Faculty Profiles - HAYASHI Satoko

Published Papers - HAYASHI Satoko

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Evaluation of electron population terms for (rSe -3)4p, (rS-3)3p, and (rO-3)2p: How do HOMO and LUMO shrink or expand depending on nuclear charges?

Waro Nakanishi, Satoko Hayashi, Kenji Narahara, Daisuke Yamaki, Masahiko Hada

Chemistry - A European Journal ( Wiley ) 14 ( 24 ) 7278 - 7284 2008.08 [Refereed]

Electron population terms (rN-3) are evaluated for N = Se, S, and O. Calculations are performed on HOMO and LUMO constructed by pure atomic 4p(Se), 3p(S), and 2p(O) orbitais, employing the 6-311+G(3d) and/or 6-311 ++G(3df,3pd) basis sets at the HF, MP2, and DFT (B3LYP) levels. Se 4+, Se2+, Se0, and Se2- with the Oh symmetry are called G(A: Se) and HSe+, H2Se, and HSe- with the C∞h or C2v symmetry are named G(B: Se), here [G(A+B: Se) in all]. HOMO and LUMO in G(A+B: N) (N=Se, S, and O) satisfy the conditions of the calculations for (rN -3). The (rSe-3)4p, (r S-3)3p, and (rO-3) 2p values correlate well with the corresponding MO energies (εN) for all calculation levels employed. Plots of (r N-3)HOMO and (rN-3) LUMO versus Q(N) (N=Se, S, and O) at the HF and MP2 levels are analyzed as two correlations. However, the plots at the DFT level can be analyzed as single correlation. A regression curve is assumed for the analysis. Behaviors of (rN-3) clarify how valence orbitals shrink or expand depending on Q(N). The applicability of (rN-3) is examined to establish a new method that enables us to analyze chemical shifts with the charge effect separately from others. A utility program derived from the Gaussian 03 (NMRANAL-NH03G) is applied to evaluate (rN -3) and examine the applicability to the NMR analysis. © 2008 Wiley-VCH Verlag GmbH &amp
Co. KGaA,.

Fine structures of 1-(arylethynylselanyl)naphthalenes: Characteristic features brought by the ethynylselanyl group

Kentaro Yamane, Satoko Hayashi, Waro Nakanishi, Takahiro Sasamori, Norihiro Tokitoh

Polyhedron ( Elsevier BV ) 27 ( 11 ) 2478 - 2486 2008.08 [Refereed]

Fine structures of 1-(arylethynylselanyl)naphthalenes [1-(p-YC6H4C{triple bond, long}CSe)C10H7: 1, Y = H (a), OMe (b), Me (c), Cl (e), CN (h), NO2 (i)] have been determined by X-ray crystallographic analysis. The structures are A for 1a-c, bearing Y that is a non-acceptor, B for 1e, 1h and 1i, having Y that is a strong acceptor, where the Se-Csp bond is perpendicular to the naphthyl plane in A, but is in the plane in B
and C is intermediate between A and B (see Scheme 1). The Y-dependence observed in 1 is just the opposite to the case of 1-(arylselanyl)naphthalenes [1-(p-YC6H4Se)C10H7]. We call the factor the "ethynyl effect", which controls the fine structures of 1. The structures of 1h and 1i are planar or almost planar. The energy lowering effect by the parallel direction between np(Se) and np(Y) must be responsible for the observations if Y is a strong acceptor. The origin of the ethynyl effect is explained by how effectively np(Se) and np(Y) interact through the C{triple bond, long}C bond. Crystal packing effects, such as the formation of dimmers, also play an important role in determining the fine structures of 1. The dimer formation in 1a-c substantially stabilizes the structures. The π-stacking of naphthyl groups may also contribute to the dimer formation. The structures in solutions are also clarified. Compound 1 exist in the A form in solutions, with some equilibration with B. The ethynyl effect as the factor that controls the fine structures of 1 is also confirmed in solution. The results are well supported by quantum chemical calculations on the structures, energy profiles and the evaluation of electron affinity. The NMR chemical shifts explain the behavior of 1 in solution. © 2008 Elsevier Ltd. All rights reserved.

