A Polymeric Structure Containing Cu2Cl2 Units Bridged by 4,4‘-Bipyridine: (PPh3)2Cu2(μ-Cl)2(μ-4,4‘-bipyridine)

Quantitative Thermal Synthesis of Cu(I) Coordination Polymers That Exhibit Thermally Activated Delayed Fluorescence

As a new environmentally friendly route for synthesizing thermally activated delayed-fluorescence (TADF) Cu(I) complexes, we successfully and quantitatively synthesized strongly emissive Cu(I) coordination polymers [Cu₂I₂(PR₃)₂(n,n'-bpy)]_∞ (CuIR-n, R = Ph, Tol; n = 3, 4; bpy = bipyridine) via the quick thermal reaction of three starting materials (CuI, PR₃, and bpy organic ligands) for 1 h in the absence of a solvent. Powder X-ray diffraction and thermogravimetric analyses revealed that melting of the organic ligands significantly promoted the coordination polymerization reaction, and the stoichiometry of three starting materials was crucial to quantitatively affording CuIR-n. Notably, the photophysical properties of CuIR-n obtained by the thermal reaction were almost the same (emission wavelength, quantum yield, and lifetime) as that obtained by generally used solution reactions, probably because CuIR-n was thermally stable enough to prevent the thermal damage and to improve the crystallinity in the heating process. The emission origin of CuIR-n was assignable to TADF at 298 K and phosphorescence at 77 K originating from the metal-to-ligand charge-transfer excited state effectively mixed with the halide-to-ligand charge transfer ((M+X)LCT) state. Thus, the thermal reaction in the melted ligand could be a promising environmentally friendly method for producing TADF Cu(I) luminophores.

One-dimensional silver(i) coordination polymers containing cyclodiphosphazane, cis-{(o-MeOC6H4O)P(µ-NtBu)}2

The 1:1 reaction between the cyclodiphosphazane cis-{(o-MeOC(6)H(4)O)P(mu-N(t)Bu)}(2) (1) and AgOTf afforded one-dimensional Ag(I) coordination polymer [Ag{mu-OTf-kappaO,kappaO}{mu-(o-MeOC(6)H(4)O)P(mu-N(t)Bu)-kappaP,kappaP}(2)](infinity) (2) containing bridging cyclodiphosphazane and trifluoromethanesulfonate (OTf) ligands. The 2:1 reaction of and AgOTf leads to the formation of simple mononuclear complex [Ag{OTf-kappaO,kappaO}({(o-MeOC(6)H(4)O)P(mu-N(t)Bu)-kappaP}(2))(2)] (3) in quantitative yield. Reaction of 1 with AgCN produces a strain-free zig-zag coordination polymer [({(o-MeOC(6)H(4)O)P(mu-N(t)Bu)-kappaP,kappaP}(2))(2)Ag(NCAgCN)](infinity) (4) irrespective of reaction stoichiometry and conditions. In complexes 3 and 4 cyclodiphosphazanes coordinate to Ag(I) centers in a monodentate fashion. Single crystal structures were established for the Ag(I) polymers 2 and 4.

Crystal engineering of coordination polymers using 4,4′-bipyridine as a bond between transition metal atoms

Coordination polymers have attracted an enormous interest among chemists due to their novel physical and chemical properties. This review describes the role of 4,4'-bipyridine in discovering various coordination polymers with novel topologies that range from one-dimensional to three dimensional. The geometries of coordination polymers of bipy include linear, zigzag, four-fold helices, molecular antenna, ladder, railroad, double, triple and quadruple chains, bilayer, square and rectangular grid, honeycomb layers, Lincoln Logs, 3D frames, diamondoid, 4(2) x 8(2) and cubic networks.

Synthesis, Structures, and Magnetic Properties of the Copper(II), Cobalt(II), and Manganese(II) Complexes with 9-Acridinecarboxylate and 4-Quinolinecarboxylate Ligands

