Syntheses and crystal structures of cyano-bridged cluster-metal layered coordination polymers [Cu(dien)]3[W4Te4(CN)12] · 9H2O and [Ni(en)(NH3)]3[W4Se4(CN)12] · 7.5H2O

Two new tetrahedral tungsten cyanide cluster compounds, [Cu(dien)]₃[W₄Te₄(CN)₁₂] · 9H₂O (1) (dien=diethylenetriamine) and [Ni(en)(NH₃)]₃[W₄Se₄(CN)₁₂] · 7.5H₂O (2) (en=ethylenediamine), were synthesized by treating aqueous solutions of the saltlike cluster compound K₆[W₄Te₄(CN)₁₂] · 5H₂O/K₆[W₄Se₄(CN)₁₂] · 6H₂O with copper(II)/nickel(II) chloride in aqueous ammonia containing dien/en. The cyano-bridged layered coordination polymeric compounds were characterized by single-crystal X-ray diffraction analysis: monoclinic, space group P2₁ for 1; trigonal, space group for 2. Structures of 1 and 2 consist of infinite neutral layers of cluster components {W₄Te₄(CN)₁₂}/{W₄Se₄(CN)₁₂} connected, one another by {Cu(dien)} or {Ni(en)(NH₃)} fragments, respectively.     

A new self-assembled inorganic-organic hybrid layered compound containing hexarhenium cluster: [MV][{Mn(CH3OH)2}{Re6Se8(CN)6}]

A new layered compound, [MV][{Mn(CH₃OH)₂}{Re₆Se₈(CN)₆}] (1) consists of a layer alternately knitted by hexarhenium cluster and Mn complex, and MV²⁺ cations (methyl viologen dication = 1,1′-dimethyl-4,4′-bipyridilium dication) reside between the layers. The title compound 1 is the first layered framework containing cyano-hexarhenium clusters with photoactive guest molecules, MV²⁺. The MV²⁺ can be partly exchanged by H₂TMB²⁺ (N,N,N′,N′-tetramethylbenzidine dication) to form a compound [H₂TMB²⁺]_x[MV²⁺]_1−x [{Mn(CH₃OH)₂}{Re₆Se₈(CN)₆}] (2) showing an electronic interaction between the layered framework and [H₂TMB]²⁺ cation.     

Octahedral cyanohydroxo cluster complex trans-[Re6Se8(CN)4(OH)2]: Synthesis, crystal structure, and properties

A hexarhenium cyanohydroxo anionic cluster complex [Re₆Se₈(CN)₄(OH)₂]⁴⁻ was synthesized for the first time starting from [Re₆Se₈(OH)₆]⁴⁻, which was crystallized as a salt of the composition Cs_2.75K_1.25[Re₆Se₈(CN)₄(OH)₂]·H₂O (1). The reaction of the complex with Cu²⁺ in an aqueous ammonia or methylamine solutions afforded [Cu(NH₃)₅]₂[Re₆Se₈(CN)₄(OH)₂]·8H₂O (2) or [{Cu(CH₃NH₂)₄}₂Re₆Se₈(CN)₄(OH)₂] (3), respectively. All of these three compounds were characterized by a single-crystal X-ray diffraction method. Compound 1 is crystallized in the tetragonal space group I4/m with eight formula units per cell (a = b = 17.4823(14) Å, c = 19.430(2) Å, V = 5938.3(10) Å³); compound 2 is crystallized in the monoclinic space group P2₁/n with two formula units per cell (a = 12.1845(13) Å, b = 8.6554(9) Å, c = 19.2568(19) Å, β = 91.081(2)°, V = 2030.5(4) Å³); compound 3 is crystallized in the orthorhombic space group Cmcm with four formula units per cell (a = 19.816(4) Å, b = 14.611(3) Å, c = 13.751(3) Å, V = 3981.2(13) Å³). The luminescence properties of 1 were studied in both aqueous solution and solid state. In addition, the electronic structure of [Re₆Se₈(CN)₄(OH)₂]⁴⁻ was elucidated by DFT calculations.     

