Source of materialToanethanol solution (5 ml) of 2 ¢ -hydroxyacetophenone (274.50 mg, 2.01 mmol) wasadded ane thanol solution (3 ml) of 1,4-bis-(aminooxy)butane (124.30 mg, 1.03 mmol). After the solution hadbeen stirred at55°Cfor 2h,the mixture wasfiltered. The residue wasw ashed successively with ethanol and ethanol/hexane (1:4),r espectively. The isolated compound wasd ried under reduced pressure and purified by recrystallization from ethanol to yield 119.10 mg of colorless crystallinesolid (yield 34 %, m.p. 132-133°C). The single crystals were obtained atRT by slow evaporationf rom amixture of tetrahydrofuran/methanol( 1:1, v / v ) and 2,2¢ -[(1,4-butylene)dioxybis(nitriloethylidyne)]-diphenol. DiscussionParticularattention hasr ecently been paid to the synthesis and study of salen and its derivatives. This is due to avarietyofreasons, not the least of which is theircrucialrole in inorganic and organometallic chemistry, e.g., they caneasily form metallosalen complexes with metalions asversatile chelating ligands. Some of them or their metalcomplexes are used in various organic reaction processes asc atalysts [1], models of reaction centers of metalloenzymes [2], have fascinating magnetic properties [3] and are nonlinearopticalmaterials [4]. They canalso be used asbiologicalm odels in understanding the structure of biomolecules and biologicalprocesses [5,6]. Most of their important features of these compounds are their preparative accessibility, diversityand structuralv ariability, which make them more attractive. Although the important properties of salen and its derivatives have been well-documented, it still seems there could be new and specific applications for such aunique group of compounds. The salen ligandsinmost of their metalcomplexes are stable insolution or solid state, however, the C = Nbonds often suffer exchange reaction asw ell ash ydrolysis. Because the oxime-type ligandsare more stable to resist the metathesis of C = Nbonds

The title compound, C19H22N2O4, was synthesized by the reaction of 2′-hydroxy­acetophenone with 1,3-bis­(amino­oxy)propane in ethanol. Intra­molecular O—H⋯N and weak C—H⋯O hydrogen bonds stabilize the three-dimensional structure. A twofold rotation axis passes through the molecule.

In the title compound, C22H28N2O6, strong intra­molecular O—H⋯N hydrogen bonds and weak inter­molecular C—H⋯O hydrogen bonds stabilize the three-dimensional supra­molecular structure.

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The performance of copper ion removal using sodium dodecyl sulfate (SDS) and its mixtures with Brij 35, Tween 80 (TW80) and Triton X-100 (TX100) by micellar-enhanced ultrafiltration (MEUF) was investigated. The effects of the molar ratio of nonionic surfactant to SDS on the critical micelle concentration (CMC) of SDS/Brij 35, SDS/TW80 and SDS/TX100, the removal efficiency of Cu(2+), the residual concentration of SDS in the permeate solution and the permeate flux were tested. The results showed that the CMCs of the mixed surfactants were sharply less than that of pure SDS. The removal efficiencies of Cu(2+) were up to the maximum values 98.3 and 95.8% when the molar ratios of Brij 35 and TW80 to SDS were 0.3, and it was 93.5% given 0.7 molar ratio of TX100 to SDS. The concentration of SDS in the permeate decreased dramatically with the addition of nonionic surfactant, and the permeate flux decreased slightly as the molar ratio increased. Compared with the performance by single SDS, the mixed SDS/Brij 35, SDS/TW80 and SDS/TX100 at an optimum composition could result in not only higher rejection of Cu(2+) but also much less dosage of surfactant and concentration of SDS in the permeate.