Abstract
Two novel salts containing the anion [Ni(mnt)2
]
− (mnt = maleonitriledithiolate) have
been synthesized. The counter-ions, [Fe(II)(L
1 or L
2
)2
], are cationic complexes where L
1 and L
2 are
methylated derivatives of 2,6-bis(pyazolyl)pyridine or pyrazine, which are similar to ligands found in a
series of spin-crossover (SCO) complexes. Both salts are characterized by variable temperature single
crystal X-ray diffraction and bulk magnetization measurements. Compound 1, [Fe(II)(L
1
)2
][Ni(mnt)2
]2
displays an incomplete and gradual SCO up to 300 K, followed by a more rapid increase in the high-spin
fraction between 300 and 350 K. Compound 2, [Fe(II)(L
2
)2
][Ni(mnt)2
]2
.MeNO2
, shows a gradual, but
more complete SCO response centered at 250 K. For compound 2, the SCO is confirmed by variable
temperature Mössbauer spectroscopy. In both cases, the anionic moieties are isolated from each other
and so no electrical conductivity is observed.