Main-group and transition-metal complexes of 1-thia-4,7-diazacyclononane, [9]aneN2S. Crystal structures of [VOCl2([9]aneN2S)]· MeCN, [Fe([9]aneN2S)2][ClO4]2, [Zn([9]aneN2S)2][PF6]2, [Ru(cym)([9]aneN2S)][BPh4]Cl2·M eCN (cym = p-cymene), [RhCl3([9]aneN2S)]·H2O and [Tl([9]aneN2S)][ClO4]

Abstract

A series of half-sandwich and sandwich complexes of the nine-membered mixed donor macrocyclic 1-thia-4,7-diazacyclononane ([9]aneN ₂ S) with metals in different oxidation states has been synthesized and characterized. In each case, the ligand provides tridentate face-capping co-ordination to the metal ion. X-Ray crystallographic structure determinations have been performed for most complexes; [Fe([9]aneN ₂ S) ₂ ] ²⁺ and [Zn([9]aneN ₂ S) ₂ ] ²⁺ display trans-octahedral N ₄ S ₂ co-ordination. The metal–nitrogen and metal–sulfur bond distances are greater than the respective lengths in the homoleptic complexes [M([9]aneN ₃ ) ₂ ] ²⁺ and [M([9]aneS ₃ ) ₂ ] ²⁺ (M = Fe or Zn, [9]aneN ₃ = 1,4,7-triazacyclononane, [9]aneS ₃ = 1,4,7-trithiacyclononane). In the complexes of metal ions with larger radii, e.g. Rh ^III and Tl ^I , the metal–sulfur distances are equal to or smaller than those in the complexes of [9]aneS ₃ . The difference between the metal–nitrogen and the metal–sulfur bond lengths varies from 0.21 Å to 0.40 Å in the complexes studied. Both λλλ and λδλ conformations of the three chelate rings formed were observed.