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The line-broadening of 81Br NMR signals observed in the presence of CyDs was applied to evaluate their binding abilities toward inorganic anions in aqueous solutions. The apparent association constants of α -CyD with anions have been found to decrease in the order SCN− > ClO4− > I− > NO3− > Br− F− > Cl−.

14-,18-, and 22-membered tetraaza macrocycles have been prepared by the reaction of acetylacetone with ethylenediamine, 1,4-butanediamine, or 1,6-hexanediamine, respectively. Their copper(II) and nickel(II) complexes were characterized by electronic and infrared spectroscopies. The 14-membered macrocycle forms a mononuclear copper(II) complex with a planar structure, whereas the 18-membered macrocycle forms a mononuclear copper(II) complex with a pseudo-tetrahedral structure, and the 22-membered macrocycle forms di- and trinuclear copper(II) complexes. The complexation and extraction abilities of these macrocycles toward copper(II) and nickel(II) ions are discussed.

Novel mono- and trinuclear iron(III) complexes with mixed ligands, FeIII(acac)(N-PhO-sal)(MeOH) 1 and FeIII3(acac)(N-PhO-sal)4 2 have been prepared and characterized, where acacH and N-PhOH-salH denote acetylacetone and N-2-hydroxyphenyl-salicylideneamine, respectively. The variable temperature magnetic susceptibilities (2-350 K) for complex 2 indicate that there is an intramolecular antiferromagnetic interaction among the iron(III) ions, and that spin-crossover behavior may take place from S = 5/2, 5/2 and 5/2 ground states to S = 1/2, 5/2 and 1/2 (Fe1, Fe2 and Fe1*) near 60 K and below.

Novel dinuclear manganese(III) complexes, MnIII2(N-PhO-sal)2(X-sal-m-xylylene) (X = H, 3-MeO) have been prepared by the ligand substitution reaction and characterized, where N-PhOH-salH and X-sal-m-xylyleneH2 denote N-2-hydroxyphenylsalicylideneamine and N,N′-di-substituted-salicylidene-m-xylylenediamine, respectively. These complexes have been found to decompose hydrogen peroxide catalytically (H2O2 /Mn < 100), cycling their oxidation levels between Mn2 (III,III) and Mn2 (II,II) with dioxygen evolution.

Four types of novel manganese complexes, MnIV (N-EtO-sal)2, MnIII(N-PhO-sal)(L), [MnIV(5,6-Benzo-L)2 (μ-O)2]2, and MnIII(L-4-Me)3 have been found to be obtained by the reactions of KMnO4 with tridentate Schiff base ligands (N-EtOH-salH, N-PhOH-salH and their derivatives) in dry MeCN, where N-EtOH-salH, N-PhOH-salH, LH, 5,6-Benzo-LH, and L-4-MeH denote N-2-hydroxyethyl-salicylideneamine, N-2-hydroxyphenyl-salicylideneamine, 2-(2-hydroxyphenyl)-benzoxazole, 2-(2-hydroxynaphthyl)-benzoxazole, and 2-(2-hydroxyphenyl)-5-methylbenzoxazole, respectively.

Novel di-μ-oxo dimanganese(IV) complexes, [MnIV(N-R-sal)2(μ-O)]2, with bidentate Schiff base ligands, N-alkyl-salicylideneamine, N-R-salH (R = n-C3H7 (Pr), n-C4H9 (Bu), n-C6H13 (Hx), n-C8H17 (Oct), n-C12H25 (Dod), or n-C18H37 (Octd)), have been prepared and characterized by spectroscopies, magnetic susceptibilities, thermal analysis and X-ray crystallography.

Novel di-μ-oxo dimanganese(IV) complexes with a series of tetradentate Schiff base ligands have been prepared and characterized by spectroscopy, magnetic susceptibility, electrochemical measurements and X-ray crystallography. The di-μ-oxo dimanganese(IV) complexes, [MnIV(μ-salophen)(μ-O)], 1 (salophen H2 = N,N′-disalicylidene-1,2-diaminobenzen), [Mn(μ-salen)(μ-O)]2, 2 (salenH2 = N,N′-disalicylidene-1,2-diaminoethane), [Mn(salen)(μ-O)]2, 3, [Mn(salipn)(μ-O)]2, 4 (salipnH2 = N,N′-disalicylidene-1,2-diaminopropane) and [Mn(salbn)(μ-O)]2, 5 (salbnH2 = N,N′-disalicylidene-1,4-diaminobutane), have been found to be obtained by the reaction of the tetradentate Schiff base ligands and potassium permanganate (KMnO4) in MeCN with stirring at room temperature. X-ray analysis revealed that these complexes are classified by two different types of di-μ-oxo manganese(IV) complexes in the coordination features of the liglands; one of them (1 and 2) has a structure in which salophen or salen ligands are coordinated to two manganese ions as a bridging bidentate ligand, whereas the other (3,4 and 5) has a structure in which salen, salipn or salbn ligands are coordinated to each manganese ion as a tetradentate ligand. These types were characterized from their IR spectra around 650 cm−1, UV-vis spectra and electrochemical properties.

The dichloromanganese (IV) complexes with bidentate Schiff bases derived from 3-nitrosalicylaldehyde with monoamines react with water to liberate molecular oxygen. This is confirmed by means of a spectrophotometry with alkaline pyrogallol solution and by using an oxygen electrode. The maximal liberation was observed at neutral pH range. The reaction products were identified to the corresponding manganese(II) complexes. These results suggest us that molecular oxygen is liberated as follows, 2MnIVL2Cl2 + 2H2O→ 2MnIIL2 + O2 + 4H+ + 4Cl−.

