Structure-switching M3L2Ir(iii) coordination cages with photo-isomerising azo-aromatic linkers

DOI: 10.1039/C8SC03499K

Authors: Samuel Oldknow (University of Leeds) , Diego Rota Martir (University of St Andrews) , Victoria E. Pritchard (University of Leeds) , Mark A. Blitz (University of Leeds) , Colin w. G. Fishwick (University of Leeds) , Eli Zysman-Colman (University of St Andrews) , Michaele J. Hardie (University of Leeds)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemical Science , VOL 46

State: Published (Approved)
Published: September 2018
Diamond Proposal Number(s): 10334

Abstract: Cyclotriguaiacylene has been functionalised with 3- or 4-pyridyl-azo-phenyl groups to form a series of molecular hosts with three azobenzene-type groups that exhibit reversible photo-isomerisation. Reaction of the host molecules with [Ir(C^N)2(NCMe)2]+ where C^N is the cyclometallating 2-phenylpyridinato, 2-(4-methylphenyl)pyridinato or 2-(4,5,6-trifluorophenyl)pyridinato results in the self-assembly of a family of five different [{Ir(C^N)2}3(L)2]3+ coordination cages. Photo-irradiation of each of the cages with a high energy laser results in E → Z photo-isomerisation of the pyridyl-azo-phenyl groups with up to 40% of groups isomerising. Isomerisation can be reversed by exposure to blue light. Thus, the cages show reversible structure-switching while maintaining their compositional integrity. This represents the largest photo-induced structural change yet reported for a structurally-integral component of a coordination cage. Energy minimised molecular models indicate a switched cage has a smaller internal space than the initial all-E isomer. The [Ir(C^N)2(NCMe)2]+ cages are weakly emissive, each with a deep blue luminescence at ca. 450 nm.

Subject Areas: Chemistry


Instruments: I19-Small Molecule Single Crystal Diffraction

Added On: 27/09/2018 13:52

Documents:
c8sc03499k.pdf

Discipline Tags:

Molecular Complexes Chemistry Organometallic Chemistry

Technical Tags:

Diffraction Single Crystal X-ray Diffraction (SXRD)