14640-21-2Relevant articles and documents
Synthesis, molecular structure, spectroscopic characterization and antibacterial activity of the pyrazine magnesium porphyrin coordination polymer
Khelifa, Arbia Ben,Ezzayani, Khaireddine,Guergueb, Mouhieddinne,Loiseau, Frederique,Saint-Aman, Eric,Nasri, Habib
, (2021)
A new material of magnesium(II) polymer compound with the formula {[MgII(TPP)(pz)]? 0.5[MgII(TPP)]?CH2Cl2}n (I), (TPP) = meso?tetraphenylporphyrinato and pz = pyrazine) was synthetized and characterized by IR, UV-visible, PL photoluminescence and 1H NMR spectroscopy studies, single-crystal XRD analyses and cyclic voltammetry. The crystal structure of (I) is made by the 1D {[Mg(TPP)(pz)]} polymeric chains (molecules I(A)) where the tetracoordinated magnesium(II) complexes [Mg(TPP)] (molecules I(B)) are located as well as the dichloromethane solvent molecules. The crystal packing of (I) is stabilized by intermolecular C[sbnd]H?Cg π interactions where Cg is the centroid of phenyl and pyrrole rings. Additionally, the photophysical properties have been evaluated by UV-visible absorption and fluorescence emission spectroscopies. The UV-visible spectrum of (I) shows a redshift Soret band value (428 nm) compared to that of the free base H2TPP porphyrin while the λmax values of the Q bands are in the range 560 – 610 nm. The optical gap of (I) was estimated at 1.99 eV. The cyclic voltammogram of the title compound presents two reversible oxidation waves and one reversible reduction wave. The HOMO and LUMO energy values were deduced from the voltammogram which are -4.96 and -2.85 eV respectively. Furthermore, bioactivity investigations revealed that the free porphyrin, the starting material [MgII(TPP)] and complex (I) could be used as potential antibacterial agents.
Ultrafast dynamics of meso-tetraphenylmetalloporphyrins: The role of dark states
Liang, Yu,Bradler, Maximilian,Klinger, Melanie,Schalk, Oliver,Balaban, Mihaela Carmen,Balaban, Teodor Silviu,Riedle, Eberhard,Unterreiner, Andreas-Neil
, p. 1244 - 1251 (2013)
Studying the relaxation pathways of porphyrins and related structures upon light absorption is crucial to understand the fundamental processes of light harvesting in biosystems and many applications. Herein, we show by means of transient absorption studies, following Q- and Soret-band excitation, and aba initio calculations on meso-tetraphenylporphyrinato magnesium(II) (MgTPP) and meso-tetraphenylporphyrinato cadmium(II) (CdTPP) that electronic relaxation following Soret-band excitation of porphyrins with a heavy central atom is mediated by a hitherto disregarded dark state. This accounts for an increased rate of internal conversion. The dark state originates from an orbital localized at the central nitrogen atoms and its energy continuously decreases along the series from magnesium to zinc to cadmium to below 2.75a eV for CdTPP dissolved in tetrahydrofuran. Furthermore, we are able to directly trace fast intersystem crossing in the cadmium derivative, which takes place within (110±20)a ps. Stab in the dark: By means of transient absorption studies, following Q- and Soret-band excitation, and aba initio calculations on meso- tetraphenylporphyrinato magnesium(II) (MgTPP) and meso-tetraphenylporphyrinato cadmium(II) (CdTPP), it is shown that electronic relaxation following Soret-band excitation of porphyrins with a heavy central atom is mediated by a hitherto disregarded dark state (see picture). Copyright
Observations on the Mechanochemical Insertion of Zinc(II), Copper(II), Magnesium(II), and Select Other Metal(II) Ions into Porphyrins
Atoyebi, Adewole O.,Brückner, Christian
, p. 9631 - 9642 (2019/03/26)
Building on a proof of concept study that showed the possibility of the mechanochemical insertion of some M(II) metals into meso-tetraphenylporphyrin using a ball mill as an alternative to traditional solution-based methods, we present here a detailed study of the influence of the many experimental variables on the reaction outcome performed in a planetary mill. Using primarily the mechanochemical zinc, copper, and magnesium insertion reactions, the scope and limits of the type of porphyrins (electron-rich or electron-poor meso-tetraarylporphyrins, synthetic or naturally occurring octaalkylporphyrins, and meso-triphenylcorrole) and metal ion sources suitable for this metal insertion modality were determined. We demonstrate the influence of the experimental metal insertion parameters, such as ball mill speed and reaction time, and investigated the often surprising roles of a variety of grinding agents. Also, the mechanochemical reaction conditions that remove zinc from a zinc porphyrin complex or exchange it for copper were studied. Using some standardized conditions, we also screened the feasibility of a number of other metal(II) insertion reactions (VO, Ni, Fe, Co, Ag, Cd, Pd, Pt, Pb). The underlying factors determining the rates of the insertion reactions were found to be complex and not always readily predictable. Some findings of fundamental significance for the mechanistic understanding of the mechanochemical insertion of metal ions into porphyrins are highlighted. Particularly the mechanochemical insertion of Mg(II) is a mild alternative to established solution methods. The work provides a baseline from which the practitioner may start to evaluate the mechanochemical metal insertion into porphyrins using a planetary ball mill.
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.