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The transient absorption spectra of the series of diamagnetic H₂TFcP, ZnTFcP, PdTFcP, and FcInTFcP compounds (TFcP(2‐)=5,10,15,20‐tetraferroceneporphyrin dianion) were investigated in polar (DMF) and non‐polar (toluene) solvents using excitation at 650 nm. The formation and the deactivation of the charge‐separated (Fc⁺‐Porphyrin^−.) state were observed in all cases. The lifetime of the charge‐separated state is nearly constant for all compounds (∼20 ps) and independent of the nature of the central ion and solvent. The formation of the triplet state in all the complexes was not observed. The third, minor long‐lived (160–480 ps) component was observed in polar DMF solvent. This component was tentatively assigned to the porphyrin species that are weakly bound to the carbonyl oxygen in DMF. DFT and TDDFT calculations on the ground state, excited state, and triplet state of the target compounds were in agreement with the experimental data.

 

A sterically strained 32π‐electron antiaromatic bis‐BODIPY macrocycle in which two BODIPY fragments are linked byp‐divinylbenzene groups was prepared and characterized. Unlike regular BODIPYs, the fluorescence in this macrocycle is quenched. The broad signals in the NMR spectra of the macrocycle were explained by the vibronic freedom of thep‐divinylbenzene fragments. The possible diradicaloid nature of the macrocycle was excluded on the basis of variable‐temperature EPR spectra in solution and in solid state, which is indicative of its closed‐shell quinoidal structure. Themeso‐C−H bond in the macrocycle and its precursor BODIPY dialdehyde3forms a weak hydrogen bond with THF and is susceptible for the nucleophilic attack by organic amines and cyanide anion. The reaction products of such a nucleophilic attack havemeso‐sp³carbon atoms and were characterized by NMR, mass spectrometry and, in one case, X‐ray crystallography. Unlike the initial bis‐BODIPY macrocycle, the adducts have strong fluorescence in the 400 nm region. The electronic structure and spectroscopic properties of new chromophores were probed by density functional theory (DFT) and time‐dependent DFT (TDDFT) calculations and correlate well with the experimental data.

 

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 

A ditriflate derivative of 2-iodoxybenzoic acid (IBX) was prepared by the reaction of IBX with trifluoromethanesulfonic acid and characterized by single crystal X-ray crystallography. IBX-ditriflate is the most powerful oxidant in a series of structurally similar IBX derivatives which is best illustrated by its ability to readily oxidize hydrocarbons and the oxidation resistant polyfluoroalcohols.