Synthesis, Structure and Characterization of Two-dimensional Network Copper Complex [Cu_3(nta)_2(azpy)_2(H_2O)_2]·6H_2O

ＩｎｔｒｏｄｕｃｔｉｏｎＣｒｙｓｔａｌｅｎｇｉｎｅｅｒｉｎｇｏｆｓｕｐｒａｍｏｌｅｃｕｌａｒａｒｃｈｉｔｅｃｔｕｒｅｓｓｕｓｔａｉｎｅｄｂｙｃｏｏｒｄｉｎａｔｅｃｏｖａｌｅｎｔｂｏｎｄｓｏｒｈｙｄｒｏｇｅｎｂｏｎｄｓｒｅｐｒｅｓｅｎｔｓａｒａｐｉｄｌｙｅｘｐａｎｄｉｎｇｆｉｅｌｄｔｈａｔｏｆｆｅｒｓｐｏ ｔｅｎｔｉａｌｆｏｒｄｅｖｅｌｏｐｍｅｎｔｏｆｎｅｗｃｌａｓｓｅｓｏｆｆｕｎｃｔｉｏｎａｌｓｏｌｉｄｓ .1,2 Ｔｈｅａｒｃｈｉｔｅｃｔｕｒｅｓｏｆｃｏｏｒｄｉｎａｔｉｏｎｐｏｌｙｍｅｒｓｃａｎｂｅ…     

[H_2N(C_2H_4)_2NH_2]_4(H_3O)[PMo_2~VMo_6~(VI)V_4~(IV)O_(40)(V~(IV)O)_2]·H_2O: A New Highly Reduced, Bicapped Pseudo-Keggin Vanadylpolymolybdophosphate

Ｐｏｌｙｏｘｏｍｅｔａｌａｔｅｓ (ＰＯＭｓ)ｃｏｎｔａｉｎｉｎｇＫｅｇｇｉｎｍｏｉ ｅｔｉｅｓｈａｖｅｂｅｅｎｒｅｃｅｉｖｉｎｇｅｘｔｅｎｓｉｖｅａｔｔｅｎｔｉｏｎｉｎｒｅｃｅｎｔｙｅａｒｓｏｗｉｎｇｔｏｔｈｅｉｒｇｒｅａｔｆｕｎｄａｍｅｎｔａｌａｎｄｐｒａｃｔｉｃａｌｉｎｔｅｒ ｅｓｔ .1Ｅｓｐｅｃｉａｌｌｙｔｈｅｕｎｕｓｕａｌｅｌｅｃｔｒｏｎｉｃｐｒｏｐｅｒｔｙ (ｈｉｇｈｎｅｇａｔｉｖｅｃｈａｒｇｅｓ) ,ｏｎｅｏｆｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｐｒｏｐｅｒｔｉｅｓｏｆＰＯＭｓ ,ｈａｓｐｏｔｅｎ…     

Crystal Structure of Binuclear Oxomolybdenum(V), [Fe(H_2O)_6][Mo_2O_4(EDTA)]·5H_2O

1　ＩＮＴＲＯＤＵＣＴＩＯＮＡｌｔｈｏｕｇｈｔｈｅｂｉｎｕｃｌｅａｒｏｘｏｍｏｌｙｂｄｅｎｕｍ (Ｖ )ｃｏｍｐｏｕｎｄｓｏｆｅｔｈｙｌｅｎｅｄｉ ａｍｉｎｅｔｅｔｒａａｃｅｔａｔｅ (ＥＤＴＡ)ｃｈｅｌａｔｅｌｉｇａｎｄｗｅｒｅｗｉｄｅｌｙｓｔｕｄｉｅｄｄｕｒｉｎｇｌａｔｅｒ 50ｓ[1～ 4],ｔｈｅｆｉｒｓｔｓｕｃｈｃｒｙｓｔａｌｓｔｒｕｃｔｕｒｅｏｆｐｏｔａｓｓｉｕｍｓａｌｔｄｉｄｎｏｔａｐｐｅａｒｕｎｔｉｌ1 967[5 ],ａｎｄａｎ ｏｔｈｅｒｓｔｒｕｃｔｕｒｅｏｆｓｏｄｉｕｍｓａｌｔｗａｓｒｅｐｏｒｔｅｄｉ…     

