2H–3,1–benzoxazine–2,1′–cyclohexane)]tricarbonylchromium(0): Experiment vs Molecular Invariom

“…An analysis of d–orbitals populations shows an excellent agreement between these values in 2a – c , regardless of the functional, the basis, and also the presence (absence) of the molecule geometry optimization (Table ). It should be noted that d–orbitals populations in molecular invarioms ( 2a – c ) were not refined as it was done for a number of spin–crossover compounds . In addition, there is a coincidence of d–orbitals populations at the qualitative level between complexes 1 and 2a – c .…”

“…It should be noted that d-orbitals populations in molecular invarioms (2a-c) were not refined as it was done for a number of spin-crossover compounds. [29] In addition, there is a coincidence of d-orbitals populations at the qualitative level between complexes 1 and 2a-c. However a noticeable difference in the experimentally determined populations of the d xz and d yz orbitals in 1 and (η 6 -C 6 H 6 )Cr(CO) 3 [36] is observed.…”

“…It should be noted that d-orbitals populations in molecular invarioms (2a-c) were not refined as it was done for a number of spin-crossover compounds. [29] In addition, there is Figure 1. Molecular structure of 1 (a: multipole refinement); molecular invarioms: 2 a (b: the isolated molecule geometry was optimized using DFT (B3LYP/aug-cc-pVDZ)), 2 b (c: the single point calculation using DFT (B3LYP/ aug-cc-pVDZ)), 2 c (d: the single point calculation using DFT (M06 / Def2TZVP)); 2 isol (e: optimized geometry of isolated molecule using DFT (B3LYP/aug-cc-pVDZ)).…”

“…This concept was successfully used to correctly identify metal atoms in coordination compounds, [26,27] analysis agostic interactions in the [Cp 2 FeH](PF 6 ) complex, [28] and estimation of the d-orbitals populations. [29] In our opinion, this concept is extremely successful for investigation the electron density distribution in organometallic compounds. Due to the fact that the metal-ligand bonds in the coordination sphere are substantially polar, the geometric characteristics (bond lengths and angles) in the coordination sphere of the metal atom with the same environment, but in different compounds may differ markedly.…”

“…The development of the invarioms approach led to the concept of “whole–molecule aspherical scattering factors” (hereafter molecular invariom). This concept was successfully used to correctly identify metal atoms in coordination compounds, analysis agostic interactions in the [Cp 2 FeH](PF 6 ) complex, and estimation of the d‐orbitals populations . In our opinion, this concept is extremely successful for investigation the electron density distribution in organometallic compounds.…”