Triple‐ring tubular MB₃₆ (M = Mg, Ca, Sr, Ba) with threefold aromaticity

Abstract

The modification with alkaline‐earth metals to the energy unfavorable triple‐ring B36 result in a family of stable triple‐ring tubular MB36 (M = Mg, Ca, Sr, Ba). The triple‐ring structures are highly energy favorable than the structures on the basis of the global‐minimum of B36 which is experimentally known as planar structure with dual aromaticity. Basic chemical bonding analysis reveals the σ and dual π aromaticity of these triple‐ring tubes, which refer to threefold aromaticity and result in the chemical stability. Large energy gap and high formation energy support their stability. Highly negative NICS values sustain the same conclusion. This findings hint the possibility of experimental synthesis of triple‐ring tube by importing metals.

OEEF-Driven Intramolecular Self-Redox of Superalkali Rb3BeB6Be′Rb′3: A High-Performance Candidate for NLO Molecular Switch

“…In this work, all quantum chemistry calculations, including geometrical optimization, frequency calculation, were done by using Gaussian16 (version A.03) program . For the field-free Rb 3 BeB 6 Be′Rb′ 3 , it is reported that the global minimum (GM) structure adopts a D 3 d symmetry, and its structure was optimized at the PBE0/def2-qzvp level, which has been suggested to be reliable for the study of boron-based clusters. − Then, based on this structure, the optimized geometries for each stationary point of Rb 3 BeB 6 Be′Rb′ 3 with different OEEFs were also calculated at the PBE0/def2-qzvp level. The natural population analysis (NPA) was calculated at the MP2, PBE0, and CASSCF­(2,2) methods with def2-qzvp basis set.…”