Crystal chemistry and physical properties of superconducting and semiconducting charge transfer salts of the type (BEDT-TTF)(4)[A(I)M(III)(C2O4)3]*PhCN (A(I) = H30,NH4,K; M(III) = Cr, Fe, Co, Al; BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene

Synthesis, structure determination by single-crystal X-ray diffraction, and physical properties are reported and compared for superconducting and semiconducting molecular charge-transfer salts with stoichiometry (BEDT-TTF)(4)[A(I)M(III)(C(2)O(4))(3)].PhCN, where A(I) = H(3)O, NH(4), K; M(III) = Cr, Fe, Co, Al; BEDT-TTF = bis(ethylenedithio) tetrathiafulvalene. Attempts to substitute M(III) with Ti, Ru, Rh, or Gd are also described. New compounds with M = Co and Al are prepared and detailed structural comparisons are made across the whole series. Compounds with A = H(3)O(+) and M = Cr, Fe are monoclinic (space group C2/c), at 150, 120 K a = 10.240(1) A, 10.232(12) A; b = 19.965(1) A, 20.04(3) A; c = 34.905(1) A, 34.97(2) A; beta = 93.69(1) degrees, 93.25(11) degrees, respectively, both with Z = 4. These salts are metallic at room temperature, becoming superconducting at 5.5(5) or 8.5(5) K, respectively. A polymorph with A = H(3)O(+) and M = Cr is orthorhombic (Pbcn) with a = 10.371(2) A, b = 19.518(3) A, c = 35.646(3) A, and Z = 4 at 150 K. When A = NH(4)(+), M = Fe, Co, Al, the compounds are also orthorhombic (Pbcn), with a = 10.370(5) A, 10.340(1) A, 10.318(7) A; b = 19.588(12) A, 19.502(1) A, 19.460(4) A; c = 35.790(8) A, 35.768(1) A, 35.808(8) A at 150 K, respectively, with Z = 4. All of the Pbcn phases are semiconducting with activation energies between 0.15 and 0.22 eV. For those compounds which are thought to contain H(3)O(+), Raman spectroscopy or C=C and C-S bond lengths of the BEDT-TTF molecules confirm the presence of H(3)O(+) rather than H(2)O. In the monoclinic compounds the BEDT-TTF molecules adopt a beta' ' packing motif while in the orthorhombic phases (BEDT-TTF)(2) dimers are surrounded by monomers. Raman spectra and bond length analysis for the latter confirm that each molecule of the dimer has a charge of +1 while the remaining donors are neutral. All of the compounds contain approximately hexagonal honeycomb layers of [AM(C(2)O(4))(3)] and PhCN, with the solvent occupying a cavity bounded by [M(C(2)O(4))(3)](3-) and A. In the monoclinic series each layer contains one enantiomeric conformation of the chiral [M(C(2)O(4))(3)](3-) anions with alternate layers having opposite chirality, whereas in the orthorhombic series the enantiomers form chains within each layer. Analysis of the supramolecular organization at the interface between the cation and anion layers shows that this difference is responsible for the two different BEDT-TTF packing motifs, as a consequence of weak H-bonding interactions between the terminal ethylene groups in the donor and the [M(C(2)O(4))(3)](3-) oxygen atoms.     

Oxidation-promoted synthesis of ferrocenyl planar chiral rhodium(iii) complexes for C–H functionalization catalysis

The chemical oxidation of rhodium(i) complexes [Rh(L)(COD)][BF4], where L is a ferrocenyl phosphine/N-heterocyclic carbene ligand, with 2 equiv. of a triaryl-aminium salt [(4-BrC6H4)3N][BF4] in acetonitrile gave planar chiral, air-stable [Rh(L–H)(MeCN)3][BF4]2 complexes where the ferrocene (C5H4CH2ImR or C5H4CH2BImCH2Mes) ring has been C–H activated at the position 2 in good to excellent yields. An important reactivity difference between our complexes and the ubiquitous [Cp*Rh(MeCN)3]X2 complex has been observed in the Grignard-type arylation of 4-nitrobenzaldehyde.     

