Long-Lived Emission from Platinum(II) Terpyridyl Acetylide Complexes

Abstract

Photoluminescence with high quantum yield and long lifetime from a triplet metal-to-ligand charge transfer (MLCT) excited state in fluid solution at room temperature has been observed for a series of platinum(II) 4'-p-tolyl-terpyridyl acetylide complexes.

Switching between Ligand‐to‐Ligand Charge‐Transfer, Intraligand Charge‐Transfer, and Metal‐to‐Ligand Charge‐Transfer Excited States in Platinum(II) Terpyridyl Acetylide Complexes Induced by pH Change and Metal Ions

“…With reference to previous spectroscopic work on similar complexes reported by ourselves and others, [17,18,36,[40][41][42] the absorption bands at wavelengths below 350 nm are assigned to the intraligand (IL) transition of the terpyridyl and acetylide ligands, while the absorption band at 350-460 nm is ascribed to the dp(Pt)!p*A C H T U N G T R E N N U N G (terpy) MLCT transition. The lowest-energy absorption band in the region of 460-700 nm is consistent with an LLCT transition from the amino-substituted acetylide ligand to the terpyridyl acceptor.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Indeed, these complexes have demonstrated promise for various applications, including optical power limiting, [20][21][22] electroluminescence, [13,[23][24][25][26] as photosensitizers for the generation of singlet oxygen [27] or hydrogen, [28] as molecular probes for biological macromolecules, [12,29] and as optical sensors. [17,18,[30][31][32][33][34] In particular, platinum(II) complexes bearing terpyridyl and acetylide ligands have been extensively investigated in view of their rich photophysical properties. [12,17,20,21,28,31,35,36] The spectroscopic properties and low-energy absorptions of these complexes may arise from metal-to-ligand charge transfer (MLCT), intraligand charge transfer (ILCT), ligand-to-l...…”

“…[17,18,[30][31][32][33][34] In particular, platinum(II) complexes bearing terpyridyl and acetylide ligands have been extensively investigated in view of their rich photophysical properties. [12,17,20,21,28,31,35,36] The spectroscopic properties and low-energy absorptions of these complexes may arise from metal-to-ligand charge transfer (MLCT), intraligand charge transfer (ILCT), ligand-to-ligand charge transfer (LLCT), or intraligand (IL) transitions, depending very much on the substitution on their terpyridyl and/or acetylide ligands. In most instances, these complexes exhibit long-lived excited states with photophysical properties consistent with a dp(Pt)!p*(terpyridyl) MLCT transition.…”

“…In most instances, these complexes exhibit long-lived excited states with photophysical properties consistent with a dp(Pt)!p*(terpyridyl) MLCT transition. [12,17] However, there are also ample examples whereby certain (5)), has been synthesized and the photophysical properties of the complexes have been examined through measurement of their UV/Vis absorption spectra, photoluminescence spectra, and transient absorptions. Complex 3 shows a lowest-energy absorption corresponding to a ligand-to-ligand charge-transfer (LLCT) transition from the acetylide to the terpyridyl ligand, whereas 4 shows an intraligand charge-transfer (ILCT) transition from the p orbital of the 4'-phenyl group to the p* orbital of the terpyridyl.…”

Dynamic scaffold of chiral binaphthol derivatives with the alkynylplatinum(II) terpyridine moiety

“…In contrast, the emission maximum of 1 in CH 3 CN only shows a slight blue shift relative to that observed in CH 2 Cl 2 ( Fig. S7B) due to the negative solvatochromism (35), without the self-assembly of the two platinum(II) terpyridine moieties to form metal···metal and π−π interactions. In the variable temperature luminescence study, upon increasing the temperature, both 2 and 3 show a decrease in 3 MMLCT emission as shown in Fig.…”