title: Porphyrin/Platinum(II) C^N^N Acetylide Complexes: Synthesis, Photophysical Properties, and Singlet Oxygen Generation.
abstract: A new class of substituted porphyrins has been developed in which a different number of cyclometalated Pt(II) C^N^N acetylides and polyethylene glycol (PEG) chains are attached to the meso positions of the porphyrin core, which are meant for photophysical, electrochemical, and in vitro light-induced singlet oxygen ((1)O2) generation studies. All of these Zn(II) porphyrin-Pt(II) C^N^N acetylide conjugates show moderate to high (ΦΔ =0.55 to 0.63) singlet oxygen generation efficiency. The complexes are soluble in organic solvents but, despite the PEG substituents, slowly aggregate in aqueous solvent systems. These conjugates also exhibit interesting photophysical properties, including near-complete photoinduced energy transfer (PEnT) through the rigid acetylenic bond(s) from the Pt(II) C^N^N antenna units to the Zn(II) porphyrin core, which shows sensitized luminescence, as shown by quenching of Pt(II) C^N^N-based luminescence. Electrochemical measurements show a set of redox processes that are approximately the sum of what is observed for the Pt(II) C^N^N acetylide and Zn(II) porphyrin units. UV/Vis spectroscopic properties are supported by DFT calculations.
authors: Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, United Kingdom. atanu.j78@gmail.com.
authors: Atanu
authors: A
authors: Jana
authors: Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, United Kingdom.
authors: Luke
authors: L
authors: McKenzie
authors: Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, United Kingdom.
authors: Ashley B
authors: AB
authors: Wragg
authors: Education Center for Global Leaders in Molecular Systems for Devices, Kyushu University, Fukuoka, 819-0395, Japan.
authors: Masatoshi
authors: M
authors: Ishida
authors: World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki (Tsukuba, Ibaraki, 305-0044, Japan.
authors: Jonathan P
authors: JP
authors: Hill
authors: Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, United Kingdom.
authors: Julia A
authors: JA
authors: Weinstein
authors: Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, United Kingdom.
authors: Elizabeth
authors: E
authors: Baggaley
authors: Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, United Kingdom. m.d.ward@sheffield.ac.uk.
authors: Michael D
authors: MD
authors: Ward
keywords: acetylide complexes; energy transfer; platinum; porphyrins; singlet oxygen; zinc