Tuning of fluorescence properties of aminoterpyridine fluorophores by N-substitution

Abstract

Several N-alkyl and N-phenyl derivatives of 6-amino- () and 6,6'-diamino-2,2':6',2''-terpyridine () were synthesized, and their fluorescence properties were studied. A successive red-shift was observed as the number of the N-substituted groups increased. It was also shown that the susceptivity of the fluorophores to a solvent varied considerably according to the mode of the N-substitution. While the monoamino-tpys (tpy: 2,2':6',2''-terpyridine) suffered almost complete quenching of their fluorescence in ethanol, the fully N-alkylated diamino-tpys and retained their fluorescence. The results show that N-substitution is a useful way to tune both the radiation energy and solvent susceptivity of the fluorescence of the amino-tpys.

p-Carboxyl-N-salicylideneanilines: Simple but efficient chromophores for one-dimensional microrods with aggregation-induced emission enhancement (AIEE) characteristics

“…Depending on different electron-withdrawing (EW) effects of substituents (-OMeo-H o-Br), the polarity of the excited singlet state would become larger with the order of -OMeo-H o-Br. When pCSA molecules substituted by EW group stacked up in solid state, intermolecular interaction of neighboring polar molecules would lower the energy level of the excited state, imparting the red-shifted emission wavelength of pCSA derivatives [57,58]. These results were also well accordant with our previous studies of AIEE colors [43].…”

“…The reason for morphology distinctions between carboxyl and chloride atom substituted salicyldeneanilines could be inferred from molecular stacking modes of X-crystals: for compound 1 (Fig. 1), intermolecular H-bonding between carboxylic acid groups as O (3) [58,59]. As for compound 5, molecules without intermolecular H-bonding tended to pack towards 3D directions (Fig.…”

Perimidine based selective colorimetric and fluorescent turn-off chemosensor of aqueous Cu2+: studies on its antioxidant property along with its interaction with calf thymus-DNA

“…The increased probability of non-radiative decay may be attributed to the hydrogen bonding of N-H group with the protic solvents. 40 …”

Towards Photocatalytic Alkane Oxidation: The Insertion of Dioxygen into a Platinum(II)–Methyl Bond

“…[12,13] The luminescent behaviour of [Pt (1) [14] In addition, several Pt II and Pt IV complexes containing alkylperoxo ligands other than methylperoxo have been reported previously, but none of these have been prepared via an O 2 insertion reaction. [15][16][17][18][19][20] The O 2 insertion reaction into the Pt II -Me bond in the complex [(PN)Pt(Me)(OOMe)] is also affected by light and the authors have proposed a radical mechanism for their insertion reaction.…”

“…It is notable that the diamino-substituted terpyridine ligand itself also shows photoluminescence. [12,13] The luminescent behavior of [Pt(1)Me] + is very different from that of [Pt(terpy)Me] + , which shows no significant photoluminescence at room temperature in CH 3 CN. [8] The formation of a platinum(II)-methylperoxo complex by insertion of O 2 into a Pt II À Me bond, as seen here, appears to be very rare.…”