Bonding and stability of elusive silaboryne (SiB) and germaboryne (GeB) with donor base ligands

• Published in: Journal of computational chemistry Vol. 44; no. 19; pp. 1673 - 1689
• Main Authors: Das, Sujit, Devi, Kavita, Suthar, Sonam, Mondal, Kartik Chandra
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 15-07-2023; Wiley Subscription Services, Inc
• Subjects: Atomic structure; borylene‐silylene/germylene; Chemical bonds; DFT; EDA‐NOCV; Electrons; Germanium; Lead; Ligands; pairwise interaction energy; QTAIM; Silicon; silicon/germanium‐boron triple bond; Stability analysis; Structural stability; Tin; pairwise interaction energy; silicon/germanium-boron triple bond; DFT; EDA-NOCV; QTAIM; borylene-silylene/germylene
• ISSN: 0192-8651; 1096-987X
• DOI: 10.1002/jcc.27118

Stabilizing the exotic chemical species possessing multiple bonds is often extremely challenging due to insufficient orbital overlap, especially involving one heavier element. Bulky aryl groups and/or carbene as ligand have previously stabilized the SiSi, GeGe, and BB triple bonds. Herein, theoretical calculations have been carried out to shed light on the stability and bonding of elusive silaboryne/germaboryne (Si/GeB triple bond) stabilized by donor base ligands ((cAAC)BE(Me)(L); E = Si, L = cAACMe, NHCMe, PMe3; E = Ge, L = cAACMe). The heavier analogues (Sn, Pb) have been further studied for comparison. Additionally, the effects of bulky substituents at the Si and N atoms on the structural parameters and stability of those species have been investigated. Energy decomposition analysis coupled with natural orbital for chemical valence (EDA‐NOCV; for Si) showed that cAAC/NHC ligands could stabilize the exotic BSi‐Me species more efficiently than PMe3 ligands. The BSi partial triple bond of the corresponding species possesses a mixture of one covalent electron sharing BSi σ‐bond and two dative π‐bonds (B ← Si, B → Si).