Magnesiumphthalocyanine: Darstellung und Eigenschaften von Halogenophthalocyaninatomagnesat, [Mg(X)Pc2−]− (X = F, Cl, Br); Kristallstruktur von Bis(triphenylphosphin)iminiumchloro(phthalocyaninato)magnesat‐Aceton‐Solvat
Abstract:Magnesiumphthalocyanin reagiert mit überschüssigem Tetra(n‐butyl)ammonium‐ oder Bis(triphenylphosphin)iminiumhalogenid ((nBu4N)X oder (PNP)X; X = F, Cl, Br) zu Halogenophthalocyaninatomagnesat ([Mg(X)Pc2−]−; X = F, Cl, Br), welches teilweise als wenig lösliches (nBu4N)‐ oder (PNP)‐Komplexsalz kristallisiert. Die Kristallstrukturanalyse von b(PNP)[Mg(Cl)Pc2−] · CH3COCH3 bestätigt die tetragonal‐pyramidale Koordinationsgeometrie des Mg‐Atoms, wobei dieses aus dem Zentrum (Ct) der inneren vier Stickstoffatome (Ni… Show more
“…Detailed experimental structures in the crystalline state [36][37][38][39][40][41] are reported in the indicated rows of Table I, and are consistent with the calculations. ͑The crystal structure of NiPc was determined more than 50 years ago, 38 and the values for the bond lengths and angles are questionable.͒ Electron diffraction structures are available for ZnPc and MgPc which permit a comparison between gas phase 42 and crystal, which are in overall agreement.…”
Electronic structure and bonding in metal phthalocyanines (MetalϭFe, Co, Ni, Cu, Zn, Mg) is investigated in detail using a density functional method. The metal atoms are strongly bound to the phthalocyanine ring in each case, by as much as 10 eV. The calculated orbital energy levels and relative total energies of these D 4h structures indicate that Fe and Co phthalocyanines have 3 A 2g and 2 E g ground states, respectively, but that these states are changed upon interaction with strong-field axial ligands. The valence electronic structures of Fe and Co phthalocyanines differ significantly from those of the others. The HOMOs in Fe, Co, and Cu phthalocyanine are metal 3d-like, whereas in Ni and Zn phthalocyanines, the HOMO is localized on the phthalocyanine ring. The first ionization removes an electron from the phthalocyanine a 1u orbital in all cases, with very little sensitivity of the ionization energy to the identity of the metal. Whereas the first reduction in Fe and Co phthalocyanine occurs at the metal, it is the phthalocyanine that is reduced upon addition of an electron to the other systems. Fe, Ni, and Cu phthalocyanines have smaller HOMO-LUMO separations than do Zn and Co phthalocyanine. There is very little variation in atomic charges within the phthalocyanine from one metal to the next.
“…Detailed experimental structures in the crystalline state [36][37][38][39][40][41] are reported in the indicated rows of Table I, and are consistent with the calculations. ͑The crystal structure of NiPc was determined more than 50 years ago, 38 and the values for the bond lengths and angles are questionable.͒ Electron diffraction structures are available for ZnPc and MgPc which permit a comparison between gas phase 42 and crystal, which are in overall agreement.…”
Electronic structure and bonding in metal phthalocyanines (MetalϭFe, Co, Ni, Cu, Zn, Mg) is investigated in detail using a density functional method. The metal atoms are strongly bound to the phthalocyanine ring in each case, by as much as 10 eV. The calculated orbital energy levels and relative total energies of these D 4h structures indicate that Fe and Co phthalocyanines have 3 A 2g and 2 E g ground states, respectively, but that these states are changed upon interaction with strong-field axial ligands. The valence electronic structures of Fe and Co phthalocyanines differ significantly from those of the others. The HOMOs in Fe, Co, and Cu phthalocyanine are metal 3d-like, whereas in Ni and Zn phthalocyanines, the HOMO is localized on the phthalocyanine ring. The first ionization removes an electron from the phthalocyanine a 1u orbital in all cases, with very little sensitivity of the ionization energy to the identity of the metal. Whereas the first reduction in Fe and Co phthalocyanine occurs at the metal, it is the phthalocyanine that is reduced upon addition of an electron to the other systems. Fe, Ni, and Cu phthalocyanines have smaller HOMO-LUMO separations than do Zn and Co phthalocyanine. There is very little variation in atomic charges within the phthalocyanine from one metal to the next.
“…The sp 3 d 2 hybrid structure of the Mg atom accommodates six ligands, four of which are the surrounding nitrogen atoms on the molecular plane and two of which are the O atoms of the solvent molecules positioned above and below the molecular plane. Up to now, no six-coordinate MgPc complexes were known, although two sorts of five-coordinate MgPc have been reported: [MgPc/(H 2 O)·(C 5 H 5 N) 2 ] and (PNP)[Mg(Cl)Pc]CH 3 COCH 3 , where PNP denotes bis(triphenylphosphine)iminium. 2 Molecular conformation of the solvated complexes: (a) MgPc/(H 2 O) 2 (NMP) 2 (crystal 1 ) and (b) MgPc/(2-methoxyethanol) 2 (crystal 2 ).…”
Magnesium phthalocyanine (MgPc) is a blue pigment whose X-phase is known to exhibit an intense near-IR-absorption. Because of this, MgPc has attracted attention as a material useful for laser printers as well as
optical disks based on GaAsAl laser diodes. The near-IR absorption has, therefore, been investigated from
the standpoints of exciton coupling effects on the basis of the crystal structure. Two kinds of six-coordinate
MgPc complexes were grown from solution and their structures were analyzed: MgPc/(H2O)2·(N-methyl-2-pyrrolidone)2 (crystal 1) and MgPc/(2-methoxyethanol)2 (crystal 2). In both crystals, two oxygen atoms of
the solvent molecule are coordinated to the central Mg atom above and below the molecular plane, forming
a distorted sp3d2 octahedron. Of these crystals, only crystal 1 exhibits a near-IR absorption whose spectral
shape is quite similar to that of the X-phase. In addition, the X-phase is also found to contain two water
molecules in the normal ambient atmosphere. The near-IR absorption in both crystal 1 and the X-phase can
reasonably be interpreted as arising from exciton coupling effects based on the molecular arrangement of
MgPc/(H2O)2.
“… a FePc from XRD; CoPc from neutron-diffraction; CuPc from gas-phase electron diffraction (GED); NiPc from GED; ZnPc from XRD, GED; MgPc from XRD, GED; and H 2 Pc from XRD and neutron-diffraction …”
We compute the electronic structure and optical excitation energies of metal-free and transition-metal phthalocyanines (H 2 Pc and MPc for M = Fe, Co, Ni, Cu, Zn, Mg) using density functional theory with optimally tuned range-separated hybrid functionals (OT-RSH). We show that the OT-RSH approach provides photoemission spectra in quantitative agreement with experiments as well as optical band gaps within 10% of their experimental values, capturing the interplay of localized dstates and delocalized π−π* states for these organometallic compounds. We examine the tunability of MPcs and H 2 Pc through fluorination, resulting in quasi-rigid shifts of the molecular orbital energies by up to 0.7 eV. Our comprehensive data set provides a new computational benchmark for gas-phase phthalocyanines, significantly improving upon other density-functional-theory-based approaches.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