Torsional angular dependence of1J(Se,Se) and fermi contact control of4J(Se,Se): Analysis ofnJ(Se,Se) (n = 1-4) based on molecular orbital theory

Waro Nakanishi, Satoko Hayashi

Chemistry - A European Journal ( Wiley ) 14 ( 18 ) 5645 - 5655 2008.06 [Refereed]

nJ(Se,Se) (n = 1-4) nuclear couplings between Se atoms were analyzed by using molecular orbital (MO) theory as the first step to investigating the nature of bonded and nonbonded nJ(Se,Se) interactions between Se atoms. The values were calculated by employing Slater-type triple ξ basis sets at the DFT level, which were applied to structures optimized with the Gaussian 03 program. The contribution from each occupied MO (Ψi) and Ψi-Ψa (Ψa = unoccupied MO) transition was evaluated separately. 1J(Se,Se) was calculated for the MeSeSeMe model compound, which showed a typical dependence on the torsion angle (φ(CMeSeSeC Me)). This dependence explains the small values (≤64Hz) of 1Jobsd(Se,Se) observed for RSeSeR′ and large values (330-380 Hz) of 1Jobse- (Se,Se) observed for 4-substituted naphtho[1,8-c,d]-1,2-diselenoles, which correspond to synperiplanar diselenides. The HOMO-+LUMO and HOMO-1 → LUMO transitions contribute the most to 1J(Se,Se) at φ = 0 and 180° to give large values of 1J-(Se,Se), whereas various transitions contribute and cancel each other out at φ = 90° to give small values of 1J-(Se,Se). Large 4Jobsd(Se,Se) values were also observed in the nonbonded Se⋯Se, Se⋯Se=O, and O=Se⋯Se=O interactions at naphthalene 1,8-positions. The Fermi contact (FC) term contributes significantly to 4J(Se,Se), whereas the paramagnetic spin-orbit (PSO) term contributes significantly to 1J-(Se,Se). 2J(Se,Se) and 3J(Se,Se) were analyzed in a similar manner and a torsional angular dependence was confirmed for 3J(Se,Se). Depending on the structure, the main contribution to nJ-(Se,Se) (H = 2, 3) is from the FC term, with a lesser contribution from the PSO term. Analysis of each transition enabled us to identify and clearly visualize the origin and mechanism of the couplings. © 2008 Wiley-VCH Verlag GmbH &amp
Co. KGaA.

Origin of 77Se NMR Chemical Shifts Revealed for Pre-α, α, β, and γ Effects

Satoko Hayashi, Waro Nakanishi （Part： Lead author )

Phosphorus, Sulfur, and Silicon and the Related Elements ( Informa UK Limited ) 183 ( 4 ) 1067 - 1071 2008.04 [Refereed]

X-ray characterization of Te(S2CNC5H10)2 and TeI2[(C13H10N2S)2] · 4C4H8TeI2; the first Te-C bond cleaved products obtained in the substitution reactions of organo(heterocyclic)tellurium(IV) derivatives

Prakash C. Srivastava, Sangeeta Bajpai, Roli Lath, Rajesh Kumar, Vikas Singh, Shrinkhala Dwivedi, Ray J. Butcher, Satoko Hayashi, Waro Nakanishi

Polyhedron ( Elsevier BV ) 27 ( 2 ) 835 - 848 2008.02 [Refereed]