Synthesis and Crystal Structure of N-Phenylbis（ferrocenecarboxyl）imide

The ferrocenyl compound,N-phenylbis(ferrocenecarboxyl)imide (C28H23NO2Fe2,Mr=517.17),was synthesized and structurally characterized by means of X-ray single-crystal dif-fraction. It crystallizes in monoclinic,space group C2/c with a=21.374(14),b=10.430(7),c= 10.741(7) ,β=114.184(8)°,V=2184(2) 3,Z=4,Dc=1.573 g/cm3,F(000)=1064,μ(MoKα)= 1.355 mm–1,T=291(2) K,the final R=0.0548 and wR=0.1437 for 1524 observed reflections with I > 2σ(I). In this compound,the nitrogen atom links two ferrocenyl groups and one phenyl group forming a novel imido derivative.     

Relationship between electrochemical potentials and substitution reaction rates of ferrocene-containing β-diketonato rhodium(I) complexes; cytotoxicity of [Rh(FcCOCHCOPh)(cod)

A series of ferrocene-containing rhodium complexes of the type [Rh(FcCOCHCOR)(cod)] (cod = 1,5-cyclooctadiene) with R = CF(3), 1, (E(pa)(Rh) = 269; E(o)'(Fc) = 329 mV vs. Fc/Fc(+)), CCl(3), 2, (E(pa) = 256; E(o)' = 312 mV), CH(3), 3, (E(pa) = 177; E(o)' = 232 mV), Ph = C(6)H(5), 4, (E(pa) = 184; E(o)' = 237 mV), and Fc = ferrocenyl = (C(5)H(5))Fe(C(5)H(4)), 5, (E(pa) = 135; E(o)'(Fc1) = 203; E(o)'(Fc2) = 312 mV), have been studied electrochemically in CH(3)CN. Results indicated that the rhodium(I) centre is irreversibly oxidised to Rh(III) in a two-electron transfer process before the ferrocenyl fragment is reversibly oxidized in a one-electron transfer process. The peak anodic (oxidation) potential, E(pa), (in V vs. Fc/Fc(+)) of the rhodium core in 1-5 relates to k(2), the second-order rate constant for the substitution of (FcCOCHCOR)(-) with 1,10-phenanthroline in [Rh(FcCOCHCOR)(cod)] to form [Rh(phen)(cod)](+) in methanol at 25 °C with the equation lnk(2) = 39.5 E(pa)(Rh) - 3.69, while the formal oxidation potential of the ferrocenyl groups in 1-5 relates to k(2) by lnk(2) = 40.8 E(o)'(Fc)-6.34. Complex 4 (IC(50) = 28.2 μmol dm(-3)) was twice as cytotoxic as the free FcCOCH(2)COPh ligand having IC(50) = 54.2 μmol dm(-3), but approximately one order of magnitude less toxic to human HeLa neoplastic cells than cisplatin (IC(50) = 2.3 μmol dm(-3)).     

Two-coordinate, quasi-two-coordinate, and distorted three coordinate, T-shaped chromium(II) amido complexes: unusual effects of coordination geometry on the lowering of ground state magnetic moments

The synthesis and characterization of the mononuclear chromium(II) terphenyl substituted primary amido-complexes Cr{N(H)Ar(Pr(i)(6))}(2) (Ar(Pr(i)(6)) = C(6)H(3)-2,6-(C(6)H(2)-2,4,6-(i)Pr(3))(2) (1), Cr{N(H)Ar(Pr(i)(4))}(2) (Ar(Pr(i)(4)) = C(6)H(3)-2,6-(C(6)H(3)-2,6-(i)Pr(2))(2) (2), Cr{N(H)Ar(Me(6))}(2) (Ar(Me(6)) = C(6)H(3)-2,6-(C(6)H(2)-2,4,6-Me(3))(2) (4), and the Lewis base adduct Cr{N(H)Ar(Me(6))}(2)(THF) (3) are described. Reaction of the terphenyl primary amido lithium derivatives Li{N(H)Ar(Pr(i)(6))} and Li{N(H)Ar(Pr(i)(4))} with CrCl(2)(THF)(2) in a 2:1 ratio afforded complexes 1 and 2, which are extremely rare examples of two coordinate chromium and the first stable chromium amides to have linear coordinated high-spin Cr(2+). The reaction of the less crowded terphenyl primary amido lithium salt Li{N(H)Ar(Me(6))} with CrCl(2)(THF)(2) gave the tetrahydrofuran (THF) complex 3, which has a distorted T-shaped metal coordination. Desolvation of 3 at about 70 °C gave 4 which has a formally two-coordinate chromous ion with a very strongly bent core geometry (N-Cr-N= 121.49(13)°) with secondary Cr--C(aryl ring) interactions of 2.338(4) ? to the ligand. Magnetometry studies showed that the two linear chromium species 1 and 2 have ambient temperature magnetic moments of about 4.20 μ(B) and 4.33 μ(B) which are lower than the spin-only value of 4.90 μ(B) typically observed for six coordinate Cr(2+). The bent complex 4 has a similar room temperature magnetic moment of about 4.36 μ(B). These studies suggest that the two-coordinate chromium complexes have significant spin-orbit coupling effects which lead to moments lower than the spin only value of 4.90 μ(B) because λ (the spin orbit coupling parameter) is positive. The three-coordinated complex 3 had a magnetic moment of 3.79 μ(B).     

