Synthesis and crystal structure of ionic multicomponent complex: ([Cr(I)(PhH)(2)].+))(2)[Co(II)TPP(C(60)(CN)(2))]-[C(60)(CN)(2)](.-).3(o-C(6)H(4)Cl(2)) containing C(60)(CN)(2).- radical anion and sigma-bonded diamagnetic Co(II)TPP(C(60)(CN)(2)) -anion

The ionic multicomponent complex complex: ([Cr(I)(PhH)(2)].+))(2)[Co(II)TPP(C(60)(CN)(2))]-[C(60)(CN)(2)](.-).3(o-C(6)H(4)Cl(2)) (Co(II)TPP: cobalt (II) tetraphenylporphyrin; Cr(PhH)(2): bis(benzene)chromium; o-C(6)H(4)Cl(2): o-dichlorobenzene) containing CoTPP(C(60)(CN)(2)- anion and C(60)(CN)(2).- radical anion was obtained. The complex has the cage structure with channels, which accommodate Cr(I)(PhH)(2)(.+) and o-C(6)H(4)Cl(2) molecules. For the first time the sigma-bonding of Co(II)TPP to the fullerene radical anion with the essentially shortened Co.C(C(60)(CN)(2)) contact of 2.282 A is observed. The sigma-bonding results in the diamagnetism of Co(II)TPP(C(60)(CN)(2))(-) anion. The nonbonded C(60)(CN)(2)(.-) radical anion retains both the C(2)(v)symmetry and the shape of the molecule. The length of the C(triple bond)N bonds is 1.141 and 1.152 A.     

The Interaction of C60, C70, and C60(CN)2 radical anions with cobalt(II) tetraphenylporphyrin in solid multicomponent complexes

A method for the synthesis of the multicomponent ionic complexes: [Cr(I)(C(6)H(6))(2) (.+)][Co(II)(tpp)(fullerene)(-)].C(6)H(4)Cl(2), comprising bis(benzene)chromium (Cr(C(6)H(6))(2)), cobalt(II) tetraphenylporphyrin (Co(II)(tpp)), fullerenes (C(60), C(60)(CN)(2), and C(70)), and o-dichlorobenzene (C(6)H(4)Cl(2)) has been developed. The monoanionic state of the fullerenes has been proved by optical absorption spectra in the UV/vis/NIR and IR ranges. The crystal structures of the ionic [[Cr(I)(C(6)H(6))(2)](.+)](1.7)[[Co(II)(tpp)(C(60))](2)](1.7-). 3.3 C(6)H(4)Cl(2) and [[Cr(I)(C(6)H(6))(2)] (.+)](2)[Co(II)(tpp)[C(60)(CN)(2)]](-)[C(60)(CN)(2) (.-)]).3 C(6)H(4)Cl(2) are presented. The essentially shortened Co.C(fullerene) bond lengths of 2.28-2.32 A in these complexes indicate the formation of sigma-bonded [Co(II)(tpp)][fullerene](-) anions, which are diamagnetic. All the ionic complexes are semiconductors with room temperature conductivity of 2 x 10(-3)-4 x 10(-6) S cm(-1), and their magnetic susceptibilities show Curie-Weiss behavior. The neutral complexes of Co(II)(tpp) with C(60), C(60)(CN)(2), C(70), and Cr(0)(C(6)H(6))(2), as well as the crystal structures of [Co(II)(tpp)](C(60)).2.5 C(6)H(4)Cl(2), [Co(II)(tpp)](C(70)). 1.3 CHCl(3).0.2 C(6)H(6), and [Cr(0)(C(6)H(6))(2)][Co(II)(tpp)] are discussed. In contrast to the ionic complexes, the neutral ones have essentially longer Co.C(fullerene) bond lengths of 2.69-2.75 A.     

Negatively charged pi-(C60-)2 dimer with biradical state at room temperature

A negatively charged pi-(C60-)2 dimer bonded by two single bonds was found in the ionic multicomponent complex {(MDABCO+).CoIITMPP}2.(C60-)2.(C6H4Cl2)2.5.(C6H5CN)1.5 (1). In contrast to the previously described diamagnetic sigma-(C60-)2 dimer, the negatively charged pi-dimer has a biradical state at room temperature: (C60*-)2 (S = 1). The behavior of spins in this dimer can be described by a model with a singlet ground state (S = 0) and a close lying excited triplet (S = 1) state with the energy gap of 2|JAF| = 70 +/- 2 cm-1. On the whole, complex 1 shows a strong antiferromagnetic interaction of spins with a Weiss constant of -34 K.     

