Crystal structure of diaquatetrakis[μ-2,2′-(methylene-bis(sulfanediyl))bis(pyridine 1-oxide)dicopper(II) dibromide diperchlorate, [Cu2(H2O)2(C11H11N2O2S2)4]Br2(ClO4)2
Zeitschrift für Kristallographie - New Crystal Structures
C 44 H 48 Br 2 Cl 2 Cu 2 N 8 O 18 S 8 ,tetragonal, P4/n (no. 85), a =13.824(1) Å, c =16.217(2) Å, V =3099.1 Å 3 , Z =2, R gt (F) =0.059, wR ref (F 2 ) =0.189, T =298 K. Source of material 2,2'-(Methylene-bis(sulfanediyl))bis(pyridine 1-oxide) (mspo) and copper salts thereof were prepared, comprising the following steps: oxidizing a2-acetylaminopyridine with hydrogen peroxide in an inert solvent to give a2-acetamido-pyridine 1-oxide, cleaving the acetyl group with mineral acid to give
... to give a2-aminopyridine 1-oxide, diazotizing the 2-aminopyridine 1-oxide and treating the diazonium salt with hydrochloric acid to give a2-chloropridine 1oxide, treating the 2-chloropridine 1-oxide with asulfhydryl-donor to give a2-mercaptopyridine 1-oxide, treating the latter with a CH 2 Br 2 to give a2,2'-(methylenebis(sulfanediyl))bis(pyridine 1oxide). Asolution of CuBr 2 (223 mg, 1m mol) in water (5 mL) was dropped slowly into asolution of mspo (532 mg, 2mmol) in EtOH (20 mL) and the pH was adjusted to 7-8 with HClO 4 .The mixed solution was stirred for 2hat80°Cand was then cooled to room temperature to give brown-yellow microcrystals, which were collectedbyfiltration, washed successivelywithH 2 Oand EtOH,and driedinvacuo.Brown-yellowsquare crystals suitable for X-ray analysis were obtained by recrystallization of the precipitate from N,N-dimethylformamide and alcohol (1:1). Elemental analysis -found: C, 33.54 %; H, 2.96 %; N, 7.34 %; calculated for C 44 H 48 Br 2 Cl 2 Cu 2 N 8 O 18 S 8 :C,33.30 %; H, 2.79 %; N, 7.06 %; m.p.: 146-148°. IR data are available in the CIF file. Experimental details The non-hydrogen atomsw ere refined anisotropically, and hydrogen atomswere added according to theoretical models. In the crystal structure, O5 and O5',O6and O6',Br1 and Br1' are disordered with occupancies of 0.86:0.14, 0.86:0.14, and 0.36:0.14, respectively. It is very difficult to locate the hydrogen atomsofcoordinated water molecules, so their information is not provided. Discussion The practical interest in heteroaromatic N-oxides is caused first of all by the fact that many of them show biological activity and extraction properties [1, 2] .Among N-oxides, there are substances possessing carcinogenic, cancerostatic, mutagenic, insecticidal, herbicidal,fungicidal, anticonvulsant,analgesic andplantgrowingp roperties. Both biological activity ande xtractional properties areconnected with complexation of N-oxide. We have been interested in the study of metal complexes of 2-mercaptopyridine 1-oxide (Hmpo) due to the fact that these complexes have been successfully used as bactericidaland antifungal agents    . The Cu(II) complex is adinuclear cage compound. Each Cu(II) coordination sphere is formed by four mspo ligands and one 96 Z. Kristallogr.