Electrochemical illumination of intramolecular communication in ferrocene-containing tris-β-diketonato aluminum(III) complexes; cytotoxicity of Al(FcCOCHCOCF3)3

The series of ferrocene-containing tris-β-diketonato aluminum(III) complexes [Al(FcCOCHCOR)(3)] (R = CF(3), 1; CH(3), 2; C(6)H(5), 3; and Fc = ferrocenyl = Fe(η(5)-C(5)H(5))(η(5)-C(5)H(4)), 4) were synthesized and investigated structurally and electrochemically; complex 1 was subjected to cytotoxicity tests. (1)H NMR-spectroscopy distinguished between the mer and fac isomers of 2 and 3. Complex 1 existed only as the mer isomer. A single crystal X-ray crystallographic determination of the structure of a mer-isomer of Al(FcCOCHCOCF(3))(3), 1, (Z = 4, space group P2(1)2(1)2(1)) demonstrated extensive delocalization of all bonds which explained the pronounced electrochemically observed intramolecular communication between molecular fragments. In contrast to electrochemical studies in CH(2)Cl(2)/[N((n)Bu)(4)][PF(6)], the use of the supporting electrolyte [N((n)Bu)(4)][B(C(6)F(5))(4)] allowed identification of all Fc/Fc(+) electrochemical couples by cyclic and square wave voltammetry for 1-4. For R = Fc, formal reduction potentials of the six ferrocenyl groups were found to be E°' = 33, 123, 304, 432, 583, and 741 mV versus free ferrocene respectively. Complex 1 (IC(50) = 10.6 μmol dm(-3)) was less cytotoxic than the free FcCOCH(2)COCF(3) ligand having IC(50) = 6.8 μmol dm(-3) and approximately 2 orders of magnitude less toxic to human HeLa neoplastic cells than cisplatin (IC(50) = 0.19 μmol dm(-3)).     

Pentasubstituted ferrocene and dirhodium(II) tetracarboxylate as building blocks for discrete fullerene-like and extended supramolecular structures

The synthesis of a penta(1-methylpyrazole)ferrocenyl phosphine oxide ligand (1) [Fe(C(5)(C(3)H(2)N(2)CH(3))(5))(C(5)H(4)PO(t-C(4)H(9))(2))] is reported together with its X-ray crystal structure. Its self-assembly behavior with a dirhodium(II) tetraoctanoate linker (2) [Rh(2)(O(2)CC(7)H(15))(4)] was investigated for construction of fullerene-like assemblies of composition [(ligand)(12)(linker)(30)]. Reaction between 1 and 2 in acetonitrile resulted in the formation of a light purple precipitate (3). Evidence for the ligand-to-linker ratio of 1:2.5 expected for a fullerene-like structure [Fe(C(5)(C(3)H(2)N(2)CH(3))(5))(C(5)H(4)PO(t-C(4)H(9))(2))](12)[Rh(2)(O(2)CC(7)H(15))(4)](30) was obtained from (1)H NMR and elemental analysis. IR and Raman studies confirmed the diaxially bound coordination environment of the dirhodium linker by comparing the stretching frequencies of the carboxylate group and the rhodium-rhodium bond with those in model compound (5), [Rh(2)(O(2)CC(7)H(15))(4)](C(3)H(3)N(2)CH(3))(2), the bis-adduct of linker 2 with 1-methylpyrazole. X-ray powder diffraction and molecular modeling studies provide additional support for the formation of a spherical molecule topologically identical to fullerene with a diameter of approximately 38 ? and a molecular formula of [(1)(12)(2)(30)]. Dissolution of 3 in tetrahydrofuran (THF) followed by layering with acetonitrile afforded purple crystals of [(1)(2)(2)](∞) (6) [Fe(C(5)(C(3)H(2)N(2)CH(3))(5))(C(5)H(4)PO(t-C(4)H(9))(2))][Rh(2)(O(2)CC(7)H(15))(4)](2) with a two-dimensional polymeric structure determined by X-ray crystallography. The dirhodium linkers link ferrocenyl units by coordination to the pyrazoles but only four of the five pyrazole moieties of the pentapyrazole ligand are coordinated. The ligand-to-linker ratio of 1:2 in 6 was confirmed by (1)H NMR spectroscopy and elemental analysis, while results from IR and Raman are in agreement with the diaxially coordinated environment of the linker observed in the solid state.     

