Two different one‐dimensional structural motifs in [catena‐{Cu(tacn)}2Pd(CN)4]Br2·[catena‐Cu(tacn)Pd(CN)4]2·H2O (tacn is 1,4,7‐triazacyclononane)

The title compound, catena‐poly[[bis[(triazacyclononane‐κ³N,N′,N′′)copper(II)]‐di‐μ‐cyanido‐κ⁴N:C‐palladate(II)‐di‐μ‐cyanido‐κ⁴C:N] dibromide bis[[(triazacyclononane‐κ³N,N′,N′′)copper(II)]‐μ‐cyanido‐κ²N:C‐[dicyanidopalladate(II)]‐μ‐cyanido‐κ²C:N] monohydrate], {[Cu₂Pd(CN)₄(C₆H₁₅N₃)₂]Br₂·[Cu₂Pd₂(CN)₈(C₆H₁₅N₃)₂]·H₂O}_n, (I), was isolated from an aqueous solution containing tacn·3HBr (tacn is 1,4,7‐triazacyclononane), Cu²⁺ and tetracyanidopalladate(2−) anions. The crystal structure of (I) is essentially ionic and built up of 2,2‐electroneutral chains, viz. [Cu(tacn)(NC)–Pd(CN)₂–(CN)–], positively charged 2,4‐ribbons exhibiting the composition {[Cu(tacn)(NC)₂–Pd(CN)₂–Cu(tacn)]²ⁿ⁺}_n, bromide anions and one disordered water molecule of crystallization. The O atom of the water molecule occupies two unique crystallographic positions, one on a centre of symmetry, which is half occupied, and the other in a general position with one‐quarter occupancy. One of the tacn ligands also exhibits disorder. The formation of two different types of one‐dimensional structural motif within the same structure is a unique feature of this compound.     

[Ni(terpy)(H2O)]‐trans‐[Ni‐(μ‐CN)2‐(CN)2]n,a one‐dimensional linear tetra­cyano­nickelate chain

The one‐dimensional chain catena‐poly­[[aqua(2,2′:6′,2′′‐terpyridyl‐κ³N)­nickel(II)]‐μ‐cyano‐κ²N:C‐[bis­(cyano‐κC)nickelate(II)]‐μ‐cyano‐κ²C:N], [Ni(terpy)(H₂O)]‐trans‐[Ni‐μ‐(CN)₂‐(CN)₂]_n or [Ni₂­(CN)₄­(C₁₅H₁₁N₃)(H₂O)], consists of infinite linear chains along the crystallographic [10] direction. The chains are composed of two distinct types of nickel ions, paramagnetic octahedral [Ni(terpy)(H₂O)]²⁺ cations (with twofold crystallographic symmetry) and diamagnetic planar [Ni(CN)₄]^2? anions (with the Ni atom on an inversion center). The [Ni(CN)₄]^2? units act as bidentate ligands bridging through two trans cyano groups thus giving rise to a new example of a trans–trans chain among planar tetra­cyano­nickelate complexes. The coordination geometry of the planar nickel unit is typical of slightly distorted octahedral nickel(II) complexes, but for the [Ni(CN)₄]^2? units, the geometry deviates from a planar configuration due to steric interactions with the ter­pyridine ligands.     

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.     

Synthesis,decomposition studies and crystal structure of a three‐dimensional CuCN network structure with protonated N‐methylethanolamine as the guest cation

The compound poly[2‐hydroxy‐N‐methylethan‐1‐aminium [μ₃‐cyanido‐κ³C:C:N‐di‐μ‐cyanido‐κ⁴C:N‐dicuprate(I)]], {(C₃H₁₀NO)[Cu₂(CN)₃]}_n or [meoenH]Cu₂(CN)₃, crystallizes in the tetragonal space group P4₃. The structure consists of a three‐dimensional (3D) anionic Cu^ICN network with noncoordinated protonated N‐methylethanolamine cations providing charge neutrality. Pairs of cuprophilic Cu atoms are bridged by the C atoms of μ₃‐cyanide ligands, which link these units into a 4₃ spiral along the c axis. The spirals are linked together into a 3D anionic network by the two other cyanide groups. The cationic moieties are linked into their own 4₃ spiral via N—H…O and O—H…O hydrogen bonds, and the cations interact with the 3D network via an unusual pair of N—H…N hydrogen bonds to one of the μ₂‐cyanide groups. Thermogravimetric analysis indicates an initial loss of the base cation and one cyanide as HCN at temperatures in the range 130–250 °C to form CuCN. We show how loss of a specific cyanide group from the 3D CuCN structure could form the linear CuCN structure. Further heating leaves a residue of elemental copper, isolated as the oxide.     

