A cubane-like [Ni4O4] cluster and a chloro-bridged dinuclear copper complex incorporating a hydroxyl-rich ligand: syntheses and crystal structures

A tetranuclear cubane-like cluster [Ni₄(HL)₄(DMSO)₂]?·?2DMSO?·?H₂O (1) and a dinuclear compound [Cu₂Cl₂(H₂L)₂]?·?1.5MeOH (2) (H₃L?=?3-(2-hydroxy-benzylideneamino)propane-1,2-diol) have been prepared and characterized by X-ray single crystal diffraction, IR, and elemental analysis. The X-ray diffraction analysis indicated that the four metals of 1 showed a Ni₄O₄ cubane arrangement, and two of the six faces of the Ni₄O₄ cubane were capped by DMSO. Complex 1 is the first reported DMSO capped Ni₄O₄ cubane cluster. Complex 2 contains a u ₂-Cl bridged dinuclear core with each Cu^II ion exhibiting pseudo square pyramidal geometry.     

Synthesis and structural characterization of mono- and dinuclear NiII and PdII complexes derived from tetradentate 1,7-bis-(pyridin-2-yl)-2,6-diaza-1,6-heptadiene

The reaction of Schiff base 1,7-bis-(pyridin-2-yl)-2,6-diaza-1,6-heptadiene (L) with either NiCl₂·6H₂O or [Pd^IICl₂(CH₃CN)₂]/Na[BF₄] in 1?:?1 stoichiometry yielded mononuclear ionic complexes, trans-[Ni^II(L)(H₂O)₂]Cl₂·3H₂O (1·3H₂O) and [Pd^II(L)][BF₄]₂ (2), respectively; the reaction of L with [Pd^IICl₂(CH₃CN)₂] in 1?:?2 ratio yielded dinuclear cis-[Pd^II ₂(μ-L)Cl₄] (3). Complexes 1–3 were characterized by vibrational spectroscopy and X-ray diffraction; diamagnetic 2 and 3 were also characterized by NMR in solution. The molecular structures of 1 and 2 displayed tetradentate coordination of L with formation of two five-membered and one six-membered chelate rings for both complexes. In 3, L showed bidentate coordination mode for each pyridylimine toward Pd^II. Complex 1 has distorted octahedral geometry around Ni^II and an extended hydrogen-bond network; distorted square planar geometry around Pd^II in 2 and 3 was observed.     

Structural Tailoring Effects on the Magnetic Behavior of Symmetric and Asymmetric Cubane‐Type Ni complexes

Using two kinds of carboxylate ligands with small but significant differences in steric size, symmetric and asymmetric Fe^II and Ni^II cubanes have been synthesized in a controlled fashion. Fast sweeping pulsed field measurements showed magnetization hysteresis loops for two cubane‐type molecular complexes, [Ni₄(μ‐OMe)₄(O₂CAr^4F‐Ph)₄(HOMe)₈] and [Ni₄(μ‐OMe)₄(O₂CAr^Tol)₄(HOMe)₆], thus suggesting single‐molecule magnet behavior. To differentiate the magnetic properties between the symmetric and asymmetric cubanes, detailed electron paramagnetic resonance (EPR) measurements were performed. From the EPR data, taken at various frequencies and temperatures, zero‐field splitting parameters D, E, and other higher‐order parameters for both cubane samples were extracted. Compared to the symmetric Ni‐cubane, the asymmetric one shows an increase in the D and E values by about 20 %, thereby suggesting structural engineering effects on the magnetic properties. By using the magnetic parameters determined by EPR, a static magnetization curve at 2 K and a temperature dependence of the magnetic susceptibility were simulated. A good agreement between theoretical and experimental data confirms the validity of the values obtained from EPR measurements.     

