Effects of deuteration on the structure and magnetic properties of bis-quinolinium tetrabromidocuprate(II) dihydrate

Abstract

The partially [d₆, 2] and fully [d₂₀, 3] deuterated analogues of (QuinH)₂CuBr₄·2H₂O (d₀, 1) were prepared and their crystal structures were determined [Quin = quinoline]. In both compounds, there is a clear disorder in the positions of the bromide ions which was resolved. This led to a reexamination of the structure of the parent, fully protonated compound (1) where a small percentage of previously unrecognized disorder was also observed and the structure rerefined. Variable temperature magnetization measurements over the range 1.8–310 K indicate that all three materials behave as magnetically well-isolated layers that can be evaluated using the 2D-quantum Heisenberg antiferromagnetic model. Final fitting results for the partially (J = −5.96(5) K) and fully (J = −5.77(2) K) deuterated compounds indicate slightly weaker exchange compared to the protonated compound (J = −6.17(3) K), likely as a result of the increased disorder in the deuterated phases.

Graphical Abstract

Keywords:

• Cu(II)
• magnetism
• deuteration
• disorder

Acknowledgements

We are grateful to Dr. Matt Polson for helpful discussions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors are grateful for funds from PCISynthesis, Inc. (now SEQENS) toward the purchase of the X-ray powder diffractometer, the National Science Foundation (IMR-0314773) toward the purchase of the MPMS SQUID magnetometer and the Kresge Foundation toward the purchase of both.