3‐(Pyridin‐4‐yl)acetylacetone: CdII and HgII compete for nitrogen coordination

3‐(Pyridin‐4‐yl)acetylacetone (HacacPy) acts as a pyridine‐type ligand towards Cd^II and Hg^II halides. With CdBr₂, the one‐dimensional polymer [Cd(μ‐Br)₂(HacacPy)Cd(μ‐Br)₂(HacacPy)₂]_∞ is obtained in which five‐ and six‐coordinated Cd^II cations alternate in the chain direction. Reaction of HacacPy with HgBr₂ results in [Hg(μ‐Br)Br(HacacPy)]_∞, a polymer in which each Hg^II centre is tetracoordinated. In both compounds, each metal(II) cation is N‐coordinated by at least one HacacPy ligand. Equimolar reaction between these Cd^II and Hg^II derivatives, either conducted in ethanol as solvent or via grinding in the solid state, leads to ligand redistribution and the formation of the well‐ordered bimetallic polymer catena‐poly[[bromidomercury(II)]‐μ‐bromido‐[aquabis[4‐hydroxy‐3‐(pyridin‐4‐yl)pent‐3‐en‐2‐one]cadmium(II)]‐di‐μ‐bromido], [CdHgBr₄(C₁₀H₁₁NO₂)₂(H₂O)]_n or [{HgBr}(μ‐Br){(HacacPy)₂Cd(H₂O)}(μ‐Br)₂]_∞. Hg^II and Cd^II cations alternate in the [100] direction. The HacacPy ligands do not bind to the Hg^II cations, which are tetracoordinated by three bridging and one terminal bromide ligand. The Cd^II centres adopt an only slightly distorted octahedral coordination. Three bromide ligands link them in a (2 + 1) pattern to neighbouring Hg^II atoms; two HacacPy ligands in a cis configuration, acting as N‐atom donors, and a terminal aqua ligand complete the coordination sphere. Classical O—H…Br hydrogen bonds stabilize the polymeric chain. O—H…O hydrogen bonds between aqua H atoms and the uncoordinated carbonyl group of an HacacPy ligand in a neighbouring strand in the c direction link the chains into layers in the (010) plane.     

Supramolecular architectures in metal(II) (Cd/Zn) halide/nitrate complexes of cytosine/5‐fluorocytosine

Three new metal(II)–cytosine (Cy)/5‐fluorocytosine (5FC) complexes, namely bis(4‐amino‐1,2‐dihydropyrimidin‐2‐one‐κN³)diiodidocadmium(II) or bis(cytosine)diiodidocadmium(II), [CdI₂(C₄H₅N₃O)₂], ( I ), bis(4‐amino‐1,2‐dihydropyrimidin‐2‐one‐κN³)bis(nitrato‐κ²O,O′)cadmium(II) or bis(cytosine)bis(nitrato)cadmium(II), [Cd(NO₃)₂(C₄H₅N₃O)₂], ( II ), and (6‐amino‐5‐fluoro‐1,2‐dihydropyrimidin‐2‐one‐κN³)aquadibromidozinc(II)–6‐amino‐5‐fluoro‐1,2‐dihydropyrimidin‐2‐one (1/1) or (6‐amino‐5‐fluorocytosine)aquadibromidozinc(II)–4‐amino‐5‐fluorocytosine (1/1), [ZnBr₂(C₄H₅FN₃O)(H₂O)]·C₄H₅FN₃O, ( III ), have been synthesized and characterized by single‐crystal X‐ray diffraction. In complex ( I ), the Cd^II ion is coordinated to two iodide ions and the endocyclic N atoms of the two cytosine molecules, leading to a distorted tetrahedral geometry. The structure is isotypic with [CdBr₂(C₄H₅N₃O)₂] [Muthiah et al. (2001). Acta Cryst. E 57 , m558–m560]. In compound ( II ), each of the two cytosine molecules coordinates to the Cd^II ion in a bidentate chelating mode via the endocyclic N atom and the O atom. Each of the two nitrate ions also coordinates in a bidentate chelating mode, forming a bicapped distorted octahedral geometry around cadmium. The typical interligand N—H…O hydrogen bond involving two cytosine molecules is also present. In compound ( III ), one zinc‐coordinated 5FC ligand is cocrystallized with another uncoordinated 5FC molecule. The Zn^II atom coordinates to the N(1) atom (systematic numbering) of 5FC, displacing the proton to the N(3) position. This N(3)—H tautomer of 5FC mimics N(3)‐protonated cytosine in forming a base pair (via three hydrogen bonds) with 5FC in the lattice, generating two fused R₂²(8) motifs. The distorted tetrahedral geometry around zinc is completed by two bromide ions and a water molecule. The coordinated and nonccordinated 5FCs are stacked over one another along the a‐axis direction, forming the rungs of a ladder motif, whereas Zn—Br bonds and N—H…Br hydrogen bonds form the rails of the ladder. The coordinated water molecules bridge the two types of 5FC molecules via O—H…O hydrogen bonds. The cytosine molecules are coordinated directly to the metal ion in each of the complexes and are hydrogen bonded to the bromide, iodide or nitrate ions. In compound ( III ), the uncoordinated 5FC molecule pairs with the coordinated 5FC ligand through three hydrogen bonds. The crystal structures are further stabilized by N—H…O, N—H…N, O—H…O, N—H…I and N—H…Br hydrogen bonds, and stacking interactions.     