邻羧基苯甲酰二茂铁钠的合成、晶体结构及电化学性质

参照文献方法合成了邻羧基苯甲酰二茂铁钠,首次培养得到了它的单晶．发现在其固态结构中,邻羧基苯甲酰二茂铁阴离子与四水合钠阳离子通过分子内氢键相互作用;分子间的氢键又把多个二茂铁衍生物分子连接成二维的网状结构．研究了标题化合物在甲醇溶液中的电化学性质．     

An in-depth correlation of perturbation of the organic-inorganic interface topology,electronic structure,and transport properties within beta''-(BEDT-TTF)(4) x (guest)(n) x [Re(6)Q(6)Cl(8)], (Q=S,Se)

An in-depth analysis of a set of 21 layered structures of metallic pseudopolymorphs of general formulation, beta'-(BEDT-TTF)(4) x (guest)(n) x [Re(6)Q(6)Cl(8)], (BEDT-TTF=bis-ethylenedithiotetrathiafulvalene; Q = S, Se; guest = H(2)O, 1,4-dioxane, THF, CCl(4), C(2)H(5)OH, CHCl(3), CH(2)ClI, CH(2)ClBr, CH(2)Cl(2), CH(2)OH-CH(2)OH, C(5)H(5)N, CH(3)COCH(3), 2-hydroxy-tetrahydrofuran, CH(3)CN, CS(2), C(6)H(6)), with diverse low-temperature behaviors, which differ solely by the nature of the cosolvent molecule selectively included during the electrocrystallization process, reveals a precise set of weak HO-H...Cl-mu-Re, (C-H)(BEDT-TTF)...Cl-mu-Re, C-H...O(guest), (C-H)(guest)...Cl-mu-Re hydrogen bonds at the organic-inorganic interface, none of which dominates any of the others and whose balance is adjusted upon substitution of one guest molecule by another. The electronic structure of the host adjusts to the weak perturbation imposed by exchanging the guest molecules and by balancing the former interfacial interactions; this correlates to a net activation of up to 0.1 eV of the energy of the HOMO level of one of the two donors, while keeping the pattern of HOMO-HOMO intermolecular interactions in the donor layer essentially unaltered. It is suggested that this controls the stability of the metallic state at low temperature or the occurrence of a metal-to-insulator phase transition for particular guests along the series. It is concluded that by allowing for numerous tiny modifications at the organic-inorganic interface within a single, robust host structure, one sees a concerted, inherently weak structural response of the system that is proportional to the magnitude of the underlying, equally weak activation of the HOMO energy of a fraction of the pi-donor molecules within the slabs; this has a sizeable influence on the macroscopic transport properties of the system.     

A chiral molecular conductor: synthesis, structure, and physical properties of [ET]3[Sb2(L-tart)2].CH3CN (ET = bis(ethylendithio)tetrathiafulvalene; L-tart = (2R,3R)-(+)-tartrate)

The salt [ET](3)[Sb(2)(L-tart)(2)].CH(3)CN (1) has been obtained by electrocrystallization of the organic donor bis(ethylendithio)tetrathiafulvalene (ET or BEDT-TTF) in the presence of the chiral anionic complex [Sb(2)(L-tart)(2)](2-) (L-tart = (2R,3R)-(+)-tartrate). This salt crystallizes in the chiral space group P2(1)2(1)2(1) (a = 11.145(2) angstroms, b = 12.848(2) angstroms, c = 40.159(14) angstroms, V = 5750.4(14) angstroms(3), Z = 4) and is formed by alternating layers of the anions and of the organic radicals in a noncentrosymmetric alpha-type packing. This compound shows a room temperature electrical conductivity of approximately 1 S.cm(-1) and semiconducting behavior with an activation energy of approximately 85 meV. Analysis of the magnetic susceptibility and band structure, however, suggests that this compound should be a narrow band gap semiconductor.     

