bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Redetermination of Diphenanthro[5,4,3-abcd: 5′,4′,3′-jklm]perylene
Authors: Oonishi Isao , Fujisawa Shoji , Aoki Junji , Danno Takaaki 
Published: July 2006

Abstract
It has been shown that the true unit cell of diphenanthro[5,4,3-abcd: 5′,4′,3′-jklm]perylene consists of three subcells in which the atomic arrangements differ slightly from each other. The model for the ordered structure has been deduced from the consideration of weak reflections. The average structure of the subcell with a=30.80, b=3.837, c=19.87 Å, β=112.5°, and Z=4 has been redetermined. The final R value is 0.103 for 1244 independent reflections. The two naphthanthrone planes in the molecule make an angle of 36°, which shows a large distortion from a planar structure.
Catalysis by Supported Metal Crystallites from Carbonyl Clusters. II. Catalytic Ethanol Synthesis from CO and H2 under Atmospheric Pressure over Supported Rhodium Crystallites Prepared from Rh Carbonyl Clusters Deposited on TiO2, ZrO2, and La2O3
Authors: Ichikawa Masaru 
Published: July 2006

Abstract
Ethanol was catalytically produced in the CO–H2 reaction under atmospheric pressure and at 150–250 °C over rhodium crystallite catalysts prepared from Rh carbonyl cluster compounds highly dispersed on La2O3, TiO2, and ZrO2. The activity and selectivity of ethanol formation depend on the kind of metal carbonyl cluster and metal oxide used as inorganic carriers. The catalysts prepared by the pyrolysis of smaller Rh carbonyl clusters such as Rh2(C5H5)2(CO)3, Rh4(CO)12, and Rh6(CO)16 on La2O3, TiO2, and ZrO2 show higher selectivity of the oxygenated products containing ethanol (main), acetaldehyde, and methanol. The ethanol contents in the oxygenated products increased considerably above 200 °C over the catalysts. CeO2 and ThO2 were also employed in the preparation of the pyrolysed catalysts to disperse the Rh carbonyl clusters, which catalyses the ethanol formation in the CO–H2 reaction at atmospheric pressure.
Azafulvenes 8. Cycloaddition Reaction of 8-Azaheptafulvene to Sulfene
Authors: Iwasaki Takahiko , Kajigaeshi Shoji , Kanemasa Shuji 
Published: July 2006

Abstract
Peri- and stereoselective cycloadducts were obtained from the reactions of 8-aryl-8-azaheptafulvenes with some sulfenes. 8-Aryl-8-azaheptafulvenes reacted with phenylsulfene to give cis [8+2] cycloadducts as the sole products which would have resulted either from the endo approach or via the endo intermediate of the two reagents. On the other hand, with benzoylsulfene trans [8+2] cycloadducts were isolated. The formation of the latter products was rationalized by considering epimerization of the initially formed cis adducts. The cis [8+2] cycloadducts to vinylsulfene did not give the trans isomers but the hydrogen migrated derivatives under the influence of bases. The mechanism of the above reactions is also discussed.
Catalytic Activities of Salicylaldehyde Derivatives. VIII. Kinetic Studies of the Catalytic Racemization of l-Glutamic Acid at 25 °C
Authors: Ando Makoto , Emoto Sakae 
Published: July 2006

Abstract
The racemization of l-glutamic acid catalyzed by 15 kinds of salicylaldehyde derivatives has been kinetically studied at 25 °C and pH 10 in the presence of copper(II) ion. When 4- and 5-substituted salicylaldehydes were used as the catalyst, Hammett’s plots for the racemization against σ− were found to be linear with fewer points deviating from the line than the plots against σ . This fact has not been observed previously, since the salicylaldehyde derivatives tested having a substituent of different value between σ and σ− were degraded during the course of reaction at 80 °C. Hammett’s plots for the reaction catalyzed by 3-substituted salicylaldehydes indicated no linear relation with either σ or σ−. These catalytic racemizations, including the case of the 6-substituted salicylaldehydes have been discussed.
Incorporation of CO2 in Butadiene Dimerization Catalyzed by Palladium Complexes. Formation of 2-Ethylidene-5-hepten-4-olide
Authors: Inoue Yoshio , Sasaki Yoshiyuki , Hashimoto Harukichi 
Published: July 2006