A Nitrilotriacetate Bridged Heteronuclear Co(II)-Na(I) Polymer: {[CoNa(NTA)(H_2O)_3]·2H_2O}_n

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｎｉｔｒｉｌｏｔｒｉａｃｅｔｉｃａｃｉｄｉｓｏｎｅｏｆｔｈｅｉｍｐｏｒｔａｎｔｄｅｒｉｖａｔｉｖｅｓｏｆｇｌｙｃｉｎｅ .Ｄｕｒｉｎｇｔｈｅｌａｓｔｄｅｃａｄｅ ,ｉｔｓｔｒｉｖａ ｌｅｎｔａｎｉｏｎ (ＮＴＡ) ,ａｓａｂｒｉｄｇｉｎｇｌｉｇａｎｄ ,ｈａｓａｔｔｒａｃｔｅｄｗｉｄｅａｔｔｅｎｔｉｏｎａｎｄｂｅｃｏｍｅｏｎｅｏｆｔｈｅｓｕｂｊｅｃｔｏｆｉｎｔｅｎｓｉｖｅｒｅｓｅａｒｃｈｆｏｒｓｅｖｅｒａｌｒｅａｓｏｎｓ .1 6ＥａｃｈＮＴＡｈａｓｔｈｒｅｅｃａｒ ｂｏｘｙｌａｔｅ…     

Crystal Structure of 〔PrAl(CF_3COO)_2(CF_3CHOO)(C_2H_5)_2(C_4H_8O)_2〕_2

１ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔｙｅａｒｓ,ａｓｅｒｉｅｓｏｆｌａｎｔｈａｎｉｄｅ ａｌｕｍｉｎｉｕｍｃｏｍｐｌｅｘｅｓｗｈｉｃｈａｒｅａｃｔｉｖｅｆｏｒｐｏｌｙ ｍｅｒｉｚａｔｉｏｎｏｆｏｌｆｉｎｓ〔１〕ｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄ．...     

New Supramolecular Complex Assembled through Hydrogen Bonds. Crystal Structure of Co(PMBP-tsc)_2 ·2DMF·2H_2O

ＩｎｔｒｏｄｕｃｔｉｏｎＭｏｌｅｃｕｌａｒｐｏｌｙｍｅｒｓｗｉｔｈｏｎｅｄｉｍｅｎｓｉｏｎａｌｏｒｍｕｌｔｉ ｄｉｍｅｎｓｉｏｎａｌｓｔｒｕｃｔｕｒｅａｓｓｅｍｂｌｅｄｔｈｒｏｕｇｈｈｙｄｒｏｇｅｎｂｏｎｄｓｉｓａｎｉｍｐｏｒｔａｎｔｒｅｓｅａｒｃｈｃｏｎｔｅｎｔｉｎｔｈｅｓｕｐｒａ ｍｏｌｅｃｕｌａｒｃｈｅｍｉｓｔｒｙａｎｄｃｒｙｓｔａｌｅｎｇｉｎｅｅｒｉｎｇ .1,2 Ｗｉｔｈｔｈｅｄｅｖｅｌｏｐ ｍｅｎｔｏｆｎｅｗｔｙｐｅｆｕｎｃｔｉｏｎａｌｍａｔｅｒｉａｌｓｓｕｃｈａｓｍｏｌｅｃｕｌａｒｍａｇｎ…     

Synthesis and Structure of Copper(Ⅱ) Complex [Cu(C_5H_5N)_2(H_2O)(C_6H_5COO)_2]

1　ＩＮＴＲＯＤＵＣＴＩＯＮＣｅｒｔａｉｎｃｏｐｐｅｒｃｏｍｐｌｅｘｅｓｈａｖｅｂｅｅｎｓｈｏｗｎｔｏｈａｖｅｕｎｕｓｕａｌｃｈｅｍｉｃａｌｐｒｏｐｅｒｔｉｅｓｓｕｃｈａｓｏｘｙｇｅｎｔｒａｎｓｆｅｒ,ｏｘｉｄａｔｉｖｅａｄｄｉｔｉｏｎａｎｄｈｏｍｏｇｅｎｏｕｓｃａｔａｌｙｔｉｃｈｙｄｒｏｇｅｎａｔｉｏｎ[1].Ｏｘｉｄａｔｉｖｅａｄｄｉｔｉｏｎｒｅａｃｔｉｏｎｓａｒｅｋｅｙｓｔｅｐｓｉｎｔｈｅａｃｔｉｖａｔｉｏｎｏｆσｂｏｎｄｓｉｎａｇｒｅａｔｎｕｍｂｅｒｏｆｃａｔａｌｙｔｉｃｐｒｏｃｅｓｓ.Ｃｏｐ…     