beta-Diiminato ligand (L) transformations in reactions of KL with PI3 and I2 [L = {N(C6H3Pr(i)2-2,6)C(H)}2CPh

The reaction of the potassium beta-diiminate KL (L = [{N(Ar)C(H)}(2)CPh](-); Ar = C(6)H(3)Pr(i)(2)-2,6) with PI(3) unexpectedly produced a phosphenium salt of the intermolecularly C,C-coupled ligand [P(I){N(Ar)CH}(2)C(C(6)H(4)-4)C(Ph)(CH[double bond, length as m-dash]NAr)(2)](+)[I(3)](-), while an intramolecularly N,N-coupled salt [N[upper bond 1 start](Ar)C(H)C(Ph)C(H)N[upper bond 1 end](Ar)](+)[I(5)](-) was isolated from KL + I(2).     

The role of diisopropanolamine (dipaH3) in cluster dimerisation and polymerisation: from spin frustrated S= 5 FeIII 6 clusters to the novel 1-D covalent polymer of mixed valence [CoII3CoIII] tetramers

The synthesis, crystal structures and magnetic properties of two hexanuclear Fe(6) clusters of general formula [Fe(6)(O)(2)(OH)(2)(O(2)CR)(10)(dipaH(2))(2)].xMeCN.yH(2)O (R = Ph, x= 5.5, y= 1 (1), R = C(Me)(3), x= 2, y= 3 (2)) are reported. The presence of the flexible amino-alcohol ligand diisopropanolamine (dipaH(3)) induces the dimerisation of two trinuclear Fe(III) complexes, [Fe(3)O(O(2)CPh)(6)(H(2)O)(3)](NO(3)) and [Fe(3)O(O(2)CC(Me)(3))(6)(H(2)O)(3)](O(2)CC(Me)(3)), to form the hexanuclear clusters 1 and 2. DC magnetic susceptibility measurements on 1 and 2 assign ground spin states of S= 5, with zero-field splitting parameters (D) of ca. 0.25 cm(-1) obtained from magnetisation isotherms. AC susceptibilities showed no maxima as a function of frequency, at low temperatures, and this confirmed the lack of single-molecule magnetic behaviour. Clusters 1 and 2 are isostructural, consisting of two fused {Fe(3)O} trinuclear units, bridged in two positions by one mu(2)-OH(-) unit and two mu(2)-O(2)CR(-) bridging carboxylates (R = Ph (), C(Me)(3)()). The two singly deprotonated dipaH(2)(-) bridging ligands span the Fe1-Fe2 edges in and via one micro(2)-bridging alcohol arm and one terminal nitrogen atom while the second alcohol arm remains free. The ground spin state of S= 5 in 1 and 2 can be attributed to the presence of spin frustration within the system. 1 and 2 join a small family of spin frustrated S= 5 Fe(6) systems the magnetism of which give weight to a recent report that it is the trans position of the two shortest Fe(2) pair frustrated exchange pathways in these Fe(6) clusters that gives rise to a ground spin state of S= 5 (trans) and not a ground spin state of S= 0 (cis). The M?ssbauer spectra of 1 and 2 show two quadrupole doublets, as expected, at 295 K, but a broad asymmetric lineshape at 77 K. The synthesis and magnetic properties of {[Co(II)(3)Co(III)(OH)(O(2)CC(Me)(3))(4)(HO(2)CC(Me)(3))(2)(dipaH)(2)].2MeCN}(n)(3) are reported. 3 is a covalently bonded 1D polymer of tetrameric cobalt clusters. The presence of the dipaH(3) ligand here not only dimerises the [Co(II)(2)(micro-H(2)O)(O(2)CC(Me)(3))(4)(HO(2)CC(Me)(3))(4)] starting complex into the tetranuclear species but also polymerises the [Co(II)(3)Co(III)] clusters in 3 by acting as the propagating ligand in the 1D chain. Magnetic susceptibility measurements on show each [Co(4)] moiety exhibits weak antiferromagnetic coupling between the three Co(II)S= 3/2 metal centres and fitted J values are given. The ambiguity in assignment of the spin ground state of S= 1/2 or 3/2 is discussed.     

