New cyanido-bridged iron(II) spin crossover coordination polymers with an unusual ladder-like topology: an alternative to Hofmann clathrates.

Two new cyanido-bridged {FeM} double chains were obtained by reacting cyanido anions [M(CN)] with complex cations [Fe(tptz)] (preformed by mixing a hydrated tetrafluoroborate salt of iron(II) and a tptz ligand, tptz = 2,4,6-tri(2-pyridyl)-1,3,5-triazine) having the general formula [Fe(tptz)M(CN)]·2HO·CHCN, where M = Pd (1) or Pt (2). Additionally, two molecular complexes formulated as [Fe(tptz)][M(CN)]·4.25HO, where M = Pd (3) or Pt (4), were subsequently obtained from the same reaction, as secondary products.

Deciphering the role of water and a zinc-doping process in a polyol-based approach for obtaining Zn/Co/Al-based spinels: toward "green" mesoporous inorganic pigments.

Two new families of zinc/cobalt/aluminum-based pigments, with a unique composition, were obtained through the polyol method. The hydrolysis process of a mixture of Co(CHCOO), Zn(acac) and Al(acac) (acac = acetylacetonate ion) in 1,4-butanediol afforded dark blue gels (wPZnxCo1-xAl), in the presence of a supplementary amount of water, and light green powders (PZnxCo1-xAl), respectively, for the water-free procedure ( = 0, 0.2, 0.

Copper(II) Oxide Nanoparticles Embedded within a PEDOT Matrix for Hydrogen Peroxide Electrochemical Sensing.

The aim of this study is the preparation of nanostructured copper(II) oxide-based materials (CuONPs) through a facile additive-free polyol procedure that consists of the hydrolysis of copper(II) acetate in 1,4-butane diol and its application in hydrogen peroxide sensing. The nonenzymatic electrochemical sensor for hydrogen peroxide determination was constructed by drop casting the CuONP sensing material on top of a glassy carbon electrode (GCE) modified by a layer of poly(3,4-ethylenedioxythiophene) conducting polymer (PEDOT). The PEDOT layer was prepared on GCE using the sinusoidal voltage method.

A rare isostructural series of 3d-4f cyanido-bridged heterometallic squares obtained by assembling [Fe{HB(pz)}(CN)] and Ln ions: synthesis, X-ray structure and cryomagnetic study.

A new series of cyanido-bridged {FeLn} neutral molecular squares of general formula [Fe{HB(pz)}(CN)(μ-CN)Ln(NO)(pyim)(PhPO)]·2CHCN [Ln = Ce (1), Pr (2), Nd (3), Gd (4), Tb (5), Dy (6) and Er (7); {HB(pz)} = hydrotris(pyrazolyl)borate, pyim = 2-(1-imidazol-2-yl)pyridine and PhPO = triphenylphosphine oxide] were obtained by reacting the low-spin [Fe{HB(pz)}(CN)] species with the preformed [Ln(pyim)(NO)(pyim)(PhPO)] complex anions (generated by mixing the nitrate salt of each Ln(III) ion with pyim and PhPO molecules). Single-crystal X-ray diffraction studies show that 1-7 are isostructural compounds that crystallize in the triclinic 1̄ space group. Their crystal structures consist of centrosymmetric cyanido-bridged {FeLn} molecular squares where two [Fe{HB(pz)}(CN)] units adopt bis-monodentate coordination modes towards two [Ln(pyim)(NO)(pyim)(PhPO)] moieties.

Flow injection enzymatic biosensor for aldehydes based on a Meldola Blue-Ni complex electrochemical mediator.

Carbon nanofibers (CNF) are efficient electrode modifiers in electrochemical biosensors that enhance the electrochemical active area, induce electrocatalytic effect toward the oxidation of the enzymatic cofactor nicotinamide adenine dinucleotide (reduced form, NADH), and enable the quantitative immobilization of enzymes. Combining CNF with efficient and stable mediators radically augments the speed of electron transfer between NADH and solid electrodes and leads to electrochemical sensors characterized by high sensitivity and stability. The main aim of this work was to investigate the performance of a novel mediator for NADH with advantageously low solubility in an electrochemical detector based on a screen-printed CNF electrode as well as its potential in biosensing.

In situ generation of PhPO in cyanido-bridged heterometallic {FeLn} molecular squares (Ln = Eu, Sm).

Two new examples of cyanido-bridged {FeLn} molecular squares, with pyim and PPhO as capping ligands at the Ln sites, exhibit weak antiferromagnetic interactions [Ln = Eu (1), Sm (2), pyim = 2-(1H-imidazol-2-yl)pyridine, PPhPO = triphenylphosphine oxide].

