Hideki Yamochi

Japan Science and Technology Agency (JST), Edo, Tōkyō, Japan

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Publications (283)528.1 Total impact

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    ABSTRACT: TTF derivatives decorated with four aryls through the sulfur bridges are employed to form the donor-acceptor type inclusion complexes with fullerenes. The key factor for the formation of inclusion complexes is the introduction of structural flexibility in TTF molecules along with the molecular size matching with fullerene. Crystallographic study indicates that the structures of the resulting complexes are stabilized by multidimensional intermolecular interaction network consisting of TTF cores, peripheral aryls, and fullerenes, which in turn gives rise to the electronic communication between the donor and acceptor as proved by the solid state absorption spectra. Moreover, the fullerene molecules form the two-dimensional sheet structure in the complexes.
    J. Mater. Chem. C. 07/2014;
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    ABSTRACT: Two salts containing fullerene C60 and indium(iii) bromide phthalocyanine (Pc) radical anions have been obtained as single crystals: (TBA(+))3(C60˙(-)){In(III)(Br)(Pc)˙(-)}(Br(-))·C6H4Cl2 (1) and (TEA(+))2(C60˙(-)){In(III)(Br)(Pc)˙(-)}·C6H4Cl2·C6H14 (2) where TBA(+) and TEA(+) are tetrabutyl- and tetraethylammonium cations, respectively. The presence of both radical anions is supported by spectra of and in the NIR and IR-ranges. The salts contain zigzag C60˙(-) chains with 10.136 and 10.383 Å center-to-center (ctc) distances in and a uniform ctc distance of 10.186 Å in . In 1, the C60˙(-) radical anions are dimerized in the 180-140 K range to form singly bonded (C60(-))2 dimers, whereas they remain monomeric in 2. Effective packing of planar In(Br)(Pc)˙(-) and spherical C60˙(-) is attained by introducing fullerene spheres between the phenylene substituents of Pc allowing the formation of multiple van der Waals contacts between them. The effective magnetic moment of at 300 K is 2.35μB, indicating a contribution of both C60˙(-) and In(Br)(Pc)˙(-) species having S = 1/2 spin state. There is strong antiferromagnetic coupling of spins between fullerenes in the chains and fullerenes and phthalocyanines in the monomeric phase of 1 with the Weiss temperature of -120 K in the 300-180 K range. The formation of diamagnetic (C60(-))2 dimers switches off magnetic coupling and magnetically isolates In(Br)(Pc)˙(-) (Weiss temperature is only -1 K in the 140-10 K range). Magnetic behavior of 2 is described by the Curie-Weiss law with weak ferromagnetic coupling of spins with Θ = +7.6 K in the 50-300 K range. Both salts manifest single Lorentzian EPR lines at room temperature with g = 1.9911 and a linewidth (ΔH) of 25.4 mT (1) and g = 1.9956 and ΔH = 7.5 mT (2) which can be attributed to both C60˙(-) and In(Br)(Pc)˙(-) species having strong exchange interaction. An asymmetric signal with the main component at g = 1.989-1.965 in the dimeric phase of 1 was attributed to the In(Br)(Pc)˙(-) radical anions.
    Dalton Transactions 07/2014; 43:13061-13069. · 3.81 Impact Factor
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    ABSTRACT: Fullerene salt {(Ph3P)3Au(+)}2(C60(•-))2(C60)·C6H4Cl2 (1) containing (Ph3P)3Au(+) cations with the C3v symmetry has been obtained as single crystals. Hexagonal corrugated fullerene layers formed in 1 alternate with the layers consisting of (Ph3P)3Au(+) and C6H4Cl2 along the c axis. According to IR spectra and peculiarities of the crystal structure, the charge on fullerenes in the layers is evaluated to be -1 for two and close to zero for one C60. These fullerenes have different cationic surroundings, and positively charged gold atoms approach closer to C60(•-). Charged and neutral fullerenes are closely packed within hexagonal layers with an interfullerene center-to-center distance of 10.02 Å and multiple short van der Waals C···C contacts. The distances between C60(•-) are essentially longer with an interfullerene center-to-center distance of 10.37 Å due to corrugation of the layers, and no van der Waals contacts are formed in this case. As a result, each C60(•-) has only three negatively charged fullerene neighbors with rather long interfullerene distances providing only weak antiferromagnetic interaction of spins in the fullerene layers with a Weiss temperature of -5 K.