Synthesis and characterisation of pyrazolic palladium compounds containing alcohol functionality:: rotation around the Pd-N bond

The ligands 1-hydroxymethylpyrazole (hl¹), 1-(2-hydroxyethyl)pyrazole (hl²) and 1-(3-hydroxypropyl)pyrazole (hl³) react with [PdCl₂(CH₃CN)₂] to give trans-[PdCl₂(hl)₂] compounds. Due to a hindered rotation around the Pd-bond, these compounds present two different conformations in solution: anti and syn. The conformation presented depends on the relative disposition of the hydroxyalkylic chains of the two pyrazolic ligands. The present study was carried out on the basis of NMR experiments. The present paper reports the crystal structure of trans-[PdCl₂(hl²)₂]. The synthesis and characterisation of compounds [Pd(hl)₄](BF₄)₂ (hl = hl¹, hl² and hl³) starting from [Pd(CH₃CN)₄](BF₄)₂ and the corresponding chlorocomplexes trans-[PdCl₂(hl)₂] are also described.     

Octahedral rhenium cluster complexes with organic ligands: Synthesis, structure and properties of [Re6Q8(3,5-Me2PzH)6]Br2 · 2(3,5-Me2PzH) (Q = S, Se)

Two new octahedral cluster complexes - [Re₆S₈(3,5-Me₂PzH)₆]Br₂ · 2(3,5-Me₂PzH) (1) and [Re₆Se₈(3,5-Me₂PzH)₆]Br₂ · 2(3,5-Me₂PzH) (2), where 3,5-Me₂PzH is 3,5-dimethylpyrazole, have been synthesized using reaction of rhenium chalcobromide complexes Cs₄[Re₆S₈Br₆] · 2H₂O and Cs₃[Re₆Se₈Br₆] · H₂O, respectively, with molten 3,5-dimethylpyrazole. Both compounds synthesized were characterized by X-ray single-crystal diffraction and chemical analysis, IR and luminescent spectra.     

Hydrothermal synthesis of copper complexes of 4′-pyridyl terpyridine: From discrete monomer to zigzag chain polymer

Seven copper complexes [Cu(L1)I₂] (1), [Cu₂(L1)₂I₂]₂[Cu₂(μ-I)₂I₂] (2), [Cu(L2)I₂] (3), [Cu₂(L2)(μ-I)I(PPh₃)] (4), [Cu₄(L2)₂(μ-I)₂I₂] (5), {[Cu(L2)I]₂[Cu₂(μ-I)₂I₂]}_n (6) and [Cu₂(L2)(μ-I)₂]_n (7) have been prepared by reactions of ligands: 4′-(2-pyridyl)-2,2′:6′,2″-terpyridine (L1) and 4′-(3-pyridyl)-2,2′:6′,2″-terpyridine (L2) with CuI in hydrothermal conditions, respectively. By alternating the oxidations states of the metal centers, increasing stoichiometric metal/ligand ratio and introducing a second ligand, the compounds, were successfully developed from mononuclear (1 and 3) to multinuclear (2, 4 and 5) and polymers (6 and 7). The synthesis of these compounds may provide an approach for the construction of coordination compounds of 4′-pyridyl terpyridine with different nuclearity.     

Selective inclusion of DMF molecules within non-covalent cavity

[Me₄P]₄[Cu₄(mnt)₄]·2CH₃CN (1), [Me₄P]₄[Cu₄(mnt)₄]·2CH₃NO₂ (2), [Me₄P]₄[Cu₄(mnt)₄]·2DMF (3) and [Me₄P]₄[Cu₄(mnt)₄]·2C₃H₃N (4) (mnt = maleonitriledithiolate, [S₂C₂(CN)₂]²⁻) clusters are readily synthesized in several solvents like acetonitrile, nitromethane, N,N-dimethylformamide and acrylonitrile to provide respective solvent as guest within the non-covalent cavity of the cluster ion. The guest species is accommodated within non-covalent cavity that is generated by two adjacent {Cu₄(mnt)₄} cores bridging with tetramethylphosphonium cation through hydrogen bonding. These hydrogen bonds are not strong and when mixed solvents were used selective DMF binding takes place to yield only complex 3 over other complexes.     