[Co(H_2O)(HPO_4)]·H_2O: The Layered Divalent Metal Monohydrogenphosphate Structure

ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｎｃｅｔｈｅｐｉｏｎｅｅｒｗｏｒｋｓｏｆＣｌｅａｒｆｉｅｌｄａｎｄｃｏｗｏｒｋｅｒｓｉｎｔｈｅ 196 0ｓ ,1,2 ｌａｙｅｒｅｄｍｅｔａｌｐｈｏｓｐｈａｔｅｓｈａｖｅａｔｔｒａｃｔｅｄｍｕｃｈａｔｔｅｎｔｉｏｎｄｕｅｔｏｔｈｅｉｒａｐｐｌｉｃａｔｉｏｎｓｏｎｉｏｎｅｘ ｃｈａｎｇｅ ,ｉｎｔｅｒｃａｌａｔｉｏｎ ,ｈｅｔｅｒｏｇｅｎｅｏｕｓｃａｔａｌｙｓｉｓａｎｄｓｏｒｐ ｔｉｏｎ .3 7Ａｍｏｎｇｔｈｅｎｕｍｅｒｏｕｓｌａｍｅｌｌａｒｐｈａｓｅｓ ,ｔｈｅｐｒｏｔｏ ｔｙｐｉｃａｌ…     

Synthesis and Crystal Structure of Two-dimensional Network Supramolecular Complex [Cu(dafo)_2(H_2O)_2](ClO_4)_2

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｓｕｐｒａｍｏｌｅｃｕｌａｒｃｏｍｐｌｅｘｅｆｏｒｍｅｄｂｙｔｈｅｗｅａｋｉｎｔｅｒａｃｔｉｏｎｓ (ｅｌｅｃｔｒｏｓｔａｔｉｃｉｎｔｅｒａｃｔｉｏｎ ,ｈｙｄｒｏｇｅｎｂｏｎｄｓ ,ｖａｎｄｅｒＷａａｌｓｆｏｒｃｅ ,ｓｈｏｒｔ ｒａｎｇｅｅｘｃｌｕｓｉｏｎｆｏｒｃｅ ,ｅｔｃ .)ｏｆｍｏｒｅｔｈａｎｔｗｏｓｏｒｔｓｏｆｓｐｅｃｉｅｓｉｓａｎｏｒｇａｎｉｚｉｎｇｅｎｔｉｔｙｔｈａｔｕｓｕａｌｌｙｐｏｓｓｅｓｓｅｓｓｐｅｃｉａｌｓｔｒｕｃｔｕｒｅａｎｄｆｕｎｃｔｉｏｎ .1Ｓｕｐ…     

Synthesis and Structural Characterization of Two Molybdenum~phosphate Cluster Compounds: (C_(14)N_(14)H_(63) )Na(H_2Mo_6P_4O_(31))_2·8H_2Oand(C_(14)N_(14)H_(63))Na(H_2Mo_6P_4O_(31) )_2·5H_2O

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｓｙｎｔｈｅｓｉｓａｎｄｓｏｒｐｔｉｏｎｐｒｏｐｅｒｔｉｅｓｏｆｏｐｅｎｆｒａｍｅ ｗｏｒｋｓｏｌｉｄｓｓｕｃｈａｓｚｅｏｌｉｔｅｓ1ａｎｄｍｅｔａｌｍｏｌｙｂｄｅｎｕｍｐｈｏｓ ｐｈａｔｅ2 ,3ｗｉｔｈｌａｒｇｅｃａｖｉｔｉｅｓｐｒｏｖｏｋｅｄｅｎｏｒｍｏｕｓｉｎｔｅｒｅｓｔｂｅ ｃａｕｓｅｏｆｔｈｅｉｒｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉｏｎｉｎｃａｔａｌｙｓｉｓ .Ｏｎｅ ,ｔｗｏ ａｎｄｔｈｒｅｅ ｄｉｍｅｎｓｉｏｎａｌｓｏｌｉｄｃｏｍｐｏｕｎｄｓｃｏｎｓｉｓｔｉｎｇｏ…     

