A Convenient Approach to Luminescent Cyclometalated Platinum(II) Complexes with Organometallic π‐Bonded Benzenedithiolate

Abstract

A family of neutral cyclometalated platinum(II) complexes [(C^N)Pt(η-S^S)] with π-bonded benzenedithiolate {(η-S^S) = Cp*Ru(C 6 H 4 S 2 )} and various cyclometalated ligands, (bzq) (4); dibenzo[f,h]quinoline (dbzq) (5)} were prepared and fully characterized. For comparison purposes the related bipyridine platinum(II) complex [(bpy)Pt(η-S^S)][OTf ] (6) was also prepared. The electrochemistry behavior of these complexes was investigated and shows the enhanced stability of these compounds toward oxidation [a] 3804 Scheme 1. Synthesis of cyclometalated platinum complexes 2-5.Scheme 2. Synthesis of the bipyridyl platinum complex 6.

Cyclometalated Rhodium and Iridium Complexes Containing Masked Catecholates: Synthesis, Structure, Electrochemistry, and Luminescence Properties

“…Under the same conditions, a second oxidation process was also observed at a more positive potential value but its reversibility was not as clearly defined as for the previous one. In analogy with reported studies on similar complexes, these two successive oxidation processes can be assigned to the Ir III /Ir IV and Ru II /Ru III redox couples, respectively. ,, …”

“…In analogy with reported studies on similar complexes, these two successive oxidation processes can be assigned to the Ir III /Ir IV and Ru II /Ru III redox couples, respectively. 25,29,40 Compared to iridium complex 3, rhodium analogue 2 exhibits the first process, which is reversible at low scan rates (e.g., 0.1 V s −1 ), showing that replacing the Ir atom metal center with an Rh one leads to a more stable oxidized species (compare Figures 4b and 5b). This process can be assigned to the Rh III /Rh IV redox couple.…”

“…Thus, using our approach, we prepared a novel class of phosphorescent [M­(N∧N) 2 (η-Cat)] 2+ compounds (Cat = η-O∧O). The presence of a Cp*Ru moiety in the organometallic ligand permits tuning the electronic properties of such molecules, affording compounds capable to absorb along the whole range of the visible spectrum and displaying interesting luminescence properties. − Therefore, these metalloligands play an important role in the design of a novel class of [(η-O∧O)­Ru­(N∧N) 2 ] 2+ complexes featuring new properties. Thus, we envisioned preparing a novel class of luminescent cyclometalated rhodium and iridium complexes containing π-bonded dioxolene ligands.…”

Fine-Tuning of Luminescence Properties of Cyclometalated Platinum(II) Complexes via Aminopyridine Derivatives

“…The pyridine (8.7 μL, 0.108 mmol) ligand was added to a solution of A (50 mg, 0.108 mmol) in acetone (10 mL). The solution was stirred for 1 h at 298 K, and then the solvent was evaporated and the residue was washed with n-hexane ( 3 J FH = 13.1 Hz, 3 J FH = 8.8 Hz, 4 J HH = 2.3 Hz, 1H, H 3 ′ of dfppy), 6.99 (t, 3 J HH = 6.6 Hz, 1H, H c of py), 7.35 (dd, 3 J PtH = 77.4 Hz, 3 J HF = 9.6 Hz, 4 J HH = 2.4 Hz, 1H, H 5 ′ of dfppy), 7.51 (dd, 3 J HH = 3 J HH = 6.6 Hz, 2H, H b of py), 7.76 (d, 3 J PtH = 16.8 Hz, 3 J HH = 5.5 Hz, 1H, H 6 of dfppy), 7.81 (dd, 3 J HH = 3 J HH = 7.7 Hz, 1H, H 4 of dfppy), 7.91 (dd, 3 J HH = 3 J HH = 7.7 Hz, 1H, H 5 of dfppy), 8.18 (d, 3 J HH = 8.4 Hz, 1H, H 3 of dfppy), 8.84 (dd, 3 J PtH = 22.9 Hz, 3 J HH = 6.6 Hz, 4 J HH = 1.2 Hz, 2H, H a of py).…”

“…The luminescent cyclometalated Pt­(II)-based complexes possessing a d 8 electronic configuration have always attracted great attention due to their outstanding excited state features and potential applications, which rely on their phosphorescence. − In the last decades, they have been widely utilized in light-emitting diodes (LEDs), − chemosensing, , bioimaging, − dye-sensitized solar cells, photo-switches, , and photocatalyst , applications. Large spin–orbit coupling induced by the Pt center facilitates an inter-system crossing phenomenon so that the triplet manifold is remarkably created and ends up in the triplet state relaxation (T 1 → S 0 radiative process) or phosphorescence.…”