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The title compound C13H12N4OS (I) is synthetized from isonicotinic hydrazide and isothiocynate. Compounds C13H11N4OCl (II) and C13H10N4S (III) where obtained upon reaction of (I) with Fe(II) or Mn(II) salts. Compound (II) is heterocyclic 1,3,4-oxadiazole while compound (III) is heterocyclic 1,2,4-triazole. The 1,3,4-oxadiazol derivative is almost planar with dihedral angle of 2.66 (8) and 5.14 (8)° between 1,3,4-oxadiazole ring and phenyl and pyridinium rings respectively; the dihedral angle between the phenyl and pyridinium rings is 3.92 (8)°. The 1,2,4-triazole derivative is non-planar. The phenyl and pyridyl rings form dihedral angles of 58.35 (5) and 58.33 (5)°, respectively, with the 1,2,4-triazole ring; the dihedral angle between the phenyl and pyridyl rings is 36.85 (4)°. In the compound (II) intramolecular hydrogen bonds of type N—H···Cl, C—H···N and C—H···Cl resulting in S(6) ring stabilize the structure. Intermolecular hydrogen bonds of type N—H···N, C—H···N, C—4···Cl link the molecule thus forming a three-dimensional network. In the structure of compound (III), intermolecular hydrogen bonds of type N—H···N, C—H···N, C—H···S1,link the monomer in a three-dimensional network.

Mononuclear complexes of 1-(pyridin-2-ylmethylidene)-2-(pyridin-2-yl)hydrazine (HL1) and 1-(pyridin-2-yl)-2-(1-(pyridin-2-yl)ethylidene)hydrazine (HL2), [Mn(HL1)(Cl2)(H2O)] (1), [Zn(HL1)(CH3COO)2]·(H2O)3 (2), [Mn(HL2)2]·(ClO4)2 (3) and [Cu(HL2)(NO3)2(H2O)] (4) were synthesized and characterized by physicochemical and spectroscopic methods and X-ray structure determination. The mononuclear compounds 1, 2 and 4 contain one ligand molecule per metal atom while the manganese (II) atom in compound 3 is coordinated to two ligand molecules. Both ligands coordinated to the transition metal center in a tridentate fashion through two Npyridyl atoms and one Nimino atom. The chloride and acetate anions coordinate in monodentate manner, respectively, in complex 1 and in complex 2. In complex 3, the perchlorate groups remain uncoordinated. In complex 4, the nitrate anions act in unidentate fashion. The molar conductance value indicates that the complexes obtained from HL1 are non-electrolytes while those obtained from HL2 are 2:1 electrolytes in DMF solutions. The X-ray structures reveal octahedral geometry for complexes 1, 3, 4 and trigonal bipyramidal environment for 2.

The title compound, (NH4)4[W2(C10H12N2O8)O6]·4H2O, was obtained from a mixture of tungstic acid, ammonia and ethylenediaminetetraacetic acid (H4edta) in a 2:4:1 ratio. The anion of the complex contains two WO3 units and one bridging edta4− ligand. Each central metal atom is tridentately coordinated by nitrogen and two carboxylate groups of the edta4− ligand, together with the three oxido ligands, producing a distorted octahedral coordination environment around each tungsten atom. The center of the carbon–carbon bond of the ethylene bridge represents a crystallographic inversion center. The crystal structure consists of a three-dimensional supramolecular framework built up by the dinuclear cations, the ammonium counter-ions and the solvent water molecules via hydrogen bonds of the N—H...O and O—H...O type.

The title compound, (NH

International audience; The compound [BiCNIm]3[DyCl6] was synthesized from a nitrile-functionalized imidazolium ionic liquid [BiCNIm][Cl] and DyCl3 ⋅ 6H2O in acetonitrile using solvothermal conditions. Structural characterization reveals that the Dy3+ ions are in a quasi-regular octahedral environment, formed by six chloride anions. The magnetic study indicates that this mononuclear compound exhibits a Single Ion Magnet behaviour. This behaviour is compared to that of other mononuclear compounds containing Dy3+ ions in various octahedral environment.