Abstract
Reaction of carbon dioxide with butadiene catalyzed by palladium–phosphine complexes was studied. When the reaction was carried out in certain polar, aprotic solvents, such as dimethylformamide (DMF), 2-ethylidene-5-hepten-4-olide was formed in about 5% yield by the incorporation of CO2 together with the formation of butadiene linear dimers. The main dimer was 1,3,7-octatriene. The ditertiary phosphines, R2PCH2CH2CH2PR2 where R is methyl or phenyl, were found to be suitable as the ligand for the olide synthesis. A possible mechanism involving the intermediate of π-allyl, σ-allyl form from two moles of butadiene and the palladium complex is proposed.
Glass Formation in the Li2O–TiO2–P2O5, MgO–TiO2–P2O5, and CaO–TiO2–P2O5 Systems
Authors: Kishioka Akira 
Published: July 2006

Abstract
The glass-forming regions in the Li2O–TiO2–P2O5, MgO–TiO2–P2O5, and CaO–TiO2–P2O5 systems have been determined. Homogeneous glasses were formed with compositions of less than 50 mol% P2O5 in all three systems. The largest quantities of TiO2 could be introduced into glass for compositions of 30 mol% P2O5. In compositions with more than 50 mol% P2O5 only a mixture of the glass and crystal was formed. With an increase in the TiO2 content, the density of the glass increased and the volume per mole of oxygen decreased. These results indicate that the TiO2 had been easily incorporated into the glass with compositions of lower P2O5 contents, contributing to the stabilization of the glass structure.
Reduced Copper Catalyzed Conversion of Primary Alcohols into Esters and Ketones
Authors: Takeshita Kenji , Nakamura Shigeaki , Kawamoto Kazuaki 
Published: July 2006

Abstract
Vapor phase reactions of a mixture of two types of primary alcohols to esters and ketones over a reduced copper catalyst have been investigated. The reactions between primary alcohols and propionaldehyde have also been investigated. The effects of the molar ratio of the reactants and the reaction temperature on the yields of esters, ketones, and aldehydes have been examined. A mixture of ethyl alcohol and propyl alcohol when passed over the catalyst, the main products have been found to be propyl acetate, ethyl acetate, propyl propionate, ethyl propionate, ethyl methyl ketone, diethyl ketone, acetone, acetaldehyde, and propionaldehyde. The formation of the ester and the ketone may be presented as follows:
(Remark: Graphics omitted.)
Photoreduction of 1-Benzyl-3-carbamoylpyridinium Chloride in Aqueous Ammonia
Authors: Matsuura Teruo , Itahara Toshio , Otsuki Toshiaki , Saito Isao 
Published: July 2006

Abstract
Irradiation of 1-benzyl-3-carbamoylpyridinium chloride (BNA+Cl−) in the presence of ascorbic acid in 28% aqueous ammonia gives the corresponding 1,4-dihydronicotinamide as the major product. The spectroscopic behavior of BNA+ in aqueous ammonia and the adduct formation between BNA+ and chloroform are also described.
Physical Properties and Constitution of the 5,6 : 11,12-Bis(epidithio)naphthacene–Iodine Complexes (TTT–In)
Authors: Inabe Tamotsu , Matsunaga Yoshio 
Published: July 2006

Abstract
The electrical resistivity of the 5,6 : 11,12-bis(epidithio)naphthacene(TTT)–iodine system was examined using poly crystalline compactions. The room-temperature resistivity reaches a minimum of 0.3 ohm cm at the composition of the well-studied metallic phase, TTT–I1.5, and a shoulder as large as 200 ohm cm occurs at the composition of the other metallic phase, TTT–I2.7. The apparent activation energy for semiconduction at the latter composition is as much as 0.13 eV, indicating some semiconductor behavior in directions other than the needle axis. The appearance of the latter phase is also manifested by a drastic increase in the Seebeck coefficient near this composition, which corresponds to a change in the amount of charge per TTT molecule from 0.68 to 0.85. The diffuse reflection spectra were recorded for TTT–I1.53 and TTT–I2.79. The resemblance between the spectrum of the iodine-rich complex and that of TTT–Br is noted.
The G-value of Nitrogen Atoms Produced in the γ-Radiolysis of Liquid Nitrogen and the Ozone Formation in the γ-Irradiated Liquid Nitrogen Solution of Oxygen
Authors: Matsumoto Akihiko , Yugeta Rei , Karasawa Hidetoshi , Sato Shin 
Published: July 2006