    Inorganic Chemistry 06/2014; 53:6850−6855. · 4.59 Impact Factor
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    ABSTRACT: (MDABCO+)(C60.−)(TPC) (1), in which MDABCO+ is N-methyldiazabicyclooctanium, TPC is triptycene, and both have threefold symmetry, is a rare example of a fullerene-based quasi-2D metal and contains closely packed hexagonal fullerene layers with interfullerene center-to-center distances of 10.07 Å at 300 K. Evidence for the metallic nature of 1 was obtained by optical and microwave conductivity measurements on single crystals. The metal is characterized by a nontypical Drude response and relatively large optical mass (m*/m0=6.7). The latter indicates a narrow-band nature, which is consistent with the calculated bandwidth of 0.10–0.15 eV. The coexistence of metallic and antiferromagnetic nonmetallic 2D layers was observed in 1 above 200–230 K. It was assumed that the nonmetallic layers undergo a transition to the metallic state below 200 K due to ordering of the fullerene and cationic sublattices. New layered complex (MQ+)(C60.−)(TPC) (2) with a hexagonal arrangement of C60.− was obtained by increasing the interfullerene distance with the bulkier N-methylquinuclidinium cations (MQ+) having threefold symmetry. The structure of 2 is characterized by increased interfullerene center-to-center distances in the layers (10.124, 10.155, and 10.177 Å at 250 K). Unit-cell doubling parallel to the 2D layer (along the b axis) was observed at low temperatures. In contrast to metallic 1, 2 exhibits a nonmetallic spin-frustrated state with an antiferromagnetic interaction of spins (the Weiss temperature is −27 K) and no magnetic ordering down to 1.9 K. It was supposed that the expanded interfullerene distances in the triangular arrangement decrease the bandwidth and suppress metallic conductivity in 2, and thus a Mott–Hubbard insulating state with antiferromagnetically frustrated spins results.
    Chemistry 05/2014; 20:7268–7277. · 5.93 Impact Factor
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    ABSTRACT: Iron hexadecachlorophthalocyanine (Cl16Pc) salts with a layered arrangement of phthalocyanine (Pc) macrocycles were obtained by the reduction of FeCl16Pc with sodium fluorenone ketyl in the presence of PPNCl [PPN+: bis(triphenylphosphine)iminium cation] and TBABr (TBA+: tetrabutylammonium cation). (PPN+)[{Fe(I)Cl16Pc}–]·0.78C6H4Cl2·0.22C6H14 (1) contains π–π stacking columns formed by dimerized {Fe(I)Cl16Pc}– anions. The side-by-side arrangement of neighboring columns results in the formation of a layered iron hexadecachlorophthalocyanine structure. (TBA+)3{[(FeCl16Pc)2]3–} (2) contains hexagonal layers formed by [(FeCl16Pc)2]3– dimers and separated by TBA+ cations. The dimers bear –3 charge and, according to optical and X-ray diffraction data, consist of a [Fe(I)(Cl16Pc)]– monoanion and a [Fe(0)(Cl16Pc)]2– dianion. These anions are bonded in the dimer by a Fe–Fe bond of 2.899(4) Å length. It was shown that the negative charge in both anions is localized on the iron atoms to form Fe(I) and Fe(0), respectively, and no electron transfer to the hexadecachlorophthalocyanine macrocycles is observed. Magnetic data indicate the presence of only one S = 1/2 spin per [(FeCl16Pc)2]3– dimer. This result is in agreement with the formation of iron(I) and iron(0) hexadecachlorophthalocyanine anions, which have the iron atoms in d7 and diamagnetic d8 electron configuration, respectively. The spins of the iron(I) atoms are arranged in a hexagonal manner and only weakly interact, which results in a Weiss temperature of –1 K because of the long distances between them (>18 Å). Previously studied anionic salts with a columnar arrangement of [Fe(I)(Cl16Pc)]– do not show EPR signals from FeI. In contrast, salt 2 shows an intense EPR signal with main components at g(per) = 2.249 and g∥ = 1.989, which are characteristic of Fe(I) with d7 electron configuration.
