Magnetism of Phthalocyanine-Based Organometallic Single Porous Sheet

Abstract

A two-dimensional (2D) periodic Fe phthalocyanine (FePc) single-layer sheet has very recently been synthesized experimentally (Abel, M.; et al. J. Am. Chem. Soc.2011, 133, 1203), providing a novel pathway for achieving 2D atomic sheets with regularly and separately distributed transition-metal atoms for unprecedented applications. Here we present first-principles calculations based on density functional theory to investigate systematically the electronic and magnetic properties of such novel organometallics (labeled as TMPc, TM = Cr-Zn) as free-standing sheets. Among them, we found that only the 2D MnPc framework is ferromagnetic, while 2D CrPc, FePc, CoPc, and CuPc are antiferromagnetic and 2D NiPc and ZnPc are nonmagnetic. The difference in magnetic couplings for the studied systems is related to the different orbital interactions. Only MnPc displays metallic d(xz) and d(yz) orbitals that can hybridize with p electrons of Pc, which mediates the long-range ferromagnetic coupling. Monte Carlo simulations based on the Ising model suggest that the Curie temperature (T(C)) of the 2D MnPc framework is ∼150 K, which is comparable to the highest T(C) achieved experimentally, that of Mn-doped GaAs. The present study provides theoretical insight leading to a better understanding of novel phthalocyanine-based 2D structures beyond graphene and BN sheets.

The origin of half-metallicity in conjugated electron systems—a study on transition-metal-doped graphyne

“…graphite, carbon nanotubes, graphene) have been proposed, thus opening a new avenue of fabricating half-metallic materials. [2][3][4][5][6][7][8][9][10][11][12][13][14][15] Since the electronegativity of carbon is stronger than that of metal elements, valence electrons will not move freely through the lattice as itinerant electrons in an alloy. Therefore, carbon-based HM materials possess unique features distinct from traditional HM alloys.…”

Synthesis and Magnetic Properties of Phthalocyanine Based Carbon Materials

“…The resulting hybrid materials are expected to exhibit high T C magnetic ordering in such phthalocyanine based carbon material (PBCM) involving local magnetic moments on the central metal ions which interact via delocalized π electrons. From the point of view of technological applications for spintronic devices, it is interesting to investigate the magnetism in PBCM [9,10].In this paper, we report the synthesis of iron PBCM by the reaction of highly chlorinated iron phthalocyanine building blocks with an alkali metal coupling reagent, and the magnetic characterization of the resulting samples indicates the presence of ferromagnetic behavior well above room temperature.…”

Synthetische kovalente und nichtkovalente zweidimensionale Materialien

“…[167] Metallhaltige Nanoblätter zeigen Redoxaktivität, Magnetismus,F luoreszenz und andere mçglicherweise nützliche physikalische Eigenschaften. [84,85] 2D-Strukturen weisen eine inhärent große Oberfläche auf und sind daher aussichtsreich für die Herstellung von Sensoren, porçsen Membranen, Nanosieben und trägerfixierten Katalysatoren. Aufz wei Dimensionen eingeschränkte Materialien bieten gegenüber ihren 1D-und 3D-Verwandten Vorteile beim Verstärken von Kompositen, Stabilisieren von Grenzflächen und als intravaskuläre Tr äger und kçnnen Zugang zu ungewçhnlichem flüssigkristallinem Verhalten bieten.…”