Platinum(II) complexes of mixed-valent radicals derived from cyclotricatechylene, a macrocyclic tris-dioxolene

DOI: 10.1039/C5SC02776D

Authors: Jonathan J. Loughrey (University of Leeds) , Nathan J. Patmore (University of Sheffield) , Amgalanbaatar Baldansuren (University of Manchester) , Alistair J. Fielding (University of Manchester) , Eric J. L. Mcinnes (University of Manchester) , Michaele Hardie (University of Leeds) , Stephen Sproules (University of Glasgow) , Malcolm A. Halcrow (University of Leeds)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemical Science

State: Published (Approved)
Published: August 2015
Diamond Proposal Number(s): 7847

Abstract: Three complexes of cyclotricatechylene (H6ctc), [{PtL}3(m3-ctc)], have been synthesised: (L ¼ 1,2-bis(diphenylphosphino)benzene {dppb}, 1; L ¼ 1,2-bis(diphenylphosphino)ethane {dppe}, 2; L ¼ 4,40- bis(tert-butyl)-2,20-bipyridyl {tBu2bipy}, 3). The complexes show three low-potential, chemically reversible voltammetric oxidations separated by ca. 180 mV, corresponding to stepwise oxidation of the [ctc]6 catecholato rings to the semiquinonate level. The redox series [1]0/1+/2+/3+ and [3]0/1+/2+/3+ have been characterised by UV/vis/NIR spectroelectrochemistry. The mono- and di-cations have class II mixed valent character, with reduced radical delocalisation compared to an analogous bis-dioxolene ystem. The SOMO composition of [1c]+ and [3c]+ has been delineated by cw EPR, ENDOR and HYSCORE spectroscopies, with the aid of two monometallic model compounds [PtL(DBsqc)]+ (DBsqH ¼ 3,5-bis(tert-butyl)-1,2-benzosemiquinone; L ¼ dppe or tBu2bipy). DF and time-dependent DF calculations confirm these interpretations, and emonstrate changes to spin-delocalisation in the ctc macrocycle as it is sequentially oxidised.

Subject Areas: Chemistry


Instruments: I19-Small Molecule Single Crystal Diffraction

Added On: 25/09/2015 13:33

Documents:
c5sc02776d.pdf

Discipline Tags:

Molecular Complexes Chemistry Inorganic Chemistry

Technical Tags:

Diffraction Single Crystal X-ray Diffraction (SXRD)