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Larsen S, Adewuyi JA, Thomas KE, Conradie J, Rousselin Y, Ung G, Ghosh A. Electronic Structure of Metallophlorins: Lessons from Iridium and Gold Phlorin Derivatives. Inorg Chem 2024; 63:9842-9853. [PMID: 38743029 PMCID: PMC11134504 DOI: 10.1021/acs.inorgchem.4c00483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 04/12/2024] [Accepted: 04/26/2024] [Indexed: 05/16/2024]
Abstract
Phlorins have long remained underexplored relative to their fully conjugated counterparts, such as porphyrins, hydroporphyrins, and corroles. Herein, we have attempted to bridge that knowledge gap with a scalar-relativistic density functional theory (DFT) study of unsubstituted iridium and gold phlorin derivatives and a multitechnique experimental study of iridium-bispyridine and gold complexes of 5,5-dimethyl-10,15,20-tris(pentafluorophenyl)phlorin. Theory and experiments concur that the phlorin derivatives exhibit substantially smaller HOMO-LUMO gaps, as reflected in a variety of observable properties. Thus, the experimentally studied Ir and Au complexes absorb strongly in the near-infrared (NIR), with absorption maxima at 806 and 770 nm, respectively. The two complexes are also weakly phosphorescent with emission maxima at 950 and 967 nm, respectively. They were also found to photosensitize singlet oxygen formation, with quantum yields of 40 and 28%, respectively. The near-infrared (NIR) absorption and emission are consonants with smaller electrochemical HOMO-LUMO gaps of ∼1.6 V, compared to values of ∼2.1 V, for electronically innocent porphyrins and corroles. Interestingly, both the first oxidation and reduction potentials of the Ir complex are some 600 mV shifted to more negative potentials relative to those of the Au complex, indicating an exceptionally electron-rich macrocycle in the case of the Ir complex.
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Affiliation(s)
- Simon Larsen
- Department
of Chemistry, University of Tromsø, N-9037 Tromsø, Norway
| | - Joseph A. Adewuyi
- Department
of Chemistry, University of Connecticut, 55 N. Eagleville Rd, Storrs, Connecticut 06269, United States
| | - Kolle E. Thomas
- Department
of Chemistry, University of Tromsø, N-9037 Tromsø, Norway
| | - Jeanet Conradie
- Department
of Chemistry, University of Tromsø, N-9037 Tromsø, Norway
- Department
of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, Republic of South Africa
| | - Yoann Rousselin
- ICMUB,
UMR CNRS 6302, Université Bourgogne Franche-Comte, BP 47870, Dijon Cedex 21078, France
| | - Gaël Ung
- Department
of Chemistry, University of Connecticut, 55 N. Eagleville Rd, Storrs, Connecticut 06269, United States
| | - Abhik Ghosh
- Department
of Chemistry, University of Tromsø, N-9037 Tromsø, Norway
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2
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Osterloh WR, Desbois N, Conradie J, Gros CP, Kadish KM, Ghosh A. Inverse Hypercorroles. Inorg Chem 2024; 63:8739-8749. [PMID: 38696617 PMCID: PMC11094798 DOI: 10.1021/acs.inorgchem.4c00344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/08/2024] [Accepted: 04/10/2024] [Indexed: 05/04/2024]
Abstract
Ground-state and time-dependent density functional theory (TDDFT) calculations with the long-range-corrected, Coulomb-attenuating CAMY-B3LYP exchange-correlation functional and large, all-electron STO-TZ2P basis sets have been used to examine the potential "inverse hypercorrole" character of meso-p-nitrophenyl-appended dicyanidocobalt(III) corrole dianions. The effect is most dramatic for 5,15-bis(p-nitrophenyl) derivatives, where it manifests itself in intense NIR absorptions. The 10-aryl groups in these complexes play a modulatory role, as evinced by experimental UV-visible spectroscopic and electrochemical data for a series of 5,15-bis(p-nitrophenyl) dicyanidocobalt(III) corroles. TDDFT (CAMY-B3LYP) calculations ascribe these features clearly to a transition from the corrole's a2u-like HOMO (retaining the D4h irrep used for metalloporphyrins) to a nitrophenyl-based LUMO. The outward nature of this transition contrasts with the usual phenyl-to-macrocycle direction of charge transfer transitions in many hyperporphyrins and hypercorroles; thus, the complexes studied are aptly described as inverse hypercorroles.