M(H2O)2(4,4′‐bipy)[C6H4(COO)2]·2H2O (M = Mn2+, Co2+) – Zwei isotype Koordinationspolymere mit Schichtstruktur

M(H₂O)₂(4,4′‐bipy)[C₆H₄(COO)₂]·2H₂O (M = Mn²⁺, Co²⁺) – Two Isotypic Coordination Polymers with Layered Structure Monoclinic single crystals of Mn(H₂O)₂(4,4′‐bipy)[C₆H₄(COO)₂]·2H₂O ( 1 ) and Co(H₂O)₂(4,4′‐bipy)[C₆H₄(COO)₂]· 2H₂O ( 2 ) have been prepared in aqueous solution at 80 °C. Space group P2/n (no. 13), Z = 2; 1 : a = 769.20(10), b = 1158.80(10), c = 1075.00(10) pm, β = 92.67(2)°, V = 0.9572(2) nm³; 2 : a = 761.18(9), b = 1135.69(9), c = 1080.89(9) pm, β = 92.276(7)°, V = 0.9337(2) nm³. M²⁺ (M = Mn, Co), which is situated on a twofold crystallographic axis, is coordinated in a moderately distorted octahedral fashion by two water molecules, two oxygen atoms of the phthalate anions and two nitrogen atoms of 4,4′‐biypyridine ( 1 : M–O 219.5(2), 220.1(2) pm, M–N 225.3(2), 227.2(2) pm; 2 : Co–O 212.7(2), 213.7(2) pm, Co–N 213.5(3), 214.9(3) pm). M²⁺ and [C₆H₄(COO)₂)]^2? build up chains, which are linked by 4,4′‐biyridine molecules to yield a two‐dimensional coordination polymer with layers parallel to (001).Thermogravimetric analysis in air of 1 indicated a loss of water of crystallization between 154 and 212 °C and in 2 between 169 and 222 °C.     

A three‐dimensional inorganic/organic hybrid material, [Ni2(4,4′‐bipy)3(H2O)2V4O12]·2.5H2O

The title compound, poly­[[[di­aqua(μ‐4,4′‐bipyridyl)­di­nickel(II)]‐bis(μ‐4,4′‐bipyridyl)‐di‐μ‐hexa­oxo­di­vana­date(2?)] 2.5‐hydrate], [Ni₂­(V₂O₆)₂­(C₁₀H₈N₂)₃­(H₂O)₂]·­2.5H₂O, has been prepared hydro­thermally and characterized by elemental analyses, IR spectroscopy and single‐crystal X‐ray diffraction. The structure consists of [V₂O₆], [Ni­(4,4′‐bipy)₄O₂] and [Ni­(H₂O)₂­(4,4′‐bipy)₂O₂] polyhedra, and water of crystallization. The Ni atoms and one bipyridyl group lie on centres of symmetry.     

A Dynamic Crystal‐to‐Amorphous Transformation Microporous ZnII Mixed Neutral‐ligand Metal‐organic Polymer {[Zn(bpp)2(μ‐4,4′‐bipy)(H2O)2](ClO4)2·H2O}n

A new rarely reported Zn^II mixed‐polypyridine coordination polymer with both rigid and flexible spacers, {[Zn(bpp)₂(μ‐4,4′‐bipy)(H₂O)₂](ClO₄)₂ · H₂O}_n ( 1 ), has been synthesized and characterized by elemental analysis, IR‐, ¹H NMR‐, ¹³C NMR spectroscopy and single‐crystal X‐ray diffraction. The thermal stability of compound 1 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The single‐crystal X‐ray structure of 1 shows that the complex has been formed from a 1D polymer as a result of bridging by the 4,4′‐bipy ligands. Solution and solid‐state luminescent spectra of the compound 1 indicate intense fluorescent emissions at ca. 353.6 and 468.8 nm, respectively. Removal of the interstitial water guest molecules results in a loss of crystallinity, but exposure to water vapor reestablishes the original structure, thus constituting 1 as a third‐generation porous framework.     