Abstract
The γ-radiolyses of liquid nitrogen solutions of nitrogen oxide and of oxygen gave nitrogen dioxide and ozone, respectively, as the main products. Over the solute concentrations from 0.01 to 0.1 mol l−1, the G-values of both products were constants: G(NO2)=3.3 and G(O3)≈7. The G-value of nitrogen dioxide in the former solution probably corresponds to the G-value of nitrogen atoms from liquid nitrogen. For the formation of ozone in the latter solution, a possible reaction mechanism is discussed. Dinitrogen oxide was found as a minor product, the G-value being about 0.1 for both solutions.
Cobalt(IV) Ammine Complexes with 5-Nitrosalicylato or Similar Ligands. IV.) Preparation, 1H-NMR, 13C-NMR, and IR Spectra
Authors: Yamamoto Yoshihisa 
Published: July 2006

Abstract
The 1H-NMR spectrum of the 5-nitrosalicylatotetraamminecobalt(IV) complex did not show the signals of phenyl protons of the salicylato ligand, but did show those of ammine protons at 3.7 (s, 6H) and 3.3 ppm (s, 6H). The 13C-NMR peaks could not be observed because of the paramagnetism. The 1H-NMR spectra of the salicylatotetraamminecobalt(III) complexes showed peaks at 3.96 (s, 6H), 3.65 (s, 3H), and 3.38 ppm (s, 3H) for the ammine protons and at 6.7–8.1 ppm (m, 4H) for the phenyl protons of the salicylato ligand. Their 13C-NMR spectra showed seven signals for the salicylato ligand. The IR peaks assignable to the rocking deformation vibration were observed at 830–855 cm−1 for the ammine ligands of 5-nitrosalicylatotetraamminecobalt(IV) complexes and at 820–840 cm−1 for those of salicylatotetraamminecobalt(III) complexes, in conformity with the view that the former complexes are actually cobalt(III) complexes of a free radical nature.
Reduction by a Model of NAD(P)H. XVII. Isotope Effects and Magnesium Ion Catalysis
Authors: Ohno Atsuyoshi , Yasui Shinro , Yamamoto Hiroyuki , Oka Shinzaburo , Ohnishi Yutaka 
Published: July 2006

Abstract
The reduction of thiopivalophenone (1) with 1-benzyl-1,4-dihydronicotinamide (BNAH) gives the same value for kinetic deuterium isotope effect (kH⁄kD) and isotopic distribution in the product (YH⁄YD) regardless of the presence or absence of magnesium ion. The reduction of methyl benzoylformate (2) with a BNAH-analog in the presence of magnesium ion also gives similar values for kH⁄kD and YH⁄YD. It has been concluded that magnesium ion stabilizes the transition state in the reduction of 2, whereas an intermediate is stabilized by magnesium ion in the reduction of 1.
Layered Compounds. LII. Syntheses of Eleven Anthracenophanes
Authors: Iwama Akio , Toyoda Toshihiro , Yoshida Misaku , Otsubo Tetsuo , Sakata Yoshiteru , Misumi Soichi 
Published: July 2006

Abstract
A series of layered cyclophanes where an anthracene ring is stacked in different modes with the same or other π-systems has been synthesized by the Hofmann elimination method or photodesulfurization for studying the transannular π-electronic interaction. Photochemical and thermal interconversions have been observed between syn-(1,4)anthracenophane and its isomer and have been discussed with reference to the X-ray crystal data. From the electronic spectra it has been established that the transannular interaction increases with overlapping between the two faced aromatic rings and that when the overlap between the two chromophores is the same, the interaction increases relative to the dimension of the faced chromophore.
Sulfenylation Accompanied by Dealkoxycarbonylation of β-Keto Esters, Geminal Diesters, and α-Cyano Ester in Hexamethylphosphoric Triamide (HMPA)
Authors: Asaoka Morio , Miyake Kazutoshi , Takei Hisashi 
Published: July 2006