In Senegal, the education and university system is characterized by the dominance of arts and humanities over science and technology. The practice of chemistry is relatively important regionally in universities (for both education and research), as well as in the industries—although with a strong contrast between these two areas. Will the dynamism of chemical associations and the recent discovery of gas and oil enable a change in the chemical sector in Senegal? Senegal is a country in West Africa with 15.3 million inhabitants where the practice of chemistry is quite established. In this article, we present the current state of chemical education, research, and industry, without forgetting, of course, the chemical associations that have become increasingly active in recent years.

Strandberg-type phosphomolybdate anions are metal-oxide clusters with general formula [HnP2Mo5O23](6−n)− (n = 0, 1, 2). The protonation/deprotonation of this anion affects its redox properties. Herein, we explain how to select the organic counterions to direct the synthesis towards the non-protonated or protonated anion. The method is illustrated with the synthesis of two new compounds (C5H16N2)3[P2Mo5O23]·4H2O (1) and (CH6N)4[H2P2Mo5O23].CH5N·4H2O (2). The two compounds were characterized by UV–Visible absorption, IR spectroscopy and single crystal X-ray diffraction. Their thermal stabilities and redox properties were also investigated.

The present investigation describes the synthesis and structural study of a metal-zinc ligand [ZnL.H 2 O], which was used to generate three dimensional supramolecular complex formulated as [Y{Zn(L)(SCN)}(SCN) 2 ].[Y{Zn(L)(SCN)} 2 (DMF) 2 ].(NO 3 ). The title compound crystallizes in the triclinic space group P-1 with the following unit cell parameters: a = 14.8987(7) A, b = 15.6725(8) A, c = 19.2339(10) A, a = 94.610(4)°, β = 103.857(4)°, γ = 101.473(4)°, V = 4234.4(4) A 3 , Z = 2, R 1 = 0.063 and w R 2 = 0.96. For this compound, the structure reveals that one heterodinuclear unit [Y{Zn(L)(SCN)}(SCN) 2 ] is co-crystallized with a heterotrinuclear unit [Y{Zn(L)(SCN)} 2 (DMF) 2 ].(NO 3 ). In the dinuclear moiety, the organic molecule acts as a hexadentate ligand and in the trinuclear unit, it acts as a pentadentate ligand with one of the oxygen methoxy group remaining uncoordinated. In both units the coordination environment of the zinc metal can be described as distorted square pyramidal. In the dinuclear unit the Y(III) is hexacoordinated while it is octacoordinated in the trinuclear unit. The environment of the Y(III) can be described as a distorted octahedral geometry in the dinuclear and as a distorted square antiprism in the trinuclear units respectively.

Acetate trinuclear metal complexes of ZnII and CoII with the potentially tridentate Schiff base ligand, having mixed phenolate, imine, and pyridine donor groups, HL, were synthesized. The complexes were characterized by microanalysis, LSI mass spectrometry, IR, UV/Vis spectroscopy, and magnetic measurements. Crystal structures of [M3L2(OAc)4] (M = ZnII, CoII) complexes, were also determined. The X-ray structures show the presence of trinuclear complexes with metal ions joined by phenolate and acetate bridging groups. The ligands coordinate to the metal ions through the imine nitrogen and their corresponding attached pyridyl and phenolate groups. The coordination environment for the metal ions is completed by bridging acetate anions to generate an octahedral coordination arrangement for the CoII complex and mixed distorted, bipyramidal trigonal and octahedral arrangements for the ZnII complex.