A cyanide‐bridged FeII–NdIII bimetallic assembly with a one‐dimensional ladder‐like chain structure

The title complex, catena‐poly[[[(2,2′‐bipyridine‐1κ²N,N′)tris(methanol‐2κO)(nitrato‐2κ²O,O′)‐μ‐cyanido‐1:2C:N‐cyanido‐1κC‐iron(II)neodymium(III)]‐di‐μ‐cyanido‐1:2′C:N;2:1′N:C] methanol solvate], {[Fe^IINd^III(CN)₄(NO₃)(C₁₀H₈N₂)(CH₃OH)₃]·CH₃OH}_n, is made up of ladder‐like one‐dimensional chains oriented along the c axis. Each ladder consists of two strands based on alternating Fe^II and Nd^III centers connected by cyanide bridges. Furthermore, two such parallel chains are connected by additional cyanide cross‐pieces (the `rungs' of the ladder), which likewise connect Fe^II and Nd^III centers, such that each [Fe(CN)₄(bipy)]²⁻ unit (bipy is 2,2′‐bipyridine) coordinates with three Nd^III centers and each Nd^III center connects with three different [Fe(CN)₄(bipy)]²⁻ units. In the complex, the iron(II) cation is six‐coordinated with a distorted octahedral geometry and the neodymium(III) cation is eight‐coordinated with a distorted dodecahedral environment.     

A cyanide‐bridged FeIII–MnII heterobimetallic one‐dimensional coordination polymer: synthesis,crystal structure,experimental and theoretical magnetism investigation

A new cyanide‐bridged Fe^III–Mn^II heterobimetallic coordination polymer (CP), namely catena‐poly[[[N,N′‐(1,2‐phenylene)bis(pyridine‐2‐carboxamidato)‐κ⁴N,N′,N′′,N′′′]iron(III)]‐μ‐cyanido‐κ²C:N‐[bis(4,4′‐bipyridine‐κN)bis(methanol‐κO)manganese(II)]‐μ‐cyanido‐κ²N:C], {[FeMn(C₁₈H₁₂N₄O₂)(CN)₂(C₁₀H₈N₂)₂(CH₃OH)₂]ClO₄}_n, ( 1 ), was prepared by the self‐assembly of the trans‐dicyanidoiron(III)‐containing building block [Fe(bpb)(CN)₂]^? [bpb^2? = N,N′‐(1,2‐phenylene)bis(pyridine‐2‐carboxamidate)], [Mn(ClO₄)₂]·6H₂O and 4,4′‐bipyridine, and was structurally characterized by elemental analysis, IR spectroscopy, single‐crystal X‐ray crystallography and powder X‐ray diffraction (PXRD). Single‐crystal X‐ray diffraction analysis shows that CP 1 possesses a cationic linear chain structure consisting of alternating cyanide‐bridged Fe–Mn units, with free perchlorate as the charge‐balancing anion, which can be further extended into a two‐dimensional supramolecular sheet structure via inter‐chain π–π interactions between the 4,4′‐bipyridine ligands. Within the chain, each Mn^II ion is six‐coordinated by an N₆ unit and is involved in a slightly distorted octahedral coordination geometry. Investigation of the magnetic properties of 1 reveals an antiferromagnetic coupling between the cyanide‐bridged Fe^III and Mn^II ions. A best fit of the magnetic susceptibility based on the one‐dimensional alternating chain model leads to the magnetic coupling constants J₁ = ?1.35 and J₂ = ?1.05 cm^?1, and the antiferromagnetic coupling was further confirmed by spin Hamiltonian‐based density functional theoretical (DFT) calculations.     