Copper(II) bis(4,4,4‐trifluoro‐1‐phenylbutane‐1,3‐dionate) complexes with pyridin‐2‐one, 3‐hydroxypyridine and 3‐hydroxypyridin‐2‐one ligands: molecular structures and hydrogen‐bonded networks

Copper(II) bis(4,4,4‐trifluoro‐1‐phenylbutane‐1,3‐dionate) complexes with pyridin‐2‐one (pyon), 3‐hydroxypyridine (hpy) and 3‐hydroxypyridin‐2‐one (hpyon) were prepared and the solid‐state structures of (pyridin‐2‐one‐κO )bis(4,4,4‐trifluoro‐3‐oxo‐1‐phenylbutan‐1‐olato‐κ²O ,O ′)copper(II), [Cu(C₁₀H₆F₃O₂)₂(C₅H₅NO)] or [Cu(tfpb‐κ²O ,O ′)₂(pyon‐κO )], (I), bis(pyridin‐3‐ol‐κO )bis(4,4,4‐trifluoro‐3‐oxo‐1‐phenylbutan‐1‐olato‐κ²O ,O ′)copper(II), [Cu(C₁₀H₆F₃O₂)₂(C₅H₅NO)₂] or [Cu(tfpb‐κ²O ,O ′)₂(hpy‐κO )₂], (II), and bis(3‐hydroxypyridin‐2‐one‐κO )bis(4,4,4‐trifluoro‐3‐oxo‐1‐phenylbutan‐1‐olato‐κ²O ,O ′)copper(II), [Cu(C₁₀H₆F₃O₂)₂(C₅H₅NO₂)₂] or [Cu(tfpb‐κ²O ,O ′)₂(hpyon‐κO )₂], (III), were determined by single‐crystal X‐ray analysis. The coordination of the metal centre is square pyramidal and displays a rare example of a mutual cis arrangement of the β‐diketonate ligands in (I) and a trans‐octahedral arrangement in (II) and (III). Complex (II) presents the first crystallographic evidence of κO‐monodentate hpy ligation to the transition metal enabling the pyridine N atom to participate in a two‐dimensional hydrogen‐bonded network through O—H…N interactions, forming a graph‐set motif R ₂²(7) through a C—H…O interaction. Complex (III) presents the first crystallographic evidence of monodentate coordination of the neutral hpyon ligand to a metal centre and a two‐dimensional hydrogen‐bonded network is formed through N—H…O interactions facilitated by C—H…O interactions, forming the graph‐set motifs R ₂²(8) and R ₂²(7).     

