Cyclic trinuclear copper(i), silver(i), and gold(i) complexes: a theoretical insight

Abstract

The metal-ligand, M-L, bonding situation in cyclic trinuclear complexes, CTCs, of copper(I), silver(I), and gold(I) was investigated in terms of the energy decomposition analysis (EDA-NOCV) and natural bond orbitals (NBOs). The anisotropy of the induced current density (ACID) and magnetic response were employed to evaluate the effect of electronic conjugation and metal-metal interactions in CTCs. The EDA-NOCV results show that the M-L bonding is stronger in gold(I) than in copper(I) or silver(I) complexes. Au(+)-L bonds present an elevated covalent character when compared with Cu(+)-L and Ag(+)-L bonds. The NBO analysis confirms the elevated covalent character observed for Au(+)-L bonds, indicating that the ligand-metal donation, L → M, and the metal-ligand back-donation, M → L, are more stabilizing in gold(I) than in copper(I) or silver(I) complexes. Both ACID and the magnetic response calculations reveal that there are cyclic conjugations in the ligands and a strong diatropic ring current indicating the presence of aromaticity. However, there is no through-bond M-L conjugation between the ligands and the metallic centers, as indicated by the absence of a continuous anisotropy boundary surface involving M-L bonds.

Remarkable Structural and Electronic Features of the Complex Formed by Trimeric Copper Pyrazolate with Pentaphosphaferrocene

“…Moreover, LUMO and LUMO+1 of folded [(CuL) 3 ] point to PP bonds involved in the interaction (see the Supporting Information, Figures S10 and S11). The total orbital interaction energy between the macrocycle and pentaphosphaferrocene is as high as −147.4 kcal mol −1 , which is even larger than the orbital energy of the Cu 2 –pyrazolate interaction (−98.5 kcal mol −1 ) 15. All of these electron density transfers lead to the extremely large energy of the folded macrocycle–pentaphosphaferrocene interaction Δ E int =−104.0 kcal mol −1 .…”

“…The total orbital interaction energy between the macrocycle andp entaphosphaferrocenei sa sh igh as À147.4 kcal mol À1 ,w hich is even larger than the orbitale nergy of the Cu 2 -pyrazolate interaction (À98.5 kcal mol À1 ). [15] All of these electron density transfers lead to the extremelyl arge energy of the folded macrocycle-pentaphosphaferrocene interaction DE int = À104.0 kcal mol À1 .C onsidering deformations of fragments prior to the interaction (51.0 and4 .0 kcal mol À1 for 1 and 2,r espectively)g ives at otal energy of complex formation DE compl = DE int ÀDE prep = À49.0 kcal mol À1 . AIM analysis [16] of the complex reveals four expected bond critical points between Cu and Pa toms.…”

Advances in bonding and properties of inorganic systems from relativistic calculations in Latin America

“…Both bonding and antibonding combinations are similarly populated in long cases, where this electronic correlation plays a relevant role in the stabilization of such interaction, as it is usual in metallophilic interactions . A similar situation has been accounted for [M 3 (L) 3 ] (M = Cu(I), Ag(I), Au(I), L = pyrazolate (pz), imidazolate, triazolates, pyridiniate and others . Unpublished results also account for this situation in four‐membered Cu(I) aggregates.…”

“…Caramori and coworkers, revealed the nature of the metal‐ligand interaction by using an energy decomposition analysis (EDA) based on two selected fragments (Figure ), in cyclic trinuclear copper(I), silver(I), and gold(I) complexes, showing that Au(I)‐ligand bonds display an elevated covalent character in comparison with their copper and silver counterparts. From NBO analysis, this character is confirmed to involve a sizable sigma ligand‐metal donation, and a metal‐ligand back‐donation, which are more stabilizing in the following order: Au(I) > Cu(I) > Ag(I).…”

Bonding and properties of superatoms. Analogs to atoms and molecules and related concepts from superatomic clusters

“…The electronic structure is rationalized as 1S 2 1P x , y 4 1D xy , x 2 − y 2 4 , highlighting the role of the ligands in the resulting superatomic shell population. Additionally, systems with large d 10 ‐d 10 interaction (~3.4Å) have been discussed in terms of the planar superatom model …”