Over the past two decades, transitions metals have been extensively employed
towards the construction (using coordination driven assembly) and operation (using
reversible metal-ligand switching motifs) of supramolecular architectures. This
Thesis details the investigation of an array of dynamic platinum(II)-based
metallosupramolecular architectures and includes a series of model studies on
switchable platinum(II) coordination modes.
Chapter Two describes the synthesis and study of a series of prototype noninterlocked
molecular machines. The inherent dynamics of intramolecular metalligand
substitution reactions (metallotrophic shifts) are exploited to drive a d8
platinum(II-)-phenanthroline component along different ligating architectures to
achieve translational (and in one case rotary) motion of the sub-molecular
components. Variable temperature NMR studies of these complexes have established
the kinetic parameters for the observed shuttling processes.
In Chapter Three, the switchable behaviour of a metal-ligand coordination motif is
reported in which a proton input is employed to modify the overall thermodynamic
bias and light is orthogonally utilized to selectively lower the energetic barrier for
the binding event to re-equilibration. A discussion of the light-promoted ligand
exchange reaction is presented, supported by a combination of TD-DFT calculations
and kinetic studies.
Chapter Four describes the exploitation of this discovered pH-switchable metalligand
motif for the stimuli-responsive reversible assembly of two dimensional and
three dimensional metallosupramolecular architectures. Whilst Chapter Five details
how this reversible motif can be exploited to induce controlled exchange between
“3+1” and “2+2” square planar platinum donor sets in response to the application
of acid-base stimuli
