Aggregation versus Biological Activity in Gold(I) Complexes. An Unexplored Concept

Abstract

The aggregation process of a series of mono- and dinuclear gold­(I) complexes containing a 4-ethynylaniline ligand and a phosphane at the second coordination position (PR3-Au-CCC6H4-NH2, complexes 1–5, and (diphos)­(Au-CCC6H4-NH2)2, complexes 6–8), whose biological activity was previously studied by us, has been carefully analyzed through absorption, emission, and NMR spectroscopy, together with dynamic light scattering and small-angle X-ray scattering. These experiments allow us to retrieve information about how the compounds enter the cells. It was observed that all compounds present aggregation in fresh solutions, before biological treatment, and thus they must be entering the cells as aggregates. Inductively coupled plasma atomic emission spectrometry measurements showed that mononuclear complexes are mainly found in the cytosolic fraction; the dinuclear complexes are mainly found in a subsequent fraction composed of nuclei and cytoskeleton. Additionally, dinuclear complex 8 affects the actin aggregation to a larger extent, suggesting a cooperative effect of dinuclear compounds.

Gold(i) complexes bearing a PNP-type pincer ligand: photophysical properties and catalytic investigations

“…The molecular structure of 3 seems to be an almost linear string arrangement of four Au atoms connected by three Au–Au contacts involving aurophilic interactions. 17…”

Supramolecular luminescent Pt(ii) tweezers: aggregation studies and 1O2 production

“…The deep knowledge of these weak interactions arises from complementary studies on different fields of research such as organic and inorganic chemistry, coordination chemistry, theoretical studies of non-covalent interactions, molecular recognition and molecular devices among others. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Regarding this, the use of transition metals (TM) as individual molecules or building blocks is particularly interesting due to their versatility. This strategy offers diverse control in the coordination geometry since TM can present a wide variety of coordination numbers that will drive the resulting geometries.…”

Highly emissive supramolecular gold(i)–BTD materials

“…Aurophilic Au⋯Au interactions have been found to play a key role in tuning the electronic and luminescence properties and the supramolecular organization of a wide range of molecular structures. 1,[19][20][21][22][23][24] and provide attractive design motifs to obtain materials with switchable luminescence in response to external stimuli, such as mechanical stress, 25 heat, 26 and solvent vapors. 27 Luminescent 2,1,3-benzothiadiazole (BTD) derivatives and gold(I) complexes have been reported separately but gold(I)-BTD systems have been scarcely explored.…”