Bridging chlorides and hydroxides: syntheses and crystal structures of binuclear and tetranuclear NiII complexes derived from a reduced Schiff-base ligand 2-(2-pyridylmethylamino)ethanesulfonic acid

Two complexes, [Ni(pmt)(Cl)] (1) and [Ni₄(pmt)₄(OH)₄]·8H₂O (2) [Hpmt = 2-(2-pyridylmethylamino)ethanesulfonic acid], were synthesized by different experimental methods in methanol-water mixed solution. Compound 1 crystallizes in triclinic, space group P?1 with unit cell parameters: a = 8.315(2) Å, b = 8.383(2) Å, c = 9.128(2) Å, α = 103.654(2)°, β = 98.125(2)°, γ = 113.154(2)°, V = 548.6(2) ų, Z = 2. A pair of chlorides is μ ₂-bridges linking two Ni^II atoms in forming binuclear complex 1. The coordination environment at Ni^II is distorted square-pyramidal geometry. Compound (2) belongs to monoclinic, space group C2/c, with a = 16.5168(15) Å, b = 18.3718(17) Å, c = 17.5473(16) Å, α = γ = 90°, β = 93.3820(10)°, V = 5315.3(8) ų, Z = 4. Four hydroxides are μ ₃-bridges joining four Ni^II atoms to generate a cubic framework as a tetranuclear complex. The configuration at each Ni^II is distorted octahedral. Both π–π stacking of pyridine rings and intermolecular hydrogen bonds stabilize the solid state structures for 1 and 2.     

Ten complexes constructed by two reduced Schiff base tetraazamacrocycle ligands: syntheses,structures, magnetic and luminescent properties

Ten new complexes, [Cu₂(L¹)(NO₃)₂]·2H₂O (1), [Cu₄(L¹)₂]·4ClO₄·H₂O (2), [Cu₂(L¹)(H₂O)₂]·(adipate) (3), [Cu₆(L¹)₂(m-bdc)₄]·2DMF·5H₂O (4), [Cu₂(L¹)(Hbtc)]·5H₂O (5), [Cu₂(L¹)(H₂O)₂]·(ntc)·3H₂O (6), [Co₂(L²)]·[Co(MeOH)₄(H₂O)₂] (7), [Co₃(L²)(EtOH)(H₂O)] (8), [Ni₆(L²)₂(H₂O)₄]·H₂O (9) and [Zn₄(L²)(OAc)₂]·0.5H₂O (10), have been synthesized. 1 displays a [Cu₂(L¹)(NO₃)₂] monomolecular structure. 2 shows a supramolecular chain including [Cu₂L¹]²⁺. In 3, two Cu(II) ions are connected by L¹ to form a [Cu₂(L¹)(H₂O)₂]²⁺ cation. In 4, the m-bdc anions bridge Cu(II) ions and L¹ anions to form a layer. Both 5 and 6 display 3-D supramolecular structures. 7 consists of both [Co₂L²]^2? and [Co(MeOH)₄(H₂O)₂]²⁺ units. 8 and 9 show infinite chain structures. In 10, Zn(II) dimers are linked by L² to generate a 3-D framework. The magnetic properties for 4 and 8 and the luminescent property for 10 have been studied.     

2‐Amino‐5‐(2‐pyridyl)‐thiadiazole as Bidentate Ligand

The amino substituted bidentate chelating ligand 2‐amino‐5‐(2‐pyridyl)‐1,3,4‐thiadiazole (H₂ L ) was used to prepare 3:1‐type coordination compounds of iron(II), cobalt(II) and nickel(II). In the iron(II) perchlorate complex [Fe^II(H₂ L )₃](ClO₄)₂·0.6MeOH·0.9H₂O a 1:1 mixture of mer and fac isomers is present whereas [Fe^II(H₂ L )₃](BF₄)₂·MeOH·H₂O, [Co^II(H₂ L )₃](ClO₄)₂·2H₂O and [Ni^II(H₂ L )₃](ClO₄)₂·MeOH·H₂O feature merely mer derivatives. Moessbauer spectroscopy and variable temperature magnetic measurements revealed the [Fe^II(H₂ L )₃]²⁺ complex core to exist in the low‐spin state, whereas the [Co^II(H₂ L )₃]²⁺ complex core resides in its high‐spin state, even at very low temperatures.     