Formation of antiferromagnetically coupled C(60)(*)(-) and diamagnetic (C(70)(-))(2) dimers in ionic complexes of fullerenes with (MDABCO(+))(2).M(II)TPP (M = Zn, Co, Mn, and Fe) assemblies

A series of ionic multicomponent complexes comprising C60 and C70 anions and coordinating assemblies of methyldiazabicyclooctane cations with metal tetraphenylporphyrins, (MDABCO+)2.MIITPP.(C60(70)-)2.Sol. (C60, M = Zn (1); C60, M = Co (2); C60, M = Mn (3); C60, M = Fe (4); C70, M = Mn (5); and C70, M = Fe (6)) has been obtained. IR- and UV-vis-NIR spectra of 1-6 justified the formation of C60*- in 1-4 and single-bonded (C70-)2 dimers in 5 and 6. Co and Mn atoms are six-coordinated in the (MDABCO+)2.MIITPP units with relatively long M-N bonds of 2.475(2), 2.553(2), and 2.511(3) A for 2, 3, and 5, respectively. Isostructural complexes 2 and 3 contain C60*- zigzag chains separated by the (MDABCO+)2.MIITPP units, whereas in 5 the layers formed by the (C70-)2 dimers alternate with those composed of the (MDABCO+)2.MnIITPP units and noncoordinating MDABCO+ cations. Negative Weiss constants of -13 (1), -2 (3), and -2 (4) K indicate the antiferromagnetic interaction of spins, which decreases the magnetic moment of the complexes below 70-120 K. The EPR signals of 1 and 4 attributed to C60*- are split into two components at the same temperatures, which broaden and shift to higher and lower magnetic fields with the temperature decrease. Complexes 2 and 3 show single EPR signals with g-factors equal to 2.1082 and approximately 2.4 at 293 K, respectively. These values are mean between those characteristic of MIITPP and C60*-, and, consequently, the signals appear due to exchange coupling between these paramagnetic species. The antiferromagnetic ordering of C60*- spins below 70-100 K shifts g-factor values closer to those characteristic of individual MIITPP (g = 2.1907 (2) and approximately 4.9 (3) at 4 K). In contrast to 1-4, complex 5 shows paramagnetic behavior with Weiss constant close to 0.     

Crystal structure and magnetic properties of an ionic C60 complex with decamethylcobaltocene: (Cp*2Co)2C60(C6H4Cl2, C6H5CN)2. Singlet-triplet transitions in the C60(2-) anion

The C(60) complex with decamethylcobaltocene, (Cp(2)Co)(2)C(60)(C(6)H(4)Cl(2), C(6)H(5)CN)(2) (1) (C(6)H(4)Cl(2) = 1,2-dichlorobenzene; C(6)H(5)CN = benzonitrile), has been obtained as single crystals by the diffusion method. The IR and UV-vis-NIR spectra show the presence of the C(60)(2)(-) and the Cp(2)Co(+) ions, which form a three-dimensional framework with channels accommodating solvent molecules. EPR and SQUID measurements show that C(60)(2)(-) has a diamagnetic singlet (S = 0) state in the 2-140 K range. The appearance of a broad EPR signal and the increase in magnetic susceptibility of 1 above 140 K are assigned to a thermal population of a close lying triplet (S = 1) state. The singlet-triplet energy gap for C(60)(2)(-) in solid 1 is estimated to be 730+/-10 cm(-)(1).     

