Strong through-space two-halide magnetic exchange of −234 K in (2,5-dimethylpyrazine)copper(ii) bromide

Abstract

An unprecedented antiferromagnetic exchange of -234 K in Cu(2,5-dimethylpyrazine)Br(2) is shown experimentally and theoretically to propagate via through-space interactions between Br ions rather than through-bond interactions.

Anion–anion interactions: their nature, energy and role in crystal formation

“…A similar situation was observed in the crystal of coordination polymer Cu 2 (2,5-dmpz)Br 2 (dmpz is dimethylpyrazine). 32 In this case, however, the magnetic exchange coupling could be attributed to the through-space interaction between neighbouring polymer chains rather than to the through-bond interaction 7Cu7Br_Br7Cu7. The strength of this interaction, which is unusually high for this type of interactions, shows the potential of its use for construction of novel magnetic materials.…”

“…The strength of this interaction, which is unusually high for this type of interactions, shows the potential of its use for construction of novel magnetic materials. 32 The analysis of the EAS for solutions of salts with cobalt and iron octahedral low-spin complexes as the complex anions 11, 33 also allowed detecting the formation of the AA associates. The existence of the latter, as it was shown by the example of the salt Li 3 AlN 2 , resulted from charge transfer that can occur between the like-charged species and is similar to that between a cation and an anion.…”

Structure, phase transition and properties of the one-dimensional antiferromagnet Cu(2,6-dimethylpyrazine)Br2

“…The observation of structural phase transition in 1 is surprising because it has never been found in its analog compounds like Cu(2,5-dimethylpyrazine)Br 2 , Cu(2,6dimethylpyrazine)(NO 3 ) 2 , or other pyrazine-based coordination complexes at ambient pressure. 2,15,[19][20][21] The linear to non-linear structural transition of [CuBr 2 ] n chains bring substantial change in the coordination environment and should have considerable impact on its 1D magnetism.…”

Low Temperature Crystal Structure and Magnetic Behavior of Bis(n-Methyl-2-Phenylethylamininium) Tetrabromidocuprate

“…A könyvjelző nem létezik.a to very significant exchange (J = -234 K). 5 The correlation between the X…X distance as well as Cu-X…X contact angle and Cu-X…X-Cu torsion angle has been established, Hiba! A könyvjelző nem létezik.a, 6 but as yet insufficient data is available to provide any quantitative magnetostructural correlations and hence we have continuing interest in the study of such compounds.…”