One‐dimensional zinc‐based coord­in­ation polymers incorporating cyanate anions

Two one‐dimensional zinc‐based coordination polymers containing cyanate anions are reported. catena‐Poly[sodium [[tricyanato­zinc(II)]‐μ‐1,4‐diaza­bicyclo­[2.2.2]octane‐κ²N:N′]], {Na[Zn(NCO)₃(C₆H₁₂N₂)]}_n, consists of linear [tricyanato­zinc(II)]‐μ‐1,4‐diaza­bicyclo­[2.2.2]octane strands in which the Zn²⁺ cations adopt trigonal–bipyramidal coordination on sites of m2 point symmetry. Na⁺ cations lie between the strands on sites of m point symmetry, coordinated in a distorted octa­hedral geometry by six O atoms of the cyanate anions. catena‐Poly[[dicyanato­zinc(II)]‐μ‐4,4′‐bipyridine‐κ²N:N′], [Zn(NCO)₂(C₁₀H₈N₂)]_n, crystallizes in the space group P2₁/n with Z′ = 5. The structure consists of zigzag strands formed by Zn²⁺ cations linked via 4,4′‐bipyridine. Each Zn²⁺ cation adopts a tetra­hedral coordination, with two sites occupied by 4,4′‐bipyridine and two cyanate anions completing the coordination sphere. The structure is closely comparable with the thio­cyanate and halide analogues [ZnX₂(C₁₀H₈N₂)] (X = NCS, Cl or Br).     

The three‐dimensional coordination network in poly[di‐μ3‐cyanido‐μ5‐[5‐(pyridin‐4‐yl)tetrazolato]‐tricopper(I)]

In the title three‐dimensional tetrazolate‐based coordination polymer, poly[bis(μ₃‐cyanido‐κ³N:C:C)[μ₅‐5‐(pyridin‐4‐yl)tetrazolato‐κ⁵N:N′:N′′:N′′′:N′′′′]tricopper(I)], [Cu₃(C₆H₄N₅)(CN)₂]_n, there are two types of coordinated Cu^I atoms. One type exhibits a tetrahedral environment and the other, residing on a twofold axis, adopts a trigonal coordination environment. The closest Cu...Cu distance is only 2.531 (2) Å, involving a bridging cyanide C atom. All four tetrazolate and the pyridine N atom of the 4‐(pyridin‐4‐yl)‐1H‐tetrazolate anion are coordinated to these Cu^I atoms and exhibit a μ₅‐bridging mode. The three‐dimensional coordination network can be topologically simplified as a rarely observed (3,3,4,5)‐connected network with the Schläfli symbol (4.6.8⁴)₂.(4².6.8⁷).(6.8²)₃.     

A novel tetrazolate‐ and cyanide‐bridged three‐dimensional heterometallic coordination polymer: crystal structure,thermal stability and magnetic properties

By using environmentally friendly K₃[Co(CN)₆] as a cyanide source, the solvothermal reaction of CuCl₂ and tetrazole (Htta) led to a novel tetrazolate‐ and cyanide‐bridged three‐dimensional heterometallic Cu^II–Co^III complex, namely poly[[hexa‐μ₂‐cyanido‐κ¹²C :N‐pentakis(μ₃‐tetrazolato‐κ³N ¹:N ²:N ⁴)cobalt(III)tetracopper(II)] monohydrate], {[Co^IIICu^II₄(CHN₄)₅(CN)₆]·H₂O}_n , (I). The crystal structure analysis reveals that it is the first example of a (6,8,8)‐connected three‐dimensional framework with a unique topology, constructed from anionic [Co(CN)₆]³⁻ and cationic [(Cu1)₂(tta)₂]²⁺ and [(Cu2Cu3)(tta)₃]⁺ units through μ₂‐cyanide and μ₃‐tetrazolate linkers. The compound was further characterized by thermal analysis, vibrational spectroscopy (FT–IR), scanning electron microscopy/energy‐dispersive X‐ray spectroscopy (SEM–EDS) and magnetic measurements. The magnetic investigation indicates that the complex exhibits antiferromagnetic coupling between adjacent Cu^II cations.     