Acetonitrile-facilitated reductive dimerization of TCNE to octacyanobutanediide, [C4(CN)8]2-, by Iron(II) chloride

The redox properties of MCl2 (M=Mn, Fe, Co) acetonitrile solvates were electrochemically and spectroscopically characterized. The three voltammogram waves at 0.86, 0.48, and 0.21 V versus SCE for FeCl(2) dissolved in MeCN are assigned as one-electron reduction potentials for [Fe(II)Cl(x)(NCMe)4-x]2-x (1相似文献   

Formation of single-bonded (C60-)2 and (C70-)2 dimers in crystalline ionic complexes of fullerenes

New ionic complexes of fullerenes C(60) and C(70) with decamethylchromocene Cp*(2)Cr.C60.(C(6)H(4)Cl(2))(2) (1), Cp*(2)Cr.C60.(C(6)H(6))(2) (2); the multicomponent complex of (Cs(+))(C70-) with cyclotriveratrylene CTV.(Cs)(2).(C70)(2).(DMF)(7).(C(6)H(6))(0.75) (3); bis(benzene)chromium Cr(C(6)H(6))(2).C60.(C(6)H(4)Cl(2))(0.7) (4), Cr(C(6)H(6))(2).C60.C(6)H(5)CN (5), Cr(C(6)H(6))(2).C70.C(6)H(4)Cl(2) (6), Cr(C(6)H(6))(2).C60 (7); cobaltocene Cp(2)Co.C60.C(6)H(4)Cl(2) (8), Cp(2)Co.C70.(C(6)H(4)Cl(2))(0.5) (9); and cesium Cs.C70.(DMF)(5) (10) have been obtained. The complexes have been characterized by the elemental analysis, IR-, UV-vis-NIR spectroscopy, EPR and SQUID measurements. It is shown that C(60)(.-) exists as a single-bonded diamagnetic (C60-)2 dimer in 1, 2, 4, 5, and 8 at low temperatures (1.9-250 K). The dimers dissociate above 160-250 K depending on donor and solvent molecules involved in the complex. C60(.-) dimerizes reversibly and shows a small hysteresis (<2 K) at slow cooling and heating rates. The single-bonded diamagnetic (C70-)2 dimers are also formed in 6, 9, and 10 and begin to dissociate only above 250-360 K. The IR and UV-vis-NIR spectra of sigma-bonded negatively charged fullerenes are presented.     

Polymorphic coordination networks responsive to CO2, moisture, and thermal stimuli: porous cobalt(II) and zinc(II) fluoropyrimidinolates

The novel porous [{M(F-pymo)(2)}(n)]2.5n H(2)O coordination networks (M=Co, Zn; F-pymo=5-fluoropyrimidin-2-olate), possessing sodalitic topology, have been synthesised and structurally characterised by means of powder diffraction methods. Thermodiffractometry demonstrated their plasticity: when heated up to 363 K, they reversibly transform into three-dimensional dehydrated [{M(F-pymo)(2)}(n)] species, with significantly different lattice parameters. Further heating induces irreversible polymorphic transformations into layered phases, in which the original MN(4) coordination sphere changes into an MN(3)O one. A mixed-metal phase, [{Co(x)Zn(1-x)(F-pymo)(2)}(n)]2.5n H(2)O, was also prepared, showing that zinc is preferentially inserted, when starting from a Co/Zn reagent ratio of 1:1. The solid-gas adsorption properties of the anhydrous 3D frameworks have been explored towards N(2), H(2) (77 K) and CH(4), CO(2) (273 K). These results show that these materials permit the diffusion of CO(2) molecules only. Remarkably, the CO(2) adsorption process for the [{Co(F-pymo)(2)}(n)] network proceeds in two steps: the first step takes place at low pressures (<600 kPa) and the second one above a threshold pressure of 600 kPa. By contrast, the [{Zn(F-pymo)(2)}(n)] network only permits CO(2) diffusion by applying pressures above 900 kPa. This type of behaviour is typical of porous networks with gated channels. The high CO(2) selectivity of these systems over the rest of the essayed probe gases is explained in terms of flexibility and polarity of the porous network. Finally, the magnetic studies on the Co(II) systems reveal that the as synthesised [{Co(F-pymo)(2)}(n)]2.5n H(2)O material behaves as an antiferromagnet with a T(N) of about 29 K. At variance, the [{Co(F-pymo)(2)}(n)] layered phase shows an unusually weak ferromagnetic ordering below 17 K, arising from a spin-canting phenomenon.     

