Intermolecular interactions involving the N-heterocyclic carbene and its heavier analogues C₂H₄N₂X: (X = C, Si, Ge, Sn, Pb) with YH₃F (Y = Si, Ge, Sn, Pb)

Abstract

The intermolecular complexes formed between imidazol-2-ylidene and its heavy-atom analogues C₂H₄N₂X: (X = C, Si, Ge, Sn, Pb) and YH₃F (Y = Si, Ge, Sn, Pb) have been optimized at the MP2/aug-cc-pVTZ level. C₂H₄N₂X: have two electron-rich moieties, one of which is the lone pair on the X atom and the other is the 6π-electron system. Three types of binding modes (type-A, type-B and type-C) can be distinguished for C₂H₄N₂X: according to the locations of YH₃F. The type-A and type-B complexes can be located for C2H4N2C:···YH₃F system, and the E_int values of the type-A complexes are much larger than those of the type-B complexes. The type-A, type-B and type-C complexes can be located for the other four systems, and the E_int values of these complexes go in the order type-B > type-C > type-A. The binding strength of the type-A complexes becomes weaker, and that of the type-B and type-C complexes becomes stronger with the increase of the X atomic number for C₂H₄N₂X:···YH₃F system, which can be clarified by the MEP maps of C₂H₄N₂X:. The NBO, AIM and SAPT analysis was employed to explore the nature of the interactions in these complexes.

GRAPHICAL ABSTRACT

KEYWORDS:

• Intermolecular interaction
• N-heterocyclic carbene
• tetrel bond
• MEP surfaces
• NBO analysis

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Scientific Research Funds from the Department of Education of Yunnan Province, China [grant number. 2020J0634].