Utility of Three-Coordinate Silver Complexes Toward the Formation of Iodonium Ions

The work herein describes the synthesis of five three-coordinate silver(I) complexes comprising a bidentate ligand L1, either bpy (2,2'-bipyridyl) or bpyMe₂ (4,4'-dimethyl-2,2'-dipyridyl), and a monodentate ligand L2, either mtz (1-methyl-1H-1,2,3-triazole), 4-Etpy (4-ethylpyridine), or 4-DMAP (N,N-dimethylpyridin-4-amine). Upon reaction of the three-coordinate silver(I) complexes with 0.5 equiv of I₂, the reactions quantitatively produce a 1:1 pair of complexes of a four-coordinate silver(I) complex [Ag(L1)₂]PF₆ and a two-coordinate iodonium complex [I(L2)₂]PF₆. The combination of [Ag(bpyMe₂)₂]PF₆ and [I(4-DMAP)₂]PF₆ gave rise to an I⁺···Ag⁺ interaction where the I⁺ acts as a nucleophile, only the second example of which, that was observed in both the solution (NMR) and solid (X-ray) states.

Construction and photocatalytic properties of two metal-mediated coordination polymers based on benzene-1,3,5-tricarboxylic acid and trans-1-(pyridin-3-yl)-2-(pyridin-4-yl)ethene

With the rapid development of modern industry, water pollution has become an intractable environmental issue facing humans worldwide. In particular, the organic dyes discharged into natural water from dyestuffs, dyeing and the textile industry are the main sources of pollution in wastewater. To eliminate these types of pollutants, degradation of organic contaminants through a photocatalytic technique is an effective methodology. To exploit more crystalline photocatalysts for the degradation of organic dyes, two coordination polymers, namely catena-poly[[(3,5-dicarboxybenzene-1-carboxylato-κO¹)silver(I)]-μ-trans-1-(pyridin-3-yl)-2-(pyridin-4-yl)ethene-κ²N:N'], [Ag(C₉H₅O₆)(C₁₂H₁₀N₂)]_n or [Ag(H₂BTC)(3,4'-bpe)]_n, (I), and poly[[(μ₃-5-carboxybenzene-1,3-dicarboxylato-κ⁴O¹,O^1':O³:O³)[μ-trans-1-(pyridin-3-yl)-2-(pyridin-4-yl)ethene-κ²N:N']cadmium(II)] monohydrate], {[Cd(C₉H₄O₆)(C₁₂H₁₀N₂)]·H₂O}_n or {[Cd(HBTC)(3,4'-bpe)]·H₂O}_n, (II), have been prepared by the hydrothermal reactions of benzene-1,3,5-tricarboxylic acid (H₃BTC) and trans-1-(pyridin-3-yl)-2-(pyridin-4-yl)ethene (3,4'-bpe) in the presence of AgNO₃ or Cd(NO₃)₂·4H₂O, respectively. These two title compounds have been structurally characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction. In (I), the Ag^I ions and organic ligands form a one-dimensional coordination chain, and adjacent coordination chains are connected by Ag...O interactions to give rise to a two-dimensional supramolecular network. Each two-dimensional network is entangled with other equivalent networks to generate an infrequent interlocked 2D→3D (2D and 3D are two- and three-dimensional, respectively) supramolecular framework. In (II), the Cd^II ions are bridged by the HBTC^2- and 3,4'-bpe ligands, which lie across centres of inversion, to give a two-dimensional coordination network. The thermal stabilities and photocatalytic properties of the title compounds have also been studied.

Syntheses and crystal structures of two new silver–organic frameworks based on N-pyrazinesulfonyl-glycine: weak Ag···O/N interaction affecting the coordination geometry

Two new metal–organic frameworks, namely, [Ag2(L)] n (1) and {[Ag2.5(L)(bpy)2]·(NO3)0.5·(H2O)4.5} n (2), where H2L=N-pyrazinesulfonyl-glycine and bpy=4,4′-bipyridine, have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analysis. X-ray diffraction crystallographic analyses indicate that 1 displays a silver carboxylate-sulfonamide layer structure containing an uncommon heptanuclear [Ag7] cluster wherein four silver(I) atoms form an Ag4 plane with in a three-connected (6, 3) net. The molecular structure of 2 has three crystallographically independent two-coordinate Ag centers with an intersecting Ag-bpy chain structure in a six-connected (3, 6) or a four-connected (4, 4) topology. The L2− ligand serves as a μ 7-(η 2-O,N), (η 2-O′,N′), O,O″,O″′,N,N″ ligand in 1 and as a μ 3-(η 2-O,N), N,O′ ligand in 2. In the crystal, a 3D supramolecular architecture is formed by coordinative bonding in 1, but through O–H···O bonding as well as π···π stacking in 2. The two compounds show a combination of coordinative bonds, ligand-supported Ag···Ag interactions and weak Ag···O/N coordinative interactions in the solid state.

Coordination assemblies of Zn(NO3)2 with 4-pyr-poly-2-ene and polycarboxylates: structural diversification and photoluminescence properties

Reactions of Zn(NO₃)₂·6H₂O with 4-pyr-poly-2-ene and five polycarboxylates afforded a series of coordination polymers with different architectures. Their thermal and photoluminescence properties were also investigated.

A series of divalent metal coordination polymers based on isomeric tetracarboxylic acids: synthesis, structures and magnetic properties

A series of M(ii) coordination polymers has been synthesized. 1–3 contain 1D infinite chains, and these 1D chains are further linked by hydrogen bonding to form 3D supramolecular networks. While 4 and 5 show tetra- or penta-nodal 3D network, respectively.