58384-89-7Relevant articles and documents
Metalloporphyrin Peroxo Complexes of Iron(III), Manganese(III), and Titanium(IV). Comparative Studies Demonstrating That the Iron(III) Complex Is Extremely Nucleophilic
Sisemore, Marlene F.,Selke, Matthias,Burstyn, Judith N.,Valentine, Joan Selverstone
, p. 979 - 984 (1997)
Peroxo Fe(III), Mn(III), and Ti(IV) porphyrin complexes were reacted with a variety of electron-rich and electron-poor organic substrates in order to compare their reactivities with those of other known metalloperoxide complexes. The peroxoiron(III) porphyrin complex was unreactive with electron-rich substrates such as tetramethylethylene, cyclohexene, triphenylphosphine, or butyllithium but was quite reactive with electron-poor substrates such as 2-cyclohexen-l-one and 2-methyl-l,4-naphthoquinone. The peroxomanganese(III) porphyrin complex was unreactive with these electron-poor olefms but did react with the strongly electron-deficient olefin tetracyanoethylene. The peroxotitanium(IV) porphyrin complex was unreactive with both electron-rich and electron-poor olefins, as well as butyllithium, but did quantitatively oxidize triphenylphosphine to triphenylphosphine oxide. These results lead to the conclusion that the peroxo Fe(III) porphyrin complex is significantly more nucleophilic than the analogous Mn(III) and Ti(IV) complexes and than several well-known nucleophilic non-porphyrin peroxometal complexes.
Scaling Up Electronic Spin Qubits into a Three-Dimensional Metal-Organic Framework
Yamabayashi, Tsutomu,Atzori, Matteo,Tesi, Lorenzo,Cosquer, Goulven,Santanni, Fabio,Boulon, Marie-Emmanuelle,Morra, Elena,Benci, Stefano,Torre, Renato,Chiesa, Mario,Sorace, Lorenzo,Sessoli, Roberta,Yamashita, Masahiro
, p. 12090 - 12101 (2018/09/27)
Practical implementation of highly coherent molecular spin qubits for challenging technological applications, such as quantum information processing or quantum sensing, requires precise organization of electronic qubit molecular components into extended frameworks. Realization of spatial control over qubit-qubit distances can be achieved by coordination chemistry approaches through an appropriate choice of the molecular building blocks. However, translating single qubit molecular building units into extended arrays does not guarantee a priori retention of long quantum coherence and spin-lattice relaxation times due to the introduced modifications over qubit-qubit reciprocal distances and molecular crystal lattice phonon structure. In this work, we report the preparation of a three-dimensional (3D) metal-organic framework (MOF) based on vanadyl qubits, [VO(TCPP-Zn2-bpy)] (TCPP = tetracarboxylphenylporphyrinate; bpy = 4,4′-bipyridyl) (1), and the investigation of how such structural modifications influence qubits' performances. This has been done through a multitechnique approach where the structure and properties of a representative molecular building block of formula [VO(TPP)] (TPP = tetraphenylporphyrinate) (2) have been compared with those of the 3D MOF 1. Pulsed electron paramagnetic resonance measurements on magnetically diluted samples in titanyl isostructural analogues revealed that coherence times are retained almost unchanged for 1 with respect to 2 up to room temperature, while the temperature dependence of the spin-lattice relaxation time revealed insights into the role of low-energy vibrations, detected through terahertz spectroscopy, on the spin dynamics.
Design of oxophilic metalloporphyrins: An experimental and DFT study of methanol binding
Olsson, Sandra,Dahlstrand, Christian,Gogoll, Adolf
supporting information, p. 11572 - 11585 (2018/08/28)
By systematic measurements we have evaluated a series of tetraphenyl metalloporphyrins and halogenated tetraphenyl metalloporphyrin derivatives for binding to ligands with oxygen containing functional groups, using methanol, acetic acid and acetone as examples. Experimental binding constants identified three metalloporphyrins with good binding to all three ligands: MgTPFPP, MgTPPBr8 and ZnTPPBr8 as well as a range of porphyrins binding to select ligands. Based on these results the optimal porphyrins can be selected for the desired binding interactions. We also show how to use DFT calculations to evaluate the potential binding between a metalloporphyrin and a ligand, which is deduced from free energies of binding ΔG, charge transfer ΔQ, and change of metal spin state. Computations on unsubstituted porphyrins in lieu of tetraphenyl porphyrin systems yield reliable predictions of binding interactions with good correlation to the corresponding experimental data. The calculations have also yielded interesting insights into the effect of halogenation in the β-position on the binding to ligands with oxygen containing functional groups.
