Supramolecular cations of (S)-, (R)-, and (RS)-Indan-1-aminium(dibenzo[18]crown-6) in magnetic [Ni(dmit)2]- salts

Magnetic crystals were formed using supramolecular cation structures that consist of (S)-AIH+(dibenzo[18]crown-6), (R)-AIH +(dibenzo[18]crown-6), or (RS)-AIH+(dibenzo[18]crown-6) (AIH+ = indan-1-aminium) as the counter cation to [Ni-(dmit) 2]- ions (dmit2- = 2-thioxo-1,3-dithiole-4,5- dithiolate), which bear one S = 1/2 spin. The resulting salts, (S)-AIH +(dibenzo[18]crown-6)[Ni(dmit)2] (1), (R)-AIH +(dibenzo-[18]crown-6)[Ni(dmit)2] (2), and (RS)-AIH +(dibenzo[18]-crown-6)[Ni(dmit)2] (3), feature supramolecular cations that are formed through the inclusion of the ammonium moiety of AIH+ into the cavity of dibenzo[18]crown-6 through N-H⋯O hydrogen bonds. Salts 1, 2, and 3 possess space groups of P2 1, P21, and P2/m, respectively, and possess similar molecular packings. Chiral cations (S)-AIH+ (salt 1) and (R)-AIH + (salt 2) yielded chiral crystals, whereas racemic (RS)-AIH + (salt 3) afforded a racemic crystal with a mirror plane. Within the crystals, alternating layers of [Ni(dmit)2]- ions and (AIH+)(dibenzo[18]crown-6) cations formed a layered structure along the b axis. Since the 21 axis of salts 1 and 2 were observed along the b axis, effective chiral magnetic interactions between the [Ni(dmit) 2]- ions were not observed. In the ac plane, weak interactions among the [Ni(dmit)2]- ions formed a two-dimensional layer. Temperature-dependent magnetic susceptibilities of salts 1, 2, and 3 exhibited a Curie-Weiss-type behavior, which shows weak antiferromagnetic interactions between the [Ni(dmit)2]- ions, with Weiss temperatures of -2.9, -2.9, and -4.2 K, respectively. © Wiley-VCH Verlag GmbH & Co. KGaA, 2005.