Crystal environments probed by EPR spectroscopy. Variations in the EPR spectra of Co(II)(octaethylporphyrin) doped in crystalline diamagnetic hosts and a reassessment of the electronic structure of four-coordinate cobalt(II)

The powder and single-crystal EPR spectra of Co(II)(OEP) (OEP is the dianion of octaethylporphyrin) doped into a range of diamagnetic crystals including simple four-coordinate hosts, H(2)(OEP), the triclinic B form of Ni(II)(OEP), the tetragonal form of Ni(II)(OEP) and Zn(II)(OEP); five-coordinate hosts, micro-dioxane)[Zn(II)(OEP)](2) and (py)Zn(II)(OEP); six-coordinate hosts, (py)(2)Zn(II)(OEP) and (py)(2)Mg(II)(OEP); and hosts containing fullerenes, C(60).2Zn(II)(OEP).CHCl(3), C(70).Ni(II)(OEP).C(6)H(6).CHCl(3), and C(60).Ni(II)(OEP).2C(6)H(6) have been obtained and analyzed. Spectra were simulated using a program that employed the exact diagonalization of the 16 x 16 complex spin Hamiltonian matrix. The EPR spectra of these doped samples are very sensitive to the environment within each crystal with the crystallographic site symmetry determining whether axial or rhombic resonance patterns are observed. For Co(II)(OEP) doped into tetragonal Ni(II)(OEP) (which displays a very large g( perpendicular ) of 3.405 and a very small g( parallel ) of 1.544) and several other crystals containing four-coordinate metal sites, the g components could not be fit using existing theory with the assumption of the usual z(2) ground state. However, reasonable agreement of the observed EPR parameters could be obtained by assuming that the unpaired electron resides in an xy orbital in the four-coordinate complexes.     

Dilacunary decatungstates functionalized by organometallic ruthenium(II), [{Ru(C6H6)(H2O)}{Ru(C6H6)}(gamma-XW10O36)]4- (X = Si, Ge)

The benzene-Ru(II)-supported dilacunary decatungstosilicate [{Ru(C6H6)(H2O)}{Ru(C6H6)}(gamma-SiW10O36)]4- and the isostructural decatungstogermanate [{Ru(C6H6)(H2O)}{Ru(C6H6)}(gamma-GeW10O36)]4- have been synthesized and characterized by multinuclear solution NMR, IR, elemental analysis, and electrochemistry. Single-crystal X-ray analysis was carried out on K4[{Ru(C6H6)(H2O)}{Ru(C6H6)}(gamma-SiW10O36)].9H2O (K-1), which crystallizes in the orthorhombic system, space group Pmn2(1), with a = 13.6702(3) A, b = 16.2419(4) A, c = 12.1397(2) A, and Z = 2, and on K4[{Ru(C6H6)(H2O)}{Ru(C6H6)}(gamma-GeW10O36)].7H2O (K-2), which also crystallizes in the orthorhombic system, space group Pmn2(1), with a = 13.6684(12) A, b = 16.297(2) A, c = 12.1607(13) A, and Z = 2. Polyanions 1 and 2 consist of a Ru(C6H6)(H2O) group and a Ru(C6H6) group linked to a dilacunary (gamma-XW10O36) Keggin fragment resulting in an assembly with idealized Cs symmetry. The Ru(C6H6)(H2O) group is bound at the lacunary polyanion site via two Ru-O(W) bonds, whereas the Ru(C6H6) group is bound on the side via three Ru-O(W) bonds. Polyanions 1 and 2 were synthesized in aqueous acidic medium at pH 2.5 by the reaction of [Ru(C6H6)Cl2]2 with [gamma-SiW10O36]8- and [gamma-GeW10O36]8-, respectively. The formal potentials are roughly the same for the first W waves of 1 and 2. However, important differences appear for the second W waves. These observations indicate different acid-base properties for the reduced forms of 1 and 2. Three oxidation processes were detected: the oxidation of the Ru center is followed first by irreversible electrocatalytic processes of the Ru-benzene moiety and then of the electrolyte. Comparison of this behavior with that of the precursor reagent, [Ru(C6H6)Cl2]2, was useful to understand the main oxidation processes. A ligand substitution reaction was observed upon addition of dimethyl sulfoxide (dmso) to 1, 2, or [Ru(C6H6)Cl2]2. This reaction facilitates substantially the oxidation of the Ru center. The dmso was oxidized with large electrocatalytic currents more efficiently in the presence of 1 and 2 than with [Ru(C6H6)Cl2]2.     