Halogenated oxo- and peroxotitanium porphyrinates as sensitizers for the photooxygenation of olefinic compounds
Esser, Peter E.,Driessen-Hoelscher, Birgit,Keim, Wilhelm
, p. 13 - 24 (2008/10/09)
A series of porphines, oxotitanium(IV) and peroxotitanium(IV) porphyrinates were tested as photosensitizers of the singlet oxygen ene reaction with cyclohexene and cis-cyclooctene. The relative order of activity is: H2(P) ≥ O=Ti(P) ≥ Ti(O2)P. Best stability is obtained for porphines or porphyrinate complexes with fluorine substituents. Oxotitanium(IV) porphyrinates are active in the decomposition of allylic hydroperoxides. The (photo)catalytic epoxidation occurs less readily than the thermal reaction at 82°C. Attempts of photocatalytic hydrogen peroxide activations lead to fast destruction of O=Ti(P).
Electrochemistry of oxo- and peroxotitanium(IV) porphyrins. Mechanism of the two-electron reduction of a η2-coordinated peroxo ligand
Malinski, Tadeusz,Chang, Dane,Latour, Jean-Marc,Marchon, Jean-Claude,Gross, Maurice,Giraudeau, Alain,Kadish, Karl M.
, p. 3947 - 3955 (2008/10/08)
The oxidation and reduction reactions of oxotitanium(IV) tetraphenylporphyrin, TiO(TPP), peroxotitanium(IV) tetraphenylporphyrin, Ti(O2)(TPP), and peroxotitanium(IV) octaethylporphyrin, Ti(O2)(OEP), in dichloromethane were investigated by electrochemical and spectroscopic techniques. Two one-electron oxidations and two one-electron reductions of the porphyrin ring were observed for TiO(TPP). Similar oxidations were found for Ti(O2)(TPP) and Ti(O2)(OEP). In addition, the peroxo complexes showed three reduction steps. The first reduction gives a porphyrin anion radical complex, which undergoes protonation by trace water followed by internal electron transfer to give a hydroperoxotitanium(III) porphyrin complex. The latter is then reduced at the porphyrin-ring system. Finally, internal transfer of two electrons cleaves the oxygen-oxygen bond of the coordinated hydroperoxide to give the oxotitanium(IV) porphyrin complex and hydroxide ion. The overall reaction is a two-electron reduction of the peroxo ligand in an ECEC mechanism. The oxotitanium(IV) complex that is obtained can be further reduced to the anion radical and the dianion of the porphyrin ring. Possible competing processes, which result in a substoichiometric reduction of the peroxo ligand, are surveyed.
Kinetics and Mechanism of the Dissociation of the Titanyl and Vanadyl Complexes of Mesotetraphenylporphyrins
Lomova, T. N.,Berezin, B. D.
, p. 563 - 566 (2007/10/02)
Titanium(IV) and vanadium(IV) complexes of tetraphenylporphin containing O2- species as extraligands have been synthesized and purified until spectroscopically pure.The rates of dissociation of the complexes in concentrated sulphuric acid have
NOVEL TITANIUM(III) PORPHYRINS WITH ARYL AXIAL LIGANDS. REDOX STOICHIOMETRY TUNED BY AXIAL LIGATION
Latour, Jean-Marc,Boreham, Christopher J.,Marchon, Jean-Claude
, p. C61 - C63 (2007/10/02)
Aryltitanium(III) porphyrin complexes have been prepared by anaerobic treatment of fluorotitanium (III) tetraphenylporphyrin with various aryl Grignard reagents.They react with dioxygen to give oxotitanium (IV) tetraphenylporphyrin and the corresponding b