Abstract
In the presence of sodium iodide, diphenyl disulfide reacted with geminal diesters, β-keto esters, and α-cyano esters in hexamethylphosphoric triamide (HMPA) at 150–160 °C to give alkyl phenyl sulfides and α-phenylthio esters, ketones, and nitriles, respectively, along with evolution of carbon dioxide.
Stereospecific Synthesis of the C-9–C-16 Segment of Carbonolide B, the Aglycon of Carbomycin B
Authors: Tatsuta Kuniaki , Yamauchi Toyoaki , Kinoshita Mitsuhiro 
Published: July 2006

Abstract
Stereospecific synthetic routes to methyl (R)-7-hydroxy-(2E,4E)-octadienoate (9) and its (2E,4Z)-isomer (16), the former which can be a useful chemical precursor to the 16-membered-ring aglycon of carbomycin B (carbonolide B), are discussed. Compound 9, corresponding to its C-9–C-16 segment, was synthesized starting with methyl 2-deoxy-α-d-arabion-hexopyranoside (2). The deoxysugar 2 was converted to the masked 2,4,6-trideoxy-d-threo-hexopyranose (6) via the 4,6-dichloro-2,4,6-trideoxy-α-d-lyxo-hexopyranoside derivative. Treatment of 6 with p-toluenesulfonyl chloride and triethylamine afforded 3-O-acetyl-1,5-anhydro-2,4,6-trideoxy-d-threo-hex-1-enitol, which by reaction with mercury(II) acetate was converted to (R)-5-hydroxy-(2E)-hexenal (8). Reaction of 8 with Wittig reagent gave the (2E,4E)-isomer 9. Compound 16 was prepared by the Wittig reaction with the 2,3-unsaturated deoxysugar, 2,3,4,6-tetradeoxy-d-glycero-hex-2-enopyranose, which was derived from methyl 2,3-anhydro-4,6-dideoxy-α-d-lyxo-hexopyranoside by treatment with potassium selenocyanate followed by acid hydrolysis.
Studies of Reactions of Amines with Sulfur Trioxide. V. Transsulfonation of Amine Salts of Some N-Substituted Amidosulfuric Acids
Authors: Kanetani Fujio , Yamaguchi Hachiro 
Published: July 2006

Abstract
4-Methylanilinium butylamidosulfate, butylammonium (4-methylphenyl)amidosulfate, and 4-methylanilinium (4-methylphenyl)amidosulfate were heated separately under reduced pressure at different temperatures ranging from 80 to 180 °C. Butylammonium butylamidosulfate was heated with 4-methylaniline under atmospheric and reduced pressure. The product compositions were determined as functions of reaction time and temperature, and the components were separated and identified. At lower temperatures (4-methylphenyl)amidosulfate and 4-methylaniline-N,2-disulfonate were the major products, while at higher temperatures 4-methylaniine-2-sulfonate and 2,6-disulfonate were the major products. The ease of N–S bond cleavage of the amidosulfate salts (RNHSO3–R′NH3+) (1) depends largely on the basicity of both the parent amine (R′NH2) (2) and the salt-forming base (R′NH2) (3). The results suggest that the initial step of the transsulfonation involves the dissociation of 1 into 3 and the free acid followed by an equilibration between RNHSO3H and RNH2+SO3− (4). It is considered that 4 may be the sulfonating species and the free amines, 2 and 3, should be the receptors of a sulfonate group. In contrast to the widely accepted scheme (transsulfonation and subsequent intramolecular rearrangement), our results show that both the transsulfonation and the rearrangement process occur concurrently and the same type of mechanism (a bimolecular displacement, viz., B+ : SO3−+B′: \ightleftarrowsB+: +B+: SO3−) may be operative.
Dipole Moments of Molecules Containing Single Chlorine Atoms
Authors: Sugie Masaaki , Takeo Harutoshi , Matsumura Chi 
Published: July 2006

Abstract
The dipole moments of CD2ClF, CHDClF, CH3CHClF, CH3CCl=CH2, and DCOCl have been determined from the J=1←0 transitions of their microwave spectra. For the analyses of the Stark effects, the method of the intermediate field case proposed by Mizushima has been used.
Flux Growth of Double Oxides of Niobium and Rare-earth Elements (Ln3NbO7)
Authors: Yamasaki Yuichi , Sugitani Yoshinori 
Published: July 2006