Neutral and ionic complexes of C60 with metal dibenzyldithiocarbamates. Reversible dimerization of C60*- in ionic multicomponent complex [Cr(I)(C6H6)2*+].(C60*-).0.5[Pd(dbdtc)2

New molecular complexes of C60 with metal(II) dibenzyldithiocarbamates, M(dbdtc)2.C60.0.5(C6H5Cl), where M=Cu(II), Ni(II), Pd(II), and Pt(II) and an ionic multicomponent complex [Cr(I)(C6H6)2*+].(C60*-).0.5[Pd(dbdtc)2] (Cr(C6H6)2: bis(benzene)chromium) were obtained. According to IR, UV-visible-NIR, and EPR spectra, involve neutral components, whereas 5 comprises neutral Pd(dbdtc)2 and C60*- and Cr(I)(C6H6)2*+ radical ions. The crystal structure of at 90 K reveals strongly puckered fullerene layers alternating with those composed of Pd(dbdtc)2. The Cr(I)(C6H6)2*+ radical cations are arranged between the layers. Fullerene radical anions form pairs within the layer with an interfullerene C...C contact of 3.092(2) A, indicating their monomeric state at 90 K. This contact is essentially shorter than the sum of van der Waals radii of two carbon atoms, and consequently, C60*- can dimerize. According to SQUID and EPR, single-bonded diamagnetic (C60-)2 dimers form in below 150-130 K on slow cooling and dissociate above 150-170 K on heating. The hysteresis was estimated to be 20 K. For the (C60-)2 dimers in, the dissociation temperature is the lowest among those for ionic complexes of C60 (160-250 K). Fast cooling of the crystals within 10 min from room temperature down to 100 K shifts dimerization temperatures to lower than 60 K. This shift is responsible for the retention of a monomeric phase of at 90 K in the X-ray diffraction experiment.     

Formation of μ(2)-hydroxo-bonded (MgPc)2OH- assemblies and (C60(-))2 dimers in ionic fullerene {(MgPc)2OH-}2·(C60(-))2·(cation+)4 complexes

Ionic complexes containing μ(2)-hydroxo-bonded (MgPc)(2)OH(-) phthalocyanine assemblies and C(60)(-) anions: {(MgPc)(2)OH(-)}(2)·(C(60)(-))(2)·(PMDAE(+))(4)·(C(6)H(5)CN)(4) (1); {(MgPc)(2)OH(-)}(2)·(C(60)(-))(2)·(TMP(+))(4)·(C(6)H(5)CN)(3)·(C(6)H(4)Cl(2))(2.5) (2) (where PMDAE(+) is the cation of N,N,N',N',N'-pentamethyldiaminoethane and TMP(+) is the N,N'N'-trimethylpiperazinium cation) have been obtained as single crystals. The ionic ground state of the complexes is justified by the EPR spectra and the spectra in the IR and NIR ranges. The C(60)˙(-) radical anions are dimerized both in 1 and 2 in the 240-220 K range. Dimerization is accompanied by the reversible transition of the complexes from paramagnetic to diamagnetic state. MgPc forms unusual (MgPc)(2)OH(-) assemblies, in which the hydroxo-anion coordinates to two MgPc molecules by a μ(2)-fashion. The length of the Mg-O bonds is 1.936-1.955(2) ?, the Mg-O-Mg angle is 133.37-135.27(4)° and the displacement of the Mg atoms out of the mean 24-atom phthalocyanine plane is 0.77-0.86 ?. The packing of spherical fullerene and planar phthalocyanine molecules is attained in a crystal by the insertion of fullerenes between phenylene groups of phthalocyanines. It has been shown that metal phthalocyanines in ionic complexes with C(60) form M(II)Pc·(L(-)) assemblies, whereas metalloporphyrins form M(II)porphyrin·(C(+)) assemblies.     

