Synthesis, X-ray characterization and regium bonding interactions of a trichlorido(1-hexylcytosine)gold(iii) complex

Abstract

We report the first gold(iii) complex with a cytosine derivative since 35 years. In the crystal structure, the complex stacks by reciprocal regium-bonding interactions. These interactions appear to be common in the Cambridge structure database.

Not Only Hydrogen Bonds: Other Noncovalent Interactions

“…A recent investigation described in detail the synthesis, X-ray characterization, and regium bonding interactions in a trichlorido-(1-hexylcytosine)gold(III) complex [67]. Moreover, this study also included an interesting search in the CSD, revealing that this type of noncovalent interaction is recurrent in X-ray structures and has remained essentially unobserved because of the underestimated van der Waals radius value tabulated for gold.…”

“…Au(I)) the more acidic the Lewis acid; see, for instance, the complex (CF3)3Au•••pyridine [63]. We cited Legon in a 2014 paper [64] In 2019, several papers were published on regium bonds, from which we have selected the following four Reference works [65][66][67][68].…”

“…Figure 5 shows the self-assembled dimer that is formed in the solid state of trichlorido-(1-hexylcytosine)gold(III) where two symmetrically equivalent Au•••Cl regium bonds are established. In 2019, several papers were published on regium bonds, from which we have selected the following four Reference works [65][66][67][68].…”

Study of Beryllium, Magnesium, and Spodium Bonds to Carbenes and Carbodiphosphoranes

“…In circulation, there also exist names that refer to individual elements of group 1 or 2, namely lithium bonds [ 17 , 18 , 19 , 20 ] and sodium bonds [ 21 , 22 ] in the former case and beryllium bonds [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ], magnesium bonds [ 23 , 29 , 30 , 31 , 32 , 33 ], and calcium bonds [ 34 ] in the latter. Interactions involving various transition metals have not been called so willingly; however, in the case of interactions in which the Lewis acid center is a metal from groups 10 or 11, the term regium bonds [ 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ] is relatively common. It is worth mentioning here that for interactions involving metals from group 11, the name coinage-metal bonds was previously introduced.…”

Combined Effect of Caspase-Dependent and Caspase-Independent Apoptosis in the Anticancer Activity of Gold Complexes with Phosphine and Benzimidazole Derivatives

“…The replacement of the S-donor ligands by N-donor ligands produced a new family gold complexes that have revealed interesting anticancer activities. These N-donor ligands include imidazoles [ 29 ], naphthalimides [ 30 ], cytosines [ 31 ], bipyridines [ 32 ], phenanthrolines [ 33 ], or benzimidazoles [ 34 , 35 , 36 ]. The biochemical mechanism of action involved in the anticancer activity of the gold complexes with N-donor ligands is presumably the same as that of auranofin, although it is a matter of study interest due to the diversity of results obtained in different investigations regarding biological targets for auranofin [ 18 , 19 , 20 , 21 , 22 ], and due to the different complex stabilization by the replacement of the thiolate ligand by the N-donor ligand.…”