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.     

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.     

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.     

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.     

An organic–inorganic hybrid compound containing imidazolium cations and a one‐dimensional lithium hexacyanidocobaltate‐based anionic framework

An organic–inorganic hybrid compound, catena‐poly[bis(3H‐imidazol‐1‐ium) [[tetracyanido‐κ⁴C‐cobalt(III)]‐μ‐cyanido‐κ²C:N‐[diaqualithium(I)]‐μ‐cyanido‐κ²N:C]], {(C₃H₅N₂)₂[CoLi(CN)₆(H₂O)₂]}_n, was synthesized by the reaction of Li₃[Co(CN)₆] with imidazolium chloride in aqueous solution. The compound crystallizes in the monoclinic space group C2/c (data collected at 273 K). In the crystal structure, neighbouring [Co(CN)₆]³⁻ anionic units are linked by Li⁺ cations through the cyanide groups in a trans mode, forming a one‐dimensional zigzag chain structure extending along the c axis. A three‐dimensional supramolecular network is formed through hydrogen‐bonding interactions and is further stabilized by weak CN...π interactions between the cyanide groups and the imidazolium cations.     

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 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.     

More crystal field theory in action: the metal–4‐picoline (pic)–sulfate [M(pic)x]SO4 complexes (M = Fe,Co, Ni,Cu, Zn,and Cd)

Seven crystal structures of five first‐row (Fe, Co, Ni, Cu, and Zn) and one second‐row (Cd) transition metal–4‐picoline (pic)–sulfate complexes of the form [M(pic)_x]SO₄ are reported. These complexes are catena‐poly[[tetrakis(4‐methylpyridine‐κN)metal(II)]‐μ‐sulfato‐κ²O:O′], [M(SO₄)(C₆H₇N)₄]_n, where the metal/M is iron, cobalt, nickel, and cadmium, di‐μ‐sulfato‐κ⁴O:O‐bis[tris(4‐methylpyridine‐κN)copper(II)], [Cu₂(SO₄)₂(C₆H₇N)₆], catena‐poly[[bis(4‐methylpyridine‐κN)zinc(II)]‐μ‐sulfato‐κ²O:O′], [Zn(SO₄)(C₆H₇N)₂]_n, and catena‐poly[[tris(4‐methylpyridine‐κN)zinc(II)]‐μ‐sulfato‐κ²O:O′], [Zn(SO₄)(C₆H₇N)₃]_n. The Fe, Co, Ni, and Cd compounds are isomorphous, displaying polymeric crystal structures with infinite chains of M^II ions adopting an octahedral N₄O₂ coordination environment that involves four picoline ligands and two bridging sulfate anions. The Cu compound features a dimeric crystal structure, with the Cu^II ions possessing square‐pyramidal N₃O₂ coordination environments that contain three picoline ligands and two bridging sulfate anions. Zinc crystallizes in two forms, one exhibiting a polymeric crystal structure with infinite chains of Zn^II ions adopting a tetrahedral N₂O₂ coordination containing two picoline ligands and two bridging sulfate anions, and the other exhibiting a polymeric crystal structure with infinite chains of Zn^II ions adopting a trigonal bipyramidal N₃O₂ coordination containing three picoline ligands and two bridging sulfate anions. The structures are compared with the analogous pyridine complexes, and the observed coordination environments are examined in relation to crystal field theory.     

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.     

A twofold interwoven two‐dimensional→two‐dimensional (2‐D→2‐D) cluster–organic network based on the [Cu2I2] cluster and the 4,4′‐(diazenediyl)dipyridine ligand: poly[[μ2‐4,4′‐(diazenediyl)dipyridine]‐μ2‐iodido‐copper(I)]