Mixed‐ligand MnII and CuII complexes with alternating 2,2′‐bipyrimidine and terephthalate bridges

The novel polymeric complexes catena‐poly[[diaquamanganese(II)]‐μ‐2,2′‐bipyrimidine‐κ⁴N¹,N^1′:N³,N^3′‐[diaquamanganese(II)]‐bis(μ‐terephthalato‐κ²O¹:O⁴)], [Mn₂(C₈H₄O₄)₂(C₈H₆N₄)(H₂O)₄]_n, (I), and catena‐poly[[[aquacopper(II)]‐μ‐aqua‐μ‐hydroxido‐μ‐terephthalato‐κ²O¹:O^1′‐copper(II)‐μ‐aqua‐μ‐hydroxido‐μ‐terephthalato‐κ²O¹:O^1′‐[aquacopper(II)]‐μ‐2,2′‐bipyrimidine‐κ⁴N¹,N^1′:N³,N^3′] tetrahydrate], {[Cu₃(C₈H₄O₄)₂(OH)₂(C₈H₆N₄)(H₂O)₄]·4H₂O}_n, (II), containing bridging 2,2′‐bipyrimidine (bpym) ligands coordinated as bis‐chelates, have been prepared via a ligand‐exchange reaction. In both cases, quite unusual coordination modes of the terephthalate (tpht²⁻) anions were found. In (I), two tpht²⁻ anions acting as bis‐monodentate ligands bridge the Mn^II centres in a parallel fashion. In (II), the tpht²⁻ anions act as endo‐bridges and connect two Cu^II centres in combination with additional aqua and hydroxide bridges. In this way, the binuclear [Mn₂(tpht)₂(bpym)(H₂O)₄] entity in (I) and the trinuclear [Cu₃(tpht)₂(OH)₂(bpym)(H₂O)₄]·4H₂O coordination entity in (II) build up one‐dimensional polymeric chains along the b axis. In (I), the Mn^II cation lies on a twofold axis, whereas the four central C atoms of the bpym ligand are located on a mirror plane. In (II), the central Cu^II cation is also on a special position (site symmetry ). In the crystal structures, the packing of the chains is further strengthened by a system of hydrogen bonds [in both (I) and (II)] and weak face‐to‐face π–π interactions [in (I)], forming three‐dimensional metal–organic frameworks. The Mn^II cation in (I) has a trigonally deformed octahedral geometry, whereas the Cu^II cations in (II) are in distorted octahedral environments. The Cu^II polyhedra are inclined relative to each other and share common edges.     

A novel three‐dimensional copper(I) cyanide coordination polymer constructed from various bridging ligands: synthesis,crystal structure and characterization

The cyanide ligand can act as a strong σ‐donor and an effective π‐electron acceptor that exhibits versatile bridging abilities, such as terminal, μ₂‐C:N, μ₃‐C:C:N and μ₄‐C:C:N:N modes. These ligands play a key role in the formation of various copper(I) cyanide systems, including one‐dimensional (1D) chains, two‐dimensional (2D) layers and three‐dimensional (3D) frameworks. According to the literature, numerous coordination polymers based on terminal, μ₂‐C:N and μ₃‐C,C,N bridging modes have been documented so far. However, systems based on the μ₄‐C:C:N:N bridging mode are relatively rare. In this work, a novel cyanide‐bridged 3D Cu^I coordination framework, namely poly[(μ₂‐2,2′‐biimidazole‐κ²N³:N^3′)(μ₄‐cyanido‐κ⁴C:C:N:N)(μ₂‐cyanido‐κ²C:N)dicopper(I)], [Cu₂(CN)₂(C₆H₆N₄)]_n, (I), was synthesized hydrothermally by reaction of environmentally friendly K₃[Fe(CN)₆], CuCl₂·2H₂O and 2,2′‐biimidazole (H₂biim). It should be noted that cyanide ligands may act as reducing agents to reduce Cu^II to Cu^I under hydrothermal conditions. Compound (I) contains diverse types of bridging ligands, such as μ₄‐C:C:N:N‐cyanide, μ₂‐C:N‐cyanide and μ₂‐biimidazole. Interestingly, the [Cu₂] dimers are bridged by rare μ₄‐C:C:N:N‐mode cyanide ligands giving rise to the first example of a 1D dimeric {[Cu₂(μ₄‐C:C:N:N)]ⁿ⁺}_n infinite chain. Furthermore, adjacent dimer‐based chains are linked by μ₂‐C:N bridging cyanide ligands, generating a neutral 2D wave‐like (4,4) layer structure. Finally, the 2D layers are joined together via bidentate bridging H₂biim to create a 3D cuprous cyanide network. This arrangement leads to a systematic variation in dimensionality from 1D chain→2D sheet→3D framework by different types of bridging ligands. Compound (I) was further characterized by thermal analysis, solid‐state UV–Vis diffuse‐reflectance and photoluminescence studies. The solid‐state UV–Vis diffuse‐reflectance spectra show that compound (I) is a wide‐gap semiconductor with band gaps of 3.18 eV. The photoluminescence study shows a strong blue–green photoluminescence at room temperature, which may be associated with metal‐to‐ligand charge transfer.     