Two new cadmium(II) coordination polymers based on bis(1,2,4‐triazol‐1‐yl)alkane ligands and pyrazine‐2,3‐dicarboxylic acid

Assemblies of pyrazine‐2,3‐dicarboxylic acid and Cd^II in the presence of bis(1,2,4‐triazol‐1‐yl)butane or bis(1,2,4‐triazol‐1‐yl)ethane under ambient conditions yielded two new coordination polymers, namely poly[[tetraaqua[μ₂‐1,4‐bis(1,2,4‐triazol‐1‐yl)butane‐κ²N⁴:N^4′]bis(μ₂‐pyrazine‐2,3‐dicarboxylato‐κ³N¹,O²:O³)dicadmium(II)] dihydrate], {[Cd₂(C₆H₂N₂O₄)₂(C₈H₁₂N₆)(H₂O)₄]·2H₂O}_n, (I), and poly[[diaqua[μ₂‐1,2‐bis(1,2,4‐triazol‐1‐yl)ethane‐κ²N⁴:N^4′]bis(μ₃‐pyrazine‐2,3‐dicarboxylato‐κ⁴N¹,O²:O³:O^3′)dicadmium(II)] dihydrate], {[Cd₂(C₆H₂N₂O₄)₂(C₆H₈N₆)(H₂O)₂]·2H₂O}_n, (II). Complex (I) displays an interesting two‐dimensional wave‐like structure and forms a distinct extended three‐dimensional supramolecular structure with the help of O—H...N and O—H...O hydrogen bonds. Complex (II) has a three‐dimensional framework structure in which hydrogen bonds of the O—H...N and O—H...O types are found.     

Cadmium nitrate coordination polymers with substituted pyridazino[4,5‐d]pyridazines

catena‐Poly[[aquabis(nitrato‐κ²O,O′)cadmium(II)]‐μ‐1,2,3,6,7,8‐hexa­hydro­cinnolino[5,4,3‐cde]cinnoline‐κN¹:κN⁶], [Cd(NO₃)₂(C₁₂H₁₂N₄)(H₂O)]_n, (I), and catena‐poly[[[bis(nitrato‐κ²O,O′)cadmium(II)]‐μ‐2,2,7,7‐tetra­methyl‐1,2,3,6,7,8‐hexahydro­cinnolino[5,4,3‐cde]cinnoline‐κN¹:κN⁶] chloro­form solvate], {[Cd(NO₃)₂(C₁₂H₁₂N₄)]·CHCl₃}_n, (II), are the first structurally examined cadmium–pyridazine coordination compounds. They possess one‐dimensional polymeric structures supported by the bidentate bridging function of the cinnolino[5,4,3‐cde]cinnoline ligands, which lie about inversion centres. The Cd atoms are seven‐coordinated in (I) and six‐coordinated in (II), involving two bidentate nitrate groups [Cd—O = 2.229 (2)–2.657 (2) Å], two N atoms of the cinnoline ligands [Cd—N = 2.252 (2)–2.425 (2) Å], and, additionally, a water O atom in (I) [Cd—O = 2.284 (2) Å]. In (I), the coordinated organic and aqua ligands form an intra­molecular O—H⋯N hydrogen bond [O⋯N = 2.730 (3) Å].     

Bis­(acetato‐κ2O,O′)(2,9‐di­methyl‐1,10‐phenanthroline‐κ2N,N′)mercury(II) in two differently hydrated crystal forms

Two differently hydrated crystal forms of the title compound, viz. bis­(acetato‐κ²O,O′)(2,9‐di­methyl‐1,10‐phenanthroline‐κ²N,N′)­mercury(II), [Hg(C₂H₃O₂)₂(C₁₄H₁₂N₂)] or [HgAc₂(dmph)] [dmph is 2,3‐di­methyl‐1,10‐phenantroline (neocuproine) and Ac is acetate], (I), and tris­[bis­(acetato‐κ²O,O′)(2,9‐di­methyl‐1,10‐phenanthroline‐κ²N,N′)­mercury(II)] hexadecahydrate, [Hg(C₂H₃O₂)₂(C₁₄H₁₂N₂)]₃·16H₂O or [HgAc₂(dmph)]₃·16H₂O, (II), are presented. Both structures are composed of very simple monomeric units, which act as the building blocks of complex packing schemes stabilized by a diversity of π–π and hydrogen‐bonding interactions.     