The reaction of organo(heterocyclic)tellurium(IV) derivative: C8H8TeI2(1,3-dihydro-2λ4-benzotellurole-2,2-diyl diiodide) with NH4S2CNC5H10 (ammonium piperidine dithiocarbamate) gives C8H8Te(S2CNC5H10)2 (1) and Te(S2CNC5H10)2 (2) or C8H8TeI(S2CNC5H10) (5) according to the reaction conditions. In such type of metathetical reactions, the formation of 2 is unprecedented and it corresponds to the first Te-C cleaved product. The reaction of 2 with CH3I, yields the oxidative addition product, CH3TeI(S2CNC5H10)2 (8). The formation of 2 is also supported through Quantum Chemical calculations. Another Te-C bond cleaved product TeI2[(C13H10N2S)2] · 4C4H8TeI2 (9) is obtained in the reaction of C4H8TeI2 (1,1,2,3,4,5-hexahydro-1,1-diiodotellurophene) with NH4S2CNHC6H5 (ammonium aniline dithiocarbamate). The reaction of 1,1,2,3,4,5,6-heptahydro-1-iodo-1-(morpholine dithiocarbamato) tellurane [C5H10TeI(S2CNC4H8O)] (10) with 1,10-phenanthroline gives an unusual product C12H8N2 · C4H10INO (11). The structures of the new complexes 2, 8, 9, 10 and 11 have been determined by the X-ray analysis. © 2008 Elsevier Ltd. All rights reserved.

Extended hypervalent E′⋯E–E⋯E′ 4c–6e (E, E′ = Se, S) interactions: structure, stability and reactivity of 1-(8-PhE′C10H6)EE(C10H6E′Ph-8′)-1′

Waro Nakanishi, Satoko Hayashi, Sayuri Morinaka, Takahiro Sasamori, Norihiro Tokitoh

New Journal of Chemistry ( Royal Society of Chemistry (RSC) ) 32 ( 11 ) 1881 - 1881 2008 [Refereed]

A new type of imido group donor: Synthesis and characterization of sulfonylimino-Δ3-bromane that acts as a nitrenoid in the aziridination of olefins at room temperature under metal-free conditions

Masahito Ochiai, Takao Kaneaki, Norihiro Tada, Kazunori Miyamoto, Hiroshi Chuman, Motoo Shiro, Satoko Hayashi, Waro Nakanishi

Journal of the American Chemical Society ( American Chemical Society (ACS) ) 129 ( 43 ) 12938 - 12939 2007.10 [Refereed]

A stable sulfonylimino-λ3-bromane, CF3SO2N--Br+C6H4-p-CF3, has been synthesized and structurally characterized for the first time. X-ray crystallographic analyses indicated a centrosymmetric dimer structure with little double-bond character for the "ylidic" Br-N bond. The iminobromane serves as an efficient imido group donor and directly undergoes aziridination of olefins stereospecifically with retention of original stereochemistry. Very interestingly, the aziridination proceeds at room temperature using limiting amounts of alkenes under transition-metal-free conditions. The observed rate constants for aziridination of cis-cyclooctene are proportional to concentration of the olefin. The results suggest the involvement of a bimolecular transition state, in which an olefin attacks the σ* N-Br orbital of iminobromane in the nitrenoid transfer process. Copyright © 2007 American Chemical Society.

Orientational effect of aryl groups in aryl selenides: How can 1H and 13C NMR chemical shifts clarify the effect?

Satoko Hayashi, Kentaro Yamane, Waro Nakanishi （Part： Lead author )

Journal of Organic Chemistry ( American Chemical Society (ACS) ) 72 ( 20 ) 7587 - 7596 2007.09 [Refereed]

(Chemical Equation Presented) Two sets of δ(H) and δ(C) are proposed by employing 9-(arylselanyl)anthracenes [9-(p-YC6H 4Se)Atc: 1] and 1-(arylselanyl)anthraquinones [1-(p-YC 6H4Se)Atq: 2] with various Y's. Structures of 1 and 2 are (A: pl) and (B: pd), respectively, for all Y examined in chloroform-d. After elucidation of the behavior of δ(H, C: 1) and δ(H, C: 2), they are applied to determine the structures in chloroform-d solutions for 1-(arylselanyl)naphthalenes (3), 1-(arylselanyl)-2-methylnaphthalenes (4), and 1-(arylselanyl)-8-bromonaphthalenes (5). Although the structure of 4 remains in (A: pl) in the solutions for all Y examined, that of 5 is (B: pd), except for Y = CN and NO2. On the other hand, 3 is shown to equilibrate between (A: pl) and (B: pd). Although the contributions of (B: pd) and (A: pl) are predominant for Y = NMe2 and NO2, respectively, the equilibrium constants change from Y to Y in the solutions. The results are supported by the quantum chemical calculations, containing the solvent effect of chloroform. These results demonstrate that δ(H, C: 1) and δ(H, C: 2), as well as δ(Se), serve as the practical standards for pl and pd, respectively, to analyze the structures of p-YC6H4ZR (Z = Se) in solutions. © 2007 American Chemical Society.

