Abstract

The photophysics of copper(II) porphyrins has been studied by a variety of techniques. Our own transient resonance Raman data on Cu(II) tetraphenylporphyrin (CuTPP) provided the first direct experimental evidence for the involvement of excited states other than triplets in the relaxation dynamics of the first excited singlet state. However, it is not yet clear if these excited states are charge-transfer (CT) or d-d in character. In order to provide definitive assignments for the relaxing states, we have undertaken investigations of a variety of substituted CuTPP's, where the phenyl moieties contain para substituents. We will begin the study by obtaining luminescence and time-resolved electronic absorption (TREA) spectra of these CuTPP's in order to determine the extent to which the substituents modulate the energies of triplet states. The TREA work will be conducted at the RLBL. Then, we will probe the relaxing states directly by time-resolved resonance Raman (TRRR) spectroscopy at Haverford. We expect that CT and d-d states will be modulated differently by inductive and resonance effects by the substituents. For example, the extent of CT determined by TRRR, will be very sensitive to the reduction potential of the porphyrin macrocycle, which is modulated by para-phenyl substitution.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR001348-17
Application #
6281067
Study Section
Project Start
1998-08-01
Project End
1999-07-31
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
17
Fiscal Year
1998
Total Cost
Indirect Cost

  Institution

Name
University of Pennsylvania
Department
Type
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104

  Publications

Sheth, Rahul A; Arellano, Ronald S; Uppot, Raul N et al. (2015) Prospective trial with optical molecular imaging for percutaneous interventions in focal hepatic lesions. Radiology 274:917-26
Roussakis, Emmanuel; Spencer, Joel A; Lin, Charles P et al. (2014) Two-photon antenna-core oxygen probe with enhanced performance. Anal Chem 86:5937-45
Courter, Joel R; Abdo, Mohannad; Brown, Stephen P et al. (2014) The design and synthesis of alanine-rich ?-helical peptides constrained by an S,S-tetrazine photochemical trigger: a fragment union approach. J Org Chem 79:759-68
Singh, Prabhat K; Kuroda, Daniel G; Hochstrasser, Robin M (2013) An ion's perspective on the molecular motions of nanoconfined water: a two-dimensional infrared spectroscopy study. J Phys Chem B 117:9775-84
Chuntonov, Lev; Ma, Jianqiang (2013) Quantum process tomography quantifies coherence transfer dynamics in vibrational exciton. J Phys Chem B 117:13631-8
Culik, Robert M; Annavarapu, Srinivas; Nanda, Vikas et al. (2013) Using D-Amino Acids to Delineate the Mechanism of Protein Folding: Application to Trp-cage. Chem Phys 422:
Kuroda, Daniel G; Bauman, Joseph D; Challa, J Reddy et al. (2013) Snapshot of the equilibrium dynamics of a drug bound to HIV-1 reverse transcriptase. Nat Chem 5:174-81
Lam, A R; Moran, S D; Preketes, N K et al. (2013) Study of the ?D-crystallin protein using two-dimensional infrared (2DIR) spectroscopy: experiment and simulation. J Phys Chem B 117:15436-43
Kuroda, Daniel G; Singh, Prabhat K; Hochstrasser, Robin M (2013) Differential hydration of tricyanomethanide observed by time resolved vibrational spectroscopy. J Phys Chem B 117:4354-64
Goldberg, Jacob M; Speight, Lee C; Fegley, Mark W et al. (2012) Minimalist probes for studying protein dynamics: thioamide quenching of selectively excitable fluorescent amino acids. J Am Chem Soc 134:6088-91

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