Two isomorphous ZnII/CoII complexes with tri‐tert‐butoxysilanethiol and histamine,and (4‐hydroxymethyl‐1H‐imidazole‐κN)bis(tri‐tert‐butoxysilanethiolato‐κ2O,S)zinc(II)

The complexes [2‐(1H‐imidazol‐4‐yl‐κN³)ethylamine‐κN]bis(tri‐tert‐butoxysilanethiolato‐κS)cobalt(II), [Co(C₁₂H₂₇O₃SSi)₂(C₅H₉N₃)], and [2‐(1H‐imidazol‐4‐yl‐κN³)ethylamine‐κN]bis(tri‐tert‐butoxysilanethiolato‐κS)zinc(II), [Zn(C₁₂H₂₇O₃SSi)₂(C₅H₉N₃)], are isomorphous. The central Zn^II/Co^II ions are surrounded by two S atoms from the tri‐tert‐butoxysilanethiolate ligand and by two N atoms from the chelating histamine ligand in a distorted tetrahedral geometry, with two intramolecular N—H...O hydrogen‐bonding interactions between the histamine NH₂ groups and tert‐butoxy O atoms. Molecules of the complexes are joined into dimers via two intermolecular bifurcated N—H...(S,O) hydrogen bonds. The Zn^II atom in [(1H‐imidazol‐4‐yl‐κN³)methanol]bis(tri‐tert‐butoxysilanethiolato‐κ²O,S)zinc(II), [Zn(C₁₂H₂₇O₃SSi)₂(C₄H₆N₂O)], is five‐coordinated by two O and two S atoms from the O,S‐chelating silanethiolate ligand and by one N atom from (1H‐imidazol‐4‐yl)methanol; the hydroxy group forms an intramolecular hydrogen bond with sulfur. Molecules of this complex pack as zigzag chains linked by N—H...O hydrogen bonds. These structures provide reference details for cysteine‐ and histidine‐ligated metal centers in proteins.     

Monodentate and bridging behaviour of the sulfur‐containing ligand 4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine in two discrete zinc(II) complexes with acetylacetonate

The Zn complexes bis(acetylacetonato‐κ²O,O′)bis{4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine‐κN¹}zinc(II), [Zn(C₅H₇O₂)₂(C₂₂H₁₇N₃S)₂], (I), and {μ‐4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine‐κ²N¹:N^1′′}bis[bis(acetylacetonato‐κ²O,O′)zinc(II)], [Zn₂(C₅H₇O₂)₄(C₂₂H₁₇N₃S)], (II), are discrete entities with different nuclearities. Compound (I) consists of two centrosymmetrically related monodentate 4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine (L1) ligands binding to one Zn^II atom sitting on an inversion centre and two centrosymmetrically related chelating acetylacetonate (acac) groups which bind via carbonyl O‐atom donors, giving an N₂O₄ octahedral environment for Zn^II. Compound (II), however, consists of a bis‐monodentate L1 ligand bridging two Zn^II atoms from two different Zn(acac)₂ fragments. Intra‐ and intermolecular interactions are weak, mainly of the C—H...π and π–π types, mediating similar layered structures. In contrast to related structures in the literature, sulfur‐mediated nonbonding interactions in (II) do not seem to have any significant influence on the supramolecular structure.     

A two‐dimensional cadmium(II) coordination polymer based on 1‐cyanomethyl‐4‐aza‐1‐azoniabicyclo[2.2.2]octane and thiocyanate ligands

A cadmium–thiocyanate complex, poly[(1‐cyanomethyl‐4‐aza‐1‐azoniabicyclo[2.2.2]octane‐κ⁴N)octakis‐μ₂‐thiocyanato‐κ⁸N:S;κ⁸S:N‐tricadmium(II)], [Cd₃(C₈H₁₄N₃)₂(NCS)₈]_n, was synthesized by the reaction of 1‐cyanomethyl‐4‐aza‐1‐azoniabicyclo[2.2.2]octane chloride, cadmium nitrate tetrahydrate and potassium thiocyanide in aqueous solution. In the crystal structure, there are two independent types of Cd^II cation (one on a centre of inversion and one in a general position) and both are in distorted octahedral coordination environments, coordinated by N and S atoms from different ligands. Neighbouring Cd^II cations are linked together by thiocyanate bridges to form a two‐dimensional network. Hydrogen‐bonding interactions are involved in the formation of a three‐dimensional supramolecular network.     

