Synthesis, structure, and magnetic characterization of a hysteretic charge-transfer salt metamagnet, decamethylferrocenium 2,3-dicyano-1,4-naphthoquinonide, [Fe(Cp*)2][DCNQ].
The synthesis and single-crystal structure of a new one-to-one charge-transfer salt, derived from decamethylferrocene and 2,3-dicyano-1,4-naphthoquinone, are described. [Fe(Cp*)2][DCNQ] crystallizes in the orthorhombic space group Pbca, with a = 17.3149(5) A, b = 14.6862(4) A, c = 21.0507(6) A, and Z = 8. Magnetization vs temperature data obtained in 100 G suggest that the compound exhibits dominant one-dimensional ferromagnetic coupling and that it subsequently undergoes an antiferromagnetic phase transition below TN approximately 4 K. Results of magnetization vs applied field experiments show that the compound is a metamagnet with a critical field of approximately 3 kG at 1.8 K. In the nominally antiferromagnetic state, apparent canting of the moments gives rise to a small amount of hysteresis. This picture is supported by ac susceptibility data. The 57Fe Mössbauer spectrum exhibits the expected decamethylferrocenium unresolved quadrupole doublet (delta = 0.53 mm/s) at 77 K and magnetic hyperfine splitting, Hint = 37.9 T, corresponding to long-range magnetic order at 1.63 K.
Yee
G T
GT
Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA.
Whitton
M J
MJ
Sommer
R D
RD
Frommen
C M
CM
Reiff
W M
WM