Gold(i) bridged dimeric and trimeric heterometallic {Cr7Ni}-based qubit systems and their characterization.

Deepak Asthana,Christopher A Muryn,Grigore A Timco,Neil A Burton,Selina Nawaz,Richard E P Winpenny,David Collison,Iñigo J Vitorica-Yrezabal,Selena J Lockyer,Robert J Woolfson

doi:10.1039/d1dt00150g

Deepak Asthana, Christopher A Muryn + Show 8 more

Open Access

https://doi.org/10.1039/d1dt00150g

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Abstract

Gold(i) bridged dimeric and trimeric structures of a ground state spin S = 1/2 heterometallic {Cr7Ni} wheel have been prepared and studied by continuous wave (CW) and pulsed wave EPR spectrometry. The {Cr7Ni} relaxation time constants (T1 and Tm) show rates matching well with previous observations. Four pulse Double Electron Resonance (DEER) studies suggest presence of more than one conformations. Small Angle X-ray Scattering (SAXS) in conjunction with Molecular Dynamic (MD) Simulations were performed to look at the possible conformations in solution. In line with DEER results, simulation data further indicated more flexible molecular geometry in solution than the one in solid state.

Highlights

ResultsThe family of {Cr7M} rings has been investigated since the first report in 2003;1 one major aim of the research has been as possible qubits for quantum information processing.2–4{Cr7Ni} has attracted special interests due to its overall S = 1/2 ground state and tunable coherence times of the spin states.[5]
Small Angle X-ray Scattering (SAXS) in conjunction with Molecular Dynamic (MD) Simulations were performed to look at the possible conformations in solution
We have extend the range of groups we can introduce to the {Cr7Ni} ring to include a sterically hindered phosphine ligand

Summary

Results

The family of {Cr7M} rings has been investigated since the first report in 2003;1 one major aim of the research has been as possible qubits for quantum information processing.[2,3,4]. Complex 4 is an unusual example of a three-coordinate gold chloride structure with a bulky monodentate phosphine ligand.[12] On one occasion while attempting to remake 4, we crystallised the {[NH2nPr2][Cr7NiF8(O2CtBu)15(O2C-C6H4-PPh2)]}3AuCl (5) (Fig. 2b) where three {Cr7Ni} rings are bound to the Au(I) centre. This forms in low yield and we have not attempted to optimise the synthesis as 5 does not appear to be present in solution (see below). Tikhonov computations[17] provide distance distributions with three main components; the middle one of the main components matches the distances predicted for the ring⋯ring contacts by molecular dynamics simulations

Discussion

Findings

Synthetic procedures