In the polymeric title compound, [CuI(C₁₀H₈N₄)]_n, the Cu^I atom is in a four‐coordinated tetrahedral geometry, formed by two I atoms and two pyridine N atoms from two different 4,4′‐(diazenediyl)dipyridine (4,4′‐azpy) ligands. Two μ₂‐I atoms link two Cu^I atoms to form a planar rhomboid [Cu₂I₂] cluster located on an inversion centre, where the distance between two Cu^I atoms is 2.7781 (15) Å and the Cu—I bond lengths are 2.6290 (13) and 2.7495 (15) Å. The bridging 4,4′‐azpy ligands connect the [Cu₂I₂] clusters into a two‐dimensional (2‐D) double‐layered grid‐like network [parallel to the (10) plane], with a (4,4)‐connected topology. Two 2‐D grid‐like networks interweave each other by long 4,4′‐azpy bridging ligands to form a dense 2‐D double‐layered network. To the best of our knowledge, this interwoven 2‐D→2‐D network is observed for the first time in [Cu₂I₂]–organic compounds.     

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.     

One‐dimensional CuII coordination polymers containing C2h‐symmetric 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate linkers

Two new one‐dimensional Cu^II coordination polymers (CPs) containing the C_2h‐symmetric terphenyl‐based dicarboxylate linker 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate (3,3′‐TPDC), namely catena‐poly[[bis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ⁴O,O′:O′′:O′′′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂]·H₂O}_n, (I), and catena‐poly[[aquabis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ²O³:O^3′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂(H₂O)]·H₂O}_n, (II), were both obtained from two different methods of preparation: one reaction was performed in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar. Both reactions afforded crystals of different colours, i.e. violet plates for (I) and blue needles for (II), both of which were analysed by X‐ray crystallography. The 3,3′‐TPDC bridging ligands coordinate the Cu^II ions in asymmetric chelating modes in (I) and in monodenate binding modes in (II), forming one‐dimensional chains in each case. Both coordination polymers contain two coordinated dimethylamine ligands in mutually trans positions, and there is an additional aqua ligand in (II). The solvent water molecules are involved in hydrogen bonds between the one‐dimensional coordination polymer chains, forming a two‐dimensional network in (I) and a three‐dimensional network in (II).     

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.     

Novel Copper(I) Clusters with 2‐(Diphenylphosphanyl)anilide Ligands. Synthesis and Crystal Structures of [Cu6X2(NHR)4] (X = Cl,Br, I; R = C6H4‐2‐PPh2)

Treatment of copper(I) halides CuX (X = Cl, Br, I) with lithium 2‐(diphenylphosphanyl)anilide [Li(HL)] in THF led to the formation of hexanuclear copper(I) complexes [Cu₆X₂(HL)₄] [X = Cl ( 1 ), Br ( 2 ), I ( 3 )]. In compounds 1 – 3 , the copper atoms are in a distorted octahedral arrangement and the amide ligands adopt a μ₃‐κP,κ²N bridging mode. Additionally there are two μ₂‐bridging halide ligands. Each of the [Cu₆X₂(HL)₄] clusters comprises two copper atoms, which are surrounded by two amide nitrogen atoms in an almost linear coordination [Cu–N: 186.2(3)–188.0(3) pm] and four copper atoms, which are connected to an amide N atom, a P atom, and a halogen atom in a distorted trigonal planar fashion [Cu–N: 199.6(3)–202.3(3) pm)].     

Syntheses and structures of discrete copper(II) and cadmium(II) supramolecular complexes based on 1,4‐diacylthiosemicarbazone ligands

