σ-Aromatic cyclic M₃⁺ (M = Cu, Ag, Au) clusters and their complexation with dimethyl imidazol-2-ylidene, pyridine, isoxazole, furan, noble gases and carbon monoxide

Abstract

The σ-aromaticity of M3(+) (M = Cu, Ag, Au) is analyzed and compared with that of Li3(+) and a prototype σ-aromatic system, H3(+). Ligands (L) like dimethyl imidazol-2-ylidene, pyridine, isoxazole and furan are employed to stabilize these monocationic M3(+) clusters. They all bind M3(+) with favorable interaction energy. Dimethyl imidazol-2-ylidene forms the strongest bond with M3(+) followed by pyridine, isoxazole and furan. Electrostatic contribution is considerably more than that of orbital contribution in these M-L bonds. The orbital interaction arises from both L → M σ donation and L ← M back donation. M3(+) clusters also bind noble gas atoms and carbon monoxide effectively. In general, among the studied systems Au3(+) binds a given L most strongly followed by Cu3(+) and Ag3(+). Computation of the nucleus-independent chemical shift (NICS) and its different extensions like the NICS-rate and NICS in-plane component vs. NICS out-of-plane component shows that the σ-aromaticity in L bound M3(+) increases compared to that of bare clusters. The aromaticity in pyridine, isoxazole and furan bound Au3(+) complexes is quite comparable with that in the recently synthesized Zn3(C5(CH3)5)3(+). The energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital also increases upon binding with L. The blue-shift and red-shift in the C-O stretching frequency of M3(CO)3(+) and M3(OC)3(+), respectively, are analyzed through reverse polarization of the σ- and π-orbitals of CO as well as the relative amount of OC → M σ donation and M → CO π back donation. The electron density analysis is also performed to gain further insight into the nature of interaction.

Noble‐Noble Strong Union: Gold at Its Best to Make a Bond with a Noble Gas Atom

“…In the second contribution, the similar observation was noted in cases of larger mixed clusters, Au n Ag m + ⋅Ar k (n+m=4, 5; k=1–4). Prompted by these studies, Pan et al . performed an ab initio study to assess the stability and bonding in M 3 (Ng) 3 + (M=Cu, Ag, Au; Ng=Ar−Rn) complexes.…”

Cooperative effects between π-hole triel and π-hole chalcogen bonds

“…[72][73][74] In addition, in some cases, H BCP gives a highly negative value even for ionic bonds. [75][76][77][78] 3.3. Chalcogen-bonded dyads Fig.…”

Systematic study of the substitution effect on the tetrel bond between 1,4-diazabicyclo[2.2.2]octane and TH3X

“…This indicates that the Si/N and Ge/N tetrel bond has a partially covalent character. [68][69][70][71][72][73][74][75][76][77] The stronger Si/N interaction has the more negative energy density than the Ge/N analogue.…”