Synthesis, spectral, thermal and biological studies of Co(III) and binuclear Ni(II) complexes with a novel amine-imine-oxime ligand

Two different metal complexes of [Co(HL)(L)(Ac)₂]·4H₂O (I) and [Ni₂(L)₂(Ac)₂]·4H₂O (II), have been synthesized with newly prepared amine-imine-oxime ligand [HL = 3-(4′-aminobiphenyl-4-ylimino)-butan-2-one oxime, Ac = CH₃COO⁻]. This ligand HL was prepared by the condensation of diacetylmonoxime with benzidine. The structure of the ligand and complexes have been proposed by elemental analyses, IR, ¹H, and ¹³C NMR, electronic spectra, magnetic susceptibility measurements, mass spectra, molar conductivity and thermo gravimetric analysis. The molar conductance measurements of the complexes in DMF solution correspond to non electrolytic nature for the complexes. Octahedral and tetrahedral geometries have been determined to the complexes of Co(III) and binuclear Ni(II) respectively. The ligand and its metal complexes were tested in vitro for their biological effects. Their activities against two gram-positive (Bacillus subtilis and Staphylococcus aureus) and one fungal specie (Candida albicans) were found. They were inactive against tested gram negative bacteria. The text was submitted by authors in English.     

Syntheses,structures of Mn(II), Ni(II), Cu(II) and Zn(II) coordination complexes based on 3,4,5-trifluorobenzeneseleninic acid and N-donor ligands

Abstract

Five new coordination complexes [Mn^II (L₁)₂(4,4′-bpy)]_n (1), [Ni^II (L₁)₂(4,4′-bpy)]_n (2), [Zn^II (L₁)₂(4,4′-bpy)]_n (3), [Cu^II (L₁)₂(phen)₂]Cl₂ (4) and [Cu^II ₂(L₁)₂(2,2′-bpy)₂]Cl₂ (5) (HL₁?=?3,4,5-trifluorobenzeneseleninic acid, 4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine and phen = 1,10-phenanthroline), have been synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analysis and IR spectroscopy. Complexes 1–3 display similar layers structures. In 1–3, the adjacent layers are further connected through π···π interactions to form three-dimensional supramolecular structures. Complexes 4 and 5 show a dimer containing an eight-membered ring. The dimer extends into three-dimensional supramolecular structures through π···π interactions, C–H···F and C–H···Cl interactions.     

Heterotrimetallic Coordination Polymers: {CuIILnIIIFeIII} Chains and {NiIILnIIIFeIII} Layers: Synthesis,Crystal Structures,and Magnetic Properties

The use of the [Fe^III(AA)(CN)₄]^? complex anion as metalloligand towards the preformed [Cu^II(valpn)Ln^III]³⁺ or [Ni^II(valpn)Ln^III]³⁺ heterometallic complex cations (AA=2,2′‐bipyridine (bipy) and 1,10‐phenathroline (phen); H₂valpn=1,3‐propanediyl‐bis(2‐iminomethylene‐6‐methoxyphenol)) allowed the preparation of two families of heterotrimetallic complexes: three isostructural 1D coordination polymers of general formula {[Cu^II(valpn)Ln^III(H₂O)₃(μ‐NC)₂Fe^III(phen)(CN)₂ {(μ‐NC)Fe^III(phen)(CN)₃}]NO₃ ? 7 H₂O}_n (Ln=Gd ( 1 ), Tb ( 2 ), and Dy ( 3 )) and the trinuclear complex [Cu^II(valpn)La^III(OH₂)₃(O₂NO)(μ‐NC)Fe^III(phen)(CN)₃] ? NO₃ ? H₂O ? CH₃CN ( 4 ) were obtained with the [Cu^II(valpn)Ln^III]³⁺ assembling unit, whereas three isostructural heterotrimetallic 2D networks, {[Ni^II(valpn)Ln^III(ONO₂)₂(H₂O)(μ‐NC)₃Fe^III(bipy)(CN)] ? 2 H₂O ? 2 CH₃CN}_n (Ln=Gd ( 5 ), Tb ( 6 ), and Dy ( 7 )) resulted with the related [Ni^II(valpn)Ln^III]³⁺ precursor. The crystal structure of compound 4 consists of discrete heterotrimetallic complex cations, [Cu^II(valpn)La^III(OH₂)₃(O₂NO)(μ‐NC)Fe^III(phen)(CN)₃]⁺, nitrate counterions, and non‐coordinate water and acetonitrile molecules. The heteroleptic {Fe^III(bipy)(CN)₄} moiety in 5 – 7 acts as a tris‐monodentate ligand towards three {Ni^II(valpn)Ln^III} binuclear nodes leading to heterotrimetallic 2D networks. The ferromagnetic interaction through the diphenoxo bridge in the Cu^II?Ln^III ( 1 – 3 ) and Ni^II?Ln^III ( 5 – 7 ) units, as well as through the single cyanide bridge between the Fe^III and either Ni^II ( 5 – 7 ) or Cu^II ( 4 ) account for the overall ferromagnetic behavior observed in 1 – 7 . DFT‐type calculations were performed to substantiate the magnetic interactions in 1 , 4 , and 5 . Interestingly, compound 6 exhibits slow relaxation of the magnetization with maxima of the out‐of‐phase ac signals below 4.0 K in the lack of a dc field, the values of the pre‐exponential factor (τ_o) and energy barrier (E_a) through the Arrhenius equation being 2.0×10^?12 s and 29.1 cm^?1, respectively. In the case of 7 , the ferromagnetic interactions through the double phenoxo (Ni^II–Dy^III) and single cyanide (Fe^III–Ni^II) pathways are masked by the depopulation of the Stark levels of the Dy^III ion, this feature most likely accounting for the continuous decrease of χ_M T upon cooling observed for this last compound.     