Two new dimeric cadmium(II) and zinc(II) sulfate complexes with 2,4,6‐tris(2‐pyridyl)‐1,3,5‐triazine and 2,2:6′,2′′‐ter­pyridine

The structures of two new sulfate complexes are reported, namely di‐μ‐sulfato‐κ³O,O′:O′′‐bis{aqua­[2,4,6‐tris(2‐pyridyl)‐1,3,5‐triazine‐κ³N¹,N²,N⁶]­cadmium(II)} tetra­hydrate, [Cd₂(SO₄)₂(C₁₆H₁₂N₆)₂(H₂O)₂]·4H₂O, and di‐μ‐sulfato‐κ²O:O′‐bis­[(2,2′:6′,2′′‐ter­pyridine‐κ³N¹,N^1′,N^1′′)­zinc(II)] dihydrate, [Cd₂(SO₄)₂(C₁₅H₁₁N₃)₂]·2H₂O, the former being the first report of a Cd(tpt) complex [tpt is 2,4,6‐tris(2‐pyridyl)‐1,3,5‐triazine]. Both compounds crystallize in the space group P and form centrosymmetric dimeric structures. In the cadmium complex, the metal center is heptacoordinated in the form of a pentagonal bipyramid, while in the zinc complex, the metal ion is in a fivefold environment, the coordination geometry being intermediate between square pyramidal and trigonal bipyramidal. Packing of the dimers leads to the formation of planar structures strongly linked by hydrogen bonding.     

A one‐dimensional nickel(II) coordination polymer containing 2,6‐dipicolinate and dipyrido[3,2‐a:2′,3′‐c]phenazine

A new coordination polymer, catena‐poly[[(dipyrido[3,2‐a:2′,3′‐c]phenazine‐κ²N,N′)nickel(II)]‐μ‐2,6‐dipicolinato‐κ⁴O²,N,O⁶:O^2′], [Ni(C₇H₃NO₄)(C₁₈H₁₀N₄)]_n, exhibits a one‐dimensional structure in which 2,6‐dipicolinate acts as a bridging ligand interconnecting adjacent nickel(II) centers to form a chain structure. The asymmetric unit contains one Ni^II center, one dipyrido[3,2‐a:2′,3′‐c]phenazine ligand and one 2,6‐dipicolinate ligand. Each Ni^II center is six‐coordinated and surrounded by three N atoms and three O atoms from one dipyrido[3,2‐a:2′,3′‐c]phenazine ligand and two different 2,6‐dipicolinate ligands, leading to a distorted octahedral geometry. Adjacent chains are linked by π–π stacking interactions and weak interactions to form a three‐dimensional supramolecular network.     

Bridging behaviour of the 2‐thiobarbiturate anion in its complexes with LiI and NaI

The structures of the Li^I and Na^I salts of 2‐thiobarbituric acid (2‐sulfanylidene‐1‐3‐diazinane‐4,6‐dione, H₂TBA) have been studied. μ‐Aqua‐octaaquabis(μ‐2‐thiobarbiturato‐κ²O:O′)bis(2‐thiobarbiturato‐κO)tetralithium(I) dihydrate, [Li₄(C₄H₃N₂O₂S)₄(H₂O)₉]·2H₂O, (I), crystallizes with four symmetry‐independent four‐coordinated Li^I cations and four independent HTBA⁻ anions. The structure contains two structurally non‐equivalent Li^I cations and two non‐equivalent HTBA⁻ anions (bridging and terminal). Eight of the coordinated water ligands are terminal and the ninth acts as a bridge between Li^I cations. Discrete [Li₄(HTBA)₄(H₂O)₉]·2H₂O complexes form two‐dimensional layers. Neighbouring layers are connected via hydrogen‐bonding interactions, resulting in a three‐dimensional network. Poly[μ₂‐aqua‐tetraaqua(μ₄‐2‐thiobarbiturato‐κ⁴O:O:S:S)(μ₂‐thiobarbiturato‐κ²O:S)disodium(I)], [Na₂(C₄H₃N₂O₂S)₂(H₂O)₅]_n, (II), crystallizes with six‐coordinated Na^I cations. The octahedra are pairwise connected through edge‐sharing by a water O atom and an O atom from the μ₄‐HTBA⁻ ligand, and these pairs are further top‐shared by the S atoms to form continuous chains along the a direction. Two independent HTBA⁻ ligands integrate the chains to give a three‐dimensional network.     

