Bis(4-amino-1-hexylpyridinium) bis(1,2-dicyanoethene-1,2-dithiolato)cuprate(II)

The complete complex anion in the title salt, (C11H19N2)2[Cu(C4N2S2)2], has 2/m symmetry while the complete cation is generated by mirror symmetry with the non-H atoms of the alkyl chain lying on the plane. A square-planar geometry based on an S4 donor set is found in the anion; the Cu—S distance is 2.2663 (5) Å. In the crystal, intermolecular N—H⋯N hydrogen bonds link the ions into layers in the bc plane comprising alternating rows of cations and anions.

The complete complex anion in the title salt, (C 11 H 19 N 2 ) 2 -[Cu(C 4 N 2 S 2 ) 2 ], has 2/m symmetry while the complete cation is generated by mirror symmetry with the non-H atoms of the alkyl chain lying on the plane. A square-planar geometry based on an S 4 donor set is found in the anion; the Cu-S distance is 2.2663 (5) Å . In the crystal, intermolecular N-HÁ Á ÁN hydrogen bonds link the ions into layers in the bc plane comprising alternating rows of cations and anions.
The [Cu(mnt) 2 ] 2dianion is located about a site of symmetry 2/m. The 1-hexyl-4-aminopyridinium cation lies on a mirror plane whereby the non-H atoms of the alkyl chain lie on the plane which bisects the 1,4 atoms of the benzene ring.
In the crystal structure, intermolecular N-H···N hydrogen bonds (Table 1) link the cations and anions to form a layer in the bc plane comprising alternating cations and anions.

Experimental
Disodium maleonitriledithiolate (468 mg, 2.5 mmol) and cupric nitrate trihydrate (302 mg, 1.25 mmol) were mixed under stirring in water (20 mL) at room temperature. Subsequently, a solution of 1-hexyl-4-aminopyridinium iodide (765 mg, 2.5 mmol) in water (10 mL) was added to the mixture. The brown precipitate that formed immediately was filtered off and washed with water. The crude product was recrystallized from acetone (20 mL) to give brown crystals. The crystals suitable for X-ray diffraction measurements were obtained by diffusing diethyl ether into the solution of the salt in acetone for 6 days.

Figures
Crystal data (C 11