Extended structures of polyiodide salts of transition metal macrocyclic complexes

Abstract

The structures of five polyiodide salts, [Co([9]aneS3)2]I11 (1), [Ni([9]aneS3)2]I6 (2), [Ni([9]aneS3)2]I10 (3), [Pd([12]aneS4)]I6 (4) and [Pd([14]aneS4)]I10·MeCN (5), containing the template cations [Co([9]aneS3)2]3+, [Ni([9]aneS3)2]2+, [Pd([12]aneS4)]2+ and [Pd([14]aneS4)]2+ ([9]aneS3 = 1,4,7-trithiacyclononane, [12]aneS4 = 1,4,7,10-tetrathiacyclododecane, [14]aneS4 = 1,4,8,11-tetrathiacyclotetradecane) exhibit a range of polyiodide and polyanionic framework structures. In (1) the charge on the CoIII cation is balanced by three I_3^- anions, which along with a neutral di-iodine molecule form I_{11}^{3-} rings in an extended structure comprising undulating chains of alternating I_{11}^{3-} rings and complex cations. In (2) the complex cation is linked to two tri-iodide anions by S...I interactions into well separated sheets of cations and anions, while in (3), I_5^- anions are linked by I...I interactions into helices which are cross-linked by S...I contacts to form sheets. Rather longer I...I contacts in (4) assemble I_3^- ions into 2 × 2 rods, which are linked into a three-dimensional network by S...I contacts. In (5) the N atom of the acetonitrile solvent molecule forms an array of four weak C—H...N hydrogen bonds to the macrocycle. The extended structure comprises corrugated zigzag chains of polyiodide rings formed by linked I_5^- units; the complex cations are attached to the polyiodide network by S...I contacts, which link the chains to form layers.