A new one-dimensional CdII coordination polymer incorporating 2,2'-(1,2-phenylene)bis(1H-imidazole-4,5-dicarboxylate)

Imidazole-4,5-dicarboxylic acid (H₃IDC) and its derivatives are widely used in the preparation of new coordination polymers owing to their versatile bridging coordination modes and potential hydrogen-bonding donors and acceptors. A new one-dimensional coordination polymer, namely catena-poly[[diaquacadmium(II)]-μ₃-2,2'-(1,2-phenylene)bis(1H-imidazole-4,5-dicarboxylato)], [Cd(C₁₆H₆N₄O₈)_0.5(H₂O)₂]_n or [Cd(H₂Phbidc)_1/2(H₂O)₂]_n, has been synthesized by the reaction of Cd(OAc)₂·2H₂O (OAc is acetate) with 2,2'-(1,2-phenylene)bis(1H-imidazole-4,5-dicarboxylic acid) (H₆Phbidc) under solvothermal conditions. In the polymer, one type of Cd ion (Cd1) is six-coordinated by two N atoms and two O atoms from one H₂Phbidc^4- ligand and by two O atoms from two water molecules, forming a significantly distorted octahedral CdN₂O₄ coordination geometry. In contrast, the other type of Cd ion (Cd2) is six-coordinated by two N atoms and two O atoms from two symmetry-related H₂Phbidc^4- ligands and by two O atoms from two symmetry-related water molecules, leading to a more regular octahedral coordination geometry. The Cd1 and Cd2 ions are linked by H₂Phbidc^4- ligands into a one-dimensional chain which runs parallel to the b axis. In the crystal, the one-dimensional chains are connected through hydrogen bonds, generating a two-dimensional layered structure parallel to the ab plane. Adjacent layers are further linked by hydrogen bonds, forming a three-dimensional structure in the solid state.

A new two-dimensional managnese(II) coordination polymer constructed by 2,2'-(1,2-phenylene)bis(1H-imidazole-4,5-dicarboxylate)

In recent years, N-heterocyclic carboxylate ligands have attracted much interest in the preparation of new coordination polymers since they contain N-atom donors, as well as O-atom donors, and have a rich variety of coordination modes which can lead to polymers with intriguing structures and interesting properties. A new two-dimensional coordination polymer, namely poly[[μ₃-2,2'-(1,2-phenylene)bis(4-carboxy-1H-imidazole-5-carboxylato)-κ⁶O⁴,N³,N^3',O^4':O⁵:O^5']manganese(II)], [Mn(C₁₆H₈N₄O₈)]_n or [Mn(H₄Phbidc)]_n, has been synthesized by the reaction of Mn(OAc)₂·4H₂O (OAc is acetate) with 2,2'-(1,2-phenylene)bis(1H-imidazole-4,5-dicarboxylic acid) (H₆Phbidc) under solvothermal conditions. In the polymer, each Mn^II ion is six-coordinated by two N atoms from one H₄Phbidc^2- ligand and by four O atoms from three H₄Phbidc^2- ligands, forming a significantly distorted octahedral MnN₂O₄ coordination geometry. The Mn^II ions are linked by hexadentate H₄Phbidc^2- ligands, leading to a two-dimensional structure parallel to the ac plane. In the crystal, adjacent layers are further connected by N-H...O hydrogen bonds, forming a three-dimensional structure in the solid state.

Nine isomorphous lanthanide–uranyl f–f bimetallic materials with 2-thiophenecarboxylic acid and terpyridine: structure and concomitant luminescent properties

Concomitant and semi-selective uranyl and lanthanide luminescence observed within a series of f–f bimetallic molecular materials (UO₂²⁺/Ln = Pr–Er).

A Series of Lanthanide-Germanate Oxo Clusters Decorated by 1,10-Phenanthroline Chromophores

A series of lanthanide-germanate oxo clusters, [Ln₈(phen)₂Ge₁₂(μ₃-O)₂₄T₁₂(H₂O)₁₆]·2H₂O [Ln = Dy (1a) and Er (1b); T = -CH₂CH₂COO^- group; phen = 1,10-phenanthroline], [Ln₈(phen)₂Ge₁₂(μ₃-O)₂₄T₁₂(H₂O)₁₆]·2phen·16H₂O [Ln = Sm (2a), Eu (2b), and Gd (2c)], and [Ho₈(phen)₂Ge₁₂(μ₃-O)₂₄T₁₂(H₂O)₁₄]·2phen·13H₂O (3), have been hydrothermally synthesized from the reactions of bis(carboxyethylgermanium sesquioxide) and Ln₂O₃ with auxiliary phen chromophores. Compounds 1a and 1b consist of cage clusters [Ln₈(phen)₂Ge₁₂(μ₃-O)₂₄T₁₂(H₂O)₁₆] and free H₂O molecules, where cage clusters are arranged in a CsCl type, while compounds 2a-2c consist of cage clusters [Ln₈(phen)₂Ge₁₂(μ₃-O)₂₄T₁₂(H₂O)₁₆], free phen, and free H₂O molecules, where cage clusters are arranged in a NaCl type. Compound 3 consists of the one-dimensional neutral chain [Ho₈(phen)₂Ge₁₂(μ₃-O)₂₄T₁₂(H₂O)₁₄]_n and free H₂O molecules. These compounds provide the first examples of p-f heterometallic [Ge-O-Ln] oxo clusters decorated by phen chromophores. The photoluminescent and magnetic properties of all compounds have been investigated.

Two bilayer metal–organic frameworks with rare trinuclear heterometal clusters and tunable photoluminescence

Two bilayer metal–organic frameworks based on rare trinuclear Pb/K and Cd/Na clusters have been solvothermally synthesized. They exhibit tunable purple-to-red-to-green and purple-to-green photoluminescence by variation of excitation light, respectively.

A Zn(ii) complex with large channels based on 3′-nitro-biphenyl-3,5,4′-tricarboxylic acid: synthesis, crystal structure, fluorescence sensing of ATP, ADP, GTP, and UTP in aqueous solution and drug delivery

A 3D Zn(ii)–MOF with large cubic channels was synthesized. It showed fluorescence sensing of ATP, ADP, GTP, and UTP. Furthermore, it exhibited a remarkable capacity for and controlled release of 5-fluorouracil.

Four Pb(ii) metal–organic frameworks with increasing dimensions: structural diversities by varying the ligands

Four complexes with 1D, 2D and 3D frameworks were synthesized by three rigid, linear ligands. The ligands' effects and luminescence properties were studied.