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Affiliation(s)
- W. Ryan Osterloh
- ICMUB
(UMR CNRS 6302), Université de Bourgogne, 9, Avenue A. Savary, BP 47870, 21078 Dijon Cedex, France
- Department
of Chemistry, University of Houston, Houston, Texas 77204-5003, United
States
| | - Nicolas Desbois
- ICMUB
(UMR CNRS 6302), Université de Bourgogne, 9, Avenue A. Savary, BP 47870, 21078 Dijon Cedex, France
| | - Jeanet Conradie
- Department
of Chemistry, UiT − The Arctic University
of Norway, N-9037 Tromso̷, Norway
- Department
of Chemistry, University of the Free State, 9300 Bloemfontein, Republic of South Africa
| | - Claude P. Gros
- ICMUB
(UMR CNRS 6302), Université de Bourgogne, 9, Avenue A. Savary, BP 47870, 21078 Dijon Cedex, France
| | - Karl M. Kadish
- Department
of Chemistry, University of Houston, Houston, Texas 77204-5003, United
States
| | - Abhik Ghosh
- Department
of Chemistry, University of the Free State, 9300 Bloemfontein, Republic of South Africa
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3
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Dash ZS, Huang RQ, Kimber AN, Olubajo OT, Polk M, Rancu OP, Zhang LL, Fu J, Nagelj N, Reynolds KG, Zheng SL, Dogutan DK. Oxygen quenching of structurally characterized [5,10,15,20-tetrakis(4-fluoro-2,6-dimethylphenyl)porphyrinato]platinum(II). Acta Crystallogr C Struct Chem 2024; 80:85-90. [PMID: 38407217 DOI: 10.1107/s2053229624001621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 02/19/2024] [Indexed: 02/27/2024] Open
Abstract
The compound [5,10,15,20-tetrakis(4-fluoro-2,6-dimethylphenyl)porphyrinato]platinum(II), [Pt(C52H40F4N4)] or Pt(II)TFP, has been synthesized and structurally characterized by single-crystal X-ray crystallography. The Pt porphyrin exhibits a long-lived phosphorescent excited state (τ0 = 66 µs), which has been characterized by transient absorption and emission spectroscopy. The phosphorescence is extremely sensitive to oxygen, as reflected by a quenching rate constant of 5.0 × 108 M-1 s-1, and as measured by Stern-Volmer quenching analysis.
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Affiliation(s)
- Zane S Dash
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Raymond Q Huang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Ana N Kimber
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Opeyemi T Olubajo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Mark Polk
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Oliver P Rancu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Lauren L Zhang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Jane Fu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Nejc Nagelj
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Kristopher G Reynolds
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Shao Liang Zheng
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Dilek K Dogutan
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
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4
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Turner EE, Pham TN, Smith SP, Ward KN, Rosenthal J, Rack JJ. Electron-Withdrawing meso-Substituents Turn On Magneto-Optical Activity in Porphyrins. Inorg Chem 2024; 63:3630-3636. [PMID: 38359443 DOI: 10.1021/acs.inorgchem.3c04004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
A series of square planar metalloporphyrins (M(TPP), TPP is 5,10,15,20-tetraphenylporphyrin and M(TPFPP), TPFPP is 5,10,15,20-tetrapentafluorophenylporphyrin; M is Zn2+, Ni2+, Pd2+, or Pt2+) with distinct meso-substituents were prepared, and their magneto-optical activity (MOA) was characterized by magnetic circular dichroism (MCD) and magneto-optical rotary dispersion spectroscopy (MORD; also known as Faraday rotation spectroscopy). MOA is crucial in the development of next-generation magneto-optical devices and quantum computing. The data show that the presence of meso-pentafluorophenyl substituents results in significant increase in MOA in comparison to the homologous phenyl group. Differences in the MOA of these metalloporphyrins are rationalized using the Gouterman four-orbital model and pave the way for rational design of improved and tailorable magneto-optical materials.
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Affiliation(s)
- Emigdio E Turner
- Department of Chemistry and Chemical Biology, Laboratory for Magneto-Optic Spectroscopy, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Trong-Nhan Pham
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19711, United States
| | - Samuel Peter Smith
- Department of Chemistry and Chemical Biology, Laboratory for Magneto-Optic Spectroscopy, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Kaytlin N Ward
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19711, United States
| | - Joel Rosenthal
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19711, United States
| | - Jeffrey J Rack
- Department of Chemistry and Chemical Biology, Laboratory for Magneto-Optic Spectroscopy, University of New Mexico, Albuquerque, New Mexico 87131, United States
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Sahu K, Angeloni S, Conradie J, Villa M, Nayak M, Ghosh A, Ceroni P, Kar S. NIR-emissive, singlet-oxygen-sensitizing gold tetra(thiocyano)corroles. Dalton Trans 2022; 51:13236-13245. [PMID: 35968801 DOI: 10.1039/d2dt01959k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Presented herein are two fully characterized gold tetrathiocyanocorroles representing a potentially significant new class of NIR-emissive 5d-metallocorroles. The four SCN groups on the bipyrrole unit of the corrole exert a powerful electron-withdrawing effect, upshifting both the oxidation and reduction potentials by roughly half a volt relative to their unsubstituted counterparts. That said, the upshift of the LUMO is somewhat higher than that of the HOMO so these complexes also exhibit a smaller HOMO-LUMO gap, as evinced in both electrochemical measurements and Q band energies (∼595 nm relative to ∼571 nm for their SCN-free counterparts). The new compounds exhibit NIR phosphorescence under ambient conditions with emission maxima around 900 nm (compared with 790 nm for simple Au triarylcorroles), phosphorescence quantum yields around 0.3%, phosphorescence lifetimes around 10 μs, and singlet oxygen sensitization with a quantum yield of around 50 ± 5% in solution, together signifying wide-ranging potential applications as triplet photosensitizers in oxygen sensing and photodynamic therapy.
