Click Reaction Driven, Highly Fluorescent Dinuclear Organogold(I) Complex Exhibits a Dual Role: A Rare Au···H Interaction and an Antiproliferative Agent

Abstract

The metal−hydrogen (M•••H) bonds in transition elements are well documented. However, the attractive Au I •••H bond interaction is rare and significant experimental evidence for it still remains a challenge. Herein, we exhibit a rare example of a C−H•••Au interaction in both the solid state and solution by employing a single-crystal X-ray diffraction study and NMR spectroscopy for the novel dinuclear Au(I) complex 1, prepared by a click reaction between organized and strained internal alkynes ((PPh 3 Au− CC−) 2 −C 6 H 4 ) as reacting partners. Furthermore, 1 was found to be highly fluorescent in nature and revealed remarkable antiproliferative properties against skin melanoma cell lines with IC 50 values ranging from 3.12 to 8.5 μM.

A Rare Intramolecular Au···H–C(sp3) Interaction in a Gold(I) N-Heterocyclic Carbene

“…From 1 H NMR, it is clear that the Au···H–C­( sp 3 ) interaction exists only in the solid state, as the N–C H 2 splitting pattern and integral value are unaltered. The Au···H–C­( sp 3 ) hydrogen-bonding interaction is common in gold­(I) phosphine complexes, while a similar interaction has not been reported with Au­(I) NHC complexes. ,,, …”

“…In addition, a dinuclear cationic gold­(I) mesoionic carbene compound containing a phosphine ligand was reported with a C­( sp 2 )–H···Au­(I) hydrogen-bonding interaction by Mobin and co-workers in 2019 (Chart , II ). In this case, a C­( sp 2 )­H···Au­(I) distance of 2.638 Å was recorded using the bridging rigid phenyl group . In this case, the influence of hydrogen bonding on the luminescence properties of gold­(I) complexes was demonstrated.…”

“…In this case, a C(sp 2 )H••• Au(I) distance of 2.638 Å was recorded using the bridging rigid phenyl group. 8 In this case, the influence of hydrogen bonding on the luminescence properties of gold(I) complexes was demonstrated. N-(9-anthracenyl)-N′-(heptyl)-benzimidazolium bromide (L•HBr) was synthesized by a solvent-free nucleophilic aromatic substitution (S N Ar) protocol at high temperature.…”

The iClick Reaction of a BODIPY Platinum(II) Azido Complex with Electron-Poor Alkynes Provides Triazolate Complexes with Good 1O2 Sensitization Efficiency

“…Over the past decade, the “iClick” [3 + 2] cycloaddition reaction of metal-azido complexes with alkynes and other dipolarophiles has emerged as a powerful synthetic method to generate five-membered heterocyclic ligands directly in the inner coordination sphere of a metal center. − The term iClick was originally coined by Veige et al., who reported on the reaction of the linear gold­(I) complexes [Au­(N 3 )­(PPh 3 )] and [Au­(CCPh)­(PPh 3 )] to form 4-phenyl-1,5-bis-triphenyl­phosphinegold­(I)-1,2,3-triazolate . Since then, a wide range of other metal-azido compounds have been explored for similar reactivity. − Interestingly, the reaction could even be performed in the inner pores of a metal–organic framework (MOF) decorated with bis­(dimethylpyrazolyl)­methane groups coordinated to a Mn­(N 3 )­(CO) 3 moiety . Recently, the iClick reaction has also been utilized as a facile way to synthesize bioconjugates , and metal complexes for bioactivity studies. − More and more information is also emerging on the influence of the metal-azido and alkyne reaction partners on the kinetics of the iClick reaction. − However, most studies have focused on the properties of the triazolates thus obtained without paying attention to kinetic issues.…”

A Topological Data Analysis perspective on noncovalent interactions in relativistic calculations

“…In order to illustrate and further extend the idea of using TDA for interatomic interactions, we have chosen a molecular system studied recently by Anderson et al, Au 4 ‐S‐C 6 H 4 ‐S′‐Au′ 4 (Figure ), which is interesting in the context of gold‐sulfur and gold‐hydrogen interactions due to their ubiquity in metalorganic complexes and on interface—a proof of many faces of the fascinating chemistry of gold . A remarkable finding of the study of Anderson et al is that it characterized the emergence of NCIs between gold and hydrogen centers, using the Quantum Theory of Atoms‐In‐Molecules (QTAIM)…”