Expanding the toolbox of the coinage bond: adducts involving new gold(iii) derivatives and bioactive molecules

Abstract

X-ray analyses of a small library of adducts between AuX3 (X=Cl, Br) and several pyridine derivatives indicate the systematic presence of quite short π -holes coinage bonds; computational studies reveal...

Periodate anions as a halogen bond donor: formation of anion⋯anion dimers and other adducts

“…This recognition motif is commonly shown by σ- and π-hole based tectons wherein the donor and acceptor atoms are directly bonded to each other. 7,9,10 Consistent with the typical HaB features, I⋯O short contacts occur on the extension of a O–I covalent bond, namely the O–I⋯O angles are very close to linearity (175.85° in 1 and 176.98° in 2 ). The observed I⋯O separations are far below the sum of van der Waals radii 20 of the involved atoms, with normalized contacts (Nc) 21 which are notably small for anion⋯anion interactions (0.91 in 1 and 0.94 in 2 ).…”

“…Elements of the p block of the periodic table have been investigated after this viewpoint, and according to the IUPAC definition, s-hole interactions given by elements of groups 17 and 16 can be named halogen bonds (HaBs) 5 and chalcogen bonds (ChBs), 6 respectively. Recently, an analogous mindset was developed also for interactions formed by elements of the d block, specifically elements of groups 7 (matere bond, MaB), 7 8 (osme bond, OmB), 8 11 (coinage bond, CiB), 9,10 and 12 (spodium bond, SpB). 11 For group 8 elements, OsÁ Á ÁN/O short contacts have been identified experimentally in neutral adducts between OsO 4 (electrophile) and pyridine/pyridine N-oxide derivatives (nucleophile).…”

Anion···Anion [AuI4]−···[AuI2]− Complex Trapped in the Solid State by Tetramethylammonium Cations

“…Therefore, this interaction can be termed as CiB, in line with recent investigations of [AuCl 4 ] − and [AuBr 4 ] − compounds. 12,13 In contrast, in the Au(I)•••I dimer, the Au(I) atom is acting as nucleophile and the iodine atom as an electrophile since a significant shift of the ED minima to the iodine electron density basin is observed. This is evidence that, in this case, the d 10 -Au(I) atom is partially donating electrons to the electrophilic σ-hole of iodine.…”

“…In particular, Resnati and collaborators 12 have shown that [AuCl 4 ] − anions are able to act as self-complementary tectons, with the gold and chlorine atoms functioning as CiB donor and acceptor sites, respectively. By using theoretical calculations and crystal engineering, it has been proved that CiBs involving gold(III) centers are strong enough to drive the formation of attractive anion•••anion 12 and anion•••neutral nucleophile 13 interactions, determining the crystal packing of Au(III) derivatives.…”

Hydrogen and halogen bond synergy in the self-assembly of 3,5-dihalo-tyrosines: structural and theoretical insights

“…Both computational tools combined are very useful to reveal noncovalent forces in real space, as recently reported for other σ-hole interactions. 31–34 The binding energy of the dimer of 1a is large (−30.4 kcal mol −1 ) due to the strong electrostatic attraction between the ammonium and carboxylate groups, confirming the dominant role of the CAHBs. The HB is characterized by a bond critical point (CP, represented as a small red sphere in Fig.…”