Decomposition Cascades of Dicoordinate Copper(I) Chalcogenides

Abstract

Cu–E, Si–E, and Cu–P bond energies of R3PCuESiR3 and CuESiR3 complexes (E = O, S, Se) have been investigated using PBE density‐functional calculations, and including empirical corrections for dispersive interactions (DFT‐D). The bond energies have been used to investigate likely pathways of molecular decomposition. The energy profile for thermal decomposition is to a large degree independent of the nature of the phosphane ligands and silyl groups. Oxides, sulfides, and selenides have qualitatively the same thermal decomposition profile. Thermal decomposition is not likely to produce copper chalcogenide units CuE, but elemental copper Cu instead. Consideration of intermolecular van der Waals attraction suggests that the linear geometry of system tBu3PCuOSiPh3 as found in the crystal is most likely due to crystal packing and intermolecular forces.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Computational Study of Iron Bis(dithiolene) Complexes: Redox Non-Innocent Ligands and Antiferromagnetic Coupling

“…Crystal packing effects might substantially distort the molecular framework. We have recently found that the presence of a crystalline environment can overcome structural preferences for geometries energetically separated by about 20 kJ/mol . We also have to keep in mind that the exemplary character of our model compounds prohibits an unbiased one-to-one comparison with the crystal structure.…”

On the Accuracy of DFT Methods in Reproducing Ligand Substitution Energies for Transition Metal Complexes in Solution: The Role of Dispersive Interactions

“…For example, molecular geometries within a crystal environment might be heavily influenced by intermolecular dispersive forces, [16,17] and in solution, one also has to consider that dispersive forces are not restricted to interactions within a molecule but are likely to include solute-solvent interactions as well. [18] Thus, the competition between intramolecular and intermolecular dispersion forces might render the consideration of dispersive interactions for the proper description of molecular energies in solution expendable, and their incorporation in turn would distort conclusions drawn from calculations based on single isolated molecules.…”

A Failure of DFT Is Not Necessarily a DFT Failure–Performance Dependencies on Model System Choices

“…Furthermore, so-called solid-state packing effects need to be considered. The authors argue that a “close look at the X-ray structure seems to exclude the possibility that the presence of the counterions (PF 6 – ) leads to a distortion of the allyl coordination geometry.” However, crystal effects are not always evident by close inspection alone; for the cation [CpClZrClZrCp 3 ] + , the negative charge field of its molecular environment in the crystal has a significant influence on the Zr–Cl distances, and the bent molecule t Bu 3 PCuOSiPh 3 (∠(Cu–O–Si) = 117° in the gas phase) undergoes linearization in the solid state due to intermolecular dispersive interactions . The capabilities and prospects of readily available atomistic simulation packages allow one to promote “crystal packing” from the status of deus ex machina to a quantifiable effect.…”

“…3 However, crystal effects are not always evident by close inspection alone; for the cation [CpClZrClZrCp 3 ] + , the negative charge field of its molecular environment in the crystal has a significant influence on the ZrÀCl distances, 10 and the bent molecule t Bu 3 PCuOSiPh 3 ( -(CuÀOÀSi) = 117°in the gas phase) undergoes linearization in the solid state due to intermolecular dispersive interactions. 11 The capabilities and prospects of readily available atomistic simulation packages 12 allow one to promote "crystal packing" from the status of deus ex machina to a quantifiable effect.…”