Synthesis and Crystal Structure of 4-Arylamino-6-chloropyrido[3,2-d]pyrimidine

The title compounds 4a～c were synthesized and characterized by IR,NMR and MS.The crystal structure of C16H13ClN4O2·HBr·H2O(I),the quaternary ammonium salt of 4c,was determined by X-ray diffraction analysis.I crystallizes in triclinic,space group P1 with a = 8.3121(8),b = 9.3885(8),c = 13.2903(12),α = 106.788(2),β = 95.204(3),γ = 110.871(2)o,V = 905.81(14)3,Z = 2,C16H16BrClN4O3,Mr = 427.68,Dc = 1.568 g/cm3,F(000) = 432.00,μ = 2.446 mm-1,R = 0.0496 and wR = 0.127.X-ray analysis reveals that C(15) in the BrCH2COOH molecule binds to the N(1) of pyrimidine ring to form the quaternary ammonium salt.Two adjacent I molecules are connected by hydrogen bonds through carboxylate oxygen,water molecule and hydrobromic acid.     

EPR studies on the thiophenodithiazolyl radical, C4H2S3N

Selective chlorination of thiophene-2,3-dithiol with SO(2)Cl(2) generates the corresponding sulfenyl chloride, 2,3-C(4)H(2)S(SCl)(2). Subsequent condensation with Me(3)SiN(3) yields the thiophenodithiazolylium salt [C(4)H(2)S(3)N]Cl, [TDTA]Cl. The structure of the cation, TDTA+, was established by X-ray diffraction as both its AsF(6)(-) and HSO(4)(-) salts. Reduction of [TDTA]Cl with Ag powder yields the radical TDTA* which was characterised by X- and Q-band (9 and 34 GHz) EPR and ENDOR studies. The spin density distributions estimated from the EPR/ENDOR measurements were found to be in very good agreement with those determined by DFT (B3LYP/6-31G*) indicating that ca 10% of the spin density is delocalised onto the thiophene ring. Comparison of the spin density distributions in TDTA* and the isoelectronic trithiatriazapentalenyl radical C(2)S(3)N(3), TTTA*, indicates that replacement of N by C-H leads to a localisation of the spin density on the dithiazolyl ring.     

Assemblies of redox-active metallodendrimers using hydrogen bonding for the electrochemical recognition of the H2PO4- and adenosine-triphosphate (ATP2-) anions

Two families of five metallodendrimers have been assembled by hydrogen bonding between the primary amino groups of DSM dendrimers G(n)-DAB-dendr-(NH(2))x (n = 1-5; x = 4, 8, 16, 32, 64) and the OH group of phenol dendrons containing a triallyl or a triferrocenylalkyl tripod in para position. These H-bonded dendrimers noted G(1)-DAB-12Fc, G(2)-DAB-24Fc, G(3)-DAB-48Fc, G(4)-DAB-96Fc, and G(5)-DAB-192Fc have been characterized as resulting from fast, reversible hydrogen bonding by the single broad signal observed in (1)H NMR for the three NH(2) + OH protons whose location depends on the concentration. The cyclic voltammograms (CVs) show a single reversible ferrocenyl wave due to the equivalence of these groups and the fast rotation of the supramolecular ensemble compared to the CV time scale. A new CV wave appears at less anodic potential upon addition of H(2)PO(4)(-) or adenosine-triphosphate (ATP(2)(-)) anion as a tetrabutylammonium salt as with previously studied ferrocenyl dendrimers. In addition, other specific and remarkable features are the fact that the new CV wave is much less intense than the initial one and the dramatically sudden disappearance of the initial CV wave at the equivalent point indicating the formation of a large supramolecular assembly with the hydrogenophosphate groups. Finally, the variation of the number of equivalent anions with the generation number to reach the equivalent point also suggests that the competition between the amino- and amido group for the interaction with hydrogenophosphate depends on the generation number. Recognition by these supramolecular dendrimers of H(2)PO(4)(-) and ATP(2)(-) follows the model of the relatively strong-interaction type in the Kaifer-Echegoyen model, which allows access to the ratio of association constants K(+)/K(0). A positive dendritic effect is found for the recognition of H(2)PO(4)(-) (i.e., the difference of potentials DeltaE(1/2) between the initial CV wave and the new one and the K(+)/K(0) value increase as the generation number increases) whereas the dendritic effect is slightly negative for the recognition of ATP(2)(-).     