Two mononuclear octahedral complexes with benzimidazole‐2‐carboxylate: supramolecular networks constructed by hydrogen bonds

The title compounds, trans‐bis(1H‐benzimidazole‐2‐carboxylato‐κ²N³,O)bis(ethanol‐κO)cadmium(II), [Cd(C₈H₅N₂O₂)₂(C₂H₆O)₂], (I), and trans‐bis(1H‐benzimidazole‐κN³)bis(1H‐benzimidazole‐2‐carboxylato‐κ²N³,O)nickel(II), [Ni(C₈H₅N₂O₂)₂(C₇H₆N₂)₂], (II), are hydrogen‐bonded supramolecular complexes. In (I), the Cd^II ion is six‐coordinated by two O atoms from two ethanol molecules, and by two O and two N atoms from two bidentate benzimidazole‐2‐carboxylate (HBIC) ligands, giving a distorted octahedral geometry. The combination of O—H...O and N—H...O hydrogen bonds results in two‐dimensional layers parallel to the ab plane. In (II), the six‐coordinated Ni^II atom, which lies on an inversion centre, shows a similar distorted octahedral geometry to the Cd^II ion in (I); two benzimidazole molecules occupy the axial sites and the equatorial plane contains two chelating HBIC ligands. Pairs of N—H...O hydrogen bonds between pairs of HBIC anions connect adjacent Ni^II coordination units to form a one‐dimensional chain parallel to the a axis. Moreover, these one‐dimensional chains are further linked via N—H...O hydrogen bonds between HBIC anions and benzimidazole molecules to generate a three‐dimensional supramolecular framework. The two compounds show quite different supramolecular networks, which may be explained by the fact that different co‐ligands occupy the axial sites in the coordination units.     

Two novel mixed‐ligand complexes containing organosulfonate ligands

The structures reported herein, viz. bis(4‐aminonaphthalene‐1‐sulfonato‐κO)bis(4,5‐diazafluoren‐9‐one‐κ²N,N′)copper(II), [Cu(C₁₀H₈NO₃S)₂(C₁₁H₆N₂O)₂], (I), and poly[[[diaquacadmium(II)]‐bis(μ‐4‐aminonaphthalene‐1‐sulfonato)‐κ²O:N;κ²N:O] dihydrate], {[Cd(C₁₀H₈NO₃S)₂(H₂O)₂]·2H₂O}_n, (II), are rare examples of sulfonate‐containing complexes where the anion does not fulfill a passive charge‐balancing role, but takes an active part in coordination as a monodentate and/or bridging ligand. Monomeric complex (I) possesses a crystallographic inversion center at the Cu^II atom, and the asymmetric unit contains one‐half of a Cu atom, one complete 4‐aminonaphthalene‐1‐sulfonate (ans) ligand and one 4,5‐diazafluoren‐9‐one (DAFO) ligand. The Cu^II atom has an elongated distorted octahedral coordination geometry formed by two O atoms from two monodentate ans ligands and by four N atoms from two DAFO molecules. Complex (II) is polymeric and its crystal structure is built up by one‐dimensional chains and solvent water molecules. Here also the cation (a Cd^II atom) lies on a crystallographic inversion center and adopts a slightly distorted octahedral geometry. Each ans anion serves as a bridging ligand linking two Cd^II atoms into one‐dimensional infinite chains along the [010] direction, with each Cd^II center coordinated by four ans ligands via O and N atoms and by two aqua ligands. In both structures, there are significant π–π stacking interactions between adjacent ligands and hydrogen bonds contribute to the formation of two‐ and three‐dimensional networks.     