How 77Se NMR Chemical Shifts Originate from Pre-α, α, β, and γ Effects: Interpretation Based on Molecular Orbital Theory

Waro Nakanishi, Satoko Hayashi, Masahiko Hada

Chemistry - A European Journal ( Wiley ) 13 ( 18 ) 5282 - 5293 2007.06 [Refereed]

Plain rules founded in a theoretical background are presented that, can be used to determine the structure of selenium compounds on the basis of 6(Se) data and to predict (5(Se) data from a given structure with satisfactory accuracy. As a first step to establish such rules, the origin of 6(Se) is elucidated on the basis of MO theory. The Se2- ion was chosen as the standard for the analysis. The concept of the pre-alpha effect is proposed, which is defined as the downfield shift due to protonation of a lone-pair orbital of Se. The pre-a effect of two protons in H,Se is explained by the generation of double sigma(Se-H) and sigma*(Se-H) through protonation of the spherical Se2- ion. The orbitals, together with n(p)(Se), result in effective transitions for the pre-alpha effect. The a effect is the downfield shift caused by the replacement of Se-H by Se-Me. The extension of HOMO-2 [4p(y)(Se)], HOMO-1 [4p(x)(Se)], and HOMO [4p(z)(Se)] over the whole Me,Se molecule is mainly responsible for the alpha effect. The beta effect originates not from the occupied-to-unoccupied (psi(i)->psi(a)) transitions but from the occupied-to-occupied (psi(i)->psi(j)) transitions. Although psi(i)->psi(j) transitions contribute to upfield shifts in Me2Se, the magnitudes become smaller as the methyl protons are substituted by Me groups one after another. The gamma effect of upfield shifts is also analyzed, although complex. The effect of p(Se)-pi(C=C) conjugation is analyzed in relation to the orientational effect. Contributions from each MO (psi(i)) and each psi(i)->psi(a) transition are evaluated separately, by using a utility program derived from the Gaussian 03 program suite (NMRANAL.-NH03G). The treatment enables us to visualize and understand the origin of Se-77 NMR chemical shifts.

Structures in 8-(methylselanyl)-1-(methylseleninyl)- and 1,8-bis(methylseleninyl)naphthalenes: Transition states involving simultaneous rotation around Se{single bond}C bonds, together with stable structures

Satoko Hayashi, Waro Nakanishi （Part： Lead author )

Journal of Molecular Structure: THEOCHEM ( Elsevier BV ) 811 ( 1-3 ) 293 - 301 2007.06 [Refereed]

The energy profile of 8-(methylselanyl)-1-(methylseleninyl)naphthalene (1) is revealed to clarify how the Se(O)Me and SeMe groups control the stereochemistry of 1, through the nonbonded Se-Se{double bond, long}O interaction. Six stable structures (SSs) and eight transition states (TSs) are optimized for 1. Frequency analysis is carried out for all SSs and TSs. The global minimum of 1 is the trans-form of 1 (1 (t-AA)), which reproduces the structure determined by the X-ray crystallographic analysis. Three Se-Se{double bond, long}O atoms in 1 (t-AA) are on the naphthyl plane and two Me groups are in trans. Next stable one is the cis-form (1 (c-AC′)). Motions in the imaginary frequencies of six TSs correspond to the rotation around an Se{single bond}CNap bond, whereas those of the two to the simultaneous rotations around the two Se{single bond}CNap bonds. Attractive interactions must play an important but additional role in the simultaneous rotations in TS. The observed structure in 1,8-bis(methylseleninyl)naphthalene (2) is also reproduced by the global minimum, where the four O{double bond, long}Se-Se{double bond, long}O atoms align linearly. NBO analysis reveals that σ(3c-4e) of the nonbonded Se-Se{double bond, long}O interaction controls the structure of 1 whereas σ(4c-4e) of the O{double bond, long}Se-Se{double bond, long}O interaction will not in 2. © 2007 Elsevier B.V. All rights reserved.

