Structural Aspect of CuCN Catalytic Cyclodimerization of N‐Allylquinolinium Halides

By a reaction between the corresponding [N‐allylquinolinium]X (X = Cl, Br, I) and CuCN in a methanolic medium crystals of [C 24 H 21 N 2 ][CuCl 1.35 Br 0.65 ] ( 1 ), [C 24 H 21 N 2 ][CuBr 2 ] ( 2 ) and [C 24 H 21 N 2 ]I ( 3 ) have been obtained and characterized structurally by X‐ray (at 100 K). Isostructural complexes 1 and 2 crystallize in monoclinic space group P2 1 /n, Z = 4: 1 a = 13.193(4), b = 19.185(5), c = 8.429(3), β = 104.85(3)°, V = 2062(1) Å 3 , R = 0.051 for 3359 reflections; 2 a = 13.373(4), b = 19.104(6), c = 8.544(3) Å, β = 104.58(3)°, V = 2112(1) Å 3 , R = 0.057 for 3297 reflections. Compound 3 crystallizes in monoclinic system, space group P2 1 /n, Z = 4, a = 8.889(2), b = 16.842(3), c = 13.294(3) Å, β = 104.71(3)° V = 1925(1) Å 3 , R = 0.034 for 4042 reflections. The same cation [C 24 H 21 N 2 ] + in the compound 1 – 3 appeared as a product of N‐allylquinolinium catalytic cyclodimerization. Neither N‐allyl nor C‐vinyl groups participate in Cu I π‐coordination in the structures of 1 and 2 , therefore [CuX 2 ] − anions can possess a linear form.