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Personal profile

Research interests

Dynamics of Reactive and Inelastic Molecular Collisions

Collisions abound in almost all chemical processes of practical interest, resulting either in chemical reactions or energy transfer. We aim to understand what happens during intermolecular collisions by preparing systems as precisely as possible and then examining the detailed motions of the products immediately afterwards, mainly through novel types of laser spectroscopy. This work is carried out jointly with Dr Matt Costen (see our joint research group webpages).

1. Dynamics of Collisions at Liquid Surfaces

Despite their widespread practical importance in, e.g., heterogeneous atmospheric chemistry and the combustion of liquid fuels, collisions at the gas-liquid interface remain relatively unexplored fundamentally. We have developed a successful, laser-based method to study reactive and inelastic collisions of gas-phase radicals at liquid surfaces (Figure 1). We have also demonstrated that it can be exploited as a new type of analytical probe of complex surfaces such as those of ionic liquids.

 

Figure 1. Schematic reaction of gas-phase O(3P) atoms at the surface of the long-chain hydrocarbon, squalane (C30H62).

2. Dynamics of Inelastic Collisions of Open-Shell Radicals

Small open-shell radicals, such as OH, CN and NO, are the key species in many gas-phase environments. Their intermolecular collisions govern the dissipation of energy and are also crucial in the interpretation of spectroscopic probes of concentrations and temperatures. We have developed several methods, including polarisation spectroscopy and frequency-modulated absorption spectroscopy, to study such collisions, with particular focus on the destruction of rotational polarisation (Figure 2).

 

Figure 2. 2-colour polarisation spectroscopy measurements of the decay of orientation of OH(X)v = 0 in different rotational levels in collisions with Ar and He at low (300 mTorr, blue) and high (1000 mTorr, red) pressures.

3. Dynamics of High-Energy Reactive Collisions

In collaboration with Prof Tim Minton at Montana State University, we have been involved in a number of studies of the dynamics of collisions of O(3P) atoms generated from a unique high-energy source. This has been exploited to study reactions at selected liquid surfaces (see above), complemented by realistic molecular dynamics simulations (Figure 3), and in on-going work on benchmark elementary gas-phase reactions such as O(3P) + D2.

 

Figure 3. Snapshot molecular dynamics simulations of the surfaces of the ionic liquids C2mim NTf2 (upper) and C12mim NTf2 (lower), showing the preferential accumulation of the longer alkyl chains at the surface of the liquid.

Research Group Contact Details

Roles & Responsibilities

  • Head of Dynamics and Structure research grouping
  • Member of Institute of Chemical Sciences Management Group
  • MChem Study Director
  • School of Engineering & Physical Sciences Representative of Heriot-Watt University Senate

Fingerprint Dive into the research topics where Kenneth George McKendrick is active. These topic labels come from the works of this person. Together they form a unique fingerprint.

  • 3 Similar Profiles
Ionic Liquids Chemical Compounds
Energy Transfer Medicine & Life Sciences
collisions Physics & Astronomy
depolarization Physics & Astronomy
Scattering Chemical Compounds
Atoms Chemical Compounds
Lasers Medicine & Life Sciences
Gases Medicine & Life Sciences

Co Author Network Recent external collaboration on country level. Dive into details by clicking on the dots.

Research Output 1997 2019

Probing Conformational Heterogeneity at the Ionic Liquid–Vacuum Interface by Reactive-Atom Scattering

Smoll, E. J., Purcell, S. M., D’Andrea, L., Slattery, J. M., Bruce, D. W., Costen, M. L., McKendrick, K. G. & Minton, T. K., 17 Jan 2019, In : Journal of Physical Chemistry Letters. 10, 2, p. 156-163 8 p.

Research output: Contribution to journalArticle

Ionic Liquids
Vacuum
Scattering
Atoms
Liquids

Real-space laser-induced fluorescence imaging applied to gas-liquid interfacial scattering

Bianchini, R. H., Roman, M. J., Costen, M. L. & McKendrick, K. G., 7 Aug 2019, In : The Journal of Chemical Physics. 151, 5, 12 p., 054201.

Research output: Contribution to journalArticle

Open Access
File
laser induced fluorescence
Gases
Fluorescence
Scattering
Imaging techniques

Collision-Energy Dependence of the Uptake of Hydroxyl Radicals at Atmospherically Relevant Liquid Surfaces

Bianchini, R., Tesa-Serrate, M. A., Costen, M. L. & McKendrick, K. G., 29 Mar 2018, In : Journal of Physical Chemistry C. 122, 12, p. 6648-6660 13 p.

Research output: Contribution to journalArticle

Open Access
File
hydroxyl radical
collision
liquid
energy
alkane

Determining the Composition of the Vacuum-Liquid Interface in Ionic-Liquid Mixtures

Smoll, E. J., Tesa-Serrate, M. A., Purcell, S., D'Andrea, L., Bruce, D. W., Slattery, J. M., Costen, M. L., Minton, T. K. & McKendrick, K. G., 1 Jan 2018, In : Faraday Discussions. 206, p. 497-522 26 p.

Research output: Contribution to journalArticle

Open Access
File
Ionic Liquids
Fluorescence
Vacuum
Scattering
Surface tension

Non-intuitive rotational reorientation in collisions of NO(A 2Σ+) with Ne from direct measurement of a four-vector correlation

Sharples, T. R., Leng, J. G., Luxford, T. F. M., McKendrick, K. G., Jambrina, P. G., Aoiz, F. J., Chandler, D. & Costen, M. L., Nov 2018, In : Nature Chemistry. 10, p. 1148–1153 6 p.

Research output: Contribution to journalArticle

Open Access
File
molecular collisions
retraining
handedness
Angular momentum
Scattering

Prizes

Fellow of the Royal Society of Edinburgh

Kenneth George McKendrick (Recipient), 2011

Prize: Election to learned society

Royal Society / Leverhulme Trust Senior Research Fellowship

Kenneth George McKendrick (Recipient), 2008

Prize: Fellowship awarded competitively

RSC Chemical Dynamics Award 2015

Kenneth George McKendrick (Recipient), 2015

Prize: Prize (including medals and awards)

Gases
Energy transfer
Liquids

Activities 2010 2010

  • 2 Membership of committee

Royal Society of Chemistry (External organisation)

Kenneth George McKendrick (Member)
2010

Activity: MembershipMembership of committee

Science & Technology Facilities Council (External organisation)

Kenneth George McKendrick (Member)
20102012

Activity: MembershipMembership of committee