Abstract
Crystals of double oxides of rare-earth and niobium Ln3NbO7, where Ln=Ho, Y, Er, Dy, and La, and those of rare-earth and tantalum Ln3TaO7, where Ln=Y, Er, and Gd, were grown by Bi2O3-B2O3 and PbF2-PbO fluxes for the Ln3NbO7, and by PbF2-PbO flux for the Ln3TaO7. The composition of Ln3NbO7 or Ln3TaO7 is not yet known in natural minerals.
Solvochromism and Thermochromism of Cobalt(II) Complexes Solubilized in Reversed Micelles
Authors: Sunamoto Junzo , Hamada Tomiko 
Published: July 2006

Abstract
Configurational change takes place between tetrahedral and octahedral species, when cobalt(II) complexes are cosolubilized in reversed micelles formed by the cationic or ampholytic detergents in chloroform. This is accompanied by the elimination-addition reaction of ligand water from and to the metal ion in the reversed micellar core. The phenomenon is interpreted in terms of solvochromism and thermochromism. The nature and state of “naked” metal ion and “free” water molecule afforded in a highly restricted field of reversed micelles have been discussed on the basis of equilibrium constants and thermodynamic parameters for the configurational change, particular attention being given to the structure of micelles. Their resemblance to the active site of metalloenzymes is also discussed.
Binuclear Metal Complexes. XXIV. Synthesis and Magnetism of Binuclear Cobalt(II) Complexes in Mixed-spin State
Authors: Torihara Naoyuki , Okawa Hisashi , Kida Sigeo 
Published: July 2006

Abstract
Binuclear cobalt(II) complexes, Co2(fsaR)(py)3 and Co2(fsaR)MeOH·1/2H2O with 3-formylsalicylic aciddiamine SchifF bases, H4fsaR (R=en, pn, bn, ch, and ph), were prepared and characterized. Mixed-spin states of these complexes were demonstrated by the cryomagnetic measurements and no spin-exchange interaction was observed between high-spin and low-spin cobalt(II) ions. The absence of spin-exchange interaction in these complexes was discussed on the basis of the electronic configuration of the low-spin cobalt(II) ion and in comparison with the antiferromagnetic Cu(II)–Co(II) (s=3⁄2) complexes with the same ligands.
Aromatic Solvent-induced Shifts (ASIS). II. Interpretation of Benzene and Hexafluorobenzene Induced Shifts by Means of the Electrostatic Interaction Model
Authors: Nikki Kunio , Nakagawa Naoya 
Published: July 2006

Abstract
The relationships between the ASIS in proton magnetic resonance and charge distribution in the solute and solvent molecules were studied. The results obtained are as follows. Protons lying in the positive charge-region of the solute dipole showed an up-field shift in C6H6 and a down-field shift in C6F6, while protons lying in the negative charge-region showed a down-field shift in C6H6 and an up-field shift in C6F6. There exists a linear relationship between the ASIS and the solute dipole moments of monosubstituted methanes, t-butyl derivatives, and para substituted toluenes. Shifts of para substituted toluenes and 4-methyl-4′-nitrobiphenyl are in good agreement with those expected from the electrostatic interaction model.
Asymmetric Synthesis Based on (2R,3S)-3,4-Dimethyl-2-phenylperhydro-1,4-oxazepine-5,7-dione. Synthesis of Highly Optically Active β-Substituted Alkanoic Acids
Authors: Mukaiyama Teruaki , Takeda Takeshi , Fujimoto Katsumi 
Published: July 2006

Abstract
A general method was worked out for the preparation of highly optically pure β-substituted alkanoic acids from aldehydes with use of (2R,3S)-6-alkylidene-3,4-dimethyl-2-phenylperhydro-1,4-oxazepine-5,7-diones(2) as key intermediates. Oxazepines(2) were prepared in high yields by treating aldehydes with (2R,3S)-3,4-dimethyl-2-phenylperhydro-1,4-oxazepine-5,7-dione(1) in the presence of titanium tetrachloride. The conjugate addition of Grignard reagents to 2 in the presence of nickel chloride, followed by hydrolysis and decarboxylation afforded highly enantiomerically pure β-substituted alkanoic acids in good yields. The addition of lithium dialkylcuprate to 2 was examined. It was found that (S)-(+)-3-phenylheptanoic acid is obtained by the reaction of lithium dibutylcuprate with (E)- and (Z)-6-benzylidene derivatives of 1, respectively.
The Carbon-13 NMR Spectra of Barbituric-acid Derivatives
Authors: Asada Shozo , Nishijo Jujiro 
Published: July 2006