    Berichte der deutschen chemischen Gesellschaft 05/2014; · 2.94 Impact Factor
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    ABSTRACT: A new salt, (MDABCO+)(C60.−) (1; MDABCO+=N-methyldiazabicyclooctanium cation), was obtained as single crystals. The crystal structure of 1 determined at 250 and 100 K showed 3D close packing of fullerenes with eight fullerene neighbors for each C60.−. These neighbors are located at 10.01–10.11 Å center-to-center distances (250 K) and van der Waals interfullerene C⋅⋅⋅C contacts are formed with four fullerene neighbors arranged in the bc plane. Fullerene ordering observed below 160 K is accompanied by the appearance of one and a half independent C60.− and trebling of the unit cell along the b axis. Fullerenes are packed closer to each other at 100 K. As a result, fullerenes are located in the three-dimensional packing at 9.91–10.12 Å center-to-center distances and 18 short interfullerene C⋅⋅⋅C contacts are formed for each C60.−. Although they are closed packed, fullerenes are not dimerized down to 1.9 K. Magnetic data indicate strong antiferromagnetic coupling of spins in the 70–300 K range with a Weiss temperature of Θ=−118 K. Magnetic susceptibility shows a round maximum at 46 K. Such behavior can be described well by the Heisenberg model for square two-dimensional antiferromagnetic coupling of spins with an exchange interaction of J/kB=−25.3 K. This magnetic coupling is one of the strongest observed for C60.− salts.
    Chemistry - An Asian Journal 04/2014; 9:1629-1635. · 4.57 Impact Factor
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    ABSTRACT: Compounds of the formula (EDO-TTF-Cl)2XF6 (EDO-TTF-Cl = 4-chloro-4′,5′-ethylenedioxytetrathiafulvalene, X = As, Sb) were prepared to examine the substituent size effect on the packing structure of the donor molecules. In these salts, a head-to-tail type donor stacking was observed. Although the AsF6 salt is a quasi-one-dimensional dimer Mott insulator, the SbF6 salt shows quasi-one-dimensional metallic behavior. Detailed crystal structure analyses revealed the correlation between the anion size and the intermolecular slipping among the donor molecules. The donor morphology, which plays an important role in the overlapping mode selectivity, is characterized by the magnitude and configuration of the out-of-plane substituent size.
    Berichte der deutschen chemischen Gesellschaft 04/2014; · 2.94 Impact Factor
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    ABSTRACT: The photoinduced phase formation in a strongly correlated crystal (EDO-TTF)2PF6 (EDO-TTF: 4,5-ethylenedioxytetrathiafulvalene) is investigated using a 12 fs laser pulse. The formation time is determined as 40 fs with observation of coherence of electron-phonon coupled excited states prior to formation. The temperature-independent dephasing time is determined as ̃22 fs up to 180 K and the frequency of phonon oscillation is ̃38 THz, corresponding to the intramolecular vibrations in EDO-TTF. The phase formation is coherently controlled by relative-phase-controlled two-pulse excitation.
    03/2014; 89(16).
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    ABSTRACT: In this study, we obtained the first cation radical solid of a highly symmetric (D6h) polyaromatic hydrocarbon, coronene, by electrooxidation. The (coronene)3Mo6Cl14 salt, which is formed with an Oh-symmetric molybdenum cluster unit Mo6Cl142–, has an isotropic cubic structure with Pmm symmetry. The presence of two orientations for the coronene molecules related by an in-plane 90° rotation (merohedral disorder) allows for fourfold symmetry along the <100> direction. The disorder has dynamic features because 2H NMR spectroscopic studies revealed that the coronene molecules undergo an in-plane flipping motion. The observation of two motional sites with significantly different rotational rates (300 Hz and 5 MHz at 103 K) in an approximate 2:1 ratio appears to be consistent with the splitting of a Raman-active A1g mode, confirming a random charge-disproportionated state instead of a uniform partially-charged state. The slower- and faster-rotating species are assigned to charge-rich and charge-poor coronenes, respectively, with respect to C–H···Cl hydrogen bonds with neighboring Mo6Cl142– cluster units. The electrical conductivity of the salt is rather high but is well-described by a three-dimensional (3D) variable-range hopping mechanism, which is possibly associated with the random charge disproportionation. These results provide a significant step forward in developing an isotropic 3D π-conducting system composed of planar π-conjugated molecules.
