Polymorphism in Bis(4-dimethylamino- pyridinium)tetrachlorocuprate(II)

Abstract

The title compound crystallizes in both a yellow and a green phase. The pyridinium cations form bifurcated hydrogen bonds to the CuCl4 2- anions to form molecular species. The packing of these molecular species force the CuCl4 2- chromophore to be distorted more toward a square planar geometry in the green phase. The packing in both phases appears to be strongly influenced by C−H···Cl electrostatic interactions.

Crystal Structures and Thermal Behavior of Isostructural Bis(dibenzyldimethylammonium) Tetrachlorometallate [M = Mn(II), Co(II), Ni(II) and Zn(II)] Solvates Crystallized from Acetonitrile and/or Methanol Solutions

“…Thus, neither static nor dynamic disorder of the Bz 2 Me 2 N + cations can be observed among these crystal structures. C-H···Cl − interactions are likely to affect the packing of 1 -5 as it is the case with bis(4-dimethylaminopyridinium)tetrachlorocuprate(II) as reported by Haddad and Willett [37].…”

“…In addition to the Jahn-Teller effect, the geometry of the CuX 4 2− anion in the solid state is influenced by many other factors, such as the electrostatic repulsion between the halogen atoms, the packing forces as well as the hydrogen bonding between the cations and anions [36]. Hydrogen bonding removes the charge from the halogen atoms and reduces the electrostatic repulsion between the halogen atoms, which allows the anions to flatten toward the square planar geometry [30,37].…”

Crystal Structures and Thermal Behavior of Bis(dibenzyldimethylammonium) Tetrabromometallates(II) [M = Mn(II), Co(II) and Zn(II)] and Their Solvates

“…The geometry of the MX 4 2− anions in the solid state is influenced by many other factors, such as the electrostatic repulsion between the halide ions, the packing forces as well as hydrogen bonding between the cations and anions [40]. The hydrogen bonding removes charge from the halogen atoms and thus reduces the electrostatic repulsions between these atoms, which allows the movement of anions toward the square planar geometry [16,41,42].…”

An Unusual Organic–Inorganic Chain-like Hybrid Complex [(CuCl)2(o-phen)]∞ (o-phen=o-phenanthroline)

“…The architectures of copper halides can be tuned at the molecular level so as to possess unusual electronic properties, various components and potential applications in areas of molecular adsorption, catalysis, electromagnetism, and photochemistry (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). It is therefore vital to design and synthesize novel organic-inorganic hybrid copper halides to explore their various properties.…”

“…Up to date, the basic copper halide skeletons of these complexes generally exhibit several geometrical motifs: cyclic Cu 2 X 2 dimeric (9), cubane tetrameric (12), zigzag polymeric (12), and ''stair step'' oligomeric (9) structures. It is noteworthy that the introduction of new organic templating agents always leads to the dramatic structural change of the basic inorganic phases (3), which has well been exemplified by the reports of Zubieta et al (3,4,8) and Willett et al (2,14,15).…”