The crystal structures have been determined and the magnetic properties investigated for four novel] n 4 the combination of the metal cation with the dicarboxylate ligand leads to the formation of infinitive chains; still the co-ordinated water molecules and the carboxylate oxygen atoms collaborate to hydrogen-bond the chains into 3-D structures. Each cadmium() and nickel() ion in 1 and 4 is coordinated in an octahedral geometry to carboxylate and water molecules. The coordination sphere around copper() ions in 2 is square planar. The structure of 3, [Cu 3 (A) 2 (OH) 2 (H 2 O) 4 ] n , is made up of ribbons linked to neighboring ones by hydrogen bonds. Each ribbon is composed of 2 crystallographically independent metal centers, Cu(1) and Cu(2), which exhibit octahedral and square pyramidal coordination geometries, respectively. Weak antiferromagnetic interactions were observed for 2, and 3 (singlet-triplet energy gap values of Ϫ2.3 and Ϫ54.5 cm Ϫ1 , respectively) and isolated nickel() ions for 4. An interpretation of the magnetic behavior was attempted. The strategy for the assembly of 1-D metal-organic chains into 3-D structures, with the use of coordinated water molecules as hydrogen bond donors and carboxylate oxygens as hydrogen bond acceptors, is also discussed.

Well-designed Ln compounds are UV converters with extremely high, triplet lifetime dependent emission QY, and show SIM behavior.

The synthesis and characterization (elemental analysis, IR, electronic and EPR spectra as well as magnetization measurements over the temperature range 1.8 K-300 K) of solid complex [Cu(5-MeOsal) 2 (µ-nia)(H 2 O)] 2 (1; 5-MeOsal = 5-methoxysalicylate, nia = nicotinamide) is reported together with the crystal structure. In blue-green complex 1, two Cu(5-MeOsal) 2 (H 2 O) units are held together by a pair of bidentate nonchelating nicotinamide ligands, which form a (CuNC 3 O) 2 ring. Each Cu atom adopts a distorted squarepyramidal geometry. The oxygen atoms from two unidentate 5-MeOsal anions occupy the trans position, a water molecule and the pyridine N atom of nicotinamide build the basal plane and a carboxamide O atom occupies the apical position. The separation between two Cu atoms within the centrosymmetric dimer is 6.940(2) Å. The dimeric units are self-

The chiral macrocyclic amines R-L and S-L derived from the 3 + 3 condensation of 2,6-diformylpyridine and (1R,2R)-1,2-diaminocyclohexane or (1S,2S)-1,2-diaminocyclohexane form enantiopure trinuclear Ni(ii) and Cu(ii) complexes [Ni(L)(HO)Cl]Cl and [Cu(L)Cl]Cl and form the dinuclear complex [Zn(L)Cl](ZnCl) with Zn(ii). The X-ray crystal structures of these complexes indicate remarkably different conformations of the ligand and different binding modes of the chloride anions. The structure of the copper(ii) derivative [Cu(R-L)Cl]Cl·CHCN·7.5(HO) indicates unsymmetrical conformation of the macrocycle with three dissimilar pentacoordinate copper(ii) ions bridged by chloride; the structure of [Ni(R-L)(HO)Cl]Cl·0.4CHCN·4.2HO is somewhat more symmetrical, with three Ni(ii) ions of distorted octahedral geometry, also bridged by a common chloride anion. On the other hand, the macrocycle is highly folded in [Zn(R-L)Cl](ZnCl)·CHCl·0.8CHOH·3.7HO, forming a cleft where the third Zn(ii) ion is held via electrostatic interactions as the ZnCl anion. The magnetic data for [Cu(R-L)Cl]Cl indicate the coexistence of antiferromagnetic and ferromagnetic interactions within the quasi isosceles tricopper(ii) core (J = -85.6 cm, j = 77.1 cm). Compound [Ni(R-L)(HO)Cl]Cl shows the presence of weak antiferromagnetic coupling (J = -2.56 cm, j = -1.54 cm) between the three Ni(ii) ions.