Atoms-in-molecules analysis of extended hypervalent five-center, six-electron (5c-6e) C2Z2O interactions at the 1,8,9-positions of anthraquinone and 9-methoxyanthracene systems

Waro Nakanishi, Takashi Nakamoto, Satoko Hayashi, Takahiro Sasamori, Norihiro Tokitoh

Chemistry - A European Journal ( Wiley ) 13 ( 1 ) 255 - 268 2007 [Refereed]

To clarify the nature of five-center, six-electron (5c-6e) C 2Z2O interactions, atoms-in-molecules (AIM) analysis has been applied to an anthraquinone, 1,8-(MeZ)2ATQ (1 (Z = Se), 2 (Z = S), and 3 (Z = O)), and a 9-methoxyanthracene system, 9-MeO-1,8-(MeZ) 2ATC (4 (Z = Se), 5 (Z = S), and 6 (Z = O)), as well as 1-(MeZ)ATQ (7 (Z = Se), 8 (Z = S), and 9 (Z = O)) and 9-MeO-1-(MeZ)ATC (10 (Z = Se), 11 (Z = S), and 12 (Z = O)). The total electronic energy density (Hb(r c)) at the bond critical points (BCPs), an appropriate index for weak interactions, has been examined for 5c-6e C2Z2O and 3c-4e CZO interactions of the np(O)⋯σ*(Z-C) type in 1-12. Some hydrogen-bonded adducts were also re-examined for convenience of comparison. The total electronic energy densities varied in the following order: O⋯O (3: Hb(rc) = 0.0028 au) = O⋯O (6: 0.0028 au) &gt
O⋯O (9: 0.0025 au) ≥ NN⋯HF (0.0024 au) ≥ O⋯O (12: 0.0023 au) ≫ H2O⋯HOH (0.0015 au) &gt
S⋯O (8: 0.0013 au) = S⋯O (2: 0.0013 au) &gt
S⋯O (11: 0.0012 au) = S⋯O (5: 0.0012 au) &gt
HF⋯HF (0.0008 au) = Se⋯O (10: 0.0008 au) = Se⋯O (4: 0.0008 au) ≥ Se⋯O (1: 0.0007 au) ≥ Se⋯O (7: 0.0006 au) ≫ HCN⋯HF (-0.0013 au). Hb(rc) values for S⋯O were predicted to be smaller than the hydrogen bond of H2O⋯HOH and Hb(r c) values for Se⋯O are very close to or slightly smaller than that for HF⋯HF in both the ATQ and 9-MeOATC systems. In the case of Z = Se and S, Hb(rc) values for 5c-6e C2Z 2O interactions are essentially equal to those for 3c-4e CZO if Z is the same. The results demonstrate that two np(O) ⋯σ*(Z-C) 3c-4e interactions effectively connect through the central np(O) orbital to form the extended hypervalent 5c-6e system of the σ*(C-Z)-np(O)⋯σ* (Z-C) type for Z = Se and S in both systems. Natural bond orbital (NBO) analysis revealed that ns(O) also contributes to some extent. The electron charge densities at the BCPs, NBO analysis, and the total energies calculated for 1-12, together with the structural changes in the PhSe derivatives, support the above discussion. © 2007 Wiley-VCH Verlag GmbH &amp
Co. KGaA.

