Abstract
Reaction of 4,4′-bipiperidine (bipip) with copper(II) bromide in aqueous HBr yielded the salts (H2bipip)CuBr4·H2O (2) and (H2bipip)2Cu2Br6 (3). Compound 2 crystallizes in the space group P21/m and forms alternating layers of the H2bipip cations and CuBr4 anions with the water molecules located in the anionic layer. Compound 3 contains Cu(I) and crystallizes in the space group P21/c and comprises stacks of H2bipip cations alternating with stacks of anions. Temperature-dependent magnetic measurements on 2 and its chloride analog, 1, show distinctly different behaviors supported by the two-halide superexchange pathway. The chloride compound (1) is best described as weakly interacting antiferromagnetic dimers (J ~ −13 K), while the bromide compound (2) exhibits very weak ferromagnetic interactions best modeled as a uniform chain with J = 2.45 (9) K (using the H = −JABΣSA·SB Hamiltonian).
Acknowledgments
The assistance of Mr Jacob Goldfine in preparation of the materials is appreciated.
Disclosure statement
No potential conflict of interest was reported by the authors.