    Berichte der deutschen chemischen Gesellschaft 03/2014; · 2.94 Impact Factor
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    ABSTRACT: Two mononuclear coordination complexes of fullerene C60 with cobalt, Co(η(2)-C60)(dppe)(C6H5CN)·C6H4Cl2 (1) and Co(η(2)-C60)(dppf)(C6H5CN)·C6H4Cl2 (2) (dppe is 1,2-bis(diphenylphosphino)ethane and dppf is 1,1'-bis(diphenylphosphino)ferrocene) have been obtained by sodium fluorenone reduction of the Co(dppe)Cl2 or Co(dppf)Br2 and C60 mixtures. The IR and visible-NIR spectra of 1 and 2 indicate the neutral state of fullerenes. Therefore, cobalt atoms formally have the zerovalent state. Cobalt coordinates to the 6-6 bond of C60 by η(2)-type coordination with Co-C bond lengths in the 2.008(3)-2.060(3) Å range. Diphosphine and benzonitrile ligands additionally coordinate to cobalt to form a distorted square-pyramidal environment for the cobalt atoms. Complexes 1 and 2 are rare examples of fullerene coordination complexes with paramagnetic metal centers. Both complexes manifest intense asymmetric EPR signals attributed to zerovalent cobalt atoms, which can be fitted by three components with g = 2.261-2.124 (1) and g = 2.258-2.092 (2). Effective magnetic moments of 1 and 2 indicate the low-spin (S = 1/2) state of Co(0). In accordance with EPR spectra, DFT calculations show that the spin density is localized mainly on the central cobalt atoms and only slightly delocalized into C60, benzonitrile, dppe, or dppf ligands.
    Inorganic Chemistry 11/2013; · 4.59 Impact Factor
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    ABSTRACT: A new salt, (PPN(+) )2 (C70 (2-) )⋅2 C6 H4 Cl2 (1), which contains C70 (2-) dianions, has been obtained as single crystals (PPN(+) =bis(triphenylphosphine)iminium cation). The C70 (2-) dianions form polymeric zigzag (C70 (2-) )n chains, in which the fullerene units are bonded through single CC bonds of length 1.581(5)-1.586(6) Å. The distance between the centers of neighboring C70 (2-) units is 10.441 Å. The optical and magnetic properties of (C70 (2-) )n have also been studied. Decreasing the symmetry of C70 in the polymer activate about 20 new IR bands in addition to the 10 IR-active bands of the starting C70 . The polymeric structure shows absorptions in the visible and NIR regions, with three main bands at 890, 1200, and 1550 nm, instead of one band of isolated C70 (2-) dianions at 1165-1184 nm. We concluded that the (C70 (2-) )n polymer was diamagnetic, with a negative molar magnetic susceptibility of -3.82×10(-4) emu mol(-1) per C70 (2-) dianion. The polymer is EPR silent and a weak narrow EPR signal in salt 1 is due to impurities, which only constitute 0.84 % of spin S=1/2 of the total amount of fullerene C70 .
    Chemistry - An Asian Journal 08/2013; · 4.57 Impact Factor
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    ABSTRACT: Protonated species of the nucleobase cytosine (C), namely the monoprotonated CH(+) and the hemiprotonated CHC(+) , were used to obtain four charge-transfer complexes of [Ni(dmit)2 ] (dmit: 1,3-dithiole-2-thione-4,5-dithiolate). Diffusion methods afforded two semiconducting [Ni(dmit)2 ](-) salts; (CH)[Ni(dmit)2 ](CH3 CN) (1) and (CHC)[Ni(dmit)2 ] (2). In salt 1, the [Ni(dmit)2 ](-) ions with a S=1/2 spin construct a uniform one-dimensional array along the molecular long axis, and the significant intermolecular interaction along the face-to-face direction results in a spin-singlet ground state. In contrast, salt 2 exhibits the Mott insulating behavior associated with uniform 1D arrays of [Ni(dmit)2 ](-) , which assemble a two-dimensional layer that is sandwiched between the layers of hydrogen-bonded CHC(+) ribbons. Multiple hydrogen bonds between CHC(+) and [Ni(dmit)2 ](-) seem to result in the absence of structural phase transition down to 0.5 K. Electrooxidation of [Ni(dmit)2 ](-) afforded the polymorphs of the [Ni(dmit)2 ](0.5-) salts, (CHC(+) )[{Ni(dmit)2 }(0.5-) ]2 (3 and 4), which are the first mixed-valence salts of nucleobase cations with metal complex anions. Similar to 2, salt 3 contains CHC(+) ribbons that are sandwiched between the 2D [Ni(dmit)2 ](0.5-) layers. In the layer, the [Ni(dmit)2 ](0.5-) ions form dimers with a S=1/2 spin and the narrow electronic bandwidth causes a semiconducting behavior. In salt 4, the CHC(+) units form an unprecedented corrugated 2D sheet, which is sandwiched between the 2D [Ni(dmit)2 ](0.5-) layers that involve ring-over-atom and spanning overlaps. In contrast to 3, salt 4 exhibits metallic behavior down to 1.8 K, associated with a wide bandwidth and a 2D Fermi surface. The ability of hydrogen-bonded CHC(+) sheets as a template for the anion radical arrangements is demonstrated.
