Planar pentacoordinate s-block metals

Abstract

The presence of a delocalized pi-bond is often considered an essential criterion for achieving planar hypercoordination. Herein, we show that sigma-delocalization could be sufficient to make the planar configuration the...

Enhancing Precatalyst Performance and Robustness through Aromaticity: Insights from Iridaheteroaromatics

“…Our calculations indicate the existence of a diatropic ring current both above the ring and within the ring plane, extending to a distance of 2.0 Å. The NICS ZZ values were calculated with incremental distances of 0.5 Å in two dimensions …”

Understanding the bonding and aromaticity of [Au3{C4H4(X)4E}3]− (X = CF3, CN, BO; E = Si, Ge): trinuclear gold superhalogens

“…To avoid misinterpretations and to properly quantify the degree of aromaticity, the ring-current strengths should be computed by integrating the current density avoiding the influence of the atomic currents. An approach based on removing valence electrons 65,69 (RVE) suggests that ring current strengths calculated in planes intersecting a nucleus account for the flux of the ring current but also for that caused by the atomic currents. The RVE approximation cannot be used in these systems to disregard this core-electron effect directly, since the energy gap between the lowest occupied σ orbital and the highest core orbital is very small.…”

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“…5 Since then, ptC has progressed enormously both theoretically 6–13 and experimentally 14–20 and has also been extended to planar hypercoordination in the main group and s-block elements. 21–27 The magic number for planar species, known as the “18-valence electron rule”, 28 has been designed in the past and shown to be effective for various systems 6,7,29,30 to understand the bonding and stability of these species.…”