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1,1,2,2,3,3,4,4-Octaisopropyltetragermetane (iPr2Ge)4 reacted with various alkynes in the presence of palladium complexes at 120 °C to afford 1,2,3,4-tetrahydro-1,2,3,4-tetragermins, Δ4-1,2,3-trigemolene, and 1H-germoles, depending on the kind of alkyne and the palladium complex employed. Terminal alkynes are more reactive than internal ones. Pd(dba)2-ETBP and Pd(acac)2-ETBP systems were found to serve as efficient catalysts. The mechanism of alkyne insertion reactions into the germanium–germanium bonds of (iPr2Ge)4 is discussed.

Hexamethyldigermane, Me3GeGeMe3, reacted with various alkynes in the presence of platinum complexes at 120 °C to afford Z–1,2-bis(germyl)ethenes in moderate to good yields. Terminal alkynes exhibit higher reactivities than internal ones. [Pt(acac)2] and [Pt(dba)2] serve as efficient catalysts, while [Pt(PPh3)4], [PtCl2(PPh3)2], and [Pt(dba)2]-phosphite were found to be inactive. Four- and six-membered cyclic oligogermanes, such as dodecamethylcyclohexagermane, (Me2Ge)6, reacted with alkynes in the presence of platinum catalysts to yield 1,4-digermacyclohexa-2,5-dienes in ca. 30% yield. The reactions of phenylacetylene with 1,2-digermacyclohexa-3,5-dienes afforded the corresponding 1,4-digermacycloocta-2,5,7-trienes in 93% yield. Bis(germyl)platinum complexes having various tertiary phosphine ligands have been prepared as models of a key intermediate in the above mentioned catalytic bis-germylation of alkynes, and their structures have been established by spectroscopic methods and X-ray crystallography. Bi...

The CN(B2Σ+–X2Σ+) emission spectrum produced in the reaction of Ar(3P2) with BrCN was observed by the use of a flowing afterglow method at argon pressures ranging from 9 mTorr to 2 Torr (1 Torr = 133.322 Pa). The pressure dependences of the intensity anomalies in the rotational lines due to the B2Σ+∼A2Πi and the B2Σ+∼4Σ+ perturbations were measured by introducing collision-partner gases in the reaction region. These pressure dependences can be explained by the “doorway” model. On the other hand, the measured pressure dependence of the effective rotational temperature in the CN(B2Σ+) state can also be reproduced by the collision-induced rotational relaxation model. The cross section for the rotational relaxation in the A2Πi state was found to be smaller than those in the B2Σ+ and 4Σ+ states. This finding is interpreted by the use of the dipole–induced dipole interaction model for the collision–induced rotational relaxation.

Binuclear octaethylporphinatoruthenium(II) complexes bridged with five diaza compounds (L), [{RuII(oep)(CO)}2(μ-L)] (H2oep = 2,3,7,8,12,13,17,18-octaethylporphin) have been synthesized. They are oxidized through two two-electron steps at a platinum electrode in CH2Cl2.

In the presence of active cationic species generated from silicon(IV) chloride and silver perchlorate, carboxylic acids or their trimethylsilyl esters react with p-trifluoromethylbenzoic anhydride to form corresponding mixed anhydrides in situ. Then the catalytic Friedel–Crafts acylation reaction between initially formed mixed anhydrides and coexisted aromatic compounds smoothly proceeds at room temperature to afford the corresponding aromatic ketones in high yields. The above two sequential reactions are effectively promoted by the active silicon(IV) catalyst under mild conditions.

In the presence of an active acidic catalyst generated from SbCl5 and AgSbF6, the sulfenylation reaction of aromatic compounds with organic disulfides smoothly proceeds in refluxing 1,2-dichloroethane to afford the corresponding unsymmetrical sulfides in high yields.

In the presence of an active catalyst generated from SiCl4 and AgClO4, the Friedel-Crafts acylation reaction between equimolar amounts of aromatic compounds and mixed anhydrides, formed in situ from free carboxylic acids (or their trimethylsilylesters) and p-trifluoromethylbenzoic anhydride, smoothly proceeds at room temperature to afford the corresponding aromatic ketones in high yields.

