Porphyrazine: An effective receptor for quantum dots

CdSe/ZnS quantum dots (C-S QD) interact spontaneously with a designed free-base porphyrazine (H 2 Pz) in toluene. Spontaneous interaction between C-S QD and H 2 Pz is observed from UV-vis investigations and it may be formulated with the help of dipole-dipole transition. Fluorescence measurements reveal that the photoluminescence (PL) of C-S QD suffers a considerable extent of quenching at its emission maximum, i.e., at 612 nm following the interaction with H 2 Pz. The self-assembly of H 2 Pz with C-S QD is quantified with the help of the evaluation of the formation constant (K) value of C-S QD-H 2 Pz system, i.e., K C−S QD−H2Pz = 1.3 × 10 5 dm 3 · mol −1 . The estimated k q value (k q = quenching constant of C-S QD–H 2 Pz system) is determined to be ∼ 2.47 × 10 12 dm 3 /mol.sec.) suggesting a static quenching mechanism for the photoexcited decay of C-S QD by H 2 Pz in solution. The results obtained from present investigations may be suitably utilized for the future application of porphyrazine as a selective host for quantum dots.