Structures of 1-(arylseleninyl)naphthalenes: O, G, and Y dependences in 8-G-1-[p-YC6H4Se(O)]C10H6

Satoko Hayashi, Hideki Wada, Takashi Ueno, Waro Nakanishi （Part： Lead author )

Journal of Organic Chemistry ( American Chemical Society (ACS) ) 71 ( 15 ) 5574 - 5585 2006.07 [Refereed]

Structures of 8-G-1-[p-YC6H4Se(O)]C 10H6 [1 (G = H), 2 (G = F), 3 (G = Cl), and 4 (G = Br): Y = H, OMe, OCH2Ph, t-Bu, Me, Cl, and NO2] and (1-C 10H7)2SeO (5) are investigated by the X-ray crystallographic analysis. Structures of 1 are all A with regard to the naphthyl group (1 (A)), where the Se-CAr and Se-O bonds are perpendicular to and parallel to the naphthyl plane, respectively. Those of 2-4 are also A. Since structures of 8-G-1-(p-YC6H4Se)C10H 6 [7 (G = F), 8 (G = Cl), and 9 (G = Br)] are all B, the results exhibit that B of 7-9 change dramatically to A of 2-4 with the introduction of O atoms. The factor to determine the A structures of 1-4 by O is called O dependence. The origin of the O dependence is the nonbonded np(O)- - -π(Nap) interaction, which results in CT from np(O) to π(Nap) since O in 1-4 is highly electron rich due to the polar Se+=O - bond and π(Nap) acts as an acceptor. There are two types of np(O)'s, npy(O) and npz(O), if the directions of the Se-O bond and the p-orbitals of π(Nap) are taken in the x- and z-axes, respectively. Double but independent np(O)- - -π(Nap) interactions in 5 lead to 5 (AA). The conformation of the p-YC6H 4Se group in 1 changes depending on Y (Y dependence), although the effect is not strong. The Y dependence is explained on the basis of the magnitude of CT of the np(O)→π(Ar) type in 1, in addition to the np(O)- - -σπ(Nap) interaction. The structure around the Se=O group in 1 is close to that of 5 (AA), if the accepting ability of the p-YC6H4Se group is similar to that of the naphthyl group. A of 2-4 are further stabilized by the np(G)- - -σ*(Se-O) 3c-4e interactions, which are called G dependence. QC calculations performed on the methyl analogues of 1-4 (11-14, respectively) reproduced the observed structures, supported the above discussion, and revealed the energy profiles. The energy-lowering effect of the O dependence would be close to the G dependence of the nonbonded n(Br)- - -σ*(Se-O) 3c-4e interaction in 14 if the steric repulsion between Br and Se is contained in the G dependence. The value is roughly predicted as 20 kJ mol-1. The structures of 1-5 are well explained by O, G, and Y dependences. © 2006 American Chemical Society.

Orientational Effect of Aryl Groups on77Se NMR Chemical Shifts: Experimental and Theoretical Investigations

Waro Nakanishi, Satoko Hayashi, Daisuke Shimizu, Masahiko Hada

Chemistry - A European Journal ( Wiley ) 12 ( 14 ) 3829 - 3846 2006.05 [Refereed]

Proposal for Sets of77Se NMR Chemical Shifts in Planar and Perpendicular Orientations of Aryl Group and the Applications

Satoko Hayashi, Waro Nakanishi （Part： Lead author )

Bioinorganic Chemistry and Applications ( Hindawi Limited ) 2006 1 - 13 2006 [Refereed]