A novel three‐dimensional copper(I) coordination polymer constructed from a copper–bromide net and nicotinic acid ligands

The title compound, poly[μ₃‐bromido‐(pyridine‐3‐carboxylato‐κN)copper(I)], [CuBr(C₆H₅NO₂)]_n, is a novel coordination polymer based on a copper–bromide net and nicotinic acid ligands. The asymmetric unit contains one copper(I) ion, one bromide ligand and one nicotinic acid ligand, all on general positions. The Cu^I atom is tetrahedral and coordinated by three bridging Br atoms and the N atom from the nicotinic acid ligand. The Cu–Br units form alternating six‐membered chair‐patterned rings in net‐like layers. The attached nicotinic acid units point alternately up and down. The layers are assembled into a three‐dimensional network via intermolecular O—H...O and C—H...Br hydrogen‐bonding interactions.     

catena‐Poly­[[(di‐2‐pyridyl­amine)­silver(I)]‐μ‐nicotinato] and catena‐poly­[[(di‐2‐pyridyl­amine)silver(I)]‐μ‐2,6‐di­hydroxy­benzoato]

In catena‐poly­[[(di‐2‐pyridyl­amine‐κ²N,N′)silver(I)]‐μ‐nico­tinato‐κ²N:O], [Ag(C₆H₄NO₂)(C₁₀H₉N₃)]_n, the Ag^I atom is tetracoordinated by two N atoms from the di‐2‐pyridyl­amine (BPA) ligand [Ag—N = 2.3785 (18) and 2.3298 (18) Å] and by one N atom and one carboxyl­ate O atom from nicotinate ligands [Ag—N = 2.2827 (15) Å and Ag—O = 2.3636 (14) Å]. Bridging by nicotinate N and O atoms generates a polymeric chain structure, which extends along [100]. The carboxyl O atom not bonded to the Ag atom takes part in an intrachain C—H⋯O hydrogen bond, further stabilizing the chain. Pairs of chains are linked by N—H⋯O hydrogen bonds to generate ribbons. There are no π–π interactions in this complex. In catena‐poly­[[(di‐2‐pyridyl­amine‐κ²N,N′)silver(I)]‐μ‐2,6‐di­hydroxy­benzoato‐κ²O¹:O²], [Ag(C₇H₅O₄)(C₁₀H₉N₃)]_n, the Ag^I atom has a distorted tetrahedral coordination, with three strong bonds to two pyridine N atoms from the BPA ligand [Ag—N = 2.286 (5) and 2.320 (5) Å] and to one carboxyl­ate O atom from the 2,6‐di­hydroxy­benzoate ligand [Ag—O = 2.222 (4) Å]; the fourth, weaker, Ag‐atom coordination is to one of the phenol O atoms [Ag⋯O = 2.703 (4) Å] of an adjacent moiety, and this interaction generates a polymeric chain along [100]. Pairs of chains are linked about inversion centers by N—H⋯O hydrogen bonds to form ribbons, within which there are π–π interactions. The ribbons are linked about inversion centers by pairs of C—H⋯O hydrogen bonds and additional π–π interactions between inversion‐related pairs of 2,6‐di­hydroxy­benzoate ligands to generate a three‐dimensional network.     

catena‐Poly­[[trans‐bis­(ethane‐1,2‐di­amine‐κ2N,N′)copper(II)]‐μ‐di­thion­ato‐κ2O:O′] and trans‐di­aqua­bis­(propane‐1,3‐di­amine‐κ2N,N′)copper(II) di­thionate

In title an­hydro­us catena‐poly­[[trans‐bis­(ethane‐1,2‐di­amine‐κ²N,N′)copper(II)]‐μ‐di­thionato‐κ²O:O′], [Cu(S₂O₆)(C₂H₈N₂)₂]_n or [{H₂N(CH₂)₂NH₂}₂Cu(O·O₂SSO₂·O)]_∞, successive Cu atoms are bridged by a single doubly charged di­thionate group, forming a one‐dimensional polymer with inversion centres at the metal atoms and the mid‐point of the S—S bond [Cu—O = 2.5744 (15) Å]. In title (hydrated) trans‐di­aqua­bis­(propane‐1,3‐di­amine‐κ²N,N′)copper(II) di­thionate, [Cu(C₃H₁₀N₂)₂(H₂O)₂](S₂O₆) or [{H₂N(CH₂)₃NH₂}₂Cu(OH₂)₂](S₂O₆), both ions have imposed 2/m symmetry. The `axial' anion components are displaced by a pair of water ligands [Cu—O = 2.439 (3) Å], the shorter Cu—O distance being compensated by the lengthened Cu—N distance [2.0443 (18), cf. 2.0100 (13) and 2.0122 (16) Å].     