Thiosemicarbazides and their metal complexes have attracted considerable interest because of their biological activities and their flexibility, which allows the ligands to bend and rotate freely to accommodate the coordination geometries of various metal centres. Discrete copper(II) and cadmium(II) complexes have been prepared by crystallization of N‐[2‐(2‐hydroxybenzoyl)hydrazinecarbonothioyl]propanamide (H₃L) with Cu(CH₃COO)₂ or Cd(NO₃)₂ in a dimethylformamide/methanol mixed‐solvent system at room temperature, affording the complexes di‐μ‐acetato‐bis{μ₄‐1‐[(2‐oxidophenyl)carbonyl]‐2‐(propanamidomethanethioyl)hydrazine‐1,2‐diido}tetracopper(II) dimethylformamide disolvate, [Cu₄(C₁₁H₁₀N₃O₃S)₂(C₂H₃O₂)₂]·2C₃H₇NO, (I), and bis{μ₂‐[(2‐hydroxyphenyl)formamido](propanamidomethanethioyl)azanido}bis[(4,4′‐bipyridine)nitratocadmium(II)] dihydrate, [Cd₂(C₁₁H₁₂N₃O₃S)₂(NO₃)₂(C₁₀H₈N₂)₂]·2H₂O, (II). Complex (I) consists of four Cu^II cations, two μ₄‐bridging trianionic ligands and two μ₂‐bridging acetate ligands, while complex (II) is composed of two Cd^II cations, two μ₂‐bridging monoanionic ligands, two nitrate ligands and two 4,4′‐bipyridine ligands. These discrete complexes are connected by hydrogen bonds and van der Waals interactions to form a three‐dimensional supramolecular architecture. Compared with (I), the phenolic hydroxy group and hydrazide N atom of the thiosemicarbazide ligand of (II) are not involved in coordination and lead to a binuclear Cd^II complex. This different coordination mode may be attributed to the larger ionic radius of the Cd^II ion compared with the Cu^II ion.     

A one‐dimensional platinum mixed‐valence complex with bridging thiocyanate S atoms: [[PtII(en)2](μ‐SCN)[PtIV(en)2](μ‐SCN)](ClO4)4 (en is ethane‐1,2‐diamine)

A new one‐dimensional platinum mixed‐valence complex with nonhalogen bridging ligands, namely catena‐poly[[[bis(ethane‐1,2‐diamine‐κ²N,N′)platinum(II)]‐μ‐thiocyanato‐κ²S:S‐[bis(ethane‐1,2‐diamine‐κ²N,N′)platinum(IV)]‐μ‐thiocyanato‐κ²S:S] tetrakis(perchlorate)], {[Pt₂(SCN)₂(C₂H₈N₂)₄](ClO₄)₄}_n, has been isolated. The Pt^II and Pt^IV atoms are located on centres of inversion and are stacked alternately, linked by the S atoms of the thiocyanate ligands, forming an infinite one‐dimensional chain. The Pt^IV—S and Pt^II...S distances are 2.3933 (10) and 3.4705 (10) Å, respectively, and the Pt^IV—S...Pt^II angle is 171.97 (4)°. The introduction of nonhalogen atoms as bridging ligands in this complex extends the chemical modifications possible for controlling the amplitude of the charge‐density wave (CDW) state in one‐dimensional mixed‐valence complexes. The structure of a discrete Pt^IV thiocyanate compound, bis(ethane‐1,2‐diamine‐κ²N,N′)bis(thiocyanato‐κS)platinum(IV) bis(perchlorate) 1.5‐hydrate, [Pt(SCN)₂(C₄H₈N₂)₂](ClO₄)₂·1.5H₂O, has monoclinic (C2) symmetry. Two S‐bound thiocyanate ligands are located in trans positions, with an S—Pt—S angle of 177.56 (3)°.     

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 dihydroxidotetracopper(II) framework supported by 4,4′‐(adamantane‐1,3‐diyl)bis(1,2,4‐triazole) and benzene‐1,3,5‐tricarboxylate bridges

The new bifunctional ligand 4,4′‐(adamantane‐1,3‐diyl)bis(1,2,4‐triazole) (tr₂ad) and benzene‐1,3,5‐tricarboxylate sustain complementary coordination bridging for the three‐dimensional framework of poly[[bis[μ₃‐4,4′‐(adamantane‐1,3‐diyl)bis(1,2,4‐triazole)‐κ³N¹:N²:N^1′]bis(μ₄‐benzene‐1,3,5‐tricarboxylato‐κ⁴O¹:O^1′:O³:O⁵)di‐μ₃‐hydroxido‐κ⁶O:O:O‐tetracopper(II)] dihydrate], {[Cu₄(C₉H₃O₆)₂(OH)₂(C₁₄H₁₈N₆)₂]·2H₂O}_n. The net node is a centrosymmetric (μ₃‐OH)₂Cu₄ cluster [Cu—O = 1.9525 (14)–2.0770 (15) Å and Cu...Cu = 3.0536 (5) Å] involving two independent copper ions in tetragonal pyramidal CuO₄N and trigonal bipyramidal CuO₃N₂ environments. One carboxylate group of the anion is bridging and the other two are monodentate, leading to the connection of three hydroxide clusters and the generation of neutral coordination layers separated by 9.3583 (5) Å. The interlayer linkage is effected by μ₃‐tr₂ad ligands, with one triazole group N¹:N²‐bridging and the second monodentate [Cu—N = 1.9893 (19), 2.010 (2) and 2.411 (2) Å]. In total, the hydroxide clusters are linked to six close neighbors within the carboxylate layer and to four neighbors via tr₂ad bridges. Hydrogen bonding of solvent water molecules to noncoordinated triazole N atoms and carboxylate groups provides two additional links for the net, which adopts a 12‐connected topology corresponding to hexagonal closest packing. The study also introduces a new type of bis(triazole) ligand, which may find wider applications for supramolecular synthesis.     