AgI and CuI binuclear macrocyclic complexes with 1‐(3‐pyridyl)­ethano­ne oxime

Bis­[μ‐1‐(3‐pyridyl)­ethanone oxime‐κ²N:N′]­bis­[nitrato­sil­ver(I)], [Ag₂(NO₃)₂(C₇H₈N₂O)₂], crystallizes as a centrosymmetric binuclear macrocylic complex containing silver(I) ions bridged by the organic 1‐(3‐pyridyl)­ethanone oxime ligand. The ligand coordinates via the pyridine and the oxime N atoms. A similar metal–ligand arrangement was found in the copper(I) complex catena‐poly­[[bis­[μ‐1‐(3‐pyridyl)­ethano­ne oxime‐κ²N:N′]­dicopper(I)]‐di‐μ‐iodo], [Cu₂I₂(C₇H₈N₂O)₂]_n, but here the centrosymmetric macrocycles are connected by double anion bridges, resulting in the formation of a one‐dimensional coordination polymer.     

Two nickel(II) bis[(pyridin‐2‐yl)methyl]amine complexes with homophthalic and benzene‐1,2,4,5‐tetracarboxylic acids

Two new Ni^II complexes involving the ancillary ligand bis[(pyridin‐2‐yl)methyl]amine (bpma) and two different carboxylate ligands, i.e. homophthalate [hph; systematic name: 2‐(2‐carboxylatophenyl)acetate] and benzene‐1,2,4,5‐tetracarboxylate (btc), namely catena‐poly[[aqua{bis[(pyridin‐2‐yl)methyl]amine‐κ³N,N′,N′′}nickel(II)]‐μ‐2‐(2‐carboxylatophenyl)aceteto‐κ²O:O′], [Ni(C₉H₆O₄)(C₁₂H₁₃N₃)(H₂O)]_n, and (μ‐benzene‐1,2,4,5‐tetracarboxylato‐κ⁴O¹,O²:O⁴,O⁵)bis(aqua{bis[(pyridin‐2‐yl)methyl]amine‐κ³N,N′,N′′}nickel(II)) bis(triaqua{bis[(pyridin‐2‐yl)methyl]amine‐κ³N,N′,N′′}nickel(II)) benzene‐1,2,4,5‐tetracarboxylate hexahydrate, [Ni₂(C₁₀H₂O₈)(C₁₂H₁₃N₃)₂(H₂O)₂]·[Ni(C₁₂H₁₃N₃)(H₂O)₃]₂(C₁₀H₂O₈)·6H₂O, (II), are presented. Compound (I) is a one‐dimensional polymer with hph acting as a bridging ligand and with the chains linked by weak C—H...O interactions. The structure of compound (II) is much more complex, with two independent Ni^II centres having different environments, one of them as part of centrosymmetric [Ni(bpma)(H₂O)]₂(btc) dinuclear complexes and the other in mononuclear [Ni(bpma)(H₂O)₃]²⁺ cations which (in a 2:1 ratio) provide charge balance for btc⁴⁻ anions. A profuse hydrogen‐bonding scheme, where both coordinated and crystal water molecules play a crucial role, provides the supramolecular linkage of the different groups.     

A novel PtII–dibenzo‐18‐crown‐6 (DB18C6) complex

The novel Pt^II–dibenzo‐18‐crown‐6 (DB18C6) title complex, μ‐[tetrakis­(thio­cyanato‐S)­platinum(II)]‐N:N′‐bis{[2,5,8,­15,18,21‐hexa­oxa­tri­cyclo­[20.4.0.1^9,14]­hexa­cosa‐1(22),9(14),10,12,23,25‐hexaene‐κ⁶O]­potassium(I)}, [K(C₂₀H₂₄O₆)]₂[Pt(SCN)₄], has been isolated and characterized by X‐ray diffraction analysis. The structure analysis shows that the complex displays a quasi‐one‐dimensional infinite chain of two [K(DB18C6)]⁺ complex cations and a [Pt(SCN)₄]^2? anion, bridged by K⁺?π interactions between adjacent [K(DB18C6)]⁺ units.     

