Molecular Lego for Functional 2D Materials: Self-Assembly and Ordering of Bi-Molecular 2D Spinlattices of M(II,III) Phthalocyanines and of Highly Crystalline Free Standing Networks

Abstract

Single layer low-dimensional materials are presently of emerging interest, also in the context of magnetism. We further developed on-surface supra-molecular architecturing to create two-dimensional spin arrays. By chemical programming of the modules, different checkerboards were produced containing metals of different oxidation and spin states, diamagnetic zinc, and a metal-free ‘spacer’. [1] 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 [2] 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 we show the the first free-standing single layer networks of calixarenes stabilized via functional groups enabling vdW, coordination and dipole-dipole, interaction. [3]Fig. 1) Graphical animation of the 2D spin arrays built by C--H - F--C bonding of two different magnetic atom bearing phthalocyanines that have been exploited to investigate the assembly and properties of Kondo lattices.[1] M. Baljozovic et al. Magnetochemistry 2021, 7, 119.[2] J. Girovsky et al. Nature Communications 2017 8:15388[3] M. Moradi, N. Opara, L.G. Tulli, C. Wäckerlin, S.J. Dalgarno, S.J. Teat, M. Baljozovic, O. Popova, E. van Genderen, A. Kleibert, H. Stahlberg, J.P. Abrahams, C. Padeste, T.A. Jung, P. Shahgaldian, Sci. Adv. 2019; 5: eaav4489 Figure 1