Abstract
The 13C nuclear magnetic resonance spectra of thirty kinds of barbituric-acid derivatives were measured, and the chemical shifts of each carbon were assigned. The correlation between chemical shifts of the ring skeletal carbon and the pKa values was examined.
Microwave Spectrum, Barrier to Internal Rotation, and Dipole Moment of Methyl Selenocyanate
Authors: Sakaizumi Takeshi , Kohri Yoshio , Ohashi Osamu , Yamaguchi Ichiro 
Published: July 2006

Abstract
Microwave rotational spectra of five isotopic species of methyl selenocyanate (CH3SeCN with 82Se, 80Se, 78Se, 77Se, and 76Se) in the ground vibrational state, and two isotopic species of methyl selenocyanate-d3 (CD3SeCN with 80Se and 78Se) in the ground and first excited states of the methyl torsional mode have been assigned in the 8.0 to 35.5 GHz frequency range. For the most abundant species in the ground vibrational state, the rotational constants determined are AA=10147±2, BA=3483.57±0.04, and C=2631.58±0.04 MHz for CH380SeCN and A=8322.57±0.81, B=3308.06±0.02, and C=2436.92±0.01 MHz for CD380SeCN. The A-E splittings due to the methyl internal rotation were observed for the rotational transitions in the ground vibrational state for the normal species and in the first excited state of the methyl torsional mode for the deuterated species. Analysis of the splittings gave a barrier height to the methyl internal rotation of 1241±50 and 1228±50 cal/mol for the CH3 and CD3 species, respectively. Stark measurements yielded the principal axis dipole moments of μa=4.35±0.04, μb=0.76±0.10, and the total dipole moment of μ=4.42±0.05 D for CH380SeCN, and μa=4.31±0.04, μb=0.67±0.07, and μ=4.36±0.04 D for CD380SeCN. The direction of the dipole moment in the molecule is discussed.
Triplet-Triplet Energy Transfer between Like Molecules
Authors: Inoue Akinori , Chuman Hiroshi , Ebara Nozomu 
Published: July 2006

Abstract
The previously proposed method of studying T-T energy trasfer between like molecules using isotopic mixtures was further improved and applied to an investigation of naphthalene and phenanthrene molecules. Critical transfer distances of 15 and 13 Å were determined for naphthalene and phenanthrene, respectively. The present method has the advantage that it is free from the effect of S-S energy transfer.
NMR Studies on Zerovalent Metal π-Complexes of Dibenzylideneacetone. I. Ligand Conformation and bonding in the Binuclear Palladium Complex
Authors: Kawazura Hiroshi , Tanaka Hisao , Yamada Koh-ichi , Takahashi Toshio , Ishii Yoshio 
Published: July 2006

Abstract
To elucidate the ligand conformation and the metal–olefin bonding nature in the binuclear palladium complex of dibenzylideneacetone, Pd2[(C6H5CH=CH)2CO]3, 1H NMR studies have been performed on the deuteriated complexes Pd2[(C6D5CH=CH)2CO]3, Pd2[(C6D5CD=CH)2CO]3, and Pd2[(C6D5CH=CD)2CO]3. Examination of the spectra has revealed that the three dibenzylideneacetone ligands which triply bridge the two Pd atoms are all in the s-cis,trans conformation. The most probable bonding scheme of the three ligands to the two Pd atoms is as follows: one Pd atom is ligated by one s-trans and two s-cis olefinic moieties and hence the other by one s-cis and two s-trans to yield a metal–olefin bonding stronger in the former combination than in the latter. A linear correlation between the couplings and the mean chemical shifts of the trans olefinic protons suggests a dominant role of metal between the couplings and the mean chemical shifts of the trans olefinic protons suggests a dominant role of metal to olefin π-back donation in differentiating the olefinic moieties in their bonding strength to the metal atoms and in retaining the characteristic rigid structure of the complex.
Resonance Energies of Nonbenzenoid Hydrocarbons
Authors: Aihara Jun-ichi 
Published: July 2006

Abstract
Resonance energies of 30 conjugated hydrocarbons and their molecular ions have been calculated on the basis of the graph-theoretical theory of aromaticity. No difficulty was found in extending the aromaticity theory to ionic conjugated species. In general, the resonance energies obtained correlated well with typical chemical features of the compounds.