Weak covalent interactions and anionic charge-sharing polymerisation in cluster environments

Abstract

We discuss the formation of weak covalent bonds leading to anionic charge-sharing dimerisation or polymerisation in microscopic cluster environments. The covalent bonding between cluster building blocks is described in terms...

Probing Anion–Molecule Complexes of Atmospheric Relevance Using Anion Photoelectron Detachment Spectroscopy

“…Figure 6 Further, the fact that both A and B can bind an electron gives rise to the possibility that the excess charge will be delocalized between A and B with concomitant partial covalent bond formation. 94 In this case, the resulting anion would not be appropriately described as an ion−molecule complex. Rather, it is a complex anion: [A−B] − .…”

Microsolvation of Hot Ions: Spectroscopy and Statistical Mechanics of Phenide–Water Interactions

“…Although often ignored, this error can be significant, especially for weak interactions. 50 To correct for it, we calculated the Ph − and H 2 O energies using the same basis set as for Ph − •H 2 O (the counterpoise correction). 51 In the Ph − calculation, ghost atoms for H 2 O were added to the optimized phenide structure in the same positions as in the Ph − •H 2 O cluster, allowing for the Ph − energy to be calculated without the water but with its basis functions in place.…”

“…This result overestimates the cluster stability due to the basis set superposition error, which is the effect of calculating the cluster energy with more basis functions than used for its building blocks. Although often ignored, this error can be significant, especially for weak interactions . To correct for it, we calculated the Ph – and H 2 O energies using the same basis set as for Ph – ·H 2 O (the counterpoise correction) .…”

A density-matrix adaptation of the Hückel method to weak covalent networks

“…The MMOs used are the lowest-energy orbitals with a vacancy for an electron or hole, as appropriate. 8,9 Formally, in a system of n identical closed-shell monomers X, let c i be the normalised MMO of X (i) , i = 1,. . ., n. The set of n MMOs {c i } serves as a minimal basis for describing the IM interactions in X n upon the addition of an electron or hole.…”

“…We set out to investigate how many identical closed-shell monomers can bind a single bonding agent (an electron or hole) in their valence orbitals in a perturbation-and excitation-free regime. We are especially interested in the physical factors that determine if the charge is localised on a few monomers or shared by many moieties, [8][9][10] perhaps resembling (in size only) the diffuse non-valence states of solvated electrons. [11][12][13][14][15][16][17][18][19] We approach charge sharing using an extension of the classic Hu ¨ckel molecular orbital (MO) theory [20][21][22][23][24][25] combined with the correlation between bond energy and bond order 26 that has long been ubiquitous in the literature.…”