    Chemistry 07/2013; · 5.93 Impact Factor
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    ABSTRACT: Ten types of neutral charge transfer (CT) complexes of coronene (electron donor; D) were obtained with various electron acceptors (A). In addition to the reported 7,7,8,8-tetracyanoquinodimethane (TCNQ) complex of 1:1 stoichiometry with a DA-type alternating π column, TCNQ also afforded a 3:1 complex, in which a face-to-face dimer of parallel coronenes (Cor-As) is sandwiched between TCNQs to construct a DDA-type alternating π column flanked by another coronene (Cor-B). Whereas solid-state (2) H NMR spectra of the 1:1 TCNQ complex formed with deuterated coronene confirmed the single in-plane 6-fold flipping motion of the coronenes, two unsynchronized motions were confirmed for the 3:1 TCNQ complex, which is consistent with a crystallographic study. Neutral [Ni(mnt)2 ] (mnt: maleonitriledithiolate) as an electron acceptor afforded a 5:2 complex with a DDA-type alternating π column flanked by another coronene, similar to the 3:1 TCNQ complex. The fact that the Cor-As in the [Ni(mnt)2 ] complex arrange in a non-parallel fashion must cause the fast in-plane rotation of Cor-A relative to that of Cor-B. This is in sharp contrast to the 3:1 TCNQ complex, in which the dimer of parallel Cor-As shows inter-column interactions with neighboring Cor-As. The solid-state (1) H NMR signal of the [Ni(mnt)2 ] complex suddenly broadens at temperatures below approximately 60 K, indicating that the in-plane rotation of the coronenes undergoes down to approximately 60 K; the rotational rate reaches the gigahertz regime at room temperature. Rotational barriers of these CT complexes, as estimated from variable-temperature spin-lattice relaxation time (T1 ) experiments, are significantly lower than that of pristine coronene. The investigated structure-property relationships indicate that the complexation not only facilitates the molecular rotation of coronenes but also provides a new solid-state rotor system that involves unsynchronized plural rotators.
    Chemistry 07/2013; · 5.93 Impact Factor
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    ABSTRACT: The fullerene salt, (TMP+)·(C60˙−)·C6H5CN (1), with a layered structure was obtained as single crystals (TMP+ is the N,N,N′-trimethylpiperazinium cation). The fullerene layers alternating with the TMP+–C6H5CN layers along the c-axis have a honeycomb arrangement of C60˙− in which each fullerene has three neighbors with interfullerene CC contacts in the 3.13–3.38 Å range. Despite the dense packing, the fullerene anions showed no intermolecular bond formation, even when down to helium temperatures. The structure of 1 was solved at 120 and 90 K. The fullerene molecules are disordered between three orientations at 120 K. The ordering transition observed in the 100–90 K range is accompanied by the trebling of the unit cell to provide three crystallographically independent fullerenes. The salt shows an asymmetric EPR signal down to 4 K which can be fitted by two Lorentzian lines with g1 = 1.9956 and a linewidth (ΔH) of 2.7 mT and g2 = 1.9815 and ΔH = 5.1 mT at room temperature. The ordering transition results in the abrupt narrowing of both lines in the 100–90 K range. The temperature dependence of the magnetic susceptibility of 1 follows the Curie–Weiss law with a negative Weiss temperature of −11 K, indicating an antiferromagnetic interaction of spins in the fullerene layers. Salt 1 is non-conducting with a room temperature resistivity of 7 × 107 Ω cm, which is probably due to the orientational disorder of the fullerenes and a relatively weak interaction between C60˙− in the layers. Indeed, the AM1 molecular orbital calculations show essentially smaller and more anisotropic overlap integrals between fullerenes than those in the layered metal (MDABCO+)·(C60˙−)·TPC.