A cyanide‐bridged heterometallic coordination polymer constructed from square‐planar [Ni(CN)4]2−: synthesis,crystal structure,thermal decomposition,electron paramagnetic resonance (EPR) spectrum and magnetic properties

Square‐planar complexes are commonly formed by transition metal ions having a d⁸ electron configuration. Planar cyanometallate anions have been used extensively as design elements in supramolecular coordination systems. In particular, square‐planar tetracyanometallate(II) ions, i.e. [M(CN)₄]²⁻ (M^II = Ni, Pd or Pt), are used as good building blocks for bimetallic Hofmann‐type assemblies and their analogues. Square‐planar tetracyanonickellate(II) complexes have been extensively developed with N‐donor groups as additional co‐ligands, but studies of these systems using O‐donor ligands are scarce. A new cyanide‐bridged Cu^II–Ni^II heterometallic compound, poly[[diaquatetra‐μ₂‐cyanido‐κ⁸C:N‐nickel(II)copper(II)] monohydrate], {[Cu^IINi^II(CN)₄(H₂O)₂]·H₂O}_n, has been synthesized and characterized by X‐ray single‐crystal diffraction analyses, vibrational spectroscopy (FT–IR), thermal analysis, electron paramagnetic resonance (EPR) and magnetic moment measurements. The structural analysis revealed that it has a two‐dimensional grid‐like structure built up of cationic [Cu(H₂O)₂]²⁺ and anionic [Ni(CN)₄]²⁻ units connected through bridging cyanide ligands. The overall three‐dimensional supramolecular network is expanded by a combination of interlayer O—H…N and intralayer O—H…O hydrogen‐bond interactions. The first decomposition reactions take place at 335 K under a static air atmosphere, which illustrates the existence of guest water molecules in the interlayer spaces. The electron paramagnetic resonance (EPR) spectrum confirms that the Cu^II cation has an axial coordination symmetry and that the unpaired electrons occupy the d orbital. In addition, magnetic investigations showed that antiferromagnetic interactions exist in the Cu^II atoms through the diamagnetic [Ni(CN)₄]²⁻ ion.     

Two lanthanum(III) complexes containing η2‐pyrazolate and η2‐1,2,4‐triazolate ligands: intramolecular C—H...N/O interactions and coordination geometries

The lanthanum(III) complexes tris(3,5‐diphenylpyrazolato‐κ²N,N′)tris(tetrahydrofuran‐κO)lanthanum(III) tetrahydrofuran monosolvate, [La(C₁₅H₁₁N₂)₃(C₄H₈O)₃]·C₄H₈O, (I), and tris(3,5‐diphenyl‐1,2,4‐triazolato‐κ²N¹,N²)tris(tetrahydrofuran‐κO)lanthanum(III), [La(C₁₄H₁₀N₃)₃(C₄H₈O)₃], (II), both contain La^III atoms coordinated by three heterocyclic ligands and three tetrahydrofuran ligands, but their coordination geometries differ. Complex (I) has a mer‐distorted octahedral geometry, while complex (II) has a fac‐distorted configuration. The difference in the coordination geometries and the existence of asymmetric La—N bonding in the two complexes is associated with intramolecular C—H...N/O interactions between the ligands.