Aryl-linked salicylaldoxime-based copper(II) helicates and "boxes": synthesis, X-ray analysis, and anion influence on complex structure

Inorg Chem. 2013 Aug 19;52(16):9327-37. doi: 10.1021/ic400829d. Epub 2013 Aug 8.

Abstract

The synthesis and spectroscopic analysis of both "metal-only" and anion encapsulated salicylaldoxime-based complexes utilizing a new 1,3-xylyl strap are described. X-ray crystallographic analysis reveals that the aromatic spacer restricts the confirmation flexibility of the resulting complexes leading to dicopper(II) double helicate and dicopper(II) 2 + 2 "box" structural forms. The choice of the structural motif is influenced by the anion present, with the copper(II) nitrate-containing complex [NO3⊂(Cu2L(3)2)](NO3)3, 4, adopting a double helicate form, whereas the analogous copper(II) bromide complexes [2Br⊂(Cu2L(3)2)](Br)2, 5, and [2Br⊂(Cu2L(3)2)](BF4)2, 6, both adopt 2 + 2 "box" structural configurations. Spectroscopic analysis has shown an enhancement in the binding strength of ClO4(-) over the anions SO4(2-) and NO3(-). The enhanced rigidity caused by the use of the 1,3-xylyl spacer in this series of complexes has favored the formation of the "double loaded" dibromide complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anions / chemistry
  • Copper / chemistry*
  • Crystallography, X-Ray
  • Models, Molecular
  • Molecular Structure
  • Organometallic Compounds / chemical synthesis*
  • Organometallic Compounds / chemistry*
  • Oximes / chemistry*

Substances

  • Anions
  • Organometallic Compounds
  • Oximes
  • salicylaldoxime
  • Copper