Zinc Oxide Spherical-Shaped Nanostructures: Investigation of Surface Reactivity and Interactions with Microbial and Mammalian Cells.

Two ZnO materials of spherical hierarchical morphologies, with hollow (ZnO) and solid cores (ZnO), were obtained through the hydrolysis of zinc acetylacetonate in 1,4-butanediol. The nature of the defects and surface reactivity for the two ZnO materials were investigated through photoluminescence, X-ray photoelectron spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy proving the coexistence of shallow and deep defects and, also, the presence of polyol byproducts adsorbed on the outer layers of the ZnO samples. The EPR spectroscopy coupled with the spin-trapping technique showed that the surface of the ZnO samples generates reactive oxygen species (ROS) like hydroxyl (OH) and singlet oxygen (O) as well as carbon-centered radicals.

Design of 3d-4f molecular squares through the [Fe{(HB(pz))}(CN)] metalloligand.

A new series of {FeIII2LnIII2} heterobimetallic squares of general formula [FeIII{HB(pz)3}(CN)(μ-CN)2Ln(pyim)x(NO3)2(H2O)y]2·zH2O [Ln = La (1), Gd (2), Tb (3) and Dy (4); {HB(pz)3}- = hydrotris(pyrazolyl)borate and pyim = 2-(1H-imidazol-2-yl)pyridine; x = 2, y = 0 (1), x = y = 1 (2-4) and z = 10 (1), 6 (2), 2.76 (3), 4 (4)] were synthesized by reacting the low-spin [FeIII{HB(pz)3}(CN)3]- complex anion with the preformed [LnIII(pyim)x(NO3)2(H2O)y]+ complex cation [formed in situ by mixing the lanthanide(iii) salt and the pyim ligand]. Single-crystal X-ray diffraction shows that 1-4 crystallize in the P1[combining macron] triclinic space group, 2-4 being isomorphous.

Three different types of bridging ligands in a 3d-3d'-3d'' heterotrimetallic chain.

A one-pot synthesis of a 3d-3d'-3d'' heterotrimetallic coordination polymer with double diphenoxido, single cyanido and bis-bidentate oxalate as alternating bridges which exhibits an overall antiferromagnetic behaviour has been developed.

Cyanido-Bridged {LnW} Heterobinuclear Complexes: Synthesis and Magneto-Structural Study.

A new series of cyanido-bridged {LnW} heterobinuclear complexes of formula [Ln(pyim)(i-PrOH)(HO)(μ-CN)W(CN)]·2HO [Ln = Gd (1), Tb (2), Dy (3), Ho (4), and Er (5); pyim = 2-(1H-imidazol-2-yl)-pyridine) and i-PrOH = isopropyl alcohol] were synthesized by one-pot reaction between (NHBu)[W(CN)] and [Ln(pyim)] complexes (generated in situ by mixing the corresponding Ln ions and the pyim ligand). Compounds 1-5 are isomorphous and crystallize in the monoclinic system P2/n space group. Their crystal structure consists of binuclear units in which the octacyanotungstate(V) anion coordinates to the corresponding Ln ion through a single cyanide ligand.

Synthesis, Crystal Structures, and Magnetic Properties of Two Novel Cyanido-Bridged Heterotrimetallic {CuMnCr} Complexes.

The self-assembly process between the heteroleptic [Cr(phen)(CN)] and [Cr(ampy)(CN)] metalloligands and the heterobimetallic {Cu(valpn)Mn} tecton afforded two heterotrimetallic complexes of formula [{Cu(valpn)Mn(μ-NC)Cr(phen)(CN)}{(μ-NC)Cr(phen)(CN)}]·2CHCN (1) and {[Cu(valpn)Mn(μ-NC)Cr(ampy)(CN)]·2CHCN} (2) [phen = 1,10-phenanthroline, ampy = 2-aminomethylpyridine, and Hvalpn = 1,3-propanedyilbis(2-iminomethylene-6-methoxyphenol)]. The crystal structure of 1 consists of neutral CuMnCr octanuclear units, where two [Cr(phen)(CN)] anions act as bis-monodentate ligands through cyanide groups toward two manganese(II) ions from two [Cu(valpn)Mn] units to form a [{Cu(valpn)Mn}Cr(CN)] square motif. Two [Cr(phen)(CN)] pendant anions in 1 are bound to the copper(II) ions with cis-trans geometry with respect to the bridging [Cr(phen)(CN)] anion.

Synthesis, crystal structure and magnetic properties of a cyanide-bridged heterometallic {CoMn} chain.