Synthesis and Crystal Structure of Manganese(II) Bipyridine Carboxylato Complexes: [(bipy)2MnII(μ‐C2H5CO2)2MnII(bipy)2](ClO4)2 and [MnII(ClCH2CO2)(H2O)(bipy)2]ClO4 · H2O (bipy = 2,2′‐bipyridine)

Two manganese(II) bipyridine carboxylate complexes, [(bipy)₂Mn^II(μ‐C₂H₅CO₂)₂Mn^II(bipy)₂}₂](ClO₄)₂ ( 1 ), and [Mn^II(ClCH₂CO₂)(H₂O)(bipy)₂]ClO₄ · H₂O ( 2 ) were prepared. 1 crystallizes in the triclinic space group P 1 with a = 8.604(3), b = 12.062(3), c = 13.471(3) Å, α = 112.47(2), β = 93.86(2), γ = 92.87(3)°, V = 1211.1(6) ų and Z = 1. In the dimeric, cationic complex with a crystallographic center of symmetry two 2,2′‐bipyridine molecules chelate each manganese atom. These two metal fragments are then bridged by two propionato groups in a syn‐anti conformation. The Mn…Mn distance is 4.653 Å. 2 crystallizes in the monoclinic space group P2₁/c with a = 9.042(1), b = 13.891(1), c = 21.022(3) Å, β = 102.00(1)°, V = 2569.3(5) ų and Z = 4. 2  is a monomeric cationic complex in which two bipyridine ligands chelate the manganese atom in a cis fashion. A chloroacetato and an aqua ligand complete the six‐coordination. Only in 2 is the intermolecular packing controlled by weak π‐stacking besides C–H…π contacts between the bipyridine ligands.     

Hydrothermal syntheses and structural characterization of two sandwich-type arsenotungstates

Two new organic–inorganic composite sandwich-type arsenotungstates [H₂dap]₆H₈[Ni₄(H₂O)₂(B-α-AsW₉O₃₄)₂]₂ · 33H₂O (1) and {[Ni(dap)₂(H₂O)]₂[Ni(dap)₂]₂[Ni₄(Hdap)₂(B-α-AsW₉O₃₄)₂]} · 4H₂O (2) (dap = 1,2-diaminopropane) have been hydrothermally synthesized by reaction of Na₈[A-α-HAsW₉O₃₄] · 11H₂O with NiCl₂ · 6H₂O in the presence of 1,2-diaminopropane and characterized by elemental analysis, IR spectra, X-ray single-crystal diffraction, and thermogravimetric analysis. 1 crystallizes in the triclinic P 1 space group with a = 16.351(6) Å, b = 16.423(6) Å, c = 19.894(7) Å, α = 110.630(6)°, β = 92.684(7)°, γ =104.946(7)°, V = 4774(3) ų, Z = 1, GOOF = 1.033, R ₁ = 0.0517, wR ₂ = 0.1086. 2 also crystallizes in the triclinic P 1 space group with a = 13.305(4) Å, b = 13.882(4) Å, c = 17.031(5) Å, α = 68.109(5)°, β = 71.511(4)°, γ = 88.407(5)°, V = 2753.5(14) ų, Z = 1, GOOF = 1.051, R ₁ = 0.0491, wR ₂ = 0.1150. Notably, 1 is a discrete structure, composed of two tetra-Ni^II substituted sandwich-type polyoxoanions [Ni₄(H₂O)₂(B-α-AsW₉O₃₄)₂]^10? with different spatial orientation, whereas 2 displays a organic–inorganic composite 2-D sheet architecture constructed by tetra-Ni^II sandwiched [Ni₄(H₂O)₂(B-α-AsW₉O₃₄)₂]^10? units by means of [Ni(dap)₂]²⁺ bridges. Some previously reported transition-metal-substituted sandwich-type polyoxotungstates have been summarized.     

