Photophysics in bipyridyl and terpyridyl platinum(II) acetylides

Influence of Counteranion on the Chiral Supramolecular Assembly of Alkynylplatinum(II) Terpyridyl Metallogels That Are Stabilised by Pt⋅⋅⋅Pt and π–π Interactions

“…According to the spectroscopic studies on alkynylplatinum(II)-terpyridyl complexes, [5][6][7] an emissive origin of a 3 MLCT excited state with some mixing of 3 LLCT character is tentatively assigned. The complexes 1-OTf, 1-PF 6 , 1-Cl, and 1-BF 4 were found to form deep cherry red, blood red, deep purple, and magenta metallogels, respectively, at critical gelation concentrations of less than 8 mg mL À1 in DMSO.…”

“…With reference to previous studies on alkynylplatinum(II)-terpyridyl complexes, [5][6][7] the high-energy absorption bands are assigned as intraligand [p!p*] transitions of the alkynyl and terpyridyl ligands, while the low-energy absorption bands are assigned as a metal-to-ligand charge transfer (MLCT) [dp(Pt)!p*A C H T U N G T R E N N U N G (tpy)] transition with mixing of an alkynyl-toterpyridine ligand-to-ligand charge transfer (LLCT) …”

“…[2] Recently, square-planar, d 8 -platinum(II)-terpyridyl complexes have attracted much attention due to their intriguing spectroscopic and luminescence properties. [4][5][6][7] The class of alkynylplatinum(II)-terpyridyl complexes exhibited drastic changes in electronic absorption and luminescence properties due to the aggregation and deaggregation processes through metal-metal and p-p interactions.[5] Recent work by us has demonstrated that this class of complexes could form metallogels through Pt···Pt and p-p interactions in relatively low gelation concentration and that they showed a drastic colour change during the sol-gel transition.[5b] In addition, the counteranions were found to influence the degree of aggregation and therefore the colour of the metallogels.[5b] Despite the development of metallogels [5b,c, 8] and chiral organogelators, [2,3] there is a lack of reports on metallogels that form helical supramolecular structures aided by metal-metal interactions. In view of the propensity of alkynylplatinum(II)-terpyridyl complexes to form metallogels as well as the effect of counteranions on their aggregation, it is anticipated that an incorporation of a chiral functionality into the system may induce the formation of helical superstructures.…”

Long-lifetime reverse saturable absorption in a bipyridyl platinum(II) complex bearing naphthalimidylethynyl-substituted fluorenylacetylide ligands

“…Large values of the ratio r T (k)/r G (k) have been reported in both in platinum(II) diimine [6][7][8][9][10][11] and terpyridine complexes [11][12][13], and the observation of phosphorescence in room temperature solutions of both classes of complexes [14,15] evidences rapid intersystem crossing, necessary to insure the accessibility of the highly absorbing, long-lived triplet state.…”

Attachment of Luminescent Neutral “Pt(pq)(C≡CtBu)” Units to Di and Tri N-Donor Connecting Ligands: Solution Behavior and Photophysical Properties

“…The interest of alkynyl platinum(II) complexes stems from their rich structural diversity [1][2][3][4], their interesting chemical reactivity [1] and more recently from their increasing potential in material science [5][6][7][8][9][10][11][12][13][14][15][16][17]. In this field, light-emitting complexes have attracted a great deal of attention owing to their use in optoelectronic devices, chemosensors, photovoltaic cells and photocatalysis.…”