The azidopentacyanoferrate(III) ion as a tecton in constructing heterometallic complexes: Synthesis, crystal structure and magnetic properties of [Mn(valphen)(H2O)2]2[(H2O)(valphen)Mn(μ-CN)Fe(CN)4(N3)]·8H2O

By employing the common precursor Na₃[Fe(CN)₅(NH₃)]·3H₂O in a new synthetic approach, the azidopentacyanoferrate(III) ion has been isolated and structurally characterized as (Ph₄As)₂[Na(H₂O)₄][Fe(CN)₅(N₃)] 1. In order to confirm its building block ability, compound 1 has been reacted with the mononuclear complex [Mn(valphen)(H₂O)₂]ClO₄ (H₂valphen represents the Schiff base resulting from the condensation of o-vanillin with 1,2-phenylenediamine in a 2:1 M ratio) to afford the new Mn^III-Fe^III heterometallic system [Mn(valphen)(H₂O)₂]₂[(H₂O)(valphen)Mn(μ-CN)Fe(CN)₄(N₃)]·8H₂O 2. The crystal structure of compound 2 reveals a supramolecular assembly generated by [(H₂O)(valphen)Mn(μ-CN)Fe(CN)₄(N₃)]²⁻ dianions and discrete [Mn(valphen)(H₂O)₂]⁺ counterions. The dynamic magnetic measurements of compound 2 point to a slow relaxation of the magnetization.     

Mixed chloride-phosphine complexes of the dirhenium core. Part 11. Reactions of [Re2Cl8] with secondary phosphines, PCy2H and PPh2H

The reaction between the dirhenium(III,III) anion, [Re₂Cl₈]²⁻, and the secondary phosphine, PCy₂H, yields a mixture of products as a result of disproportionation, namely, a dirhenium(II,III) chloride-phosphine complex 1,3,6-Re₂Cl₅(PCy₂H)₃ (1) and a dirhenium(IV) face-sharing bioctahedral compound with bridging phosphido groups, [Buⁿ ₄N][Re₂(μ-PCy₂)₃Cl₆] (2). The diphenylphosphine analogue of 2, [Buⁿ ₄N][Re₂(μ-PPh₂)₃Cl₆] (3) has been similarly prepared from the reaction of [Re₂Cl₈]²⁻ with PPh₂H. An interesting dirhenium(III,III) complex, [Buⁿ ₄N]₂[Re₂(μ-PPh₂)₂(PPh₂H)₂Cl₆] (4) having both neutral terminal phosphines and anionic phosphido bridges, has also been isolated as an intermediate in the latter system. Crystal structures of 1-4 have been determined by X-ray crystallography. The compounds were also characterized by cyclic voltammetry, IR and ³¹P NMR spectroscopy.     

Reactivity of phenyldi(2-thienyl)phosphine towards group 7 metal carbonyls: Carbon-phosphorus bond activation

Addition of phenyldi(2-thienyl)phosphine (PPhTh₂) to [Re₂(CO)_10−n(NCMe)_n] (n = 1, 2) affords the substitution products [Re₂(CO)_10−n(PhPTh₂)_n] (1, 2) together with small amounts of fac-[ClRe(CO)₃(PPhTh₂)₂] (3) (n = 2). Reaction of [Re₂(CO)₁₀] with PPhTh₂ in refluxing xylene affords a mixture which includes 2, [Re₂(CO)₇(PPhTh₂)(μ-PPhTh)(μ-H)] (4), [Re₂(CO)₇(PPhTh₂)(μ-PPhTh)(μ-η¹,κ¹(S)-C₄H₃S)] (5) and mer-[HRe(CO)₃(PPhTh₂)₂] (6). Phosphido-bridged 4 and 5 are formed by the carbon-phosphorus bond cleavage of the coordinated PPhTh₂ ligand, the cleaved thienyl group being retained in the latter. Reaction of [Mn₂(CO)₁₀] with PPhTh₂ in refluxing toluene affords [Mn₂(CO)₉(PPhTh₂)] (7) and the carbon-phosphorus bond cleavage products [Mn₂(CO)₆(μ-PPhTh)(μ-η¹,η⁵-C₄H₃S)] (8) and [Mn₂(CO)₅(PPhTh₂)(μ-PPhTh)(μ-η¹,η⁵-C₄H₃S)] (9). Both 8 and 9 contain a bridging thienyl ligand which is bonded to one manganese atom in a η⁵-fashion.     

