Self-Assembly and Magnetic Order of Bi-Molecular 2D Spin Lattices of M(II,III) Phthalocyanines on Au(111)

Single layer low-dimensional materials are presently of emerging interest, including in the context of magnetism. In the present report, on-surface supramolecular architecturing was further developed and employed to create surface supported two-dimensional binary spin arrays on atomically clean non-magnetic Au(111). By chemical programming of the modules, different checkerboards were produced combining phthalocyanines containing metals of different oxidation and spin states, diamagnetic zinc, and a metal-free ‘spacer’. In an in-depth, spectro-microscopy and theoretical account, we correlate the structure and the magnetic properties of these tunable systems and discuss the emergence of 2D Kondo magnetism from the spin-bearing components and via the physico-chemical bonding to the underlying substrate. The contributions of the individual elements, as well as the role of the electronic surface state in the bottom substrate, are discussed, also looking towards further in-depth investigations.

Synthesis, DFT calculations, photophysical, photochemical properties of peripherally metallophthalocyanines bearing (2-(benzo[d] [1,3] dioxol-5-ylmethoxy) phenoxy) substituents

4-(2-(benzo[d] [1, 3] dioxol-5-ylmethoxy) phenoxy) phthalonitrile was first prepared as a starting material. Then, this new phthalonitrile derivative was reacted with Zn and Co salts to obtain new phthalocyanine complexes. Phthalocyanine complexes were evaluated by fluorescence emission, extinction, and absorption measurements. Aggregation studies show the compliance with the lambert-beer law in the concentration range studied for peripheral phthalocyanine compounds. The density functional theory (DFT) calculations of the metallophthalocyanines compounds were performed using B3LYP / 6-31G in Zn-Pc and B3LYP / LanL2DZ in Co-Pc to derive structural optimization, HOMO-LUMO energy parameters, and NLO properties. The calculated values of M-Pcs with different center atoms were obtained close to each other. Molecular electronic surface (MEP) maps of the studied compounds are mapped and discussed. The HOMO-LUMO energy gaps of our compounds studied are around 2.1 eV. The docking studies were performed with the phthalonitrile.

Unconventional magnonic surface and interface states in layered ferromagnets

Electronic surface, interface and edge states are well-known concepts in low-dimensional solids and have already been utilised for practical applications. It is expected that magnons–the bosonic quasiparticles representing the magnetic excitations– shall also exhibit such exotic states. However, how these states are formed in layered magnetic structures is hitherto unknown. Here we bring the topic of magnonic surface and interface states in layered ferromagnets into discussion. We provide experimental examples of synthetic layered structures, supporting our discussions and show that these states can be tailored in artificially fabricated structures. We demonstrate that the magnonic surface or interface states may show peculiar features, including "standing” or "ultrafast” states. We argue that these states can drastically change their electronic and magnonic transport properties. In this way one can design layered ferromagnets which act as magnon conductor, semiconductor and insulator of specific states.