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 (dmit 2– = 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 P 2 1 , P 2 1 , and P 2/ 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 2 1 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 aCurie–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, 69451 Weinheim, Germany, 2005)