A Novel Two‐Dimensional Layer Structure Built from a Tetracobalt( II )‐p‐sulfonatothiacalix[4]arene Cluster Unit

The novel coordination polymer [Co4(TCAS)(μ4‐SO4)(4,4′‐Hbipy)2]n (TCAS = the octaanion of p‐sulfonatothiacalix[4]arene) (1) has been synthesized hydrothermally and characterized. X‐ray diffraction analyses reveal a two‐dimensional (2D) layer structure built from the [Co4(TCAS)(μ4‐SO4)]2– unit. The tetranuclear cobalt(II) clusters bridged by the μ4‐SO42– and phenoxy groups of the same TCAS provide a unique trapeziform magnetic mode; magnetic studies in the temperature range 2–300 K show weak antiferromagnetic interactions between the four cobalt(II) centers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)