Formation and structural chemistry of the unusual cyanide-bridged dinuclear species [Ru2(NN)2(CN)7] (NN = 2,2′-bipyridine or 1,10-phenanthroline)

Crystallisation of simple cyanoruthenate complex anions [Ru(NN)(CN)₄]²⁻ (NN = 2,2′-bipyridine or 1,10-phenanthroline) in the presence of Lewis-acidic cations such as Ln(III) or guanidinium cations results, in addition to the expected [Ru(NN)(CN)₄]²⁻ salts, in the formation of small amounts of salts of the dinuclear species [Ru₂(NN)₂(CN)₇]³⁻. These cyanide-bridged anions have arisen from the combination of two monomer units [Ru(NN)(CN)₄]²⁻ following the loss of one cyanide, presumably as HCN. The crystal structures of [Nd(H₂O)_5.5][Ru₂(bipy)₂(CN)₇] · 11H₂O and [Pr(H₂O)₆][Ru₂(phen)₂(CN)₇] · 9H₂O show that the cyanoruthenate anions form Ru-CN-Ln bridges to the Ln(III) cations, resulting in infinite coordination polymers consisting of fused Ru₂Ln₂(μ-CN)₄ squares and Ru₄Ln₂(μ-CN)₆ hexagons, which alternate to form a one-dimensional chain. In [CH₆N₃]₃[Ru₂(bipy)₂(CN)₇] · 2H₂O in contrast the discrete complex anions are involved in an extensive network of hydrogen-bonding involving terminal cyanide ligands, water molecules, and guanidinium cations. In the [Ru₂(NN)₂(CN)₇]³⁻ anions themselves the two NN ligands are approximately eclipsed, lying on the same side of the central Ru-CN-Ru axis, such that their peripheries are in close contact. Consequently, when NN = 4,4′-^tBu₂-2,2′-bipyridine the steric bulk of the t-butyl groups prevents the formation of the dinuclear anions, and the only product is the simple salt of the monomer, [CH₆N₃]₂[Ru(^tBu₂bipy)(CN)₄] · 2H₂O. We demonstrated by electrospray mass spectrometry that the dinuclear by-product [Ru₂(phen)₂(CN)₇]³⁻ could be formed in significant amounts during the synthesis of monomeric [Ru(phen)(CN)₄]²⁻ if the reaction time was too long or the medium too acidic. In the solid state the luminescence properties of [Ru₂(bipy)₂(CN)₇]³⁻ (as its guanidinium salt) are comparable to those of monomeric [Ru(bipy)(CN)₄]²⁻, with a ³MLCT emission at 581 nm.     

Synthesis and structures of lithium salts of two cluster iodoarsenate(III)s and a periodohexaantimonate(III)