First‐row transition metal–pyridine (py)–sulfate [(py)xM](SO4) complexes (M = Ni,Cu and Zn): crystal field theory in action

The crystal structures of three first‐row transition metal–pyridine–sulfate complexes, namely catena‐poly[[tetrakis(pyridine‐κN)nickel(II)]‐μ‐sulfato‐κ²O:O′], [Ni(SO₄)(C₅H₅N)₄]_n, (1), di‐μ‐sulfato‐κ⁴O:O‐bis[tris(pyridine‐κN)copper(II)], [Cu₂(SO₄)₂(C₅H₅N)₆], (2), and catena‐poly[[tetrakis(pyridine‐κN)zinc(II)]‐μ‐sulfato‐κ²O:O′‐[bis(pyridine‐κN)zinc(II)]‐μ‐sulfato‐κ²O:O′], [Zn₂(SO₄)₂(C₅H₅N)₆]_n, (3), are reported. Ni compound (1) displays a polymeric crystal structure, with infinite chains of Ni^II atoms adopting an octahedral N₄O₂ coordination environment that involves four pyridine ligands and two bridging sulfate ligands. Cu compound (2) features a dimeric molecular structure, with the Cu^II atoms possessing square‐pyramidal N₃O₂ coordination environments that contain three pyridine ligands and two bridging sulfate ligands. Zn compound (3) exhibits a polymeric crystal structure of infinite chains, with two alternating zinc coordination environments, i.e. octahedral N₄O₂ coordination involving four pyridine ligands and two bridging sulfate ligands, and tetrahedral N₂O₂ coordination containing two pyridine ligands and two bridging sulfate ligands. The observed coordination environments are consistent with those predicted by crystal field theory.     

A one‐dimensional lead(II) coordination polymer with terminal and bridging 5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylate ligands

In the coordination polymer catena‐poly[[[diaqua[5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ²N³,O⁴]lead(II)]‐μ‐5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ³N³,O⁴:N²] dihydrate], {[Pb(C₁₀H₆N₃O₄)(H₂O)₂]·2H₂O}_n, the two 5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylate ligands have different coordination modes, one being terminal and the other bridging. The bridging ligand links Pb^II cations into one‐dimensional coordination polymer chains. The structure is also stabilized by intra‐ and interchain π–π stacking interactions between the pyridine rings, resulting in the formation of a two‐dimensional network. Extensive hydrogen‐bonding interactions lead to the formation of a three‐dimensional supramolecular network.     

Variation of hydrogen‐bonded networks in hexa­fluoro­phosphate salts of amidate‐bridged dirhodium(II,III) complexes with axial aqua ligands

In diaqua­tetra‐μ‐acetamidato‐κ⁴N:O;κ⁴O:N‐di­rhodium(II,III) hexa­fluoro­phosphate, [Rh₂(C₂H₄NO)₄(H₂O)₂]PF₆, and diaqua­tetra‐μ‐acetamidato‐κ⁴N:O;κ⁴O:N‐di­rho­dium(II,III)hexa­fluoro­phosphate dihydrate, [Rh₂(C₂H₄NO)₄(H₂O)₂]PF₆·2H₂O, the cations and anions lie on inversion centers. Diaqua­tetra‐μ‐propionamidato‐κ⁴N:O;κ⁴O:N‐dirhodium(II,III) hexa­fluoro­phosphate dihydrate, [Rh₂(C₃H₆NO)₄(H₂O)₂]PF₆·2H₂O, and diaqua­tetra‐μ‐butyramidato‐κ⁴N:O;κ⁴O:N‐dirhodium(II,III) hexa­fluoro­phosphate, [Rh₂(C₄H₈NO)₄(H₂O)₂]PF₆, crystallize with two crystallographically independent complexes that lie on inversion centers. In all of the structures, the dirhodium units are hydrogen bonded to one another. The hydrogen‐bonded networks vary with the alkyl substituents.