    New Journal of Chemistry 06/2013; · 2.97 Impact Factor
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    ABSTRACT: Ultrafast processes can now be studied with the combined atomic spatial resolution of diffraction methods and the temporal resolution of femtosecond optical spectroscopy by using femtosecond pulses of electrons or hard X-rays as structural probes. However, it is challenging to apply these methods to organic materials, which have weak scattering centres, thermal lability, and poor heat conduction. These characteristics mean that the source needs to be extremely bright to enable us to obtain high-quality diffraction data before cumulative heating effects from the laser excitation either degrade the sample or mask the structural dynamics. Here we show that a recently developed, ultrabright femtosecond electron source makes it possible to monitor the molecular motions in the organic salt (EDO-TTF)2PF6 as it undergoes its photo-induced insulator-to-metal phase transition. After the ultrafast laser excitation, we record time-delayed diffraction patterns that allow us to identify hundreds of Bragg reflections with which to map the structural evolution of the system. The data and supporting model calculations indicate the formation of a transient intermediate structure in the early stage of charge delocalization (less than five picoseconds), and reveal that the molecular motions driving its formation are distinct from those that, assisted by thermal relaxation, convert the system into a metallic state on the hundred-picosecond timescale. These findings establish the potential of ultrabright femtosecond electron sources for probing the primary processes governing structural dynamics with atomic resolution in labile systems relevant to chemistry and biology.
    Nature 04/2013; 496(7445):343-346. · 38.60 Impact Factor
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    ABSTRACT: Ionic compounds containing radical anions of metal-free phthalocyanine (H2Pc˙-): (H2Pc˙-)(cryptand[2,2,2][Na+])·1.5C6H4Cl2 () and (H2Pc˙-)(TOA+)·C6H4Cl2 () have been obtained as single crystals for the first time. Their crystal structures have been determined, and optical and magnetic properties have been investigated. The H2Pc˙- radical anions have a slightly bowl-like shape with four pyrrole nitrogen atoms located below the molecular plane, while four phenylene substituents are located above this plane. Changes in the average length of N-C and C-C bonds in H2Pc˙- in comparison with those in neutral H2Pc indicate that negative charge is mainly delocalized over the 24-atom phthalocyanine ring rather than the phenylene substituents. The H2Pc˙- formation is accompanied by a shift of up to 10 cm-1 and disappearance of some intense IR-active bands whereas the band of the N-H stretching mode is shifted by 21-27 cm-1 to larger wavenumbers. New bands attributed to H2Pc˙- appear in the NIR spectra of the salts with maxima at 1033 and 1028 nm for and , respectively. The formation of H2Pc˙- is accompanied by the splitting of the Soret and Q-bands of H2Pc into several bands and their blue-shift up to 32 nm. Narrow EPR signals with g = 2.0033 and linewidth of 0.16-0.24 mT at room temperature in the spectra of the salts were attributed to the H2Pc˙- radical anions. According to SQUID measurements they have S = 1/2 spin states with effective magnetic moments of 1.73 () and 1.78 () μB at 300 K. Magnetic behavior of and follows the Curie-Weiss law with negative Weiss temperatures of -0.9 and -0.5 K, respectively, indicating weak antiferromagnetic interactions of spins. The EPR signal splits into two lines below 120 and 80 K for and , respectively and these lines are noticeably broadened below 25 K.
