Linear Multiselenium Interactions in Dicationic Oligomers of 1,5‐(Diselena)canes: Behavior of Semc σ(mcc‐nee) (6≤mc≤16) Elucidated with QTAIM Dual Functional Analysis

Abstract

Abstract The intrinsic dynamic and static nature mc center‐ne electron interactions of the σ‐type σ(mcc‐nee) were elucidated for the Se‐Se interactions in dicationic oligomers of Se(CH2CH2CH2)2Se (1 (Se, Se)) [n2+ (Se, Se): n=1–8], especially for mc≥6, where n2+ (Se, Se: n=1–8) are abbreviated by n2+ (n=1–8), respectively. QTAIM dual functional analysis (QTAIM‐DFA) was applied to the interactions. Perturbed structures generated using coordinates derived from the compliance constants (Cii) were employed for QTAIM‐DFA. Each Se‐*‐Se in 12+ and 22+ has the nature of CT‐TBP (trigonal bipyramidal adduct formation through CT) and Cov‐w (weak covalent), respectively, which supply the starting points of the investigations. The asterisk emphasizes the existence of a bond critical point on the interaction. All Se‐*‐Se in 32+ are classified by the regular closed shell (r‐CS) interactions and characterized as CT‐MC (molecular complex formation through CT), which are denoted as r‐CS/CT‐MC, except for the central interaction, of which nature is r‐CS/CT‐TBP. Most interactions in 42+–82+ are r‐CS/t‐HBwc (typical‐HB with covalency) but some are pure‐CS/t‐HBnc (t‐HB with no covalency). The linear Se2n2+ interactions in 22+–82+ seem close to those without any limitations, since the nature of Se‐*‐Se inside and outside of (CH2CH2CH2)2 are very similar with each other. The linear Se2n2+ interactions in 32+–82+ are shown to be analyzed as σ(mcc‐nee: 6≤mc≤16), not by the accumulated σ(3c–4e).

Keywords

• ab initio calculations
• natural bond orbital analysis
• nonbonded interactions
• QTAIM
• selenides