The burgeoning field of metal − organic frameworks or porous coordination polymers has received increasing interest in recent years. In the last decade these microporous materials have found several applications including storage and separation of gases, sensors, catalysis and functional materials. In order to better design new metal − organic frameworks and porous coordination polymers with specific functionalities a fundamental issue is to achieve a basic understanding of the relationship between molecular parameters and structures, preferred adsorption sites and properties by using using modern theoretical methods. The focus of this mini-review is a description of the potential and emerging applications of metal − organic frameworks.

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The isolation and characterization of new lanthanide complexes of formula [Ln(Q(L))(3)(EtOH)(H2O)], (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, HQ(L) = 1-phenyl-3-methyl-4-phenylacetylpyrazol-5-one) [Ln(Q(L))(3)(H2O)(2)] (L = La or Lu), [Ln(Q(S))(3)(EtOH)(H2O)] (Ln = Tb or Eu; HQ(s) = 1-phenyl-3-methyl-4-thienoylpyrazol-5-one, [Tb(Q(o))(3)(EtOH)(H2O)] (HQ(o) = 1-phenyl-3-methyl-4-furanoylpyrazol-5-one) [Tb(Q(F))(3)(H2O) (HQ(F) = 1-phenyl-3-methyl-4-trifluoroacetylpyrazol-5-one) and [NBu4][Ln(Q)(4)] (Ln = Eu or Tb, Q = Q(F) or Q(L)) is reported. The crystal structure of the tris(beta-diketonate) complexes [Nd(Q(L))(3)(EtOH)(H2O)], [Dy(Q(L))(3)(EtOH)(H2O)](EtOH), and [Eu(Q(s))(3)(H2O)(EtOH)] containing eight-coordinate lanthanide ions in a square antiprismatic environment has been determined. The coordination environment in the tetrakis complex [NBu4][Eu(Q(F))(4)] is also close to the square antiprismatic one. Photoluminescence (PL) and phosphorescence studies of selected derivatives are reported

By reaction of 1-phenyl-3-methyl-4-R-C(᎐ ᎐ O)-pyrazol-5-one (HQ T : R = CH 2 C(CH 3 ) 3 ; HQComplex 1 has a molecular structure with a slightly distorted octahedral coordination of the cadmium atom with EtOH and Q T ligands trans to each other. When the reaction between HQ T or HQ C and Cd(O 2 CCH 3 ) 2 ؒ2H 2 O was carried out in the presence of bidentate N-donor ligands L (L = 1,10-phenanthroline, 2,2Ј-bipyridyl, N,NЈ,NЈ-trimethylethylenediamine or tetramethylethylenediamine), [Cd(Q T ) 2 (L)] and [Cd(Q C ) 2 (L)] were always obtained. In the six-coordinate derivatives [Cd(Q C ) 2 (1,10-phenanthroline)] and [Cd(Q T ) 2 (tetramethylethylenediamine)] the cadmium atom is in a strongly distorted octahedral environment due to steric requirements of the bidentate N 2 -donor ligands. All complexes synthesized have been characterized spectroscopically by IR, 1 H and 113 Cd NMR. The behavior in solution is also discussed.

The reaction of RSnCl3 (R = Me, Ph, or Bun) and SnX4 acceptors (X = Cl, Br, or I) with equimolar amounts of tris(pyrazol-1-yl)methane ligands L (L = HC(pz)3, HC(4-Mepz)3, HC(3,5-Me2pz)3, HC(3,4,5-Me3pz)3, or HC(3-Mepz)2(5-Mepz) yields ionic 1:1 [{LSnRCl2}+][{SnRCl4}-] or [{LSnX3}+][{SnX5}-] and 2:1 [{LSnRCl2}+]2[{SnRCl5}2-] or [{LSnX3}+]2[{SnX6}2-] complexes, depending strongly on the number and position of the Me groups on the azole ring of the neutral ligand. These complexes, stable in air, have been characterized in the solid state (IR, MS-FAB) as well as in solution (1H- and 119Sn-NMR, conductivity, and molecular weight determinations). The crystal and molecular structure of [{HC(4-Me2pz)3Sn n BuCl2}+]2[{Sn n BuCl5}2-], [{HC(3,5-Me2pz)3SnMeCl2}+][{MeSnCl4}-], and [{HC(3,4,5-Me3pz)3SnBr3}+][{SnBr5}-] was determined by X-ray crystallography. The structures of the cations are very similar, the Sn atom being in a strongly distorted octahedral environment with the Sn−N bonds in the range 2.22−2.33 Å, whereas in the anions the Sn atoms are five-coordinate (trigonal-bipyramidal) in [MeSnCl4]- and [SnBr5]- and six-coordinate (octahedral) in [SnnBuCl5]2-.