Crystal Structure and Magnetism of a Well Isolated 2D-Quantum Heisenberg Antiferromagnet, (Quinolinium)₂CuBr₄·2H₂O, and Its Anhydrous Form

Abstract

Reaction of quinoline with HBr and CuBr(2) generates a mixture of two compounds, (quinolinium)(2)CuBr(4).2H(2)O (1) and (quinolinium)(2)CuBr(4) (2) for which single-crystal X-ray structures have been solved. Compound 1 crystallizes in the monoclinic space group C2/c as layers of tetrabromocuprate ions which are separated by intervening layers of quinolinium ions. Compound 2 crystallizes in the triclinic space group P1. Magnetic data analysis reveals that 1 behaves as a 2D-quantum Heisenberg antiferromagnet with 2J/k(B) = -6.17(3) K within the layers. High field magnetization data at low temperatures suggests that T(N) must be less than 1.8 K for 1, yielding a figure of merit |k(B)T(N)/2J| < 0.29, which indicates excellent isolation between the layers. Magnetic exchange in compound 2 was much weaker and was fit to a linear chain antiferromagnet with 2J/k(B) = -1.59(3) K.

Hyperinsulinemia promotes metastasis to the lung in a mouse model of Her2-mediated breast cancer

“…Our results demonstrate that MTB/TAN/MKR +/+ mice demonstrate higher levels of phosphorylated IR/IGF-IR than MTB/TAN control mice, suggesting that insulin is acting through its cognate receptor and/or the highly homologous IGF-IR to promote mammary tumor growth. In human breast cancer tissues phosphorylated IR/IGF-IR has been reported to be a prognostic marker of poor outcome for breast cancer, regardless of subtype (27). The ratio of IR isoform A (IR-A) to isoform B (IR-B) is also important in breast cancer, and recently a higher IR-A/IR-B ratio has been observed in the luminal B subtype of breast cancer (28).…”

Synthesis, structure, and magnetic properties of a family of copper(II) complexes and salts of isoquinoline: (Isoquinoline) Cu(X)2 [X = Cl, Br] and (isoquinolinium)2CuX4(H2O) [X = Cl, Br; n = 0,1]

“…13,14 There has been extensive research into metal halide complexes and salts with quinoline (Quin) and substituted quinoline molecules as ligands or cations (in their protonated form, QuinH), of the general form (Quin)2MX2 and (QuinH)2 [MX4], and into the relationship between the structures of those compounds and their magnetic behavior. 15,16,17,18,19,20,21,22 Quinoline is a useful ligand due to its size, which can effectively separate the magnetic species into a variety of lattice types. Ideally, this keeps the magnetic exchange in one or two dimensions, leading to changes in the nature of the magnetic interactions.…”

Tetrahalidocuprates(ii)—structure and EPR spectroscopy. Part 1: Tetrabromidocuprates(ii)

“…8,[15][16][17][18] Moreover, the magnetism and magnetochromism of tetrabromidocuprates(II) was recently analyzed by J. D. Woodward et al [19][20][21] Tetrabromidocuprates have also been used as interesting building blocks for magnetic materials e.g. spin-ladder materials or layered structures by C. P. Landee, J. J. Novoa, M. M. Turnbull et al [22][23][24][25][26] Finally, tetrahalidocuprate(II) complexes have been used as catalysts or catalyst precursors. 27,28 Liquid crystalline ionic liquids on the basis of tetrahalidometalates (M = Co, Ni) have been reported first in 1996 by C. J. Bowlas, D. W. Bruce and K. R. Seddon.…”