cited By 9; International audience; New hybrid compounds have been synthesized by functionalization of cobalt and copper layered hydroxides by salen complexes. Two kinds of compounds have been obtained from [M(SalenSO 3Na 2)] (M = Cu 2+, Ni 2+, Co 2+ and Zn 2+) and the preintercalated copper and cobalt hydroxides Cu 2(OH) 3(DS) and Co 2(OH) 3(DS 0) [SalenSO 3Na 2 = N,N'-bis(5-sulfonatosalicylidene)-1,2-diaminoethane disodium salt, DS - = dodecylsulfate, DS 0 - = dodecylsulfonate]. The reaction of [M(SalenSO 3Na 2)] with layered copper hydroxide led to the anion-exchanged compounds Cu 2(OH) 3.00(CuSalenSO 3) 0.50·0.20H 2O [Cu(SalenSO 3),Cu (1)] and Cu 2(OH) 3.24(NiSalenSO 3) 0.38·2.6H 2O [Ni(SalenSO 3),Cu (2)] where M = Cu 2+ or Ni 2+. Similarly, the reaction with layered cobalt hydroxide leads to the exchanged compounds Co 2(OH) 3.18(NiSalenSO 3) 0.41·4.0H 2O [Ni(SalenSO 3),Co (6)] and Co 2(OH) 3.44(CoSalenSO 3) 0.28·3.7H 2O [Co(SalenSO 3),Co (8)] where M = Ni 2+ or Co 2+. The reaction of [M(SalenSO 3)Na 2] with layered copper hydroxide where M = Co 2+ or Zn 2+ and that of layered cobalt hydroxide where M = Cu 2+ or Zn 2+ resulted in the modification of the host structure because of concomitant partial cation exchange between the salen complex and the inorganic layers. Mixed-ion-exchanged compounds were obtained, Cu 1.16Co 0.84(OH) 3.28(CoSalenSO 3) 0.36·6.4H 2O [Co(SalenSO 3),Cu/Co (4)], Cu 0.7Zn 1.30(OH) 3.20(ZnSalenSO 3) 0.40·2.11H 2O [Zn(SalenSO 3),Cu/Zn (3)], Co 1.72Cu 0.28(OH) 3.28(CuSalenSO 3) 0.36·3.20H 2O [Cu(SalenSO 3),Co/Cu (5)] and Co 0.80Zn 1.20(OH) 3.20(ZnSalenSO) 0.40·2.25H 2O [Zn(SalenSO 3),Co/Zn (7)]. The magnetic behaviour of the compounds is drastically modified depending on the structure of the inorganic layers induced by the functionalization and partial cation exchange. The hybrid copper layered hydroxides show antiferromagnetic (for 3) or weak ferromagnetic (for 1, 2 and 4) behaviour. The cobalt analogues 5, 6 and 8 are ferrimagnets with ordering temperatures at ca. 6 K, whereas the Co/Zn heterometallic layered simple hydroxide 7 presents dominant antiferromagnetic interactions.

Coordination complexes derived from chiral and nonchiral sulfonato salen ligands {(SalenSO 3 )Na 2 : N,N'-bis(5-sulfonatosalicylidene)-1,2-diaminoethane disodium salt, [(R,R) and (S,S)-CySalenSO 3 ]NaK: (R,R) and (S,S)-N,N'-bis(5-sulfonato-salicylidene)-1,2-diaminocyclohexane sodium-potassium salt) have been synthesized. The crystal structures of the chiral and nonchiral Ni" complexes [Ni(SalenSO 3 )]Na 2 (1) and [Ni((R,R)CySalenSO 3 )]NaK (2) were solved. The other chiral and nonchiral sulfonato salen complexes, [Cu(SalenSO 3 )]Na 2 (4), [Cu((R,R)CySalenSO 3 )]NaK (5), [Cu((S,S)CySalen-SO 3 )]NaK (6) and [Zn(SalenSO 3 )]Na 2 (7) got hydrolyzed before suitable crystals could form. Yet, their hydrolysis led to the formation of single crystals of the residues of total or partial hydrolysis: 5-sulfonatosalicylaldehyde sodium salt (A), N-(5-sulfonatosalicylidene)-1,2-diaminoethane copper(II) [Cu-(SalSO 3 )] (8) and (R,R)-N-(5-sulfonatosalicylidene)-1,2-diaminocyclohexane copper(II) {Cu[(R,R)CySalSO 3 ]} (9). All compounds were studied with IR and UV/Vis spectroscopy; chiral compounds were also investigated by circular dichroism. The magnetic properties of the copper compounds were investigated. Whereas 8 shows intermolecular antiferromagnetic interactions between mononuclear Cu II complexes, 7 presents a weak intramolecular ferromagnetic coupling (J = 0.66 cm -1 , H = -JŜ Cu1 Ŝ Cu2 ), which has been rationalized by DFT calculations.