Topological insights in polynuclear Ni/Na coordination clusters derived from a schiff base ligand

This article presents the syntheses, crystal structures, topological features and magnetic properties of two Ni^II/Na^I coordination clusters formulated [Ni ₃ ^II Na(L1)₃(HL1)(MeOH)₂] (1) and [Ni ₆ ^II Na(L1)₅(CO₃)(MeO)(MeOH)₃(H₂O)₃]·4(MeOH) 2(H₂O) [2 4(MeOH) 2(H₂O)] where H₂L1 is the semi-rigid Schiff base ligand (E)-2-(2-hydroxy-3-methoxybenzylideneamino)-phenol). Compound 1 possesses a rare Ni ₃ ^II Na^I cubane (3M4-1) topology, and compound 2 is the first example in polynuclear Ni/Na chemistry that exhibits a 2,3,4M7-1 topology.     

Synthesis,spectroscopic, and thermal analyses of trinuclear Mn(II), Co(II), Ni(II), and Zn(II) complexes with some sulfa derivatives

New bi- and trihomonuclear Mn(II), Co(II), Ni(II), and Zn(II) complexes with sulfa-guanidine Schiff bases have been synthesized for potential chemotherapeutic use. The complexes are characterized using elemental and thermal (TGA) analyses, mass spectra (MS), molar conductance, IR, ¹H-NMR, UV-Vis, and electron spin resonance (ESR) spectra as well as magnetic moment measurements. The low molar conductance values denote non-electrolytes. The thermal behavior of these chelates shows that the hydrated complexes lose water of hydration in the first step followed by loss of coordinated water followed immediately by decomposition of the anions and ligands in subsequent steps. IR and ¹H-NMR data reveal that ligands are coordinated to the metal ions by two or three bidentate centers via the enol form of the carbonyl C=O group, enolic sulfonamide S(O)OH, and the nitrogen of azomethine. The UV-Vis and ESR spectra as well as magnetic moment data reveal that formation of octahedral [Mn₂L¹(AcO)₂(H₂O)₆] (1), [Co₂(L¹)₂(H₂O)₈] (2), [Ni₂L¹(AcO)₂(H₂O)₆] (3), [Mn₃L²(AcO)₃(H₂O)₉] (5), [Co₃L²(AcO)₃(H₂O)₉] · 4H₂O (6), [Ni₃L²(AcO)₃(H₂O)₉] · 7H₂O (7), [Mn₃L³(AcO)₃(H₂O)₆] (9), [Co₂(HL³)₂(H₂O)₈] · 4H₂O (10), [Ni₃L³(AcO)₃(H₂O)₉] (11), [Mn₃L⁴(AcO)₃(H₂O)₉] · H₂O (13), [Co₂(HL⁴)₂(H₂O)₈] · 5H₂O (14), and [Ni₃L⁴(AcO)₃(H₂O)₉] (15) while [Zn₂L¹(AcO)₂(H₂O)₂] (4), [Zn₃L²(AcO)₃(H₂O)₃] · 2H₂O (8), [Zn₃L³(AcO)₃(H₂O)₃] · 3H₂O (12), and [Zn₃L⁴(AcO)₃(H₂O)₃] · 2H₂O (16) are tetrahedral. The electron spray ionization (ESI) MS of the complexes showed isotope ion peaks of [M]⁺ and fragments supporting the formulation.     

