Synthesis and Ion-Binding Studies of a Platinum(II) Terpyridine Complex with Crown Ether Pendant. X-ray Crystal Structure of [Pt(trpy)(S-benzo-15-crown-5)]PF₆

Electronic structures and optical properties of neutral substituted fluorene-based cyclometalated platinum(II)–acetylide complexes: A DFT exploration

“…Recently, they also developed tridentate cyclometalated Pt(II) lumophores with C^N^N ligand (HC^N^N = 6-aryl-2,2 0 -bipyridine) [33,[54][55][56][57][58]. Compared to N^N^N (or tpy, 2,2 0 ,6 0 ,2 00 -terpyridine) and C^N^C (HC^N^CH = 2,6-diphenylpyridine) congeners [59][60][61][62], two advantages of the C^N^N ligand have emerged: the strongly r-donating carbanion would increase the energy difference between the ligand field and the MLCT states with superior emissive properties, and associating with the anionic alkynyl ligand affords neutrality to the cyclometalated Pt(II) r-alkynyl moiety framework. Seneclauze and Ziessel have developed various combinations of mono-or diethynyl-substituted fluorene building blocks connected via a r-bonded ethynyl linkage to ortho-metallated Pt(C^N^N) segments [63].…”

Highly Phosphorescent Crystals of Square‐Planar Platinum Complexes with Chiral Organometallic Linkers: Homochiral versus Heterochiral Arrangements, Induced Circular Dichroism, and TD‐DFT Calculations

“…On the basis of the previous spectroscopic studies on [Pt(terpy)Cl] + , which showed a low‐energy MLCT absorption band at 400 nm, as well as the electron‐donating behavior of the thiolate group, the low‐energy absorption band is tentatively assigned as admixtures of pπ(RS)→π*(terpy) ligand‐to‐ligand charge transfer (LLCT) transition and dπ(Pt)→π*(terpy) metal‐to‐ligand charge transfer (MLCT) transition. Similar assignments have also been reported for the related platinum(II) complexes . Upon incorporation of tert ‐butyl substituents on the terpyridine ligand, a blue shift of the low‐energy absorption band in rac ‐ 3 , ( pR , R )‐ 3 , and ( pS , S )‐ 3 (482 nm) is observed relative to rac ‐ 2 , ( pR , R )‐ 2 , ( pS , S )‐ 2 (496 nm).…”

“…[OTf] 2 [19] and the related neutral organometallo-ligands, the high-energyabsorption band is attributed to p!p*intraligand (IL) transitions of terpyridine.B esides the IL transitions, al owenergyb road absorption band at 482-496 nm is observed. On the basis of the previous spectroscopic studies on [Pt(terpy)Cl] + , [8,18,20,[40][41][42] which showed al ow-energy MLCT absorption band at 400 nm, as well as the electron-donating behavior of the thiolate group, the low-energy absorption band is tentatively assigned as admixtures of pp(RS)!p*(terpy) ligand-toligand charge transfer (LLCT) transition and dp(Pt)!p*(terpy) metal-to-ligand charget ransfer (MLCT) transition. Similara ssignmentsh ave also been reportedf or the relatedp latinum(II) complexes.…”

“…Similara ssignmentsh ave also been reportedf or the relatedp latinum(II) complexes. [42][43][44][45] Upon incorporation of tert-butyl substituents on the terpyridinel igand,ablue shift of the low-energy absorptionb and in rac-3,( pR,R)-3,a nd (pS,S)-3 (482 nm) is observed relative to rac-2,( pR,R)-2,( pS,S)-2 (496 nm). This can be attributed to the presence of the three tert-butyl groups on the terpyridyl ligandse xerting as trong positive inductive effect, raising the p*(tBu 3 terpy) orbital energy and giving rise to ahigherMLCT absorption energy.…”

Synthesis, crystal structure, photophysical property and metal ion-binding behavior of a cyclometalated platinum(ii) terpyridylacetylide with efficient π-conjugation degree

“…1,2 The "Chromophore-Spacer-Receptor" model has been generally designed, and the transition metal complexes with electronic transition in visible/near-IR region, high quantum efficiency and long lifetime have been extensively employed as uorophores instead of the organic counterparts. 3 Owing to their intriguing spectroscopic and luminescence properties, square-planar platinum(II) polypyridyl complexes imparted with metal-binding units, such as P-and N-donor crown ether pendants, 4 S-benzo-15-crown-5, 5 4-ethynylbenzo-15-crown-5, 6 5,17-diethynyl-25,27-dimethoxycalix [4]crown-5, 7 bipyridylacetylides, 8 and terpyridylacetylides, 9 have been reported in such investigations. Since the strong ligand eld effect of the cyclometalated carbon raises the energy of the d-d states to reduce the non-radiation decay probability, cyclometalated platinum(II) complexes with tridentate phenylsubstituted pyridine [(N^C^N) motif] [10][11][12][13][14][15][16] and bipyridine [(C^N^N) motif] [17][18][19][20][21][22] as well as the related diphenyl-substituted pyridine [(C^N^C) motif] 23,24 ligands are good emitters with high quantum yields at room temperature, which are expected to be used as better candidates in chemosensors.…”