A novel catalyst system consisting of antimony(V) chloride (SbCl5) and lithium perchlorate (LiClO4) effectively promotes the Friedel-Crafts acylation reaction of aromatic compounds with acid anhydrides.

The CN(B2Σ+–X2Σ+) 14–14 emission band was observed in the reaction of Ar(3P0,2) with BrCN by the use of the flowing afterglow method. The intensity anomalies in the rotational lines at N′ = 7 due to the B2Σ+(ν = 14)∼4Π(ν = 7) perturbation were measured as a function of the pressure of Ar or He introduced as a collision partner in the reaction region, the ambient pressure being varied from 9 to 2000 mTorr (1 Torr = 133.322 Pa). The intensities of the perturbed lines relative to that of the rotational band envelope increased with the ambient pressure in the low pressure region in the cases of both Ar and He. On the other hand, they decreased with pressure in the higher pressure region. The pressure dependence of the intensity anomaly for He followed that for Ar, although higher pressure of He was necessary to attain the same level of the intensity anomaly for Ar. These pressure dependences can be explained semiquantitatively by a model with collisional rotational relaxations in the quartet and doublet manif...

The oxidation of 4-substituted N,N-dialkylanilines with molecular oxygen using a catalytic amount of cobalt(II) chloride efficiently proceeds in the presence of acetic anhydride to give N-alkylacetanilides in good yields along with N-alkylformanilides.

The dynamics of dissociative excitation of BrCN or ICN producing CN(B2Σ+) radicals by Ar(3P2) or Kr(3P2) was investigated by using the flowing afterglow method. The observed vibrational distributions of CN(B) are consistent with the reported reaction mechanism for the CN(B) formation initiated by the transfer of the excitation energy of the metastable atom to the cyanide molecule.

The build-up time constants of Tn←T1 transition bands were measured with 4-hydroxybenzophenone, Michler’s ketone, 2-nitrofluorene, 1-nitropyrene, and 9-nitroanthracene in solution with the aid of picosecond spectroscopy. All the compounds exhibit fast build-up of the Tn←T1 absorption with the time constants smaller than 100 ps. The picosecond kinetics of these nonfluorescent compounds are interpreted in terms of the electronic structures of initial and final states relevant to radiationless transitions.

A flowing-afterglow method was applied to the formation of CN(B2Σ+) from CH3CN by impact of metastable argon atoms, Ar(3P2,0). Emission spectra of CN B2Σ+-X2Σ+ (violet band) were analyzed to estimate the energies distributed to the vibrational and rotational motions of CN(B2Σ+). In comparison with the CN(B2Σ+) produced from HCN under similar experimental conditions, relative populations in excited vibrational states are smaller. The effective rotational temperatures range from 5000±1000 K (v=0–2) to 2000±1500 K (v=5–10). An intensity anomaly caused by the rotational perturbation with A2II is used for estimating the ratio of the formation rates of CN B2Σ+ and A2Π, FB/FA, to be 0.19±0.05.

The time dependence of fluorescence intensity after picosecond laser excitation and the steady-state fluorescence intensity were measured in order to study the mechanism of fluorescence quenching of anthracene by maleic anhydride in 1,4-dioxane. The nonlinear relationship between the reciprocal of steady-state fluorescence intensity and quencher concentration was observed for this system and interpreted in terms of the transient effect in the quenching process. The kinetic study by picosecond laser photolysis supports this interpretation. The reaction radius (R) and the sum of diffusion constants of both reactants (D) at various temperatures were determined by applying the diffusion model of Andre et al. The observed values are R=7.2 A, D=1.46×10−5 cm2 s−1 (22 °C), 1.87×10−5 cm2 s−1 (50 °C), 2.42×10−5 cm2 s−1 (75°C). Studies of the main path in the quenching process by nanosecond laser photolysis suggest the existence of an extra path in the quenching process which overwhelms the fluorescent exciplex form...