Cobalt(II) complexes with pyridine and 5-[(E)-2-(aryl)-1-diazenyl]-quinolin-8-olates: synthesis,electrochemistry and X-ray structural characterization

Abstract

Nine new cobalt(II) compounds, trans-[Co(L^PAQ)₂(Py)₂] (1), trans-[Co(L^PAQ)₂(3-MePy)₂] (2), trans-[Co(L^MeAQ)₂(Py)₂] (3), trans-[Co(L^OMeAQ)₂(Py)₂] (4), trans-[Co(L^OEtAQ)₂(Py)₂]·2(H₂O) (5), trans-[Co(L^CAQ)₂(Py)₂] (6), trans-[Co(L^BAQ)₂(Py)₂] (7), cis-[Co(L^BAQ)₂(3-MePy)₂] (8a) and trans-[Co(L^BAQ)₂(3-MePy)₂]·2(3-MePy) (8b) (primary ligand: L^XAQ?=?substituted 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-olate; secondary ligands: Py?=?pyridine, 3-MePy = 3-methylpyridine), have been synthesized and characterized by elemental analysis, IR and UV-vis spectroscopy. Magnetic measurements of the cobalt compounds were performed in solution by ¹H NMR spectroscopy using the Evans’ method while their redox properties were studied by cyclic voltammetry. Single-crystal X-ray diffraction analysis of the compounds revealed their octahedral geometries and trans configuration, except for 8a, which has a cis configuration. Intermolecular noncovalent interactions were detected, π···π interactions in 5, C?–?H···π interactions in 2 and C?–?H···π edge-to-face (T-shaped) arrangements in 3, 4, 6, and 7.     

Synthesis and Crystal Structures of Manganese(II) and ­Cobalt(II) Complexes with 2, 6‐Dimethoxybenzoic Acid and Additional N‐Donor Ligands

Three coordination compounds [Mn₃(dmb)₆(H₂O)₄(4, 4′‐bpy)₃(EtOH)]_n ( 1 ) and [M(dmb)₂(pyz)₂ (H₂O)₂] [M^II = Co ( 2 ), Mn ( 3 )] (Hdmb = 2, 6‐dimethoxybenzoic acid, 4, 4′‐bpy = 4, 4′‐bipyridine, pyz = pyrazine) were synthesized and characterized by single‐crystal X‐ray diffraction analysis. Compound 1 consists of infinite 1D polymeric chains, in which the metal entities are bridged by 4, 4′‐bpy ligands. There are four crystallographically independent Mn^II atoms in the linear chain with different coordination modes, which is only scarcely reported for linear polymers. The isostructural crystals of 2 and 3 are composed of neutral mononuclear complexes. In crystal the complexes are combined into chains by intermolecular O–H ··· N hydrogen bonds and π–π interactions between antiparallel pyrazine molecules.     

Transition metal complexes with thiosemicarbazide-based ligands,Part IX. Cobalt(II) and nickel(II) complexes with 2-furaldehydeS-methylisothiosemicarbazone; crystal and molecular structure of aqua-bis(2-furaldehydeS-methylisothiosemicarbazone)cobalt(II)-diperchlorate

Summary The reaction of a warm ethanolic solution of Co^II perchlorate or rodanide and Ni^II acetate with 2-furaldehydeS-methylisothiosemicarbazone (HL), yielded the complexes [Co(HL)₂(H₂O)](ClO₄)₂ (1), [Co(HL)₃] [Co(NCS)₄] (2) and NiL₂, respectively. Both Co^II complexes are high-spin, whereas the Ni^II complex is in lowspin state (diamagnetic). An x-ray analysis of (1) showed it to have atrans-trigonal bipyramidal configuration in which one coordination site in the equatorial plane is occupied by one H₂O molecule. HL, a bidentate ligand, is coordinatedvia N(1) and N(4). The tris(ligand) cation in complex (2) has an octahedral configuration. Complex NiL₂ has a square-planar configuration.The deep purple plate-like crystals of (1) are monoclinic with space group C2/c, having cell parameters:a=11.369(3),b=13.029(4),c=17.438(5) Å; =103.39(2)^o. The structure was solved by the heavy-atom method and refined by least-squares method to an R value of 0.060 for 1761 observed reflections.     