New magnetic copper(II) coordination polymers with the polynitrile ligand (C[C(CN)2]3)2- and N-donor co-ligands

Reactions between CuCl2 and K2tcpd (tcpd2- = [C10N6]2- = (C[C(CN)2]3)2-) in the presence of neutral co-ligands (bpym = 2,2'-bipyrimidine, and tn = 1,3-diaminopropane) in aqueous solution yield the new compounds [Cu2(bpym)(tcpd)2(H2O)4] x 2H2O (1), [Cu(tn)(tcpd)] (2), and [Cu(tn)2(tcpd)] x H2O (3), which are characterized by X-ray crystallography and magnetic measurements. Compound 1 displays a one-dimensional structure in which the bpym ligand, acting with a bis-chelating coordination mode, leads to [Cu2(bpym)]4+ dinuclear units which are connected by two mu2-tcpd2- bridging ligands. Compound 2 consists of a three-dimensional structure generated by [Cu(tn)]2+ units connected by a mu4-tcpd2- ligand. The structure of 3 is made up of centrosymmetric planar [Cu(tn)]2+ units connected by a mu2-tcpd2- ligand leading to infinite zigzag chains. In compounds 1 and 3, the bridging coordination mode of the tcpd2- unit involves only two nitrogen atoms of one C(CN)2 wing, while in 2, this ligand acts via four nitrogen atoms of two C(CN)2 wings. Despite this difference, the structural features of the tcpd2- units in 1-3 are essentially similar. Magnetic measurements for compound 1 exhibit a maximum in the chi(m) vs T plot (at approximately 150 K) which is characteristic of strong antiferromagnetic exchange interactions between the Cu(II) metal ions dominated by the magnetic exchange through the bis-chelating bpym. The fit of the magnetic data to a dimer model gives J and g values of -90.0 cm(-1) and 2.12, respectively. For compounds 2 and 3 the thermal variations of the magnetic susceptibility show weak antiferromagnetic interactions between the Cu(II) metal ions that can be well reproduced with an antiferromagnetic regular S = 1/2 chain model that gives J values of -0.07(2) and -0.18(1) cm(-1) with g values of 2.12(1) and 2.13(1) for compounds 2 and 3, respectively (the Hamiltonian is written in all the cases as H = -2JS(a)S(b)).     

Formation and coordination modes of the C4E4 moiety (E = COOMe) bound to two palladium(II) moieties

The transmetallation of the palladacyclopentadiene complex Pd{C(COOMe)C(COOMe)C(COOMe)C(COOMe)}(bipy) with the dicationic Pd(II) complex [Pd(bipy)(CH(3)CN)(2)][BF(4)](2) afforded a terminally σ-palladated diene complex [Pd(2){μ-η(1):η(1)-C(COOMe)C(COOMe)C(COOMe)C(COOMe)}(bipy)(2)(CH(3)CN)(2)][BF(4)](2). It was revealed by X-ray crystallographic analysis that replacement of the acetonitrile ligands in a terminally σ-palladated diene complex with PPh(3) ligands resulted in the conformation change of the σ-palladated diene moiety from skewed s-cis to planar s-trans. Treatment of a bis-triphenylphosphine dipalladium complex [Pd(2)(PPh(3))(2)(CH(3)CN)(4)][PF(6)](2) with dimethoxyacetylene dicarboxylate (DMAD) (1 equiv.) in acetonitrile resulted in the insertion of DMAD to the Pd-Pd bond to afford [Pd(2){μ-η(1):η(1)-C(COOMe)C(COOMe)}(PPh(3))(2)(CH(3)CN)(4)][PF(6)](2). Addition of the second DMAD gave the ylide-type complex [Pd(2){μ-η(2):η(3)-C(COOMe)C(COOMe)C(COOMe)C(COOMe)(PPh(3))}(PPh(3))(2)(CH(3)CN)(3)][PF(6)](2) of which the structure was determined by X-ray crystallographic analysis.     

2[Mn(acacen)]+ + 1[Fe(CN)5NO]- polynuclear heterobimetallic coordination compounds of different dimensionality in the solid state

