The Preparation and Structure of [(2,4-Dimethyl-8-ethyl-5,8-diazadec-4-ene-2-amine)chlorocopper(II)] Perchlorate

Copper(II) chloride and perchlorate, N,N-diethylethane-1,2-diamine, react in (m)ethanol with acetone and ammonia to form [(2,4-dimethyl-8-ethyl-5,8-diazadec-4-ene-2-amine)chlorocopper(II)] perchlorate, C12H27Cl2CuN3O4, , monoclinic, C2/c, (Hall-C2/c); a, 26.418(1), b, 9.7385(4); c, 14.0993(5) ？; β, 91.134(3)°. This has copper(II) in tetrahedrally distorted square-planar coordination by one primary, one tertiary, and one imine nitrogen atom and the chloride ion. 1. Introduction Amine compounds of copper(II) and nickel(II) have been reported to react with 4-amino-4-methylpentan-2-one (diacetonamine, amp) to form compounds with ligands which have primary amine groups condensed with amp, forming additional β-imino-amine chelate rings [1–3]. Compounds formed with ethane-1,2-diamine, propane-1,2-diamine, 1,5-diamino-3-azapentane (diethylenetriamine), 1,8-diamino-3,6-diazaoctane (triethylenetetramine), 1,7-diamino-4-azaheptane (dipropylenetriamine), N-6-amino-4,6-dimethyl-3-azahept-3-enyl-piperazine, 2-aminoethyl-2-pyridine, and 2-amino-ethanol have been reported [1–3]. Structures of compounds formed with propane-1,2-diamine and 1,8-diamino-3,6-diazaoctane have been reported [4]. Related compounds have been prepared by reaction of copper metal, Reinecke’s salt, NH4[Cr(NCS)4(NH3)2]·H2O, and acetone in DMF with tris(2-aminoethyl)amine [5] or N,N-dimethylethylene-1,2-diamine [6]. Copper(II) and nickel(II) ammine complexes react with acetone to form compounds of the simplest ligand of this type, 2-methyl-4-imine-pentan-2-amine, and compounds of this ligand with a variety of metal ions have been described. We now report the facile formation of [(2,4-dimethyl-8-ethyl-5,8-diazadec-4-ene-2-amine)chlorocopper(II)] perchlorate, [Cu(deenim)Cl]ClO4, by reaction of (N,N-diethylethane-1,2-diamine), equimolar amounts of copper(II) chloride and perchlorate with acetone (or mesityl oxide) plus ammonia; see Figure 1. The compound is relatively resistant to hydrolysis and can be recrystallised from hot water. Compounds of other amines, such as those mentioned previously, which were prepared by using amp, can generally be more simply prepared by reacting the metal-amine compound in (m)ethanol with acetone and ammonia; the isolation of products for these labile systems is largely determined by the formation of polychelate ligands with additional aminoimine chelate rings, which better satisfy the optimal coordination number of the cation and the presence of appropriate counter ions which generate a low solubility product. Figure 1: The formation of [Cu(deenim)Cl]ClO 4. The