Ferrocenyl β-diketonato-based Cu(II)-oxo clusters with Cu7 and Cu10 cores

Crystallization of [Cu(β-diketonate)(PPh₃)₂] (1a, β-diketonate=1-ferrocenyl-butane-1,3-dionato (= fb); 1b,?=?1,3-diferrocenyl-propane-1,3-dionato (= dfp)) from ethanol, layered with a mixture of pentane/diethyl ether of ratio 1?:?1 (v/v) in air, afforded Cu(II)-oxo clusters [Cu₁₀(fb)₈(O)₄(tmdd)₂]·1.5Et₂O (2) and [Cu₇(dfp)₆(O)₂(OH)₂(tmdd)]·2Et₂O (3), respectively, in minor yield (tmdd?=?1κ ² C,3κ ² C-tetramethyldisiloxane-1,3-diolato). These clusters were obtained in somewhat better yield when HOSiMe₂OSiMe₂OH was added to the crystallization mixtures. The molecular structures of 2 and 3 in the solid state are reported.     

Synthesis,crystal structure,and luminescent properties of metal complexes bearing 2,6-pyridine-diacylhydrazide ligands: supramolecular assemblies via intermolecular interactions

Four metal complexes of N,N′-bis(salicyl)-2,6-pyridine-dicarbohydrazide ligand (H₆L), [Co^II(H₄L)(H₂O)₂]·2DMF (1), [Zn^II(H₄L)(H₂O)₂]·2DMF (2), [Cd^II(H₄L)(Py)₂]·DMF·Py (3), and [Co^IICo₂^III(H₄L)₄(H₂O)₄]·DMF·H₂O (4), were synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction analysis. Structural studies revealed that complexes 1–3 present discrete mononuclear structures and complex 4 displays a centrosymmetric mixed-valence trinuclear structure. All four complexes are further extended into interesting two- or three-dimensional supramolecular frameworks. The luminescent properties of 2 and 3 were studied, which show emissions with maxima at 485 nm upon excitation at 396 nm for 2 and 476 nm upon excitation at 397 nm for 3, respectively.     

Synthesis and Crystal Structures of Four Novel Mo(W)/Cu/S Polymers Containing Thiolato Bridging Ligands

Four novel M/Cu/S polymers [Et₄N][MS₄Cu₃(S₂COEt)₂] (1a: M=Mo; 1b: M=W) and Et₄N][MS₄Cu₂SEt] (2a: M=Mo; 2b: M=W) have been prepared by reactions of [Et₄N]₂[MS₄] with CuS₂COEt and CuSEt. X-ray crystal structure determinations reveal that the polymeric anions of complexes 1a and 1b both consist of MS₄Cu₃ building blocks linked via bidentate [S₂COEt]⁻ bridging ligands to form 1D polymeric chains. The anion structures of the polymeric compounds 2a and 2b contain MS₄Cu₂ repeating units which are connected via μ-SEt⁻ ligands forming a zigzag chain running down the crystallographic b axis.     

Coordination polymers of CuII and NiII with 3-pyridin-3-yl-benzoate: crystal structures and magnetic properties

Coordination polymers of Cu^II and Ni^II with 3-pyridin-3-yl-benzoic acid (3,3-Hpybz), {[Cu(3,3-pybz)₂(CH₃OH)]·(DMF)} _n (1) and {[Ni(3,3-pybz)₂(H₂O)]?·?(H₂O)} _n (2), were synthesized and characterized by single-crystal X-ray diffraction, thermogravimetric analyses, elemental analysis, and IR spectroscopy. In 1, Cu^II ions are linked by paired 3,3-pybz ligands to generate an in?nite 1-D double-strand chain. However, Ni^II ions in 2 are linked by the 3,3-pybz to form a 2-D corrugated network with a simple (4,4) topology; these 2-D layers are further enlarged to form the final 3-D supramolecular edifice via strong aromatic π–π stacking interactions and O–H?···?O hydrogen bonds. Magnetic properties of 1 and 2 have also been investigated.