1,5,9-Trithia[9]ferrocenophane was prepared by the reaction of 1,1′-bis(3-chloropropylthio)ferrocene with sodium sulfide. The complexes of 1,5,9-trithia[9]ferrocenophane, along with 1,4,7-trithia[7]ferrocenophane, with copper(I), silver(I), mercury(II), and palladium(II) salts were prepared. Some interaction between the iron atom and the metal atoms coordinated to the thia-crown moiety was suggested from their spectral data in the solution for the complexes of 1,4,7-trithia[7]ferrocenophane with mercury(II) and palladium(II) salts and the complex of 1,5,9-trithia[9]ferrocenophane with silver(I) tetrafluoroborate.

The reaction of ethyl (Z)-3-nitro-2-alkenoate (1) with one or two equivalents of bromine azide gave a one-to-one mixture of ethyl (E)-2-azido-3-nitro-2-alkenoate (3) and 4-ethoxycarbonyl-1,2,5-oxadiazole 2-oxide (5), or ethyl 3-bromo-2,2-diazido-3-nitroalkanoate (6), respectively, and the subsequent thermal and photochemical reactions of (E)-3 gave 2-ethoxycarbonyl-3-nitro-l-azirine, together with a small amount of 5. The addition of bromine to 1, and the subsequent elimination of hydrogen bromide from the product, gave exclusively, the (Z)-2-bromo derivative (9). The reduction of 6 and 9 with diethyl phosphonate was examined, and the reaction mechanisms were discussed.

1,7-Dithia-4-selena[7]- and 1,9-dithia-5-selena[9](1,1′)ferrocenophanes were prepared. These compounds, as well as 1,4,7-trithia[7]- and 1,5,9-trithia[9](1,1′)ferrocenophanes, were treated with (CH3CN)4Pd(BF4)2 or (CH3CN)4Pt(BF4)2 to give the corresponding 1/1 complexes in good yield. The spectral data of these complexes confirmed that there exsisted a dative Fe–Pd or Fe–Pt bond in these bimetallic complexes.

カルボニル化合物によるアミンからの水素引き抜き反応は電荷移動型の中間体を経て進むとされている。事実,ベンゾフェノン(BP)-トリエチルアミン(TEA)系のアセトニトリル溶液では励起後10psにアニオンラジカルの吸収がみえ,30ps後にはケチルラジカルに変化している(ShaeferとPeters,1980)。しかし,この報告では3BP*の減衰についての記述がなく,また電荷移動の速度が芳香族アミンからのそれらより速いことから1BP*からの反応を否定できない。著者らはTEAを溶媒とし3BP*による水素引き抜き反応をピコ秒分光によつて研究した。TEAは基底状態ではBPと錯体をつくらずまた極性もアセトニトリルより低いので1BP*からの反応(電荷移動)の効率は低く,3BP*からの拡散律速でない過程を見ることができる。ピコ秒分光はOMA二次元使用によるスペクトル測定およびエシエロンを用いた時間変化の測定の両面から行なった。その結果はじめに3BP*が生成し50psの寿命で減衰する。励起後150psの吸収スペクトルは完全にケチルラジカルの吸収スペクトルであった。1BP*および3BP*のいずれからのアニオンラジカルの生成も観測されなかった。これは電荷移動後1のプロトン移動がきわめて速いため,あるいは直接の水素移動(電子およびプロトンの移動が同時)によると考えられる。3BP*によるTEAからの水素引き抜きは50psの時定数で起きると結論される。

Emission spectra from CH(A2Δ) formed in the reaction of positive ionic species of argon with CH3CN were studied by the flowing-afterglow method. The rotational distributions for the v′=0, 1, and 2 of CH(A2Δ) are characterized by effective rotational temperatures of ca. 5000, 2000, and 1500 K, respectively, whereas the distributions in lower levels (N′\lesssim11), especially for v′=0, are characterized by that of ca. 700 K. The average vibrational and rotational energies distributed in the CH radicals produced initially are estimated to be 0.32±0.04 and 0.34±0.06 eV, respectively.

Tetrathia- and trithia[n]ferrocenophanes formed 1:1 complexes with Pd(BF4)2. The spectral data proved the presence of a Fe–Pd bonding interaction for the Pd(II) complexes of 1,5,9-trithia[9]-and 1,4,7-trithia[7](1,1′)ferrocenophanes.