The orientational effect of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E1"><mml:mrow><mml:mi>p</mml:mi><mml:mtext>-</mml:mtext><mml:msub><mml:mrow><mml:mtext>YC</mml:mtext></mml:mrow><mml:mn>6</mml:mn></mml:msub><mml:msub><mml:mtext>H</mml:mtext><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>(Ar) on<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E2"><mml:mi>δ</mml:mi></mml:math>(Se) is elucidated for ArSeR, based on experimental and theoretical investigations. Sets of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E3"><mml:mi>δ</mml:mi></mml:math>(Se) are proposed for<bold>pl</bold>and<bold>pd</bold>employing 9-(arylselanyl)anthracenes (<bold>1</bold>) and 1-(arylselanyl)anthraquinones (<bold>2</bold>), respectively, where Se–<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E4"><mml:mrow><mml:msub><mml:mi>C</mml:mi><mml:mi>R</mml:mi></mml:msub></mml:mrow></mml:math>in ArSeR is on the Ar plane in<bold>pl</bold>and perpendicular to the plane in<bold>pd</bold>. Absolute magnetic shielding tensors of Se (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E5"><mml:mi>σ</mml:mi></mml:math>(Se)) are calculated for ArSeR (R = H, Me, and Ph), assuming<bold>pl</bold>and<bold>pd</bold>, with the DFT-GIAO method. Observed characters are well reproduced by the total shielding tensors (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E6"><mml:mrow><mml:msup><mml:mi>σ</mml:mi><mml:mtext>t</mml:mtext></mml:msup></mml:mrow></mml:math>(Se)). The paramagnetic terms (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E7"><mml:mrow><mml:msup><mml:mi>σ</mml:mi><mml:mtext>P</mml:mtext></mml:msup></mml:mrow></mml:math>(Se)) are governed by<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E8"><mml:mrow><mml:msup><mml:mi>σ</mml:mi><mml:mtext>P</mml:mtext></mml:msup><mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mtext>Se</mml:mtext><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mtext>xx</mml:mtext></mml:mrow></mml:msub><mml:mo>+</mml:mo><mml:msup><mml:mi>σ</mml:mi><mml:mtext>P</mml:mtext></mml:msup><mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mtext>Se</mml:mtext><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mtext>yy</mml:mtext></mml:mrow></mml:msub></mml:mrow></mml:math>, where the direction of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E9"><mml:mrow><mml:msub><mml:mtext>n</mml:mtext><mml:mtext>P</mml:mtext></mml:msub></mml:mrow></mml:math>(Se) is set to the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E10"><mml:mi>z</mml:mi></mml:math>-axis. The mechanisms of the orientational effect are established both for<bold>pl</bold>and<bold>pd</bold>. Sets of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E11"><mml:mi>δ</mml:mi></mml:math>(Se:<bold>1</bold>) and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E12"><mml:mi>δ</mml:mi></mml:math>(Se:<bold>2</bold>) act as the standards for<bold>pl</bold>and<bold>pd</bold>, respectively, when<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E13"><mml:mi>δ</mml:mi></mml:math>(Se) of ArSeR are analyzed based on the orientational effect.

The Structure of 1-(Arylthio)naphthalenes, Together with the Selenium and Oxygen Derivatives in Crystals and Solutions

Waroˆ Nakanishi, Satoko Hayashi, Takahito Nakai

Phosphorus, Sulfur, and Silicon and the Related Elements ( Informa UK Limited ) 180 ( 5-6 ) 1431 - 1432 2005.03 [Refereed]

Extended Hypervalent 5c–6e Interactions: Linear Alignment of Five C─Z- - -O- - -Z─C (Z = S, Se) Atoms in Anthraquinone and Anthracene Systems

Warô Nakanishi, Satoko Hayashi, Takashi Furuta, Norio Itoh, Yusaku Nishina, Makoto Yamashita, Yohsuke Yamamoto

Phosphorus, Sulfur, and Silicon and the Related Elements ( Informa UK Limited ) 180 ( 5-6 ) 1351 - 1355 2005.03 [Refereed]

How Do G–Se Nonbonded and Y–Se Through π -Bond Interactions Determine the Structures of 8-G-1-( p-YC6H4Se)C10H6?