Effect of counteranion X on the spin crossover properties of a family of diiron(II) triazole complexes [Fe(II)2(PMAT)2](X)4

Seven diiron(II) complexes, [Fe(II)(2)(PMAT)(2)](X)(4), varying only in the anion X, have been prepared, where PMAT is 4-amino-3,5-bis{[(2-pyridylmethyl)-amino]methyl}-4H-1,2,4-triazole and X = BF(4)(-) (1), Cl(-) (2), PF(6)(-) (3), SbF(6)(-) (4), CF(3)SO(3)(-) (5), B(PhF)(4)(-) (6), and C(16)H(33)SO(3)(-) (7). Most were isolated as solvates, and the microcrystalline ([3], [4]·2H(2)O, [5]·H(2)O, and [6]·?MeCN) or powder ([2]·4H(2)O, and [7]·2H(2)O) samples obtained were studied by variable-temperature magnetic susceptibility and Mo?ssbauer methods. A structure determination on a crystal of [2]·2MeOH·H(2)O, revealed it to be a [LS-HS] mixed low spin (LS)-high spin (HS) state dinuclear complex at 90 K, but fully high spin, [HS-HS], at 293 K. In contrast, structures of both [5]·?IPA·H(2)O and [7]·1.6MeOH·0.4H(2)O showed them to be [HS-HS] at 90 K, whereas magnetic and M?ssbauer studies on [5]·H(2)O and [7]·2H(2)O revealed a different spin state, [LS-HS], at 90 K, presumably because of the difference in solvation. None of these complexes undergo thermal spin crossover (SCO) to the fully LS form, [LS-LS]. The PF(6)(-) and SbF(6)(-) complexes, 3 and [4]·2H(2)O, appear to be a mixture of [HS-LS] and [HS-HS] at low temperature, and undergo gradual SCO to [HS-HS] on warming. The CF(3)SO(3)(-) complex [5]·H(2)O undergoes gradual, partial SCO from [HS-LS] to a mixture of [HS-LS] and [HS-HS] at T(1/2) ≈ 180 K. The B(PhF)(4)(-) and C(16)H(33)SO(3)(-) complexes, [6]·(1)/(2)MeCN and [7]·2H(2)O, are approximately [LS-HS] at all temperatures, with an onset of gradual SCO with T(1/2) > 300 K.     

Contribution of spin and anisotropy to single molecule magnet behavior in a family of bell-shaped Mn11Ln2 coordination clusters

The synthesis, structures, and magnetic properties of a family of isostructural "bell-shaped" heterometallic coordination clusters [Mn(III)(9)Mn(II)(2)La(III)(2)(μ(4)-O)(7)(μ(3)-O)(μ(3)-OH)(2)(piv)(10.8)(O(2)CC(4)H(3)O)(6.2)(NO(3))(2)(OH(2))(1.5)(MeCN)(0.5)]·12CH(3)CN·2H(2)O (1) and [Mn(III)(9)Mn(II)(2)Ln(2)(μ(4)-O)(7)(μ (3)-O)(μ(3)-OH)(2)(piv)(10.6)(O(2)CC(4)H(3)O)(6.4)(NO(3))(2)(OH(2))]·nCH(3)CN·H(2)O (Ln = Pr(III), n = 8 (2); Ln = Nd(III), n = 10 (3); Ln = Eu(III), n = 17 (4); Ln = Gd(III), n = 13 (5); piv = pivalate) are reported. The complexes were obtained from the reaction of [Mn(III)(2)Mn(II)(4)O(2)(piv)(10)(4-Me-py)(2.5)(pivH)(1.5)] and Ln(NO(3))(3)·6H(2)O in the presence of 2-furan-carboxylic acid (C(4)H(3)OCOOH) in CH(3)CN. Compounds 1-5 are isomorphous, crystallizing in the triclinic space group P1 with Z = 2. The Mn(III) and Mn(II) centers together form the shell of the bell, while the two Ln(III) centers can be regarded as the bell's clapper. The magnetic properties of 1-4 reveal dominant antiferromagnetic interactions between the magnetic centers leading to small spin ground states; while those of 5 indicate similar antiferromagnetic interactions between the manganese ions but with unusually strong ferromagnetic interactions between the Gd(III) ions leading to a large overall spin ground state of S = 11-12. While ac and dc magnetic measurements confirmed that Mn(11)Gd(2) (5) is a single-molecule magnet (SMM) showing hysteresis loops at low temperatures, compounds 1-4 do not show any slow relaxation of the magnetization, indicating that the S = 7 spin of the ferromagnetic Gd(2) unit in 5 is a necessary contribution to its SMM behavior.     

