About

Felix R. Fischer is a Professor of Chemistry at the University of California, Berkeley, born in 1980. He holds a diploma in Chemistry from Ruperto-Carola University, Heidelberg (2004), and a Ph.D. from the Swiss Federal Institute of Technology, Zurich (2008). He was a Leopoldina Postdoctoral Fellow at Columbia University, New York, from 2008 to 2011. His research focuses on organic synthesis, carbon nanomaterials, molecular electronics, and scanning probe microscopy. Fischer's group uniquely combines organic synthesis with advanced atomically resolved scanning probe imaging techniques, engaging in highly interdisciplinary research that spans molecular organic synthesis, condensed matter physics, and electrical engineering. His work involves the rational bottom-up design and molecular synthesis of carbon nanomaterials with atomically defined structures, their controlled assembly into hierarchically ordered architectures, and the exploration of their physical properties emerging from quantum confinement effects. Fischer aims to understand, fine-tune, and harness the properties of nanoscale materials by developing novel synthetic tools that allow atomic-level control over geometric parameters, leading to the creation of designer quantum materials with tunable electronic structures. His contributions have advanced the understanding of highly tunable semiconductors, metallic band structures, long-range magnetic ordering, and symmetry-protected topological states, extending beyond traditional physics of materials like graphene.

Research topics

• Condensed matter physics
• Quantum mechanics
• Physics
• Materials science
• Nanotechnology

Selected publications

• Pseudo–Jahn–Teller Distortion in a One-Dimensional π-Conjugated Polymer

  Journal of the American Chemical Society · 2026-02-14 · 2 citations

  articleOpen accessCorresponding

  Structural distortions in low-dimensional π-conjugated systems profoundly influence their electronic properties, but the control of such behavior in laterally extended systems remains challenging. Here we demonstrate that a one-dimensional conjugated polymer─poly-(difluorenoheptalene-ethynylene) (PDFHE)─undergoes a pronounced out-of-plane backbone distortion, equivalent to a spontaneous symmetry breaking (SSB) of its mirror symmetry. We synthesized PDFHE on noble metal surfaces and characterized its structure and electronic states using low-temperature scanning tunneling microscopy (STM). Rather than adopting a planar, high-symmetry conformation, PDFHE relaxes into nonplanar isomers stabilized by a pseudo–Jahn–Teller (PJT) distortion having mirror-odd out-of-plane character. The distortion lowers the total energy and increases the band gap, providing a concise rationale for the observed symmetry breaking. Density functional theory calculations corroborate these findings, providing a microscopic explanation for the SSB. Our results show that even in mechanically robust extended π-systems, subtle electron–lattice coupling can spontaneously drive significant structural rearrangements, even in mechanically robust extended π-systems.

  PublisherOA PDFDOI

• Ferromagnetic Insulator to Metal Transition in Noncentrosymmetric Graphene Nanoribbons

  Journal of the American Chemical Society · 2026-04-09

  articleSenior authorCorresponding

  Engineering sublattice imbalance within the unit cell of bottom-up synthesized graphene nanoribbons (GNRs) represents a versatile tool for realizing custom-tailored quantum nanomaterials. The interaction between low-energy zero-modes (ZMs) not only contributes to frontier bands but can form the basis for magnetically ordered phases. Here, we present the bottom-up synthesis of a noncentrosymmetric GNR that places all ZMs on the majority sublattice sites. Scanning tunneling microscopy and spectroscopy reveal that strong electron–electron correlations, leading to the Stoner magnetic instability, drive the system into a ferromagnetically ordered insulating ground state featuring a sizable band gap of Eg ∼1.2 eV. At higher temperatures, a chemical transformation induces an insulator-to-metal transition that quenches the ferromagnetic order. Tight-binding (TB), density functional theory, and GW calculations corroborate our experimental observations. This work showcases how control over molecular symmetry, sublattice polarization, and ZM hybridization in bottom-up synthesized nanographenes can open a path to the exploration of many-body physics in rationally designed quantum materials.