Treatment of the lithium β-diketiminate Li[{N(C₆H₃-2,6)C(Me)}₂CH] with an equivalent portion of arsenic(III) iodide unexpectedly afforded [Li(thf)₄]₂[As₈I₂₆] (1) in modest yield. Another new cluster anion featured in [Li(thf)₄]₂[Li(thf)₆][As₇I₂₄]·1.5(thf) (2) was obtained in excellent yield from lithium iodide and four equivalents of AsI₃ in thf. Using the same stoichiometry and solvent, but with SbI₃ in place of AsI₃, furnished in good yield [Li(thf)₄]₄[Sb₆I₂₂]·2(thf) (3). The structures of the new crystalline orange (1, 3) or orange/red (2) salts was established by single crystal X-ray diffraction. Each anion of 1-3 may be factorised into respectively [(AsI₂)₆(AsI)₂(μ₂-I)₁₀(μ₅-I)₂]²⁻ (1), [{(AsI₂)(μ₂-I)(μ₃-I)}₆As]³⁻ (2) and [(SbI₃)₂(SbI₂)₂(SbI)₂(μ₂-I)₆(μ₃-I)₄]⁴⁻ (3). Each As atom in 2 and each Sb atom in 3 is the centre of a six-coordinate distorted octahedron, while the arsenic atoms in 1 have either four- or six-coordinate environments.     

Self-assembly of four three-dimensional reduced molybdenum(V) phosphates decorated with transitional metal complexes

Four new three-dimensional materials built from reduced molybdenum(V) phosphates as building blocks and transitional metal (Co, Zn and Cd) complexes as linkers, (Hbpy)₂[Co(bpy)(H₂O)]₂[Co(H₂PO₄)₂ (HPO₄)₆(MoO₂)₁₂(OH)₆] (1), [Co(H₂O)₄]₂[Co(Hbpy)(H₂O)]₂[Co(bpy)][Co(HPO₄)₄(PO₄)₄(MoO₂)₁₂(OH)₆] · 6H₂O (2), Na₂[Zn(Hbpy)(H₂O)₂]₂[Zn(Hbpy)]₂[Zn(HPO₄)₂(PO₄)₆(MoO₂)₁₂(OH)₆] · 4H₂O (3), (H₂bpy)₂[Cd(bpy)(H₂O)]₂[Cd(bpy)(H₂O)₂]₂[Cd(HPO₄)₄(PO₄)₄(MoO₂)₁₂(OH)₆] · 2H₂O (4) (bpy = 4,4′-bipyridine), have been synthesized and characterized by elemental analyses, IR, TG, and single crystal X-ray diffraction. The 3-D framework of 1 is constructed from Co[P₄Mo₆]₂ dimers bonded together with [Co(bpy)]_n coordination polymer chains. In compound 2, the Co[P₄Mo₆]₂ dimers are linked by both [Co(bpy)] complex chains and the cobalt dimers to form a 3-D framework. Compounds 1 and 2 represent the first examples of reduced molybdenum(V) phosphates decorated with transition metal complexes chains. The 3-D framework of 3 is constructed from Zn[P₄Mo₆]₂ dimers bonded together with [Zn(bpy)] coordination complexes and [Zn(bpy)(H₂O)₂] complexes. In compound 4, the Cd[P₄Mo₆]₂ dimers are coordinated with [Cd(bpy)(H₂O)] and [Cd(bpy)(H₂O)₂] complexes to construct a 3-D structure. To our best knowledge, it is the first time that linear ligand 4,4′-bpy molecules have been grafted into the backbone of reduced molybdenum phosphates. Furthermore, the magnetic properties of compounds 1 and 2 are reported.     

Synthesis and structural characterization of several dirhenium(III) compounds

Reaction between Re₂(OAc)₄Cl₂ and N,N′-dicyclohexylbenzamidine (HDCyBA) under molten conditions yielded Re₂(DCyBA)₂Cl₄ (1); reaction of [Bu₄N]₂[Re₂Cl₈] with N,N′-di(3-methoxyphenyl)formamidine (HDmAniF) resulted in Re₂(DmAniF)₂Cl₄ (2); reaction of cis-Re₂(OAc)₂Cl₄ with HDmAniF under reflux conditions resulted in cis-Re₂(OAc)₂(DmAniF)₂Cl₂ (3). Reaction between Re₂(OAc)₄Cl₂ and α,α,α′,α′-tetramethyl-1,3-benzenedipropionic acid (H₂esp) under reflux conditions led to Re₂(esp)₂Cl₂ (4). Crystallographic studies of compounds 1-4 revealed Re-Re bond lengths of 2.1679(6), 2.1804(5), 2.2468(7), and 2.2304(6) Å, respectively, which are consistent with the presence of Re-Re quadruple bond. Also reported are electrochemical properties of compounds 1-4.     