Luminescent properties of three structures built from 3‐cyano‐4‐dicyanomethylene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olate and cadmium

Yellow–orange tetraaquabis(3‐cyano‐4‐dicyanomethylene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olato‐κN³)cadmium(II) dihydrate, [Cd(C₈HN₄O₂)₂(H₂O)₄]·2H₂O, (I), and yellow tetraaquabis(3‐cyano‐4‐dicyanomethylene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olato‐κN³)cadmium(II) 1,4‐dioxane solvate, [Cd(C₈HN₄O₂)₂(H₂O)₄]·C₄H₈O₂, (II), contain centrosymmetric mononuclear Cd²⁺ coordination complex molecules in different conformations. Dark‐red poly[[decaaquabis(μ₂‐3‐cyano‐4‐dicyanomethylene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olato‐κ²N:N′)bis(μ₂‐3‐cyano‐4‐dicyanomethylene‐1H‐pyrrole‐2,5‐diolato‐κ²N:N′)tricadmium] hemihydrate], [Cd₃(C₈HN₄O₂)₂(C₈N₄O₂)₂(H₂O)₁₀]·0.5H₂O, (III), has a polymeric two‐dimensional structure, the building block of which includes two cadmium cations (one of them located on an inversion centre), and both singly and doubly charged anions. The cathodoluminescence spectra of the crystals are different and cover the wavelength range from UV to red, with emission peaks at 377 and 620 nm for (III), and at 583 and 580 nm for (I) and (II), respectively.     

A new two‐dimensional cadmium coordination polymer with 1H‐imidazole‐4‐carboxylate and oxalate

The title compound, poly[aqua(μ₂‐1H‐imidazole‐4‐carboxylato‐κ³N³,O:O′)hemi(μ₂‐oxalato‐κ⁴O¹,O²:O^1′,O^2′)cadmium(II)], [Cd(C₄H₃N₂O₂)(C₂O₄)_0.5(H₂O)]_n, exhibits a two‐dimensional network. The Cd^II cation is coordinated to one N atom and two carboxylate O atoms from two 1H‐imidazole‐4‐carboxylate (Himc) ligands, two carboxylate O atoms from the bridging oxalate anion and one ligated water molecule; these six donor atoms form a distorted octahedral configuration. The oxalate anion lies on a centre of inversion. The Himc ligands connect the Cd^II cations to form –Cd–Himc–Cd–Himc–Cd– zigzag chains, with a Cd...Cd separation of 5.8206 (6) Å along the b direction, which are further linked by tetradentate oxalate anions to generate a two‐dimensional herringbone architecture in the ab plane. These layers are extended to form a three‐dimensional supramolecular framework via O—H...O and N—H...O hydrogen bonds and π–π stacking interactions. The solid‐state photoluminscent behaviour of the title compound has been investigated at room temperature.     

The synthesis,crystal structure and magnetic properties of a one‐dimensional terbium(III)–octacyanidomolybdate(V) assembly

A one‐dimensional cyanide‐bridged coordination polymer, poly[[aquadi‐μ‐cyanido‐κ⁴C:N‐hexacyanido‐κ⁶C‐(dimethylformamide‐κO)bis(3,4,7,8‐tetramethyl‐1,10‐phenanthroline‐κ²N,N′)terbium(III)molybdate(V)] 4.5‐hydrate], [MoTb(CN)₈(C₁₆H₁₆N₂)₂(C₃H₇NO)(H₂O)]·4.5H₂O}_n, has been prepared and characterized through IR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. The compound consists of one‐dimensional chains in which cationic [Tb(tmphen)₂(DMF)(H₂O)]³⁺ (tmphen is 3,4,7,8‐tetramethyl‐1,10‐phenanthroline) and anionic [Mo^V(CN)₈]³⁻ units are linked in an alternating fashion through bridging cyanide ligands. Neighbouring chains are connected by three types of hydrogen bonds (O—H...O, O—H...N and C—H...O) and by π–π interactions to form a three‐dimensional supramolecular structure. In addition, magnetic investigations show that ferromagnetic interactions exist in the compound.     

