Mechanochemistry with mechanical bonds

Any force developed at the macroscopic scale can induce dramatic changes at the molecular scale, even breaking covalent bonds.[1] Indeed, mechanical force is a formidable source of energy that, with its ability to distort, bend and stretch chemical bonds, is unique in its ability to promote reaction pathways that are otherwise inaccessible to traditional methods of activation. A precise control of this force can be achieved when the chemical entity that is the subject of the mechanical force (a “mechanophore”) is embedded within a polymeric backbone.[2-5] Pulling both ends of a macromolecule apart creates highly directional strain with its highest intensity in the middle of the chain in a way reminiscent to a tug-of-war. The activation can be performed in solution, with the help of ultrasounds, or in the solid state, by simple stretching.

Mechanical bonds have always fascinated chemists because of their intriguing nature and an undeniable aesthetic appeal. Since the first synthesis of a catenane in 1960, mechanical bonds have been used in a variety of contexts and their dynamic properties have been exploited to build molecular machines and new materials. The ability of their subcomponents to undergo large amplitude displacement, such as macrocycle shuttling in a rotaxane, make them ideal structures for mechanical coupling. We are currently investigating the rich array of mechanochemical behaviours displayed by catenanes and rotaxanes.[3-5] We have recently demonstrated that the activity of a mechanophore is altered when a rotaxane is used as a force actuator,[4] that rotaxanes under tension act as a lever that accelerate the dissociation of interlocked covalent bonds,[5] and that catenanes can act as mechanical protecting groups.[5]

In this project you will use interlocked architectures (catenane/rotaxane) to promote unusual mechanochemical transformations and processes. You will investigate their activation both in solution, using ultrasounds, and in the solid-state by mechanical stretching, and explore their properties. This project could lead to the development of self-healing materials and to the creation of chemical systems able to perform complex synthetic tasks.

You will be trained in synthetic organic, polymer, and supramolecular chemistry.

For more information on the group visit: www.deboresearchgroup.com

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Application/inquiries: please contact Prof. Guillaume De Bo at [email protected] (including a CV).

Entry requirements

Applicants are expected to hold, or about to obtain, a minimum upper second class Master degree (or equivalent) in in Chemistry or Polymer Chemistry. An experience in synthetic organic chemistry, synthetic polymer chemistry or supramolecular chemistry is desirable. 

How to apply:

You will need to submit an online application through our website here: https://uom.link/pgr-apply

When you apply, you will be asked to upload the following supporting documents: 

• Final Transcript and certificates of all awarded university level qualifications

• Interim Transcript of any university level qualifications in progress

• CV

• You will be asked to supply contact details for two referees on the application form (please make sure that the contact email you provide is an official university/ work email address as we may need to verify the reference)

• English Language certificate (if applicable)

Equality, diversity and inclusion is fundamental to the success of The University of Manchester, and is at the heart of all of our activities. We know that diversity strengthens our research community, leading to enhanced research creativity, productivity and quality, and societal and economic impact. We actively encourage applicants from diverse career paths and backgrounds and from all sections of the community, regardless of age, disability, ethnicity, gender, gender expression, sexual orientation and transgender status.

We also support applications from those returning from a career break or other roles. We consider offering flexible study arrangements (including part-time: 50%, 60% or 80%, depending on the project/funder).