Time resolved studies of dual emission and photoinduced energy transfer in a Tris methoxy coumarin derivative of a cryptand and its complex with Tb(NO3)3

Protein-Mediated Efficient Synergistic “Antenna Effect” in a Ternary System in D2O Medium

“…The distances calculated are within 10 Å in each case. This suggests the exchange mechanism involving the lowest triplet state of respective Trp residues and 5 D 4 state of Tb(III) operating in the ET process. − Furthermore, the energy levels of the T 1 state of Trps of proteins and of catechin and the emissive state of Tb(III) are depicted in Figure . The position of the energy levels of the T 1 states is an indication of synergistic energy transfer in the ternary system.…”

Photoinduced energy transfer from the triplet state of naphthalene moiety in the Tb3+/Eu3+ complexes of a specially designed naphthalene cryptand

“…Earlier studies of Schlyer et al [9] on Tb-alkaline phosphatase system, the emphasis is given on through space ET. In our earlier studies with Tb-alkaline phosphatase system [11] and Tb 3+ complex of a tris methoxy coumarin derivative of a cryptand [48], we also emphasized that through space ET mechanism is operative.…”

Discovery of a New Class of Immunosuppressants from Trichothecium roseum Co‐inspired by Cross‐Kingdom Similarity in Innate Immunity and Pharmacophore Motif

“…The key features to derive efficient “antenna effect” for Ln III through this mechanism are (i) the ligand system coordinated to Ln III must have a highly absorbing π‐π* singlet state (S 1 ) to enhance the population of the lowest π‐π* triplet (T 1 ) through intersystem crossing; (ii) the corresponding lowest π‐π* triplet (T 1 ) of the ligand acting as the donor state must be suitably located compared to the emissive state of Ln III to minimize back ET (an energy gap of at least 2000–3000 cm –1 between T 1 and the emissive state of Ln III has been prescribed6d); (iii) the first coordinating sphere of Ln III should be protected from vibronic coupling with O–H, C–H, N–H oscillators in the medium, and (iv) the complex must be kinetically stable in the desired medium. The presence of a charge transfer (CT) state [arising from metal to ligand (MLCT) or from metal to counter anion] between the S 1 and the T 1 states of the ligand or between the T 1 state and the emissive state of Ln III could facilitate a nonradiative path and thus diminishing the efficiency of energy transfer 6e,7a–7c…”