A theoretical investigation on Cu/Ag/Au bonding in XH2P⋯MY(X = H, CH3, F, CN, NO2; M = Cu, Ag, Au; Y = F, Cl, Br, I) complexes

Abstract

Intermolecular interaction of XH2P···MY (X = H, CH3, F, CN, NO2; M = Cu, Ag, Au; Y = F, Cl, Br, I) complexes was investigated by means of an ab initio method. The molecular interaction energies are in the order Ag < Cu < Au and increased with the decrease of RP···M. Interaction energies are strengthened when electron-donating substituents X connected to XH2P, while electron-withdrawing substituents produce the opposite effect. The strongest P···M bond was found in CH3H2P···AuF with −70.95 kcal/mol, while the weakest one was found in NO2H2P···AgI with −20.45 kcal/mol. The three-center/four-electron (3c/4e) resonance-type of P:-M-:Y hyperbond was recognized by the natural resonance theory and the natural bond orbital analysis. The competition of P:M–Y ↔ P–M:Y resonance structures mainly arises from hyperconjugation interactions; the bond order of bP–M and bM–Y is in line with the conservation of the idealized relationship bP–M + bM–Y ≈ 1. In all MF-containing complexes, P–M:F resonance accounted for a larger proportion which leads to the covalent characters for partial ionicity of MF. The interaction energies of these Cu/Ag/Au complexes are basically above the characteristic values of the halogen-bond complexes and close to the observed strong hydrogen bonds in ionic hydrogen-bonded species.

Exploring Nature and Predicting Strength of Hydrogen Bonds: A Correlation Analysis Between Atoms‐in‐Molecules Descriptors, Binding Energies, and Energy Components of Symmetry‐Adapted Perturbation Theory

“…Next, we investigate whether good correlations could be found between other properties at the BCP and the BE. The electronic energy density H ( r ) at the BCP position may behave as a useful index for characterizing the nature of HB interaction, as it has been involved in many QTAIM studies for HB systems and other kinds of weakly interacting complexes . It is expected that H BCP has a somewhat implicit correlation with HB strength, a stronger HB interaction should correspond to a more negative H BCP .…”

Understanding Regium Bonds and their Competition with Hydrogen Bonds in Au2:HX Complexes

“…The NBO analysis shows the presence of two resonance forms for RB complexes in agreement with previous results reported for complexes between phosphine and aurous salts. [20] The dominant resonance form dissociates the complex within the original separated moieties (Au 2 and HX molecules), while the second most important resonance structure corresponds to a situation in which the outer Au atom is negatively charge and the Lewis base HX and the inner Au atom are forming a positive charged fragment altogether. This second resonance form is evidently important, since, in general, has an enhancing effect on the regium bond as the interaction becomes stronger ( Table 5).…”

“…The nature of the complexes between H 2 O and H 2 S acting as Lewis basis and AuCl as Lewis acid has been analyzed using AIM and NBO methods . The intermolecular interaction between phosphines (XH 2 P with X=H, CH 3 , F, CN, NO 2 ) and MY molecules (M=Cu, Ag, Au and Y=F, Cl, Br, I) has been studied . Cooperativity in ternary complexes that involve regium bond has been explored .…”

“…[19] The intermolecular interaction between phosphines (XH 2 P with X=H, CH 3 , F, CN, NO 2 ) and MY molecules (M=Cu, Ag, Au and Y=F, Cl, Br, I) has been studied. [20] Cooperativity in ternary complexes that involve regium bond has been explored. [21] The spectroscopic properties of the Au 2 systems have been calculated using DFT and coupled cluster levels.…”

Rivalry between Regium and Hydrogen Bonds Established within Diatomic Coinage Molecules and Lewis Acids/Bases

“…[29] The complexes between a variety of phosphines and halo derivatives of noble metals were studied at MP2 level showing that the interaction energy order is Ag < Cu < Au. [30] The aim of the present paper is to explore the complexes formed by Ag 2 , Cu 2 , CuÀ Ag, CuÀ Au and AgÀ Au with several molecules that can act either as hydrogen bond donors or regium bond acceptors (FH, ClH, OH 2 , SH 2 , HCN, HNC, HCCH, NH 3 and PH 3 ), ( Figure 1) complexes which were previously studied for Au 2 :XH complexes. [31] The structures and spectroscopic characteristics of the RÀ R' binary clusters were described experimentally [32] and studied theoretically.…”