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Affiliation(s)
- Kasturi Sahu
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar - 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400 094, India.
| | - Sara Angeloni
- Department of Chemistry "G. Ciamician", University of Bologna, via Selmi 2, 40126 Bologna, Italy.
| | - Jeanet Conradie
- Department of Chemistry, UiT - The Arctic University of Norway, N-9037 Tromsø, Norway. .,Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, Republic of South Africa
| | - Marco Villa
- Department of Chemistry "G. Ciamician", University of Bologna, via Selmi 2, 40126 Bologna, Italy.
| | - Manisha Nayak
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar - 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400 094, India.
| | - Abhik Ghosh
- Department of Chemistry, UiT - The Arctic University of Norway, N-9037 Tromsø, Norway.
| | - Paola Ceroni
- Department of Chemistry "G. Ciamician", University of Bologna, via Selmi 2, 40126 Bologna, Italy.
| | - Sanjib Kar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar - 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400 094, India.
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Abstract
The Gouterman four-orbital model conceptualizes porphyrin UV-visible spectra as dominated by four frontier molecular orbitals-two nearly degenerate HOMOs and two exactly degenerate LUMOS under D 4h symmetry. These are well separated from all the other molecular orbitals, and normal spectra involve transitions among these MOs. Unusual spectra occur when additional orbitals appear in this energy range, typically as a consequence of the central coordinated atom. For example, metals with empty d orbitals in a suitable energy range may lead to charge transfer from porphyrin (ligand) to metal, that is, so-called LMCT transitions. Metals with filled p or d orbitals may lead to charge transfer from metal to porphyrin, MLCT transitions. These cases lead to additional peaks and/or significant redshifts in the spectra and were classified as hyperporphyrins by Gouterman. Cases in which spectra are blueshifted were classified as hypsoporphyrins; they are common for relatively electronegative late transition metal porphyrins. Many of the same principles apply to porphyrin analogues, especially corroles. In this Perspective, we focus on two newer classes of hyperporphyrins: one reflecting substituent effects in protonated or deprotonated free-base tetraphenyporphyrins and the other reflecting "noninnocent" interactions between central metal ions and corroles. Hyperporphyrin effects on spectra can be dramatic, yet they can be generated by relatively simple changes and subtle structural variations, such as acid-base reactions or the selection of a central metal ion. These concepts suggest strategies for engineering porphyrin or porphyrinoid dyes for specific applications, especially those requiring far-red or near-infrared absorption or emission.
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Affiliation(s)
- Carl C. Wamser
- Department
of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States
| | - Abhik Ghosh
- Department
of Chemistry and Arctic Center for Sustainable Energy, UiT − The Arctic University of Norway, N-9037 Tromsø, Norway
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Conradie J, Wamser CC, Ghosh A. Understanding Hyperporphyrin Spectra: TDDFT Calculations on Diprotonated Tetrakis( p-aminophenyl)porphyrin. J Phys Chem A 2021; 125:9953-9961. [PMID: 34714662 PMCID: PMC8630795 DOI: 10.1021/acs.jpca.1c06621] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/08/2021] [Indexed: 11/29/2022]
Abstract
A detailed TDDFT study (with all-electron STO-TZ2P basis sets and the COSMO solvation model) has been carried out on the effect of diprotonation on the UV-vis-NIR spectra of free-base tetraphenylporphyrin and tetrakis(p-aminophenyl)porphyrin. The diprotonated forms have been modeled as their bis-formate complexes, i.e., as so-called porphyrin diacids. The dramatic redshift of the Q-band of the TAPP diacid has been explained in terms of an elevated "a2u" HOMO and lowered LUMOs, both reflecting infusion of aminophenyl character into the otherwise classic Gouterman-type frontier MOs. The exercise has also yielded valuable information on the performance of different exchange-correlation functionals. Thus, the hybrid B3LYP functional was found to yield a substantially better description of key spectral features, especially the diprotonation-induced redshifts, than the pure OLYP functional. Use of the range-separated CAMY-B3LYP functional, on the other hand, did not result in improvements relative to B3LYP.
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Affiliation(s)
- Jeanet Conradie
- Department
of Chemistry, UiT − The Arctic University
of Norway, N-9037 Tromsø, Norway
- Department
of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, Republic of South Africa
| | - Carl C. Wamser
- Department
of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States
| | - Abhik Ghosh
- Department
of Chemistry, UiT − The Arctic University
of Norway, N-9037 Tromsø, Norway
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