Warô Nakanishi, Satoko Hayashi

Phosphorus, Sulfur, and Silicon and the Related Elements ( Informa UK Limited ) 180 ( 3-4 ) 961 - 964 2005.02 [Refereed]

Extend Hypervalent 5c-6e Interactions: Linear Alignment of Five C-Se- - -O- - -Se-C Atoms in Anthraquinone and 9-Methoxyanthracene Bearing Arylselanyl Groups at the 1,8-Positions

Warô Nakanishi, Satoko Hayashi, Norio Itoh

Journal of Organic Chemistry ( American Chemical Society (ACS) ) 69 ( 5 ) 1676 - 1684 2004.03 [Refereed]

The structures of 1,8-bis(phenylselanyl)anthraquinone (1a), 1,8-bis(phenylselanyl)-9-methoxyan-thracene (2a), and 1,8-bis(phenylselanyl)anthracene (3a) are determined by X-ray crystallographic analysis, together with the derivatives. The Se-Ci (Ph) bonds in 1a are placed on the anthraquinone plane (both type B) and the phenyl planes are perpendicular to the anthraquinone plane. The structure around the Se atoms in 2a is very close to that of 1a: the conformations of the PhSe groups are both type B. Consequently, the five Ci-Se- - -O- - -Se-Ci atoms in 1a and 2a align linearly. The nonbonded Se- - -O distances in 1a and 2a are 2.673-2.688 and 2.731-2.744 Å, respectively, which are about 0.7 Å shorter than the sum of van der Waals radii of the atoms. The extended hypervalent σ*(Ci-Se)- - -np(O)- - -σ*(Se-Ci) 5c-6e interactions are strongly suggested for the origin of the linear alignment of the five atoms in 1a and 2a. The 5c-6e must be constructed by the connection of the two hypervalent np(O)- - -σ*(Se-Ci) 3c-4e interactions through the central n p(O). The five Ci-Se- - -H- - -Se-Ci atoms never align linearly in 3a. To reveal the nature of 5c-6e in 1a and 2a, QC calculations are performed on HaHbASe- - -O(=CH2)- - -BSeHa′Hb′ (model a) and HaHbASe- - -OH2- - -BSeHa′Hb′ (model b) with the B3LYP/6-311++G(3df,2pd) method, where the nonbonded Se- - -O distances are fixed at 2.658 Å. Four conformers, a (AA-cis), a (AA-trans), a (AB), and a (BB), are optimized to be stable for model a, where a (AA) shows both type A for the ASe-Hb and BSe-Hb′ bonds in model a. Three conformers, b (AA-cis), b (AB), and b (BB), are stable for model b. The bonding models in AA, AB, and BB correspond to 3c-6e, 4c-6e, and 5c-6e, respectively. The models become more stable by 42 ± 5 kJ mol-1, if the type A conformation of each Se-H bond changes to type B. No noticeable saturation is observed in the stabilization for each change. QC calculations are also performed on 1a-3a at the B3LYP level. Three conformers are evaluated to be stable for 1a and 2a. The relative energies of 1a (AA-trans), 1a (AB), and 1a (BB) are 0.0, -31.5, and -60.6 kJ mol -1, respectively, and those of 2a (AA-cis), 2a (AB), and 2a (BB) are 0.0, -24.4, and -36.5 kJ mol-1, respectively. These results demonstrate that the origin of the linear alignment of the five C-Se- - -O- - -Se-C atoms in 1a and 2a is the energy lowering effect by the extended hypervalent 5c-6e interactions of the σ*(C-Se)←n p(O)→σ*(Se-C) type. The π-conjugation between π(C=O) and npz(Se) through the π-framework of anthraquinone must also contribute to stabilize the BB structure of 1a, where z is the direction perpendicular to the anthraquinone plane.

First Br4four centre–six electron and Se2Br5seven centre–ten electron bonds in nonionic bromine adducts of selenanthrene

Warô Nakanishi, Satoko Hayashi, Shigehiro Yamaguchi, Kohei Tamao

Chem. Commun. ( Royal Society of Chemistry (RSC) ) ( 2 ) 140 - 141 2004 [Refereed]

First linear alignment of five C–Se⋯O⋯Se–C atoms in anthraquinone and 9-(methoxy)anthracene bearing phenylselanyl groups at 1,8-positions

Warô Nakanishi, Satoko Hayashi, Norio Itoh

Chem. Commun. ( Royal Society of Chemistry (RSC) ) ( 1 ) 124 - 125 2003 [Refereed]

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