Synthesis and crystal structures of bis(imidazolidine-2-thione-κS)bis(thiocyanato-κS)mercury(II) and bis(cyanido)bis(μ₂ -imidazolidine-2-thione-κS)mercury(II).Hg(CN)₂

Abstract

Two mercury(II) complexes containing imidazolidine-2-thione (Imt) and thiocyanate or cyanide ligands, [Hg(Imt)2(SCN)2] (1) and [Hg(Imt)2(CN)2].Hg(CN)2(2), have been prepared and characterized by IR and NMR spectroscopy and X-ray crystallography. In compound1, the mercury atom is located on a two-fold rotation axis and is coordinated to two thione sulfur atoms of imidazolidine-2-thione (Imt) and to two sulfur atoms of thiocyanate in a distorted tetrahedral mode with the S-Hg-S bond angles in the range of 98.96(3)–148.65(6)°. In2, the mercury atom is hexa-coordinated having a distorted octahedral geometry composed of two cyanide C atoms [Hg-C=2.055(5) Å] and four weakly bound thione S atoms of imidazolidine-2-thione (Imt) [Hg-S=3.1301(13) and 3.1280(13) Å]. One free Hg(CN)2molecule is also present in the crystal. In both complexes, the molecular structure is stabilized by N-H…N and N-H…S hydrogen bonding interactions.

Influence of the Coligand onto the Magnetic Anisotropy and the Magnetic Behavior of One-Dimensional Coordination Polymers

“…Some compounds based on transition metal thiocyanates with these ligands are known including [Cd­(NCS) 2 (L) 2 ] n (L = aniline, morpholine or ethylenethiourea) and [Ni­(NCS) 2 (ethylenethiourea) 2 ] n . Furthermore, some compounds containing tetrahedrally coordinated metal cations of composition [Cu­(NCS)­(morpholine) 2 ] n , [Cu­(NCS)­(ethylenethiourea)] n , M­(NCS)­(ethylenethiourea) 2 (M = Cu, , Ag , ), and Hg­(NCS) 2 (ethylenethiourea) 2 are also known.…”

Anisotropic Thermal Expansion of Structurally Related Lanthanide–Mercury(II) Cyanide Coordination Polymers

“…To that end, mercury­(II) cyanide is a linker that provides such a design strategy. This linear building block can bridge metal centers through the N-cyano groups to give coordination polymers; however, there are few examples where this is the only role of the mercury­(II) cyanide linker. , More typically, the coordinately unsaturated and soft Lewis acidic mercury center accepts ligands, which often dictates the architecture of the supervening structure. − An example of this is the reaction of Hg­(CN) 2 with simple metal halides, in which the halide anions migrate to the mercury centers while the metal cations associate with the N-cyano groups of the mercury­(II) cyanide; the anionic [Hg­(CN) 2 Cl x ] x − moieties thereby generated then aggregate together, creating supramolecular motifs such as chains, sheets, and nets. − , This strategy has previously been used in tandem with transition metal halide salts and ancillary chelating ligands to design birefringent coordination polymers; , however, mercury­(II) cyanide has not yet been used in combination with f-block metals. Herein, we extend this design strategy to the lanthanides, describing the synthesis, structures, and thermal expansion of coordination polymers built from LnCl 3 · x H 2 O and Hg­(CN) 2 .…”