Axial ligand mediated switchable rotary motions in a ferrocene-bridged diiron(III) porphyrin dimer

Pandey, Anjani K.; Sanfui, Sarnali; Khan, Firoz Shah Tuglak; Rath, Sankar Prasad

doi:10.1016/j.jorganchem.2019.05.002

Cited by 15 publications

(2 citation statements)

References 76 publications

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“…Because of their excellent thermal, photochemical, and chemical stability, metallocenyl and, in particular, ferrocenyl-containing porphyrins ,,− and related compounds such as phthalocyanines, − BODIPYs, − aza-BODIPYs, ,− and BOPHYs , have attracted a lot of academic interest in recent years. Not surprisingly, the overwhelming majority of investigated metallocenyl porphyrinoids consists of ferrocenyl substituents appended to the macrocycle in almost every exploitable position. , On the contrary, the examples of molecular systems containing both a porphyrinoid macrocycle or analogues dye and a ruthenocenyl substituent are quite rare.…”

Section: Introductionmentioning

confidence: 99%

Similar, Yet Different: Long-Range Metal–Metal Coupling and Electron-Transfer Processes in Metal-Free 5,10,15,20-Tetra(ruthenocenyl)porphyrin

et al. 2021

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The electronic structure, redox properties, and long-range metal–metal coupling in metal-free 5,10,15,20-tetra(ruthenocenyl)porphyrin (H2TRcP) were probed by spectroscopic (NMR, UV–vis, magnetic circular dichroism (MCD), and atmospheric pressure chemical ionization (APCI)), electrochemical (cyclic voltammetry, CV, and differential pulse voltammetry, DPV), spectroelectrochemical, and chemical oxidation methods, as well as theoretical (density functional theory, DFT, and time-dependent DFT, TDDFT) approaches. It was demonstrated that the spectroscopic properties of H2TRcP are significantly different from those in H2TFcP (metal-free 5,10,15,20-tetra(ferrocenyl)porphyrin). Ruthenocenyl fragments in H2TRcP have higher oxidation potentials than the ferrocene groups in the H2TFcP complex. Similar to H2TFcP, we were able to access and spectroscopically characterize the one- and two-electron oxidized mixed-valence states in the H2TRcP system. DFT predicts that the porphyrin π-system stabilizes the [H2TRcP]+ mixed-valence cation and prevents its dimerization, which is characteristic for ruthenocenyl systems. However, formation of the mixed-valence [H2TRcP]2+ is significantly less reproducible than the formation of [H2TRcP]+. DFT and TDDFT calculations suggest the ruthenocenyl fragment dominance in the highest occupied molecular orbital (HOMO) energy region and the presence of the low-energy MLCT (Rc → porphyrin (π*)) transitions in the visible region with energies higher than the predominantly porphyrin-centered Q-bands.

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Section: Introductionmentioning

confidence: 99%

Similar, Yet Different: Long-Range Metal–Metal Coupling and Electron-Transfer Processes in Metal-Free 5,10,15,20-Tetra(ruthenocenyl)porphyrin

et al. 2021

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“…The chemistry of functional dyes connected to redox-active fragments, and in particular to ferrocene groups, has gained significant interest because of their potential use in photocatalysis, molecular electronics, redox-switchable fluorescence, and light-harvesting applications. , Electronic communication between the ferrocene groups and the excited-state dynamics (in particular the formation and lifetime of charge-separated states) in ferrocene-containing porphyrins, , phthalocyanines, , BODIPYs, , aza-BODIPYs, , and BOPHYs were probed by a variety of spectroscopic, electrochemical, and theoretical methods. Because of their excellent photophysical properties, the use of the electron-deficient BODIPY analogues is attractive for solar light-harvesting applications.…”

Section: Introductionmentioning

confidence: 99%

Probing Electronic Communication and Excited-State Dynamics in the Unprecedented Ferrocene-Containing Zinc MB-DIPY

et al. 2020

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The electronic communication between two ferrocene groups in the electron-deficient expanded aza-BODIPY analogue of zinc manitoba-dipyrromethene (MB-DIPY) was probed by spectroscopic, electrochemical, spectroelectrochemical, and theoretical methods. The excited-state dynamics involved sub-ps formation of the charge-separated state in the organometallic zinc MB-DIPYs, followed by recovery of the ground state via charge recombination in 12 ps. The excited-state behavior was contrasted with that observed in the parent complex that lacked the ferrocene electron donors and has a much longer excited-state lifetime (670 ps for the singlet state). Much longer decay times observed for the parent complex without ferrocene confirm that the main quenching mechanism in the ferrocene-containing 4 is reflective of the ultrafast ferrocene-to-MB-DIPY core charge transfer (CT).

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Stepwise Oxidations in a Cofacial Copper(II) Porphyrin Dimer: Through‐Space Spin‐Coupling and Interplay between Metal and Radical Spins

Kumar¹,

Sanfui²,

Sciortino

et al. 2020

Chemistry A European J

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Abstractcis and trans‐copper(II) porphyrin dimers have been synthesized, in which two CuII porphyrin macrocycles are bridged through a rigid ethene linker for possible through‐space and through‐bond spin‐couplings between the paramagnetic CuII centers. It has been found that the two macrocycles come closer after 1 e− oxidation, however, they move far apart upon further 1 e− oxidation leading to transformation of the cis to the trans isomer. Detailed investigations are performed here on the interactions between the two porphyrin macrocycles, between two unpaired spins of closely spaced CuII centers, and also between the unpaired spins of metal and porphyrin π–cation radicals. Spectroscopic investigations along with the X‐ray structure of the 2 e−‐oxidized complex displayed strong electronic communications through the bridge between two porphyrin π–cation radicals. The counterion I9− is stabilized in an unusual trigonal‐pyramidal structure in the 2 e−‐oxidized complex in which the central iodide ion is bound with four iodine (I2) molecules. Variable‐temperature magnetic study revealed strong antiferromagnetic coupling between the two porphyrin π–cation radical spins (Jr–r) in the 2 e−‐oxidized complex. DFT calculations suggest stabilization of the triplet state, which is also in good agreement with the experiment. Ab initio molecular dynamics allowed the variation of the structural details to be followed upon stepwise oxidations and also the final isomerization process including its associated energy barrier.

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Axial ligand mediated switchable rotary motions in a ferrocene-bridged diiron(III) porphyrin dimer

Cited by 15 publications

References 76 publications

Similar, Yet Different: Long-Range Metal–Metal Coupling and Electron-Transfer Processes in Metal-Free 5,10,15,20-Tetra(ruthenocenyl)porphyrin

Similar, Yet Different: Long-Range Metal–Metal Coupling and Electron-Transfer Processes in Metal-Free 5,10,15,20-Tetra(ruthenocenyl)porphyrin

Probing Electronic Communication and Excited-State Dynamics in the Unprecedented Ferrocene-Containing Zinc MB-DIPY

Stepwise Oxidations in a Cofacial Copper(II) Porphyrin Dimer: Through‐Space Spin‐Coupling and Interplay between Metal and Radical Spins

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