Depending on the synthetic conditions, five heterometallic Mn(III)Fe(II) polynuclear compounds with the same ratio of constituents, 2[Mn(acacen)](+)/[Fe(CN)(5)NO](2-), of different nuclearity and dimensionality (0D, 1D, 2D) were isolated. A [Mn(acacen)MeOH](2)[Fe(CN)(5)NO]·1.5MeOH, 1 complex has been prepared by reaction of Mn(III)/Schiff base (SB) complex, [Mn(acacen)Cl] (H(2)acacen is N,N'-ethylenebis(acetylacetoneimine)) with sodium nitroprusside (NP). Single crystal X-ray diffraction analyses reveal that crystallization of 1 from coordinating or non-coordinating solvents results in different coordination polynuclear materials: from C(2)H(5)OH [{Mn(acacen)H(2)O}(2)Fe(CN)(5)NO]·C(2)H(5)OH, 2, a trinuclear complex is formed; from CH(3)CN [{Mn(acacen)H(2)O}(4)Fe(CN)(5)NO][Fe(CN)(5)NO]·4CH(3)CN, an ionic compound with a pentanuclear bimetallic cation is formed 3; from i-C(3)H(7)OH [{Mn(acacen)}(2)(i-PrOH)Fe(CN)(5)NO](n), a coordination chain polymer 4 is formed; from toluene [{Mn(acacen)}(2)Fe(CN)(5)NO](n), a layered network 5 is formed. As the magnetic measurements show, for all compounds the weak interaction between Mn(III)S = 2 spins through the NP bridge is antiferromagnetic and exhibits no significant photoactivity.     

Pentanuclear cyanide-bridged complexes based on highly anisotropic Co(II) seven-coordinate building blocks: synthesis, structure, and magnetic behavior

Pentagonal-bipyramidal complexes [Co(DABPH)X(H(2)O)]X [X = NO(3) (1), Br (2), I (3)] were synthesized, and their magnetic behavior was investigated. Simulation of the magnetization versus temperature data revealed the complexes to be highly anisotropic (D ≈ +30 cm(-1)) and the magnitude of the anisotropy to be independent of the nature of the axial ligands. The reaction of 1 with K(3)[M(CN)(6)] (M = Cr, Fe) produces the pentametallic clusters [{Co(DABPH)}(3){M(CN)(6)}(2)(H(2)O)(2)] [M = Cr (4), Fe (5)]. Both clusters consist of three {Co(DABPH)} moieties separated by two {M(CN)(6)} fragments. In 4, the central and terminal Co(II) ions are bound to cyanide groups cis to one another on the bridging {Cr(CN)(6)}, whereas in 5, the connections are via trans cyanide ligands, resulting in the zigzag and linear structures observed, respectively. Magnetic investigation revealed ferromagnetic intramolecular interactions; however, the ground states were poorly isolated because of the large positive local anisotropies of the Co(II) ions. The effects of the local anisotropies appeared to dominate the behavior in 5, where the magnetic axes of the Co(II) ions were approximately colinear, compared to 4, where they were closer to orthogonal.     

The satellite-shaped Co-15 Polyoxotungstate, [Co6(H2O)30{Co9Cl2(OH)3(H2O)9(beta-SiW8O31)3}]5-

The 15-cobalt-substituted polyoxotungstate [Co(6)(H(2)O)(30){Co(9)Cl(2)(OH)(3)(H(2)O)(9)(beta-SiW(8)O(31))(3)}](5-) (1) has been characterized by single-crystal XRD, elemental analysis, IR, electrochemistry, magnetic measurements, and EPR. Single-crystal X-ray analysis was carried out on Na(5)[Co(6)(H(2)O)(30){Co(9)Cl(2)(OH)(3)(H(2)O)(9)(beta-SiW(8)O(31))(3)}].37H(2)O, which crystallizes in the hexagonal system, space group P6(3)/m, with a = 19.8754(17) A, b = 19.8754(17) A, c = 22.344(4) A, alpha= 90 degrees, beta = 90 degrees, gamma = 120 degrees, and Z = 2. The trimeric polyanion 1 has a core of nine Co(II) ions encapsulated by three unprecedented (beta-SiW(8)O(31)) fragments and two Cl(-) ligands. This central assembly {Co(9)Cl(2)(OH)(3)(H(2)O)(9)(beta-SiW(8)O(31))(3)}(17-) is surrounded by six antenna-like Co(II)(H(2)O)(5) groups resulting in the satellite-like structure 1. Synthesis of 1 is accomplished in a simple one-pot procedure by interaction of Co(II) ions with [gamma-SiW(10)O(36)](8-) in aqueous, acidic NaCl medium (pH 5.4). Polyanion 1 was studied by cyclic voltammetry as a function of pH. The current intensity of its Co(II) centers was compared with that of free Co(II) in solution. Our results suggest that 1 keeps its integrity in solution. Magnetic susceptibility results show the presence of both antiferro- and ferromagnetic coupling within the (Co(II))(9) core. A fully anisotropic Ising model has been employed to describe the exchange-coupling and yields g = 2.42 +/- 0.01, J(1) = 17.0 +/- 1.5 cm(-1), and J(2) = -13 +/- 1 cm(-(1). Variable frequency EPR studies reveal an anisotropic Kramer's doublet.     