Synthesis and crystal structure of heteronuclear La( III )‐Cu(II ) complex { [LaCu2(NTA)2(4,4′‐bpy)(H2O)3]NO3·5H2O}n

A novel La( III )‐Cu( II ) heterometallic coordination polymer {[LaCu₂(NTA)₂(4,4′‐bpy)(H₂O)₃]NO₃·5H₂O]_n, where H₃NTA denotes nitrilotriacetic acid and 4,4′‐bpy denotes 4, 4‐bipyridine, was synthesized and characterized by IR spectrum, elemental analysis and X‐ray diffraction. The complex crystallizes in the triclinic space group Pi with cell parameters a = 1.33710(10) nm, b = 1,44530(10) nm, c =1.0949(2) nm, α = 71.905(7)°, β = 74.327(7)°, γ = 64.427(9)°, V = 1.7912(4) nm³and Z = 2. It consists of heterometallic units, in which each La( II ) ion is coordinated in a distorted monocapped square antiprism by three oxygen atoms from water molecules and six carboxyl oxygen atoms from five NTA^3? ions, and each Cu( I ) ion is coordinated by one nitrogen atom from 4,4′‐bpy and one nitrogen atom, three oxygen atoms from NTA^3?. In the title complex, La( I ) ions and Cu( II ) ions are connected by the heterometallic bridging of NTA^3?, constructing a two‐dimensional network structure along the [110]. And it is extended into an infinite three‐dimensional network structure by the formation of homometallic bridging of Cu‐4, 4′‐bpy‐Cu, exhibiting a certain inclusion ability.     

Diverse Coordinative Functions of 4,4′‐Bipyridine Generating Abundant Weak Interactions and Novel Fluorescent Property in Cadmium(II)‐4‐sulfobenzoate Polymer

The cadmium(II) 4‐sulfobenzoate complex with 4,4′‐bipyridine, {[Cd₂(4,4′‐bipy)₄(4‐sb)₂(H₂O)₃] · 4H₂O}_n, has been synthesized and characterized by elemental analysis, IR, DTA‐TG, fluorescence analysis, powder X‐ray analysis, and single‐crystal X‐ray structural determination. Structural analysis showed that the complex contains two Cd atoms in an unsymmetrical unit. The Cd1 atom displays a seven‐coordinated geometry, which is a capped anti‐trigonal prismatic structure, whereas the Cd2 atom has an octahedral coordination. The 4,4′‐bipyridine ligands in the complex have three coordination behaviors, i.e., monodentate, dimeric linker, and polymeric bridge, which is the first example showing three coordinative functions for 4,4′‐bipyridine ligands in one complex. Moreover, three coordinative functions of 4,4′‐bipyridine ligands in this polymer lead to abundant weak interactions and novel fluorescent properties, which is benefit for design and preparation of functional materials in specific usage.     

The layered compound poly[μ2‐4,4′‐bipyridyl‐di‐μ2‐chlorido‐mercury(II)]

The title compound, [HgCl₂(C₁₀H₈N₂)]_n, features two‐dimensional [HgCl₂(4,4′‐bipy)]_n neutral networks (4,4′‐bipy is 4,4′‐bipyridine), based on an octahedral Hg atom coordinated by four μ₂‐Cl atoms and two μ₂‐4,4′‐bipy ligands in trans positions, yielding a HgCl₄N₂ octahedron. The structure has mmm symmetry about the Hg atoms, with most of the atoms on at least one mirror plane, but the unsubstituted C atoms of the 4,4′‐bipy rings are disordered across a mirror plane. Photoluminescent investigations reveal that the title compound displays a strong emission in the green region, which probably originates from a ligand‐to‐ligand charge‐transfer transition.     

An unusual P312 framework for the Ni(4,4′‐bipyridine)(H2O)4 chain

catena‐Poly[[[tetra­aqua­nickel(II)]‐μ‐4,4′‐bipyridine‐κ²N:N′] thio­sulfate dihydrate], {[Ni(C₁₀H₈N₂)(H₂O)₄]S₂O₃·2H₂O}_n, (I), and catena‐poly[[[tetra­aqua­nickel(II)]‐μ‐4,4′‐bipyridine‐κ²N:N′] sulfate methanol solvate monohydrate], {[Ni(C₁₀H₈N₂)(H₂O)₄]SO₄·CH₄O·H₂O}_n, (II), are built up of {[Ni(4,4′‐bipy)(H₂O)₄]²⁺}_n chains (4,4′‐bipy is 4,4′‐bipyridine) inter­woven in an unusual P3₁ fashion. Voids are filled by the corresponding counter‐anions and solvate mol­ecules, defining a complex three‐dimensional network surrounding them. In both structures, the cationic chains evolve around a set of twofold axes passing through the Ni^II ions and bis­ecting the aromatic amines through their N (and their opposite C) atoms.     