Three Co(III)-Fe(II) complexes based on hexacyanoferrates: Syntheses, spectroscopic and structural characterizations

Red or orange crystals of [Co(NH₃)₆]₂Cl₂[Fe(CN)₆] · 4H₂O (1), [Co(en)₃]₂Cl₂[Fe(CN)₆] · 2H₂O (2) and [Co(en)₃]₄[Fe(CN)₆]₃ · 21.6H₂O (3) were isolated from the aqueous systems Co³⁺-L_N-[Fe(CN)₆]⁴⁻ (L_N = NH₃, en = 1,2-diaminoethane). In all isolated samples the combination of Mössbauer (δ values were from the range −0.07 to −0.08 mm/s) and IR spectra (ν(CN) stretching vibrations in the range 2015-2047 cm⁻¹) confirms the presence of low spin Fe(II) in [Fe(CN)₆]⁴⁻ anions. X-ray structure analyses corroborate the ionic character of all studied compounds. These contain diamagnetic [Co(NH₃)₆]³⁺ (1) or [Co(en)₃]³⁺ (2 and 3) complex cations and diamagnetic [Fe(CN)₆]⁴⁻ complex anions. In compounds 1 and 2 chloride anions are present, too. All three compounds contain water of crystallization, in compound 3 as many as 21.6 molecules per formula unit.     

Mixed-ligand compounds incorporating quadruply bonded dimolybdenum(II) core: Syntheses, structures and reactivity studies

Reaction of cis-[Mo₂(OAc)₂(CH₃CN)₆][BF₄]₂ with NP-Et,Me (2-ethyl-3-methyl-1,8-naphthyridine) in acetonitrile provides trans-[Mo₂(NP-Et,Me)₂(OAc)₂(CH₃CN)][BF₄]₂ (1). Partial protonation of 1 by HBF₄·Et₂O in acetonitrile leads to trans-[Mo₂(NP-Et,Me)₂(OAc)(CH₃CN)₃][BF₄]₃ (2). In both compounds, NP-R ligands are arranged in a head-to-head (HH) fashion leaving one of the axial sites vacant. Substitution of acetonitriles by NP-Me (3-methyl-1,8-naphthyridine) in trans-[Mo₂(NP-tz)₂(OAc)(CH₃CN)₂][BF₄]₃ provides trans-[Mo₂(NP-tz)₂(OAc)(NP-Me)][BF₄]₃ (3) with retention of configuration. Fully solvated dimolybdenum(II) compound reacts with NP-NH₂ to provide [Mo₂(NP-NH₂)₂(NP-NH)(CH₃CN)₂][BF₄]₃ (4) in which the NP-NH₂ ligands are trans and arranged in a HH fashion. The deprotonated ligand (NP-NH⁻) binds the dimetal unit utilizing naphthyridine nitrogen and amido nitrogen. Treatment of [Mo₂(NP-tz)₂(CH₃CN)₄][CF₃SO₃]₄ with bpym (2,2′-bipyrimidine) followed by crystallization in air provided an oxo complex [Mo₂(NP-tz)₂(μ₂-O)₂(bpym)₂][CF₃SO₃]₄ (5). Compounds 1-5 have been characterized by a variety of spectroscopic techniques and by X-ray crystallography. The reactivity pattern is rationalized based on ligand labilities and thermodynamic stabilities.     