The role of carboxylate ligands in two novel cyanido-bridged 2D coordination networks Cu(II)-W(V) and Mn(II)-Nb(IV)

We report on the synthesis, molecular structure and magnetic properties of two novel coordination polymers: [{Cu(II)(4)(pic)(2)(H(2)O)(2)(MeOH)}{W(V)(CN)(8)}(2)]·MeOH·4H(2)O (1) and [{Mn(II)(3)(HCOO)(2)(H(2)O)(4)}{Mn(II)(H(2)O)(3)(HCONH(2))}(2){Nb(IV)(CN)(8)}(2)]·4HCONH(2)·2H(2)O (2). The single-crystal X-ray diffraction analysis of 1 shows that its molecular structure can be interpreted as a cyanido bridged (3,4,7)-connected 2D bilayer built of two different subnets sharing the tungsten centers. The magnetic measurements suggest that the system reveals long-range ferromagnetic ordering between Cu(II) and W(V) centers below 13.4 K. The molecular structure of (2) reveals a 2D topology of layers built of cyanido and formato bridging ligands. The system reveals ferrimagnetic behavior with a critical temperature at 17.8 K.     

The reversible formation of a single-bonded (C(60)(-))(2) dimer in ionic charge transfer complex: Cp*(2)Cr.C(60)(C(6)H(4)Cl(2))(2). The molecular structure of (C(60)(-))(2)

A new ionic complex of C60 with decamethylchromocene, Cp*2Cr.C60(C6H4Cl2)2 (1), has been obtained. The fullerides are monomeric in 1 at room temperature, whereas they form a single-bonded (C60-)2 dimer at low temperatures, the structure of which has been studied by the X-ray diffraction on a single crystal at 100 K. The length of the intercage C-C bond is 1.597(7) A and the interfullerene distance is equal to 9.28 A. A phase transition attributed to the reversible C60*- dimerization is observed in the 220-200 K range. The transition is accompanied by changes in the unit cell parameters, the decrease of the magnetic moment from 4.20 muB (S = 3/2, 1/2) to 3.88 muB (S = 3/2) and the appearance of EPR signal from Cp*2Cr+, simultaneously.     

Synthesis and structural characterization of bi- and trimetallic octacyanometalate(IV) complexes: [Delta,Lambda-MII(en)3][cis-MII(en)2(OH2)][MIV(CN)8].2H2O and [cis-MII(en)2(OH2)]2[(mu-NC)2MIV(CN)6].4H2O (MII = Mn, Co, Ni; MIV = Mo, W)

Treatment of [M(II)(en)(3)][OTs](2) or methanolic ethylenediamine solutions containing transition metal p-toluenesulfonates (M(II) = Mn, Co) with aqueous K(4)M(IV)(CN)(8).2H(2)O or Cs(3)M(V)(CN)(8) (M(IV) = Mo, W; M(V) = Mo) affords crystalline clusters of [M(II)(en)(3)][cis-M(II)(en)(2)(OH(2))(mu-NC)M(IV)(CN)(7)].2H(2)O (M(IV) = Mo; M(II) = Mn, 1; Ni, 5; M(IV) = W; M(II) = Mn, 2; Ni, 6) and [cis-M(II)(en)(2)(OH(2))](2)[(mu-NC)(2)M(IV)(CN)(6)].4H(2)O (M(IV) = Mo; M(II) = Co, 3; Ni, 7; M(IV) = W; M(II) = Co, 4) stoichiometry. Each cluster contains cis-M(II)(en)(2)(OH(2))(mu-NC)(2+) units that likely result from dissociative loss of en from [M(II)(en)(3)](2+), affording cis-M(II)(en)(2)(OH(2))(2)(2+) intermediates that are trapped by M(IV)(CN)(8)(4-).