To explore the relationships between the structures of ligands and their complexes, we have synthesized and characterized a series of metal complexes with two structurally related ligands, 9-acridinecarboxylic acid (HL(1)) and 4-quinolinecarboxylate acid (HL(2)), [Cu(2)(mu(2)-OMe)(2)(L(1))(2)(H(2)O)(0.69)](n) 1, [Cu(2)(L(1))(4)(CH(3)OH)(2)] 2, [Cu(3)(L(1))(6)(CH(3)OH)(6)].3H(2)O 3, [Mn(3)(L(1))(6)(CH(3)OH)(6)].3H(2)O 4, [Co(3)(L(1))(6)(CH(3)OH)(6)].3H(2)O 5, [Cu(L(2))(2)](n) 6, [Mn(L(2))(2)(H(2)O)](n) 7, and [Co(L(2))(2)(H(2)O)](n) 8. 1 is a three-dimensional (3D) polymer with an interpenetrating NbO type network showing one-dimensional (1D) channels, whereas 2 and 3 take bi- and trinuclear structures, respectively, because of the differences in basicity of the reaction systems in preparing the three complexes. 4 and 5 have trinuclear structures similar to that of 3. In 1-5, ligand L(1) performs different coordination modes with N,O-bridging in 1 and O,O'-bridging in 2-5, and the metal ions also show different coordination geometries: square planar in 1, square pyramidal in 2, and octahedral in 3-5. 6 has a two-dimensional structure containing (4,4) grids in which L(2) adopts the N,O-bridging mode and the Cu(II) center takes square planar geometry. 7 and 8 are isostructural complexes showing 1D chain structures, with L(2) adopting the O,O-bridging mode. In addition, the intermolecular O-H...N hydrogen bonds and pi-pi stacking interactions further extend the complexes (except 1 and 6), forming 3D structures. The magnetic properties of 2-7 have been investigated and discussed in detail.

3D Coordination Polymers with Nitrilotriacetic and 4,4‘-Bipyridyl Mixed Ligands: Structural Variation Based on Dinuclear or Tetranuclear Subunits Assisted by Na−O and/or O−H···O Interactions

The reactions of Cu(II) with the mixed nitrilotriacetic acid (H3NTA) and 4,4'-bipyridyl (4,4'-bpy) ligands in different metal-to-ligand ratios in the presence of NaOH and NaClO4 afforded two complexes, Na3[Cu2(NTA)2(4,4'-bpy)]ClO4 x 5H2O (1) and [Cu2(NTA) (4,4'-bpy)2]ClO4 x 4H2O (2). The two complexes have been characterized by elemental analysis, IR, XRD, and single-crystal X-ray diffraction. 1 contains a basic doubly negatively charged [Cu2(NTA)2(4,4'-bpy)]2- dinuclear unit which was further assembled via multiple Na-O and O-H...O interactions into a three-dimensional (3D) pillared-layer structure. 2 features a two-dimensional (2D) undulated brick-wall architecture containing a basic doubly positively charged [Cu4(NTA)2(4,4'-bpy)2]2+ tetranuclear unit. The 2D network possesses large cavities hosting guest molecules and was further assembled via O-H...O hydrogen bonds into a 3D structure with several channels running in different directions.

Low-Dimensional Hybrid Copper Halides with Novel D6R Cu6I6 Cores

Two low-dimensional hybrid copper halides, (2,2'-bipy)Cu(3)I(3) (1) and (2,2'-bipy)Cu(4)I(4) (2) (2,2'-bipy = 2,2'-bipyridine), with novel D6R (double six-membered rings) Cu(6)I(6) cores were synthesized by hydro(solvo)thermal reactions and characterized by single-crystal X-ray diffraction.

Grid-Type Two-Dimensional Magnetic Multinuclear Metal Complex: Strands of {[CuII(μ-4,4‘-bpy)]2+}n Cross-Linked by Octacyanotungstate(V) Ions

Reaction of the preorganized strands of ([Cu(II)(mu-4,4'-bpy)](2+))n (4,4'-bpy = 4,4'-bipyridine) with [W(V)(CN)(8)](3)(-) leads to a novel cyano-bridged Cu(II)(3)W(V)(2) complex [Cu(mu-4,4'-bpy)(DMF)(2)][Cu(mu-4,4'-bpy)(DMF)](2)[W(V)(CN)(8)](2).2DMF. 2H(2)O 1. The structure of 1 consists of the expected 2-dimensional grid-type network which is built of infinite ([Cu(II)(mu-4,4'-bpy)](2+))n chains cross-linked by octacyanotungstate units. The Cu(II)-NC-W(V)-CN-Cu(II) linkage exhibits the topology of a 3,2-chain. The skeleton of the layer is additionally stabilized by a hydrogen bond network formed by terminal cyano ligands of the [W(CN)(8)](3-) moiety and water molecules. The distance between the adjacent Cu(3)(II)W(2)(V) chains within the layer is 11.12 A along the a axis. The layers are connected by H-bonds of NCN-NDMF-NCN linkages into 3-D supramolecular architecture. The magnetic properties correspond to a dominant ferromagnetic coupling within the Cu(II)(3)W(V)(2) pentamer units (J = +35(4) cm(-1)) and much weaker effective AF interunit coupling which include both intra- and inter-3,2-chain interactions between pentamers (J' = -0.05(1) cm(-1)).