  PublisherDOI

• Pseudo–Jahn–Teller Distortion in a One-Dimensional π-Conjugated Polymer

  Journal of the American Chemical Society · 2026-02-14

  articleCorresponding

  Structural distortions in low-dimensional π-conjugated systems profoundly influence their electronic properties, but the control of such behavior in laterally extended systems remains challenging. Here we demonstrate that a one-dimensional conjugated polymer─<i>poly</i>-(difluorenoheptalene-ethynylene) (PDFHE)─undergoes a pronounced out-of-plane backbone distortion, equivalent to a spontaneous symmetry breaking (SSB) of its mirror symmetry. We synthesized PDFHE on noble metal surfaces and characterized its structure and electronic states using low-temperature scanning tunneling microscopy (STM). Rather than adopting a planar, high-symmetry conformation, PDFHE relaxes into nonplanar isomers stabilized by a pseudo-Jahn-Teller (PJT) distortion having mirror-odd out-of-plane character. The distortion lowers the total energy and increases the band gap, providing a concise rationale for the observed symmetry breaking. Density functional theory calculations corroborate these findings, providing a microscopic explanation for the SSB. Our results show that even in mechanically robust extended π-systems, subtle electron-lattice coupling can spontaneously drive significant structural rearrangements, even in mechanically robust extended π-systems.

  PublisherDOI

• One-dimensional heterocyclic carbene–Au metal–organic frameworks bridging ultra-high vacuum models and scalable liquid-phase growth

  Applied Surface Science · 2025-11-21

  articleOpen access
  PublisherOA PDFDOI

• Magnetically and optically active edges in phosphorene nanoribbons

  Nature · 2025-03-12 · 11 citations

  articleOpen access

  Abstract Nanoribbons, nanometre-wide strips of a two-dimensional material, are a unique system in condensed matter. They combine the exotic electronic structures of low-dimensional materials with an enhanced number of exposed edges, where phenomena including ultralong spin coherence times 1,2 , quantum confinement 3 and topologically protected states 4,5 can emerge. An exciting prospect for this material concept is the potential for both a tunable semiconducting electronic structure and magnetism along the nanoribbon edge, a key property for spin-based electronics such as (low-energy) non-volatile transistors 6 . Here we report the magnetic and semiconducting properties of phosphorene nanoribbons (PNRs). We demonstrate that at room temperature, films of PNRs show macroscopic magnetic properties arising from their edge, with internal fields of roughly 240 to 850 mT. In solution, a giant magnetic anisotropy enables the alignment of PNRs at sub-1-T fields. By leveraging this alignment effect, we discover that on photoexcitation, energy is rapidly funnelled to a state that is localized to the magnetic edge and coupled to a symmetry-forbidden edge phonon mode. Our results establish PNRs as a fascinating system for studying the interplay between magnetism and semiconducting ground states at room temperature and provide a stepping-stone towards using low-dimensional nanomaterials in quantum electronics.

  PublisherOA PDFDOI

• Orbital Engineering Band Degeneracy in a Dual-Square Carbon-Oxide Framework

  ACS Nano · 2025-04-10 · 5 citations

  articleOpen accessSenior authorCorresponding

  -space formed by the incidental touching of two bands that share the same energy but belong to discrete eigenstates─arise in the presence of symmetries that preclude effective hybridization. Despite recent advances in the design, bottom-up assembly, and engineering of exotic electronic states in graphene nanomaterials, the extension of this approach to access synthetic two-dimensional (2D) quantum materials derived from metal- or covalent-organic frameworks (COFs) has lagged behind. Here we present a molecular orbital engineering approach for designing and fabricating an edge-centered dual square lattice within a π-conjugated 2D-tetraoxa[8]circulene (2D-TOC) COF. First-principles calculations and scanning tunnelling spectroscopy reveal the emergence of Frontier states at the center of a 3 × 3 lattice that give rise to Dirac nodal-lines in 2D-TOC. Our findings not only provide a general guide for the design of conjugated COFs with custom tailored electronic properties from molecular fragments but enable the exploration of emergent topological phenomena in synthetic 2D materials with potential application for high-speed, low-power data processing, transmission, and storage.

  PublisherDOI

• Ring-Expansion Metathesis Polymerization under Confinement

  Journal of the American Chemical Society · 2025-02-26 · 7 citations

  article

  The cationic molybdenum alkylidyne N-heterocyclic carbene (NHC) complex [Mo(C-p-OMeC6H4)(OCMe(CF3)2)2 (IMes)][B(ArF4] (IMes = 1,3-dimesitylimidazol-2-ylidene) was selectively immobilized inside the pores of ordered mesoporous silica (OMS) with pore diameters of 66, 56, and 28 Å and used in the ring-expansion metathesis polymerization (REMP) of cyclic olefins to yield cyclic polymers. A strong confinement effect was observed for cis-cyclooctene (cCOE), 1,5-cyclooctadiene (COD), (+)-2,3-endo,exo-dicarbomethoxynorborn-5-ene ((+)-DCMNBE), and 2-methyl-2-phenylcycloprop-1-ene (MPCP), allowing for the synthesis of low-molecular-weight cyclic polymers even at a high monomer concentration. The exclusive formation of cyclic polymers was demonstrated by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. Confinement also influences stereoselectivity, resulting in a pronounced increase in Z-selectivity and in an increased cis-syndiospecificity.