A novel polymer ligand (Poly-L) in which 6,8,15,17-tetramethyl-dibenzo-5,9,14,18-tetraazacyclotetradecene (L) is present as an integral part of the polymer backbone was synthesized and its solvent extraction of copper(II) and nickel(II) was investigated in comparison with L. The complexation reactions of Poly-L with the above metal ions were found to be much faster than those of L, with a high selectivity for copper(II).

Some chloromanganese(III) Schiff base complexes react with hydrogen chloride to give deep green complexes with the empirical formula of MnLCl2 or MnL′2Cl2, where H2L denotes quadridentate ligands such as N,N′-disalicylideneethylenediamine and its analogs, and where HL′ denotes bidentate ligands such as N-butylsalicylideneamine and its analogs. These complexes are nonelectrolytes in acetonitrile. Their magnetic moments at room temperature fall within the range of 3.9 to 4.1 BM, and the magnetic susceptibilities obey the Curie-Weiss law with small θ values over the temperature range of 77 to 300 K, indicating that the oxidation state of the manganese ions in these complexes is +IV. The electronic spectra show an intense band around 16000 cm−1 which can be assigned to a charge-transfer transition. In the cyclic voltammograms, two cathodic waves are observed at half-peak potentials around +0.9 V and −0.2 V(vs. SCE); they can be assigned to the reductions of Mn(IV) to Mn(III) and of Mn(III) to Mn(II) respectiv...

A series of monomeric chloroiron(III) complexes with the quadridentate or quinquedentate Schiff bases such as N,N′-disalicylideneethylenediamine or bis[3-(salicylideneamino)propyl]amine react with superoxide ions, O2−, in dimethyl sulfoxide to give the corresponding μ-oxo dimers. The polymeric chloroiron(III) complexes with the polymeric (oligomeric) Schiff bases derived from 5,5′-methylenedisalicylaldehyde and triamines react with O2− in dimethyl sulfoxide to give the oxygenated complexes, probably dioxygen adducts, FeIII–O2−. This is suggested by the absorption spectra and the polarographic measurements.

The ethylenediamine adduct of bis(3-nitro-2,4-pentanedionato) copper (II) was prepared in ethanol, and characterized by spectroscopic and elemental analyses. The thermal reaction of the adduct in the solid phase resulted in the formation of a tetraaza macrocyclic copper(II) complex by the intramolecular condensation.

The chlorobis(N-alkylsalicylideneaminato)manganese(III) complexes, MnIII(N-Rsai)2Cl, react with hydrogen chloride to give the corresponding dichloromanganese(IV) complexes, MnIV(N-Rsai)2Cl2, as deep green crystals; R can be n-C3H7, n-C4H9, i-C4H9, n-C6H13, c-C6H11, n-C8H17, n-C12H25, n-C18H37, CH2C6H5, or CH2CH2C6H5. These complexes were characterized by the magnetic susceptibilities, electronic spectra, infrared spectra, and cyclic voltammograms. The complexes (R=n-C12H25 and n-C18H37) are found to be stable toward water in the solid state. A trans, six-coordinate configuration is proposed for these Mn(IV) complexes on the basis of the infrared spectra.

A series of methoxy substituted triarylphosphines RnPh3-np where R can be 2-MeOPh, 4-MeOPh, 2,6-MeOPh, and 2,4,6-MeOPh and n=1, 2, and 3, has been prepared and employed as extractants for gallium(III) from hydrochloric acid solutions. Their extractabilities for gallium(III) were found to become more effective with their increased basicities.

The reactions of the chloromanganese(III) complexes of the Schiff bases derived from salicylaldehydes or β-diketones and diamines or monoamines with superoxide ion, O2−, in dimethyl sulfoxide were investigated. The complexes were found to react to give either the oxygenated Mn Schiff base complexes or the reduced Mn(II) Schiff base complexes. The difference in the reactivity toward O2− was correlated to the polarographic half-wave potentials corresponding to the reduction of Mn(III) to Mn(II) of the complexes. Some oxygenated complexes were isolated and characterized.

18- and 22-membered tetraaza macrocycles were prepared from acetylacetone and 1,4-diaminobutane or 1,6-diaminohexane, respectively. Their copper(II) complexes were characterized by electronic spectroscopy and the copper(II) complex of the 18-membered macrocycle was found to be pseudo-tetrahedral.

By the reaction of MnII(salen) (salen=N,N′-ethylenebis(salicylideneiminato) dianion) and its analogues with molecular oxygen in organic solvents, three types of complexes including as structural units the MnIII–O2–MnIII,–(–MnIV–O–)–n, and MnIV=O bonds respectively, have been obtained, and characterized by means of their electronic and infrared spectra, by thermogravimetric analysis, and in terms of their magnetic properties. The lower magnetic moments for [MnIII(salen)]2O2 and –[–MnIV(salen)–O–]–n than those expected have been interpreted in terms of antiferromagnetic interactions. The oxo complex was found to give the catena-oxo complex quantitatively in a DMF, DMSO, or Py solution. The effects of the oxygen partial pressure and the nature of the substituent in the organic part on the complex formation were investigated. A lower partial pressure of oxygen has the advantage of yielding the μ-peroxo complex in a higher yield. A discussion of the reaction mechanism is also included.

The polymeric Mn(III) Schiff base complexes react with superoxide ions (O2−) in dimethyl sulfoxide (DMSO) to give the oxygenated complexes, while the corresponding monomeric Mn(III) complexes are reduced with O2− to the Mn(II) complexes.