Hu, Y.L., Lin, J.H., Han, S., Chen, W.Q., Yu, L.L., Zhou, D.D., Yin, W.T., Zuo, H.R., Zhou, J.R., Yang, L.M. and Ni, C.L. (2012) Syntheses, Crystal Structures and Properties of Two New Ion-Pair Complexes by Self-Assembly of Bis(maleonitriledithiolate)copper(II)/nickel(III) Anion and Substituted 4-Dimetylaminopyridinium. Synthetic Metals, 162, 1024-1029.
http://dx.doi.org/10.1016/j.synthmet.2012.04.011

has been cited by the following article:

• TITLE: Synthesis, Crystal Structure and Infrared Characterization of Bis(4-dimethylamino-pyridinium) Tetrachlorocuprate

  AUTHORS: Mahjouba Ben Nasr, Frédéric Lefebvre, Chérif Ben Nasr

  KEYWORDS: Crystal Structure, 4-Dimethylaminopyridine, Hydrogen Bonds, π-π Interactions, DFT Calculations

  JOURNAL NAME: American Journal of Analytical Chemistry, Vol.6 No.5, April 13, 2015

  ABSTRACT: The chemical preparation, crystal structure and spectroscopic characterization of a novel organic-inorganic hybrid material, bis(4-dimethylaminopyridinium) tetrachlorocuprate, have been reported. This compound crystallizes in the monoclinic system in space group C2/c and cell parameters a = 12.4356 (18), b = 12.0901 (17), c = 14.094 (2) Å, β = 115.303 (2)°, Z = 4 and V = 1915.8 (5) Å3. In the title salt, (C7H11N2)2CuCl4, both 4-dimethylaminopyridinium cations are protonated at their pyridine N atoms. The geometry of the CuCl2-4 ions is intermediate between tetrahedral and square planar. The atomic arrangement can be described by an alternation of inorganic layers built up by tetrachlorocuprate anions and organic layers formed by 4-dimethylaminopyridinium cations. The organic layers are located in sandwich between the inorganic layers. The anionic and cationic layers are held together by N-H···Cl and C-H···Cl hydrogen bonds into a three-dimensional network. The individual cations are π-π stacked with their neighbors at a distance of 3.7622 (5) Å. The vibrational absorption bands were identified by infrared spectroscopy and DFT calculations allowed their attribution.