Cyclophane with eclipsed pyrene units enables construction of spin interfaces with chemical accuracy

Chemical Science, vol. 12, pp. 8430–8437

Abstract

Advanced functionality in molecular electronics and spintronics is orchestrated by exact molecular arrangements at metal surfaces, but the strategies for constructing such arrangements remain limited. Here, we report the synthesis and surface hybridization of a cyclophane that comprises two pyrene groups fastened together by two ferrocene pillars. Crystallographic structure analysis revealed pyrene planes separated by ∼352 pm and stacked in an eclipsed geometry that approximates the rare configuration of AA-stacked bilayer graphene. We deposited this cyclophane onto surfaces of Cu(111) and Co(111) at submonolayer coverage and studied the resulting hybrid entities with scanning tunnelling microscopy (STM). We found distinct characteristics of this cyclophane on each metal surface: on non-magnetic Cu(111), physisorption occurred and the two pyrene groups remained electronically coupled to each other; on ferromagnetic Co(111) nanoislands, chemisorption occurred and the two pyrene groups became electronically decoupled. Spin-polarized STM measurements revealed that the ferrocene groups had spin polarization opposite to that of the surrounding Co metal, while the pyrene stack had no spin polarization. Comparisons to the non-stacked analogue comprising only one pyrene group bolster our interpretation of the cyclophane's STM features. The design strategy presented herein can be extended to realize versatile, three-dimensional platforms in single-molecule electronics and spintronics.

Authors 10

1. Marvin Metzelaars Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   52074 Aachen

   Germany

   Institute of Inorganic Chemistry

   RWTH Aachen University

   Institute of Inorganic Chemistry, RWTH Aachen University, 52074 Aachen, Germany

2. Sebastian Schleicher

   Forschungszentrum Jülich

   Affiliation as printed

   52428 Jülich

   Forschungszentrum Jülich

   Germany

   Peter Grünberg Institute (PGI-6)

3. Takuma Hattori

   Forschungszentrum Jülich

   Affiliation as printed

   52428 Jülich

   Forschungszentrum Jülich

   Germany

   Peter Grünberg Institute (PGI-6)

4. Bogdana Borca

   Forschungszentrum Jülich · National Institute of Materials Physics

   Affiliation as printed

   52428 Jülich

   Forschungszentrum Jülich

   Germany

   National Institute of Materials Physics

   Peter Grünberg Institute (PGI-6)

   National Institute of Materials Physics, Atomistilor 405A, Magurele, Ilfov, Romania

5. Frank Matthes

   Forschungszentrum Jülich

   Affiliation as printed

   52428 Jülich

   Forschungszentrum Jülich

   Germany

   Peter Grünberg Institute (PGI-6)

6. Sergio Sanz

   Forschungszentrum Jülich

   Affiliation as printed

   52428 Jülich

   Forschungszentrum Jülich

   Germany

   Peter Grünberg Institute (PGI-6)

7. Daniel E. Bürgler corresponding

   Forschungszentrum Jülich

   Affiliation as printed

   52428 Jülich

   Forschungszentrum Jülich

   Germany

   Peter Grünberg Institute (PGI-6)

8. Jeff Rawson corresponding Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   52074 Aachen

   Germany

   Institute of Inorganic Chemistry

   Peter Grünberg Institute (PGI-6)

   RWTH Aachen University

   Institute of Inorganic Chemistry, RWTH Aachen University, 52074 Aachen, Germany

9. Claus Michael Schneider

   Forschungszentrum Jülich

   Affiliation as printed

   52428 Jülich

   Forschungszentrum Jülich

   Germany

   Peter Grünberg Institute (PGI-6)

10. Paul Kögerler Aachen Institute of Inorganic Chemistry

    RWTH Aachen University

    Affiliation as printed

    52074 Aachen

    Germany

    Institute of Inorganic Chemistry

    Peter Grünberg Institute (PGI-6)

    RWTH Aachen University

    Institute of Inorganic Chemistry, RWTH Aachen University, 52074 Aachen, Germany