The assembly reaction between the low-spin [Co(dmphen)(CN)] metalloligand and the [Mn(salen)(HO)] complex cation yielded the one-dimensional compound {[Mn(salen)(μ-NC)Co(dmphen)(CN)]·2HO} (1), which behaves as a ferrimagnetic chain, the intrachain magnetic coupling being J = -1.71(1) cm.

A new family of [Cu(II)Ln(III)M(V)] heterotrimetallic complexes (Ln = La, Gd, Tb; M = Mo, W): model systems to probe exchange interactions and single-molecule magnet properties.

Four isostructural trinuclear 3d-4f-4(5)d heterotrimetallic complexes, with the general formula [L(2)CuLn(H2O)5(μ-NC)M(CN)7], were obtained from the association of binuclear 3d-4f complexes and {M(V)(CN)8}(3-) metalloligands (M = Mo, Ln = La ; M = W, Ln = La ; M = Mo, Ln = Gd ; M = Mo; Ln = Tb , where H2L(2) = 1,2-ethanediylbis(2-iminomethylene-6-methoxy-phenol)). The metalloligand coordinates through a single-cyanido group at the apical position of the copper(ii) ion belonging to the {Cu(II)Ln(III)} binuclear complex. The analysis of the magnetic data for the La(iii) derivatives (compounds and ), in the 1.

Magneto-structural variety of new 3d-4f-4(5)d heterotrimetallic complexes.

Three families of heterotrimetallic chains (type 1-type 3), with different topologies, have been obtained by reacting the 3d-4f complexes, [{Cu(L(1))}xLn(NO3)3] with x = 1 or 2, formed in situ by the reaction of Schiff-base bi-compartmental [Cu(II)(L(1))] complexes and lanthanide(iii) salts, with (NHBu3)3[M(CN)8] (M = Mo(V), W(V)). For type 1 series of compounds, 1-D coordination polymers, with the general formula [{Cu2(valpn)2Ln}{M(CN)8}]·nH2O·mCH3CN (where H2valpn = 1,3-propanediylbis(2-iminomethylene-6-methoxy-phenol), result from the association of trinuclear {CuLn(III)} moieties and [M(V)(CN)8](3-) anions acting as tri-connecting spacers [Ln = La (1), Ce (2), Eu (3), Tb (4), Ho (5), M = Mo; Ln = Tb (6), Ho (7), M = W; m = 0, n = 1.5 (7) and 2 (1-4, 6); n = 1, m = 1 (5)].

Two-dimensional coordination polymers constructed by [Ni(II)Ln(III)] nodes and [W(IV)(bpy)(CN)6]2- spacers: a network of [Ni(II)Dy(III)] single molecule magnets.

Three isomorphous two-dimensional (2D) coordination polymers of general formula {[Ni(II)(valpn)Ln(III)(NO3)(H2O)(μ-NC)4W(IV)(bipy)(CN)2]·xH2O·yCH3CN}n have been synthesized by reacting Ph4P[W(V)(CN)6(bipy)] with the heterodinuclear [Ni(II)Ln(III)(valpn)(O2NO)3] complexes [H2valpn = 1,3-propanediyl-bis(2-iminomethylene-6-methoxyphenol), bipy = 2,2'-bipyridine, and Ln = Gd (1), Dy (2), and Tb (3) with x = 2 (1), 3.9 (2), and 3.35 (3) and y = 2.

Low-dimensional 3d-4f complexes assembled by low-spin [Fe(III)(phen)(CN)4]- anions.

The synthesis, crystal structure, and magnetic properties of four new mixed 3d-4f complexes with formulas [{Fe(III)(phen)(CN)(4)}(4)Gd(2)(III)(bpym)(NO(3))(2)(H(2)O)(4)]·2CH(3)CN·2H(2)O}(n) (1), [{Fe(III)(phen)(CN)(4)}(4)Tb(2)(III)(bpym)(H(2)O)(8)]·(NO(3))(2)·2CH(3)CN}(n) (2), [{Fe(III)(phen)(CN)(4)}(4)Sm(III)(bpym)(NO(3))(2)(H(2)O)(5)]·2CH(3)CN}(n) (3), and [{Fe(III)(phen)(CN)(4)}(2)Pr(2)(III)(bpym)()(NO(3))(4)(H(2)O)(2)](n) (4) (phen = 1,10-phenanthroline and bpym = 2,2'-bipyrimidine) are discussed here. Compounds 1-3 are isomorphous and their structure consists of neutral ladder-like motifs where the rungs are made up by bpym-bridged dilanthanide(III) cations and the rods are defined by [Fe(phen)(CN)(4)](-) units adopting a bis-monodentate coordination mode through two of its four cyanide ligands. The electroneutrality in this family is achieved by either a chelating [at the Gd(III) (1) and Sm(III) (3)] or free [at the Tb(III) (2)] nitrate group and a peripheral [Fe(phen)(CN)(4)](-) entity, which act as a monodentate ligand across one of its four cyanide groups toward the rare-earth cation (1-3).