    Dalton Transactions 03/2013; · 3.81 Impact Factor
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    ABSTRACT: Ternary complexes of (Me4P(+))·{[Fe(I)Pc(-2)](-)}·TPC (1) and (Me4P(+))·{[Fe(I)Pc(-2)](-)}·(TBPDA)0.5 (2) containing iron(I) phthalocyanine anions, tetramethylphosphonium cations (Me4P(+)), and neutral structure-forming triptycene (TPC) or N,N,N',N'-tetrabenzyl-p-phenylenediamine (TBPDA) molecules have been obtained as single crystals. In contrast to previously studied ionic compounds with monomeric [(Fe(I)Pc(-2)](-) anions, the anions form coordination {[Fe(I)Pc(-2)](-)}2 dimers both in 1 and 2, in which a nitrogen atom of one phthalocyanine anion weakly coordinates to the iron(I) atom of neighboring [Fe(I)Pc(-2)](-). The Fe···N distances in the dimers are 3.08(1) and 3.12(1) Å in 1 at 280 K and 2.986(5) (100 K) and 3.011(5) Å (180 K) in 2. The {[Fe(I)Pc(-2)](-)}2 dimers are packed in the layers in 1 arranged parallel to the ac plane and in isolated chains in 2 arranged along the a axis. Extended Hückel based calculation of intermolecular overlap integrals showed stronger and weaker π-π interactions within and between phthalocyanine dimers, respectively, both in 1 and 2. EPR signals of both complexes manifest two components. An major low-field asymmetric component is attributed to the Fe(I) atoms with the d(7) configuration. An origin minor narrow signal with g-factor close to the free-electron value (g = 2.0018-2.0035) is assigned to partial electron density transfer from the iron(I) center to the phthalocyanine macrocycle and the formation of the [Fe(II)Pc(-3)](-) species. Effective magnetic moments of the complexes of 1.69 (1) and 1.76 μB (2) correspond to the contribution of about one S = (1)/2 spin per formula unit in accordance with low-spin state of [Fe(I)Pc(-2)](-). Negative Weiss temperatures of -7.6 K (1) and -13 K (2) in the 30-300 K range indicate antiferromagnetic interaction of spins in the phthalocyanine dimers. The multicomponent approach was previously proposed for the anionic fullerene complex formation. It also seems very promising to design and synthesize anionic phthalocyanine complexes with one- and two-dimensional macrocycle arrangements.
    Inorganic Chemistry 03/2013; · 4.59 Impact Factor
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    ABSTRACT: We examined the initial excited state before photoinduced phase transition in a charge transfer complex (EDO-TTF)2PF6 and revealed the conversion process to the photoinduced phase and the electronic coherence at the excited state.
    03/2013;
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    ABSTRACT: The magnetic metal-bridged fullerene dimer {Co(Ph3P)(C6H5CN)}2(μ2- η2,η2-C60)2 was synthesized for the first time and studied by X-ray crystallography and magnetic susceptibility methods. The dimers, in which two fullerene C60 cages are η2- bonded through two Co(0) atoms (S = 1/2), have a triplet (S = 1) state and transfer to a diamagnetic singlet (S = 0) ground state below 50 K (J/kB = −28.6 K). The theoretical calculations show that C60 can work as an efficient spin coupler between paramagnetic metals.
    Organometallics 01/2013; 32:4038−4041. · 4.15 Impact Factor

Publication Stats

1k Citations
528.10 Total Impact Points

Institutions

  • 2014
    • Japan Science and Technology Agency (JST)
      Edo, Tōkyō, Japan
  • 1991–2014
    • Kyoto University
      • Division of Chemistry
      Kioto, Kyōto, Japan
    • University of California, Santa Barbara
      Santa Barbara, California, United States
  • 2013
    • Russian Academy of Sciences
      • Institute of the Problems of Chemical Physics
      Moskva, Moscow, Russia
    • Meijo University
      • Faculty of Agriculture
      Nagoya-shi, Aichi-ken, Japan
  • 1992–2010
    • Osaka University
      • • Department of Macromolecular Science
      • • Department of Chemistry
      • • Institute for Protein Research
      Suika, Ōsaka, Japan
  • 2005
    • Tokyo Institute of Technology
      • Department of Materials Science and Engineering
      Tokyo, Tokyo-to, Japan
  • 1994
    • Tokyo University of Science
      • Department of Applied Physics
      Edo, Tōkyō, Japan
  • 1988–1991
    • The University of Tokyo
      • Institute for Solid State Physics
      Tokyo, Tokyo-to, Japan
    • Tohoku University
      Japan
  • 1987–1988
    • Nagoya University
      • Department of Chemistry
      Nagoya-shi, Aichi-ken, Japan