Ultrafast Photosensitization of Phthalocyanines through Their Axial Ligands

Abstract

We have studied the energy transfer properties of a novel silicon phthalocyanine that coordinates two anthracene-9-carboxylate groups in the form of trans axial ligands. Our objectives were to generate a system with auxiliary chromophores that enhance the light absorption properties of the macrocycle in a specific region in the UV and to evaluate the efficiency and time scales for energy transfer. The ligand coordination through a carboxylate group directly attached to the anthracenic system allows for close proximity of the donor and acceptor chromophores. The energy transfer process was observed to be nearly 100% efficient and to occur on a time scale of 370 fs. From the energy relations of the donor and acceptor states and the observed dynamics, the initial energy transfer step is likely to involve upper electronic states of the phthalocyanine rather than the states of the lowest-energy vibroelectronic Q bands.

Generating Singlet Oxygen Bubbles: A New Mechanism for Gas–Liquid Oxidations in Water

“…Si phthalocyanine (Pc) was selected because it possessed a strong absorption in the red spectral region (extinction coefficients >10 5 M -1 cm -1 ), and the 1 O 2 quantum yield (Φ Δ ) was reported to be ∼0.2. 16,17 …”

Synthesis and Photodynamics of Stilbenyl‐Azopyrroles: Two‐Photon Controllable Photoswitching Systems

“…For excited state dynamics for one‐ (400 nm) and two‐photon (800 nm) excitation, we used both femtosecond fluorescence up‐conversion and transient absorption spectroscopy. Both instruments are described in detail elsewhere . Briefly, the setups are based on a regenerative amplified Ti : Sapphire laser centered at 800 nm, with a repetition frequency of 1 kHz, temporal width of 180 fs and 0.8 mJ per pulse.…”

Silicon phthalocyanines: synthesis and resurgent applications

“…Unlike etherification, esterification reactions proceeded easily in the absence of a base. The reaction completion times ranged from as short as of 30 min to as long as 48 h. 20,[51][52][53][54][55][56] The SiPc bis-esters, 5 were obtained as blue solids in moderate (~30%) to high (~90%) yields. )2)] in 4) was stirred with trichloroacetic acid in dichloromethane at room temperature for 5 h (Scheme 5A).…”