Mark Johnson

About

Mark Johnson is the Arthur T. Kemp Professor of Chemistry and a member of the Yale faculty since 1985. His research interests are centered on physical chemistry, specifically the mechanisms of complex synthetic pathways at the molecular level. He combines multi-dimensional laser spectroscopies, reaction dynamics, cryogenic ion chemistry, and bioanalytical methodologies to access transient species in solution, expanding the scope of chemistry addressed in his work. His laboratory develops and utilizes sophisticated instrumentation, including a new class of spectrometers that integrate FTIR-like capabilities with mass spectrometry, to study chemical processes with high precision. Professor Johnson's work involves understanding chemical processes in condensed phases by extracting key species directly from solutions, freezing them into well-defined geometries, and characterizing the potential energy surfaces that govern reactions. His research projects include structural characterization of host-guest linkages in supramolecular chemistry, photochemical conversion of intermediates in catalytic transformations of CO2 and H2O into solar fuels, and elucidation of micro-hydration regimes involved in charge translocation and covalent bond formation. His approach often involves close collaboration with inorganic, organic synthesis, and chemical biology groups, and his laboratory designs custom instruments to meet these scientific challenges. Throughout his career, he has been…

Research topics

• Chemistry
• Chemical physics
• Physics
• Stereochemistry
• Chromatography
• Physical chemistry
• Materials science
• Photochemistry
• Crystallography
• Organic chemistry

Selected publications

• Demystifying the Diffuse Vibrational Spectrum of Aqueous Protons Through Cold Cluster Spectroscopy

  Annual Review of Physical Chemistry · 2021 · 29 citations

  Senior authorCorresponding

  (aq).

  DOI

• Vibrational spectroscopy of the cryogenically cooled O- and N-protomers of 4-aminobenzoic acid: Tag effects, isotopic labels, and identification of the E,Z isomer of the O-protomer

  International Journal of Mass Spectrometry · 2020 · 27 citations

  Senior authorCorresponding
  DOI

• Isolating the Contributions of Specific Network Sites to the Diffuse Vibrational Spectrum of Interfacial Water with Isotopomer-Selective Spectroscopy of Cold Clusters

  The Journal of Physical Chemistry A · 2020 · 20 citations

  O is introduced without isotopic scrambling, an important advantage afforded by the cluster regime. The resulting patterns provide an unprecedented picture of the intrinsic line shapes and spectral complexities associated with excitation of the individual OH groups, as well as the correlation between the frequencies of the two OH groups on the same water molecule, as a function of network site. The properties of the surrounding water network that govern this frequency map are evaluated by dissec…

  DOI

• Intra-cluster Charge Migration upon Hydration of Protonated Formic Acid Revealed by Anharmonic Analysis of Cold Ion Vibrational Spectra

  The Journal of Physical Chemistry A · 2023-09-05 · 16 citations

  articleCorresponding

  The rates of many chemical reactions are accelerated when carried out in micron-sized droplets, but the molecular origin of the rate acceleration remains unclear. One example is the condensation reaction of 1,2-diaminobenzene with formic acid to yield benzimidazole. The observed rate enhancements have been rationalized by invoking enhanced acidity at the surface of methanol solvent droplets with low water content to enable protonation of formic acid to generate a cationic species (protonated for…

  PublisherDOI

• Spectroscopic Evidence for Doubly Hydrogen-Bonded Cationic Dimers in the Solid, Liquid, and Gaseous Phases of Carboxyl-Functionalized Ionic Liquids

  The Journal of Physical Chemistry B · 2024-05-22 · 12 citations

  articleSenior authorCorresponding

  Intermolecular interactions determine whether matter sticks together, gases condense into liquids, or liquids freeze into solids. The most prominent example is hydrogen bonding in water, responsible for the anomalous properties in the liquid phase and polymorphism in ice. The physical properties are also exceptional for ionic liquids (ILs), wherein a delicate balance of Coulomb interactions, hydrogen bonds, and dispersion interactions results in a broad liquid range and the vaporization of ILs a…

  PublisherDOI

Recent grants

• U.S.-Japan Cooperative Research: Chemical Reactions of Microclusters in Gas Phase and Interaction with Surfaces

  NSF · $21k · 1991–1994

• MRI: Development of a hybrid mass spectrometry platform with mass-selective optical spectroscopy of cryogenic ions

  NSF · $500k · 2018–2021

• Spectroscopic characterization of elementary species in water-mediated chemistry using size-selected clusters

  NSF · $508k · 2006–2009

Frequent coauthors

• Kenneth D. Jordan

  University of Pittsburgh

  87 shared

• Gary H. Weddle

  Fairfield University

  81 shared

• Nathan I. Hammer

  University of Mississippi

  72 shared

• Joseph Roscioli

  Aerodyne Research

  67 shared

• Eric G. Diken

  Smiths Detection (United States)

  65 shared

• Anne B. McCoy

  University of Washington

  60 shared

• Patrick Ayotte

  50 shared

• William H. Robertson

  The University of Texas at El Paso

  47 shared

Labs

• Johnson LabPI

Awards & honors

• NSF Presidential Young Investigator (1987)
• Camille and Henry Dreyfus: Distinguished New Faculty (1985)
• Teacher-Scholar (1990)
• Professeur Invité, Université de Paris-Sud (1988 & 1994)
• Invited Lecturer by The Chemical Society of Brazil (1997)

Similar researchers at Yale University

• William Jorgensenh-123
• Jon Ellmanh-111
• Patrick Hollandh-92