Structural Pitstops and Turnoffs on the Way to the Birefringent 2-D Layer Structure \(\{\hbox{(tmeda)M[Hg(CN)}_{2}]_{2}\}[\hbox{HgCl}_{4}]\) (M=Cu, Ni)

  • Neil D. Draper
  • Michael J. Katz
  • Raymond J. Batchelor
  • Daniel B. Leznoff
Article

DOI: 10.1007/s10904-006-9017-z

Cite this article as:
Draper, N., Katz, M., Batchelor, R. et al. J Inorg Organomet Polym (2005) 15: 447. doi:10.1007/s10904-006-9017-z

Abstract

The reaction of N,N,N′,N′-tetramethylethylenediamine (tmeda) and NiCl2 with the soft, Lewis acidic Hg(CN)2 and HgCl2 in ethanol formed the 2-D layer structure {(tmeda)Ni[Hg(CN)2]2}[HgCl4] (1), isostructural to the Cu(II) analogue. Complex 1 crystallizes in the tetragonal, non-centric \(P \overline{4} {\text{ }}2_{1}\) m space group and contains a 2-D cationic layer of {(tmeda)Ni[Hg(CN)2]2}2+ units in which the six-coordinate Ni(II) centres are bridged by four Hg(CN)2 groups and capped by a tmeda ligand. This array is interspersed with a layer of [HgCl4]2− anions, which form bridging Hg–Cl bonds with the Hg(CN)2 units. The formation of 1 is very sensitive to reaction conditions; the addition of water to the mixture yields the related “structural pitstop” 2-D array {(tmeda)Ni(H2O)[Hg(CN)2]}{[Hg(CN)Cl]2Cl2}·H2O (2), in which the halide migration among Hg(II) centres is incomplete. The larger zero-field splitting D-values of 6.91(1) cm−1 for 1 vs. 2.85(4) cm−1 for 2 indicate that some weak antiferromagnetic interactions are likely present in 1. The reaction of tmeda/Cu(ClO4)2·6H2O with Hg(CN)2 yields [Cu(tmeda)(μ-OH)(ClO4)]2[Hg(CN)2(H2O)2][Hg(CN)2] (3) which is composed of [Cu(tmeda)(μ-OH)(ClO4)]2 dimers in which the \(\hbox{ClO}_4^{-}\) anions cis-bridge the copper(II) centres in the axial positions as well as bind to two adjacent Hg(CN)2 moieties; the perchlorate anion is acting as a rare η4–μ4–ClO4 ligand. N-cyano interactions also exist between the Hg(II) centres; overall, a 2-D corrugated sheet structure which stacks via Cl–O–Hg bridges to yield a 3-D array is formed. The χMT value for 3 decreases with decreasing temperature; a maximum in χM vs. T at 20 K is also observed. This is consistent with antiferromagnetic interactions within the copper(II) dimer, which were fit with the Bleaney-Bowers model to yield J=−23.1(1) cm−1, g=2.113(5) and a paramagnetic impurity P=0.017(1).

Keywords

Copper(II) and nickel(II) complexes mercury cyanide ligands coordination polymers magnetic properties 

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Neil D. Draper
    • 1
  • Michael J. Katz
    • 1
  • Raymond J. Batchelor
    • 1
  • Daniel B. Leznoff
    • 1
  1. 1.Department of ChemistrySimon Fraser UniversityBurnabyCanada

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