Heterometallic Au(I)–Cu(I) Clusters: Luminescence Studies and¹O₂Production

Abstract

Two different organometallic gold­(I) compounds containing naphthalene and phenanthrene as fluorophores and 2-pyridyldiphenylphosphane as the ancillary ligand were synthesized (compounds 1 with naphthalene and 2 with phenanthrene). They were reacted with three different copper­(I) salts with different counterions (PF6 –, OTf–, and BF4 –; OTf = triflate) to obtain six Au­(I)/Cu­(I) heterometallic clusters (compounds 1a–c for naphthalene derivatives and 2a–c for phenanthrene derivatives). The heterometallic compounds present red pure room-temperature phosphorescence in both solution, the solid state, and air-equilibrated samples, as a difference with the dual emission recorded for the gold­(I) precursors 1 and 2. The presence of Au­(I)–Cu­(I) metallophilic contacts has been identified using single-crystal X-ray diffraction structure resolution of two of the compounds, which play a direct role in the resulting red-shifted emission with respect to the gold­(I) homometallic precursors. Polystyrene (PS) and poly­(methyl methacrylate) (PMMA) polymeric matrices were doped with our luminescent compounds, and the resulting changes in their emissive properties were analyzed and compared with those previously recorded in the solution and the solid state. All complexes were tested to analyze their ability to produce 1O2 and present very good values of ΦΔ up to 50%.

Investigating the Impact of Packing and Environmental Factors on the Luminescence of Pt(N^N^N) Chromophores

“…Based on our previous experience, the dispersion of luminophores within this type of matrices may improve their emission properties regarding emission quantum yields and lifetimes. 23 , 52 − 54 The recorded emission spectra indicate that the intermolecular packing, responsible for the resulting MMLCT emission is observed to be not favored in these media while the 3 IL monomer is the emissive species instead ( Figure 4 and Table 2 ). Vibronically structured bands are herein displayed due to a well distribution of the molecules within the thin film media, and they present, as expected, higher emission quantum yields and larger emission lifetimes.…”

“…The design and synthesis of coordination polymers, where the metal centers coordinated to specific ligands in a polymeric chain (being the metal part of the polymeric structure), has been extensively explored. − , Nevertheless, the introduction of metallic chromophores as side pending chains within an organic polymer is less explored and even less, the particular use of metal centers suitable to establish metal···metal interactions, playing particular roles in the 2D and 3D structure of metallopolymers or metal coordinating polymers and also in the resulting emissive properties. Regarding this, poly­(4-vinylpyridine), PV, is a very good option due to the presence of pyridyl pending groups, suitable for coordination to a large number of metals and for this reason, it has been used as support of metal-containing polymers, metal nanoparticles, or metal films with several applications such as (photo)­sensing or catalysis. − Nevertheless, the coordination of specific metals well-known to establish metallophilic contacts is scarcely explored. − The use of these metals is of great importance regarding the development of luminescent materials since the resulting photophysical properties are strongly affected by the interplay of different noncovalent interactions such as M···M but also hydrogen bonding, π–π stacking or halogen bonding, among others. − Platinum­(II), with d 8 configuration, is one of the most studied metals suitable for metallophilic contacts and with relevant emissive properties. The involvement of several intra- and intermolecular contacts has resulted in the modulation of the intrinsic luminescence that can be tuned on energies (emission wavelength), intensities (quantum yields), or lifetimes (from a few ns to hundreds of microseconds).…”

Identification of a Sonically Activated Degrader of Methionine Adenosyltransferase 2A by an in Silico Approach Assisted with the Hole–Electron Analysis

“…The sonically generated ROS was mainly singlet oxygen ( 1 O 2 ) rather than hydroxyl radical (OH·) or superoxide anion (O 2 – ), as investigated by the electron spin resonance (SI, Figure S5) and the spectroscopic methods (SI, Figure S6). , Additionally, H3 displayed red fluorescence with a maximum emission wavelength of 600 nm, which were longer than the previously reported MAT2A inhibitors (SI, Figure S7).…”

“…These results indicate that the specific MAT2A degrading capacity of H3 can expectedly lower the drug dosage and reduce the toxicity to liver tissue caused by high-dose MAT2A inhibitors. Additionally, H3 displayed moderate permeability ( P app ) and a low efflux ratio (ER) in MDR1-MDCKII cells . It also displayed a low human hepatocyte intrinsic clearance (CL int ).…”

Effect of substituents on the 1O2 production and biological activity of (N^N^N)Pt(py) complexes

“…Some TMCs have been explored as PS, e.g. Ru( ii ) polypyridyl complexes, 11 iridium( iii ), 12 gold( i ) complexes, 13–15 and platinum( ii ) complexes. 16–19…”