Poly[diaquabis(μ‐4,4′‐bipyridine‐κ2N:N′)bis(ethane‐1,2‐diol)di‐μ‐sulfato‐dicopper(II)]

The title compound, [Cu₂(SO₄)₂(C₁₀H₈N₂)₂(C₂H₆O₂)₂(H₂O)₂]_n, contains two crystallographically unique Cu^II centres, each lying on a twofold axis and having a slightly distorted octahedral environment. One Cu^II centre is coordinated by two bridging 4,4′‐bipyridine (4,4′‐bipy) ligands, two sulfate anions and two aqua ligands. The second is surrounded by two 4,4′‐bipy N atoms and four O atoms, two from bridging sulfate anions and two from ethane‐1,2‐diol ligands. The sulfate anion bridges adjacent Cu^II centres, leading to the formation of linear ...Cu1–Cu2–Cu1–Cu2... chains. Adjacent chains are further bridged by 4,4′‐bipy ligands, which are also located on the twofold axis, resulting in a two‐dimensional layered polymer. In the crystal structure, extensive O—H...O hydrogen‐bonding interactions between water molecules, ethane‐1,2‐diol molecules and sulfate anions lead to the formation of a three‐dimensional supramolecular network structure.     

Crystallographic report: a double chain coordination polymer: {[Zn(H2O)6][Zn(3,3′,4,4′‐benzophenonetetracarboxylate)H2O]·4H2O}n

The double‐chain coordination polymer, {[Zn(H₂O)₆][Zn(bbtc)H₂O]·4H₂O}_n (bbtc = 3,3′, 4,4′‐benzophenonetetracarboxylate), features two kinds of zinc center. One is octahedrally coordinated by six aqua ligands and the other is coordinated by four carboxylate oxygen atoms, derived from three bbtc ligands, and a water molecule, forming a geometry intermediate between square‐pyramidal and trigonal bipyramidal. Copyright © 2003 John Wiley & Sons, Ltd.     

A new three‐dimensional cobalt(II) coordination polymer based on V‐shaped 3,4′‐oxydibenzoate: synthesis,crystal structure and magnetic properties

A new coordination polymer (CP), namely poly[(μ‐4,4′‐bipyridine)(μ₃‐3,4′‐oxydibenzoato)cobalt(II)], [Co(C₁₄H₈O₅)(C₁₀H₈N₂)]_n or [Co(3,4′‐obb)(4,4′‐bipy)]_n ( 1 ), was prepared by the self‐assembly of Co(NO₃)₂·6H₂O with the rarely used 3,4′‐oxydibenzoic acid (3,4′‐obbH₂) ligand and 4,4′‐bipyridine (4,4′‐bipy) under solvothermal conditions, and has been structurally characterized by elemental analysis, IR spectroscopy, single‐crystal X‐ray crystallography and powder X‐ray diffraction (PXRD). Single‐crystal X‐ray diffraction reveals that each Co^II ion is six‐coordinated by four O atoms from three 3,4′‐obb^2? ligands, of which two function as monodentate ligands and the other as a bidentate ligand, and by two N atoms from bridging 4,4′‐bipy ligands, thereby forming a distorted octahedral CoN₂O₄ coordination geometry. Adjacent crystallographically equivalent Co^II ions are bridged by the O atoms of 3,4′‐obb^2? ligands, affording an eight‐membered Co₂O₄C₂ ring which is further extended into a two‐dimensional [Co(3,4′‐obb)]_n sheet along the ab plane via 3,4′‐obb^2? functioning as a bidentate bridging ligand. The planes are interlinked into a three‐dimensional [Co(3,4′‐obb)(4,4′‐bipy)]_n network by 4,4′‐bipy ligands acting as pillars along the c axis. Magnetic investigations on CP 1 disclose an antiferromagnetic coupling within the dimeric Co₂ unit and a metamagnetic behaviour at low temperature resulting from intermolecular π–π interactions between the parallel 4,4′‐bipy ligands.