1D Coordination Polymers from Zinc(II) and Cadmium(II) Halides and 2,2′‐Dithiobis(pyridine N‐oxide): Isostructurality and Structural Diversity

Group 12 halides and 2,2′‐dithiobis(pyridine N‐oxide) (dtpo) form the crystalline the 1D coordination polymers [ZnX₂(μ‐dtpo‐κ²O:O′)]_n [X = Cl ( 1 ), Br ( 2 ), I ( 3 )], [Cd₃(μ‐Cl)₄Cl₂(μ‐dtpo‐κ²O:O′)₂(CH₃OH)₂]_n ( 4 ), [(CdBr₂)₂(μ₃‐dtpo‐κ³O,O:O′)₂(H₂O)₂]_n ( 5 ), and [(CdI₂)₂(μ‐dtpo‐κ²O:O′)₃]_n ( 6 ) in methanol. The compounds were structurally characterized by single‐crystal X‐ray analysis. Compounds 1 – 3 represent an isomorphous series of single‐stranded coordination polymers, whereas the Cd^II derivatives are structurally diverse. The metal nodes in 4 and 5 are trinuclear and dinuclear cadmium clusters, respectively. In 4 and 5 , the metal nodes are linked into double‐stranded 1D coordination polymers by two dtpo bridging ligands. Compound 6 contains mononuclear CdI₂ units as nodes and can be viewed as an alternating copolymer of CdI₂(μ‐dtpo‐κ²O:O′)₂ and CdI₂(μ‐dtpo‐κ²O:O′) entities. Owing to the disulfide moiety, the dtpo bridging ligand inevitably exhibits an axially chiral angular structure. The dtpo ligand adopts various coordination modes through the pyridine N‐oxide oxygen atoms.     

mer‐Diaquabis(1H‐imidazole‐κN3)[orotato(2–)]cobalt(II)

In the title complex, mer‐diaqua[2,6‐dioxo‐1,2,3,6‐tetrahydropyrimidine‐4‐carboxylato(2−)]bis(1H‐imidazole‐κN³)cobalt(II), [Co(C₅H₂N₂O₄)(C₃H₄N₂)₂(H₂O)₂], the Co^II ion is coordinated by a deprotonated N atom and the carboxylate O atom of the orotate ligand, two imidazole N atoms and two aqua ligands in a distorted octahedral geometry. The title complex exists as discrete doubly hydrogen‐bonded dimers, and a three‐dimensional network of O—H...O and N—H...O hydrogen bonds and weak π–π interactions is responsible for crystal stabilization.     

A new one‐dimensional cadmium(II) coordination polymer incorporating 4‐[4‐(1H‐imidazol‐1‐yl)phenyl]pyridine and 5‐hydroxybenzene‐1,3‐dicarboxylate ligands

The design and synthesis of new organic lgands is important to the rapid development of coordination polymers (CPs). However, CPs based on asymmetric ligands are still rare, mainly because such ligands are usually expensive and more difficult to synthesize. The new asymmetric ligand 4‐[4‐(1H‐imidazol‐1‐yl)phenyl]pyridine (IPP) has been used to construct the title one‐dimensional coordination polymer, catena‐poly[[[aqua{4‐[4‐(1H‐imidazol‐1‐yl‐κN³)phenyl]pyridine}cadmium(II)]‐μ‐5‐hydroxybenzene‐1,3‐dicarboxylato‐κ³O¹,O^1′:O³] monohydrate], {[Cd(C₈H₄O₅)(C₁₄H₁₁N₃)₂(H₂O)]·H₂O}_n, under hydrothermal reaction of IPP with Cd^II in the presence of 5‐hydroxyisophthalic acid (5‐OH‐H₂bdc). The Cd^II cation is coordinated by two N atoms from two distinct IPP ligands, three carboxylate O atoms from two different 5‐OH‐bdc²⁻ dianionic ligands and one water O atom in a distorted octahedral geometry. The cationic [Cd(IPP)₂]²⁺ nodes are linked by 5‐OH‐bdc²⁻ ligands to generate a one‐dimensional chain. These chains are extended into a two‐dimensional layer structure via O—H…O and O—H…N hydrogen bonds and π–π interactions.