Synthesis, magnetic properties and crystal structures of two compounds: [Cu(en)(H2O)]2[Fe(CN)6]·4H2O and [Cu(en)2][KFe(CN)6] (en=ethylenediamine)

Two new heterometallic complexes, [Cu(en)(H₂O)]₂[Fe(CN)₆]·4H₂O (1) and [Cu(en)₂][KFe(CN)₆] (2), have been isolated from the reactions of CuCl₂ and en with K₃[Fe(CN)₆] in different molar ratios. Both complexes have been characterized by X-ray analyses, IR spectra and elemental analyses. Complex 1 is a cyanide bridged bimetallic assembly, its crystal structure consists of a two-dimensional polymeric sheet with two different rings, one a four-membered square ring and another a 12-membered hexagonal ring. The Fe(II) ion of 1 has two terminal, two linear bridging and two 1,1 en-on bridging cyanide groups. In the crystal structure of 2, the neighboring [Fe(CN)₆]³⁻ units are bridged by the K⁺ and the [K[Fe(CN)₆]]²⁻ units forming a three-dimensional network structure. The [Cu(en)₂]²⁺ units fill in the holes of the network acting as counter cations and charge compensations. Variable temperature magnetic susceptibility studies of 1 indicate that the complex exhibits ferromagnetic interaction between the Cu(II) ions.     

Two three-dimensional cyano-bridged bimetallic cadmium(II) and copper(II)-copper(I) mixed-valence polymer compounds: Crystal structures and thermal stability analysis and magnetic properties

Two cyano-bridged cadmium(II) and copper(II)-copper(I) mixed-valence polymer compounds 1 and [Cu^II(en)₂]_0.5[CdCu^I(CN)₃] · Cl · H₂O 2 (en = 1,2-ethanediamine) through systematically varying the solution environment have been synthesized and structurally characterized by single crystal X-ray diffraction analysis. The cyano anions connected the copper and cadmium centres with bidentate or tridentate bridging modes resulting in two complicated 3D networks for 1 and 2. Compound 1 has a rare 5,6-connected network, while compound 2 can be reduced to a 6-connected α-Po net. The magnetic and thermal properties of 1 and 2 are also studied.     

Cyano-bridged cluster-metal coordination compound: synthesis and crystal structure of [Cu(NH3)3][Cu(NH3)4][Cu(NH3)5][W4Te4(CN)12]·5H2O

Dark-brown single crystals of the title compound 1 were obtained in high yield by layering a CuCl₂ solution in 25% aqueous ammonia on a glycerol solution of K₆[W₄Te₄(CN)₁₂]·5H₂O. The complex 1 was characterized by single crystal X-ray diffraction analysis and IR spectroscopy. The X-ray structure of 1 reveals a polymeric chain cyano-bridged cluster-metal coordination compound. The [W₄Te₄(CN)₁₂]⁶⁻ cluster anions are linked one to another by Cu²⁺ cations through coordination by nitrogen atoms of the CN groups.     

New pyridine-monoacylhydrazidate-coordinated transition-metal complexes

By applying the hydrothermal in situ acylation reactions between alkyl-substituted pyridine-2,3-dicarboxylic acids and hydrazine hydrate, six pyridine-monoacylhydrazidate-coordinated transition-metal complexes [Mn(MPDH)₂] 1, [M(MPDH)₂(H₂O)₂]·2H₂O (M²⁺ = Co²⁺2, Zn²⁺3), [Mn(EPDH)₂(H₂O)₂] 4 and [M(EPDH)₂(H₂O)₂] (M²⁺ = Zn²⁺5, Co²⁺6) (MPDH = 6-methylpyridine-2,3-dicarboxylhydrazidate; EPDH = 5-ethylpyridine-2,3-dicarboxylhydrazidate) were obtained. Although only compound 1 is a 1-D chained coordination polymer and the others are the mononuclear molecular entities, they all further self-assemble into the interesting supramolecular networks via hydrogen-bonded interactions between pyridine-monoacylhydrazidate ligands. Two Zn²⁺ compounds 3 and 5 possess the fluorescence properties with maximum emissions at 517 nm for 3 and 530 nm for 5 upon excitation, respectively. The magnetic analysis for compound 1 indicates there exists the antiferromagnetic interactions between the Mn(II) ions.