Single crystals of new open-framework lanthanide sulphate nitrite La(NO2)(SO4)(H2O) has been synthesized, in the presence of 2,6-diformyl-4-chlorophenol. His structure has been determined by X-ray diffraction data: the complex crystallizes in the tetragonal system, space group P43, with a = 7.0028(2) (A), b = 7.0028(2) (A), c = 11.8341(4) A, V = 580.34(3) A3, Z = 4, D c = 3.582 Mg m−3. The three-dimensional (3D) framework of this compound is built up by the linkages of lanthanide atoms and the oxygen atoms of the sulphate $$ {\left( {{\text{SO}}^{{{\text{2}} - }}_{{\text{4}}} } \right)} $$ and nitrite $$ {\left( {{\text{NO}}^{ - }_{{\text{2}}} } \right)} $$ groups. The lanthanum atom is 9-fold coordinated. The structure is unfamiliar in lanthanide chemistry and this compound represents the first example of nitrite lanthanide sulphate complex. An unfamiliar structure in lanthanide chemistry represented by the first example of nitrite lanthanide sulphate complex is described.

A series of trivalent lanthanide complexes of type [Ln(L) NO 3 )(S) n ](NO 3 ) m (S ′ ) n , have been synthesized by the reaction of 2,6-diacetylpyridine-bis-(benzoylhydrazone) (H 2 L) with lanthanide(III) nitrates in ethanol. These complexes have been characterized by analysis, molar conductance, magnetic measurements, infrared spectral studies and X-ray diffraction. The analytical data revealed the formation of 1:1 (metal:ligand) stoichiometry. Molar conductance in dmf gives 2:1 electrolytes in all the complexes. Magnetic moment values are close proximity of the Van Vleck values. IR study suggests the coordination of the ligand through the azomethine and the oxygen of the hydrazonic moiety. The nitrate ion is also found to be bidentate in all the complexes. The crystal structures were determined. 6 , C 27 H 31 N 6 O 7 S 2 Gd: a = b =8.6821(4) A, c =84.363(5) A, tetragonal P 4 1 2 1 2 and Z =8. bf 7, C 25 H 25 N 6 O 6 SDy: a =11.750(3) A, b =13.250(3) A, c =36.000(6) A, β =98.50(2), monoclinic, C 2/ c , Z =8. 9 , C 24 H 25 N 6 O 7 Yb: a =10.750(2) A, b =17.750(3) A, c =14.250(4) A, β =99.00(2), monoclinic, P 2 1 / n , Z =4. In these complexes the lanthanide ion assumes a nine coordinated geometry for Gd and an eight coordinated geometry for Dy and Yb.

The title compound, C(22)H(18)N(4)O(2)S(2), was characterized by (1)H and (13)C NMR, solid-state IR spectroscopy and X-ray crystallographic techniques. The crystal structure determination reveals that the twisting modes of the two side arms are different [C-N-C-O and C-N-C-N torsion angles = -1.2 (3) and 1.1 (3)°, respectively, in one arm and 24.1 (3) and -5.1 (3)°, respectively, in the other]. The crystal structure involves N-H⋯O and N-H⋯S hydrogen bonds.

The title compound [Dy 2 (C 22 H 16 ClN 4 O 5 ) 3 ](SCN) 3 (H 2 O)(CH 3 OH) has been synthesized and its crystal structure determined by single X-ray diffraction at room temperature. The two nine coordinated Dy(III) are bound to three macromolecules ligand through the phenolic oxygens of the p -chlorophenol moieties, the nitrogen atoms and the carbonyl functions of the hydrazonic moieties. The phenolic oxygen atoms of the 2-hydroxybenzoyl groups are not bonded to the metal ions. In the bases of the coordination polyhedra the six Dy-N bonds are in the range 2.563(13)-2.656(13) A and the twelve Dy-O bonds are in the range 2.281(10)-2.406(10) A. KEY WORDS: Dysprosium(III) complex, 5-Chloro-1,3-diformyl-2-hydroxybenzene-bis-(2- hydroxybenzoylhydrazone), Crystal structure Bull. Chem. Soc. Ethiop. 2003 , 17(2), 167-172.

Synthesis of new heterometallic layered magnets with controlled chirality have been achieved by insertion of chiral and non-chiral salen-type Ni(II) complexes into copper and cobalt layered simple hydroxides.