Coordination polymer

About: Coordination polymer is a research topic. Over the lifetime, 11988 publications have been published within this topic receiving 212219 citations.

Polynuclear lanthanide complexes of a series of bridging ligands containing two tridentate N,N′,O-donor units: Structures and luminescence properties

Abstract: A set of three potentially bridging ligands containing two tridentate chelating N,N′,O-donor (pyrazole–pyridine–amide) donors separated by an o, m, or p-phenylene spacer has been prepared and their coordination chemistry with lanthanide(III) ions investigated. Ligand L1 (p-phenylene spacer) forms complexes with a 2 : 3 M : L ratio according to the proportions used in the reaction mixture; the Ln2(L1)3 complexes contain two 9-coordinate Ln(III) centres with all three bridging ligands spanning both metal ions, and have a cylindrical (non-helical) ‘mesocate’ architecture. The 1 : 1 complexes display a range of structural types depending on the conditions used, including a cyclic Ln4(L1)4 tetranuclear helicate, a Ln2(L1)2 dinuclear mesocate, and an infinite one-dimensional coordination polymer in which metal ions and bridging ligands alternate along the sequence. ESMS studies indicate that the 1 : 1 complexes form a mixture of oligonuclear species {Ln(L1)}n in solution (n up to 5) which are likely to be cyclic helicates. In contrast, ligands L2 and L3 (with o- and m-phenylene spacers, respectively) generally form dinuclear Ln2L2 Ln(III) complexes in which the two ligands may be arranged in a helical or non-helical architecture about the two metal ions. These complexes also contain an additional exogenous bidentate bridging ligand, either acetate or formate, which has arisen from hydrolysis of solvent molecules promoted by the Lewis-acidity of the Ln(III) ions. Luminescence studies on some of the Nd(III) complexes showed that excitation into ligand-centred π–π* transitions result in the characteristic near-infrared luminescence from Nd(III) at 1060 nm.

[H2bpy]2[{Cu(btepy)2}Mo5P2O23]·4H2O: A Three‐Dimensional Framework Built from Transition‐Metal Coordination Polymer Sheets Pillared by Polyoxomolybdophosphate Clusters

Abstract: [H 2 bpy] 2 [{Cu(bpy) 2 }Mo 5 P 2 O 2 3 ].4H 2 O (1; bpy = 4,4'-bipyridine) contains the first three-dimensional framework based on two-dimensional transition metal coordination polymer sheets pillared by polyoxomolybdophosphateclusters. It crystallises in the C2/c monoclinic space group with a = 17.630(4) A, b = 13.670(3) A, c = 25.111(5) A, and β = 106.61(3)°. Thermogravimetric analysis shows that guest molecules (H 2 O and free bpy ligands) can be easily removed from 1 by simple heat treatment without losing the three-dimensional framework. Moreover, the paramagnetic properties of the {Cu(bpy) 2 } arrays, make this material an interesting magnetic solid based on polyoxometallate clusters.

Auxiliary ligand-controlled photochromism and decolourization of two bipyridinium-based metal–organic hybrid materials with various water clusters

Abstract: Two bipyridinium-based metal–organic hybrid materials, {[Cd(Bpyen)0.5(p-BDC)(H2O)Br]·5H2O} (1) and {[Cd(Bpyen)(o-BDC)Br2]·8H2O} (2), have been synthesized. 1 is a 2D coordination polymer while 2 shows 1D chain-like structure. Both compounds exhibit rapid color change under light irradiation. However, the decolourization of the photochromic products is very different. The influence of the auxiliary ligands on the photochromism and decolourization process of the bipyridinium-based hybrid materials has been explored. Interestingly, water molecules are encapsulated in these two compounds and form novel water aggregates consisting of novel water building units, such as the (H2O)10 water cluster in 1 and the (H2O)12 water cages in 2 through hydrogen-bond interactions. The effect of these water aggregates on the stability of the two compounds has been studied.

An Unusual 3D Entangled Co(II) Coordination Polymer Directed by Ferromagnetic Molecular Building Block

Abstract: A fascinating 3D entangled metal−organic framework, namely, {[Co2(bcp)2]·3H2O}n (1), was obtained through the solvothermal generation of flexible and long dicarboxylate (bcp) and metal salt. The crystal structure contains a 1D metal chain with bcp ligands wrapped around it in a wavy line and features an unusual entangled topological net. Furthermore, the magnetic behavior of 1 was also studied and indicated the existence of ferromagnetic interaction and long-range ordering character.