Ru-Fe异金属化合物及其在Au表面上SAM的电化学研究

为使不对称Ru-Fe化合物能在表面上自组装形成单分子膜,对trans-RuCl(dppm)₂(C≡CFc)[Fc=C₅H₄FeC₅H₅,dppm=(C₆H₅)₂PCH₂P(C₆H₅)₂](1)进行修饰,得到Ru(dppm)₂(C≡CFc)(C≡CPhOCH₃)(2),[Ru(dppm)₂(C≡CFc)(N≡CCH₂CH₂NH₂)][PF₆](3)和[Ru(dppm)₂(C≡CFc)(N≡CCH₂CH₂NHC(O)·(CH₂)₁₀SH)][PF₆](4),并详细研究了该系列化合物的电化学性质.循环伏安结果显示出Ru周围配体得失电子能力的差别,直接影响了Ru中心的氧化-还原性,但这种影响并没有通过共轭的炔键传递到二茂铁中的Fe中心.化合物4可以在Au表面上自组装形成稳定、有序的单分子膜.还利用循环伏安法研究了单分子膜的形成过程及其表面覆盖率.     

Novel one-dimensional polymers generated from p-Ferrocenylbenzoate: syntheses, structures, and magnetic properties

Treatment of p-ferrocenylbenzoate [p-HOOCH4C6Fc, Fc = (eta5-C5H5)Fe(eta5-C5H5)] with Mn(OAc)2 x 2H2O or Cd(OAc)2 x 2H2O afforded one-dimensional linear chain polymer [[Mn(OOCH4C6Fc)2(mu2-OH2)(H2O)2](H2O)]n (1), double-bridge polymer [Mn(mu2-OOCH4C6Fc)2(phen)]n (phen = phenanthroline) (2), and ladderlike framework [[Cd(mu2-OOCH4C6Fc)(eta2-OOCH4C6Fc)(bbp)](CH3OH)]n (bbp = 4,4'-trimethylene-dipyridine) (3). The solution-state cyclic voltammograms indicate that the half-wave potentials of the ferrocenyl moieties in these polymers are all shifted to positive potential compared to that of sodium p-ferrocenylbenzoate. Both 1 and 2 behave as 1D Heisenberg Mn(II) chains with weak intrachain antiferromagnetic interactions between the local high-spin Mn(II) ions, and the exchange coupling parameters J (-5.20 and -3.25 cm(-1) for 1 and 2, respectively) are larger than those of most of the reported di-Mn(II) complexes that contain mu2-aqua and mu2-carboxylato units and one-dimensional Mn(II) carboxylic polymers.     

Spin crossover behavior in a family of iron(II) zigzag chain coordination polymers

The paper reports the synthesis and detailed characterization of two new Fe(II) compounds: [Fe(pyim)(2)(bpen)](ClO(4))(2).2C(2)H(5)OH (2) and [Fe(pyim)(2)(bpe)](ClO(4))(2).C(2)H(5)OH (3) (pyim = 2-(2-pyridyl)imidazole, bpen = 1,2-bis(4-pyridyl)ethane, and bpe = 1,2-bis(4-pyridyl)ethene). Both compounds and the earlier synthesized [Fe(pyim)(2)(bpy)](ClO(4))(2).2C(2)H(5)OH (1) (bpy = 4,4'-bipyridine) form a family of one-dimensional spin crossover coordination polymers. Variable-temperature magnetic susceptibility measurements and M?ssbauer spectroscopy have revealed rather gradual spin transitions centered at 176 and 198 K for 2 and 3, respectively. The fitting of magnetic properties with the regular solution model leads to the enthalpy and entropy of spin transitions and the cooperativity parameter equal to DeltaH = 12.3 kJ mol(-1), DeltaS = 68.5 J mol(-1) K(-1), Gamma = 1.80 kJ mol(-1) for 2 and DeltaH = 13.6 kJ mol(-1), DeltaS = 68.1 J mol(-1) K(-1), Gamma = 2.05 kJ mol(-1) for 3. The crystal structures of 2 and 3, resolved by X-ray diffraction at 293 K, belong to the monoclinic space group C2/c (Z = 4). Both compounds display a one-dimensional infinite zigzag-chain structure. The polymer chains are stacked into two-dimensional sheets through intermolecular pi-interactions. The crystal packing of both compounds encloses two kinds of channels in which the counter ions and ethanol molecules are inserted. The DFT calculations of binuclear fragments extracted from three polymers resulted in the energy gaps between the LS and HS states being ordered as the observed transition temperatures. The influence of bridging ligands in the studied family of compounds was found in the modulation of the energy gap between the LS and HS states, leading to different transition temperatures.