  PublisherDOI

• Mesoporous Confinement Enables Activity Boost in Cooperative Asymmetric Catalysis in Analogy to Enzymes

  ACS Catalysis · 2025-11-26

  articleOpen access

  Enzymes achieve outstanding rate accelerations by combining cooperative functional group activation with confinement inside precisely organized active sites, which reduce entropic costs and enforce productive orientations of activated substrates. Here, we translate these principles into artificial cooperative asymmetric catalysis using mesoporous confinement. Embedding a chiral bifunctional catalyst into ordered mesoporous silica creates a synthetic analogue of enzymatic pockets, in which cooperative activation and nanoscale confinement act synergistically. By such confinement, reaction half-lives could be reduced by up to 97% in asymmetric 1,4-additions. Kinetic analyses attribute this enhancement to entropic advantages of confinement, while molecular dynamics simulations reveal narrowing of the catalyst’s conformational space closely paralleling precise enzymatic preorganization as molecular origin. Unlike enzymes, however, the mesoporous framework remains tunable, allowing linker length and pore size to systematically adjust reactivity. This work establishes confinement engineering as a versatile strategy to design “unnatural active sites” that merge enzymatic efficiency with synthetic catalyst flexibility. It could thus bridge the gap between nature’s precision and the versatility of synthetic chemistry.

  PublisherDOI

• Kinetic Isotope Effect in the Radical Step-Growth Termination of On-Surface Synthesized Graphene Nanoribbons

  Nano Letters · 2025-06-02

  articleOpen accessSenior authorCorresponding

  Bottom-up on-surface synthesis has emerged as a versatile tool to access and finely tune the electronic structure of nanographenes. The controlled generation of reactive intermediates catalyzed and stabilized by a supporting substrate has enabled the design, assembly, and characterization of a wide range of exotic tailor-made quantum materials. Even under these tightly controlled conditions, the growth of extended structures remains limited by termination processes and undesired side reactions. Here, we identify an H atom transfer as one principal contributor to the radical step growth termination that limits the on-surface growth of N = 7 armchair graphene nanoribbons (7-AGNRs) on Au(111) surfaces. Analysis of 7-AGNR lengths grown from protiated and deuterated molecular precursors reveals a primary kinetic isotope effect of KIE ∼ 1.4. First-principles density functional theory calculations suggest that a concerted H atom transfer mechanism that involves the breaking of a C–H/D bond in the transition state is associated with radical chain termination.

  PublisherDOI

• Chemical Engineering in Sustainable Transport Solutions

  American Journal Of Chemistry And Chemical Engineering · 2025-06-30

  articleOpen access1st authorCorresponding

  The transition to sustainable transport solutions is essential to reducing the environmental impact of transportation, which is a significant contributor to greenhouse gas emissions and pollution. Chemical engineering plays a pivotal role in the development of sustainable transport technologies, such as alternative fuels, energy-efficient vehicles, and innovative propulsion systems. This article explores the contributions of chemical engineering to sustainable transport solutions, focusing on the production of biofuels, hydrogen, and electric vehicle batteries, as well as the development of efficient propulsion systems and sustainable infrastructure. The paper also discusses the challenges and future opportunities for chemical engineers in advancing sustainable transport solutions.

  PublisherOA PDFDOI

Recent grants

• Reaction Tomography - Atomically Resolved Imaging of Chemical Transformations with Molecular Functionalized SPM Tips

  NSF · $475k · 2018–2021

• Engineering Strongly Correlated Quantum Phases Through Symmetry Breaking in GNRs

  NSF · $480k · 2022–2025

• CAREER: Introducing Hierarchical Architectures into Advanced Functional Organic Materials Controlling the Secondary and Tertiary Structure of Carbon Nanocoils

  NSF · $625k · 2015–2020

Frequent coauthors

• Michael F. Crommie

  Kavli Energy NanoScience Institute

  248 shared

• Steven G. Louie

  Lawrence Berkeley National Laboratory

  182 shared

• Danny Haberer

  University of California, Berkeley

  99 shared

• Tomas Marangoni

  DuPont (United States)

  98 shared

• Jeffrey Bokor

  84 shared

• Rebecca A. Durr

  79 shared

• Yea‐Lee Lee

  68 shared

• Daniel J. Rizzo

  63 shared

Awards & honors

• Thieme Chemistry Journals Award (2011)
• ACS PRF Doctoral New Investigator Award (2012)
• DOE Early Career Award (2012)
• Packard Fellowship For Science and Engineering (2013)
• NSF Early Career Award (2015)