Self-assembly of [Cu(II)Tb(III)]3+ and [W(CN)8]3- tectons: a case study of a mixture containing two complexes showing slow-relaxation of the magnetization.

The reaction of [Cu(valen)] with Tb(NO(3))(3) and (Bu(3)NH)(3)[W(CN)(8)] affords two types of crystals: [{W(CN)(8)}Cu(valen)Tb(OH(2))(5)]·2H(2)O (1, a discrete trinuclear complex) and [{W(CN)(8)}Cu(valen)Tb(OH(2))(4)]·CH(3)CN·H(2)O (2, an infinite zig-zag chain), both compounds showing slow relaxation of the magnetization (H(2)valen is the Schiff base resulting from the reaction of o-vanillin with 1,2-ethanediamine).

[W(bipy)(CN)6]-: a suitable metalloligand in the design of heterotrimetallic complexes. The first Cu(II)Ln(III)W(V) trinuclear complexes.

The first 3d-4f-5d heterotrimetallic complexes using [W(V)(bipy)(CN)(6)](-) as a metalloligand were synthesized (bipy = 2,2'-bipyridine). The structural and magnetic properties of three [Cu(II)Ln(III)W(V)] complexes (Ln = Gd, Ho, Tb) are discussed.

Magnetic coupling in discrete cyano-bridged Mn(III)-Fe(III) motifs: synthesis, crystal structure, magnetic properties and theoretical study.

The preparation, crystal structures and magnetic properties of the heterobimetallic complexes of formula [Mn(III)(n-MeOsalen)(H(2)O)(mu-CN)Fe(III)(bpym)(CN)(3)]·mH(2)O with n = m = 3 (1) and n = 4 and m = 2 (2) [n-MeOsalen(2-) = N,N'-ethylenebis(n-methoxysalicylideneiminate) dianion and bpym = 2,2'-bipyrimidine] are reported. 1 and 2 are dinuclear neutral species where the cyano-bearing low-spin unit [Fe(III)(bpym)(CN)(4)](-) acts as a monodentate ligand towards the [Mn(III)(SB)(solv)(x)](+) entity (SB = tetradentate Schiff-base) through one of its four cyano groups. Adjacent heterobimetallic units are interlinked through hydrogen bonds involving the coordinated water molecule of one dinuclear unit and the phenolate oxygen atoms of the neighbouring one to afford pairs of dimers with values of the interdimer Mn···Mn distance of 4.

Unprecedented coexistence of cyano-bridged Mn4(III)Cr(III) and Mn2(III)Cr(III) heterobimetallic complexes in one single crystal.

The penta-[{MnIII(4-MeO-salen)(H2O)(micro-CN)}4CrIII(CN)2]+ and trinuclear [{MnIII(4-MeO-salen)(H2O)(micro-CN)}2CrIII(CN)4](-) units coexist in 1 with weak antiferromagnetic interactions which are overcome by a dc magnetic field of 2.5 T.

[M(III)(bpym)(CN)(4)](-): a suitable building block to design ferrimagnetic cyano-bridged heterobimetallic chains (M = Fe, Cr; bpym = 2,2'-bypyrimidine).

Two cyano-bridged M(III)Mn(III) [M = Fe () and Cr ()] ferrimagnetic chains are reported; exhibits metamagnetism with two critical fields of 1250 G and 2.0 T which correspond to the overcoming by the applied dc field of the inter- and intrachain magnetic interactions, respectively.

Evidence for increased exchange interactions with 5d compared to 4d metal ions. Experimental and theoretical insights into the ferromagnetic interactions of a series of trinuclear [{M(CN)8}3-/NiII] compounds (M = MoV or WV).

Two main questions are addressed in this study: (i) What increase of exchange interaction can be expected when replacing a paramagnetic metal ion with a heavier congener located farther down the periodic table (i.e., 3d-4d-5d), and (ii) for a molecular unit with higher coordination numbers, eight in the present case, how is the magnetic information transferred from the metal ion to its ligand set? Qualitative and quantitative investigations on a series of trimetallic cyano-bridged {MoV(CN)8-NiII} and {WV(CN)8-NiII} compounds revealed ferromagnetic interactions but with a strength modulated by the spin organization and their nature.