Halide–propene complexes: validated DSD-PBEP86-D3BJ calculations and photoelectron spectroscopy

Abstract

Anion photoelectron spectroscopy has been used to determine the electron binding energies of the X-···C3H6 (X = Cl, Br, I) complexes. To complement the experimental spectra the DSD-PBEP86-D3BJ functional has...

Closing the Shell: Gas‐Phase Solvation of Halides by 1,3‐Butadiene

“…[14] Similarly each halide structure also shows trends in their complex dissociation energy (D 0 ) values that correspond to previously studied halide-propene complexes, with the chloride complexes being the most stable and the iodide complexes being the least stable. [14] Comparing the two bidentate complexes in the halide-propene and halide-butadiene complexes, the larger hydrocarbon chain is more stable. This is attributed to the delocalisation of donated electron density in the diene such that the charge density gradients are constructive, whereas in the propene complex the induced dipoles contain destructive vector components.…”

“…In the neutral complexes, each of the vdW complexes exhibit similar D 0 values to comparative halide-propene complexes. [14] The most stable neutral complexes are the 7cis and 7trans structures respectively, as the halogen exhibits similar interaction with the π-system as the halogen-propene complexes. Despite the increase in complex stability in these cases, the 7cis structure still retains the imaginary mode (132i cm À 1 ) and it is not significantly stabilised with respect to the butadiene monomer.…”

“…[23À 27] The DSD-PBEP86-D3BJ functional was chosen for its efficacy in describing long-range interactions and applicability to similar systems previously. [14,28] For Cl additional diffuse functions are included and for Br and I, effective core potentials are included for the AVTZ basis set. [29,30] Starting geometries utilised a number of different bonding arrangements with respect to the double bonds of the butadiene molecules similarly to previously studied ethene and propene complexes.…”

“…The def2 basis set was chosen here based on the reliability of the def2QZVPD basis set for troublesome cases. [14] These were compared with a minimum structure representing the I À ⋯(C 4 H 6 ) 2 complex where the butadiene monomers interacted with the iodide similarly to the 2trans conformer of the monosolvated complex. The results of these calculations are shown in Figure 9, where two minima and a transition state were determined for the 4-vinylhexene complex and one structure was determined for the trimer complex.…”

Noncovalent chalcogen and tetrel bonding interactions: Spectroscopic study of halide–carbonyl sulfide complexes

“…In contrast, and due to the system size, trimer complexes of halides with two carbonyl sulfide molecules were optimized utilizing the DSD‐PBEP86‐D3BJ 75 double‐hybrid density functional with the AVTZ basis sets. The DSD‐PBEP86‐D3BJ double‐hybrid was chosen for several reasons: namely, it has been benchmarked with respect to experimental anion photoelectron spectroscopy of noncovalently bound complexes, 76 the functional has previously been used in order to optimize trimer complexes involving halides where the CCSD(T) method was no longer feasible, 77 and the performance of the functional associated with the GMTKN55 database 78 . Each optimization was followed by harmonic vibrational analysis at the corresponding level of theory in order to confirm the identity of the geometry as a minimum on the potential energy surface.…”