bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Synthesis and Studies of Several [2.2.2]Ferrocenophane Derivatives
Authors: Kasahara Akira , Izumi Taeko , Shimizu Iwao , Oikawa Tadashi , Umezawa Hiroshi , Hoshino Isao 
Published: July 2006

Abstract
Several ferrocenophanes, in which the two cyclopentadienyl rings are linked by acetylenic and olefinic bonds and aromatic rings, have been synthesized via the titanium-induced reductive coupling of the corresponding formyl compounds. The structures of these ferrocenophane compounds were determined by means of their IR and NMR spectra. The transannular π-electronic interactions between the two chromophores were examined on the basis of the electronic spectra.
Synthetic Studies on the Validamycins. IV. Synthesis of Dl-Valienamine and Related Branched-chain Unsaturated Aminocyclitols
Authors: Toyokuni Tatsushi , Ogawa Seiichiro , Suami Tetsuo 
Published: July 2006

Abstract
The first synthesis has been achieved of the racemates of valienamine and its related, branched-chain unsaturated aminocyclitols. Two synthetic routes for valienamine were developed, one of which is stereoselective and highly efficient. The key transformation is a stereospecific SN2′ attack (apofacial) by an azide ion on the allyl chloride, prepared by regioselective epoxidation of the conjugated diene followed by treatment with hydrochloric acid. Some information is described which is furnished from 13C NMR spectra for the new branched-chain unsaturated aminocyclitols and cyclitols.
The Cycloaddition of N,N-Diethyl-1,3-butadienylamine with Some Diarylnitrilimines
Authors: Oida Tatsuo , Tanimoto Shigeo , Ikehira Hideyuki , Okano Masaya 
Published: July 2006

Abstract
The cycloaddition of N,N-diethyl-1,3-butadienylamine with some diarylnitrilimines was investigated. 1,3-diaryl-4-vinylpyrazoles, (1,3-diaryl-2-pyrazolin-5-yl)acetaldehydes, 1,3-diaryl-4-(1,3-diaryl-2-pyrazolin-5-yl)pyrazoles, and 1,3-diarylpyrazoles were obtained.
Cyclic Peptides. XV. Synthesis of [4-α-Hydroxyalanine]AM-toxin II
Authors: Noda Kosaku , Nakashima Junko , Lee Sannamu , Izumiya Nobuo 
Published: July 2006

Abstract
An AM-toxin II analog, cyclo(–l-Ala1–l-Hmb2–l-App3–Hyala4–), with an α-hydroxyalanine (Hyala) residue in place of dehydroalanine in position 4 was synthesized from pyruvoyl–l-Ala–l-Hmb–l-App–amide (Hmb, 2-hydroxy-3-methylbutanoic acid; App, 2-amino-5-phenylpentanoic acid) by intramolecular condensation between the pyruvoyl and carbamoyl groups. The synthetic peptide did not show the toxic activity of AM-toxin II.
Study of Ion Transport across Amphoteric Ion Exchange Membrane. II. Transport of Symmetric Tetraalkylammonium Chlorides
Authors: Kaibara Kozue , Sonoda Hideaki , Nagata Yoshihiko , Kimizuka Hideo 
Published: July 2006

Abstract
Transport characteristics of NH4Cl, (CH3)4NCl (TMA–Cl), (C2H5)4NCl (TEA–Cl), (n-C3H7)4NCl (TPA–Cl), and (n-C4H9)4NCl (TBA–Cl) across homogeneous type amphoteric ion exchange membrane (1.0-PA-29, Kanegafuchi Chem. Ind.) were studied. Membrane potentials and conductances of the concentration cell systems were measured to calculate the membrane permeabilities which represent a measure of ionic permselectivity. Membrane potential changed considerably with cationic species and the membrane tended to behave more anionic selectively with increasing bulkiness of cations. The cationic permeabilities calculated from electrochemical data were PNH4&gt;PTMA&gt;PTEA&gt;PTPA&gt;PTBA. Membrane permeabilities to chloride ions, PCl, were greater than those to cations in all the systems studied and it was interesting that PCl values and their dependencies on external electrolyte concentration were almost unchanged irrespective of the difference in cationic species. The present experiment was designed in order to examine the effects of ionic size on the transport processes across homogeneous type amphoteric ion exchange membrane. The obtained results indicated that the hydrated radius of permeant ion is an important factor to control the ionic transport processes and to reveal the potentiometric selectivity in these systems. It was suggested that the ion transport across homogeneous type amphoteric ion exchange membrane is strongly affected by hydrodynamic properties of permeant ion, but scarcely influenced by ionic charges of which effects are well known to be exclusive in the uniform cation and anion exchange membranes.
The Precipitation of Human Fibrinogen by Zinc Chloride
Authors: Maeda Hiroshi , Kishi Takaaki , Ikeda Shoichi 
Published: July 2006

Abstract
The precipitation of human fibrinogen by ZnCl2 was studied by measuring the turbidity and the protein concentration in the supernatant (referred as solubility). Different kinetic patterns, either fast or slow, were observed in both solubility and turbidity depending on whether ZnCl2 concentration (CM) was larger or smaller than the critical concentration. In the slow pattern, the increase of the turbidity and the decrease of the solubility both occurred slowly and almost linearly with time. In the fast pattern, these changes occurred rapidly and stationary values were reached within 30 min for the turbidity and 2 h for the solubility. These two stationary values were found to be linearly related to each other. The stationary solubility decreased as CM increased, while it increased with the total amount of the protein. The dissolution of the precipitates was very slow resulting in a practically irreversible precipitation. A gelation model was proposed to account for these characteristic features, according to which fibrinogen molecules were linked to each other through the ’bond’ mediated by a zinc atom.
Stereochemical Investigation on Asymmetrically Modified Raney Nickel Catalyst. Mode of Interaction between Modifying Reagent and Substrate in the Enantioface-differentiating Process
Authors: Tai Akira , Harada Tadao , Hiraki Yuji , Murakami Sigeki 
Published: July 2006

Abstract
The mode of enantioface-differentiating hydrogenation with asymmetrically modified Raney nickel (MRNi) was investigated by using various sorts of modifying reagents and substrates. The optical yields (O.Y.) of the hydrogenation of methyl acetoacetate over MRNi for different modifying reagents occured in the following order: (Remark: Graphics omitted.), (Remark: Graphics omitted.). The hydrogenation of various substrates of the structure, (Remark: Graphics omitted.), over tartaric acid-modified Raney nickel (TA–MRNi), gave high optical yields only when the substituent –Y functioned as a good hydrogen bond acceptor like a carbonyl group, and two pairs of hydrogen bondings between substrate and two hydroxyl groups of tartaric acid were available. As for the stereochemistry of the reaction in such a case, (R,R)-TA–MRNi always gave (R)-product in excess. Based on the stereochemistry of the reaction and the role of hydrogen bonds between modifying reagent and substrate, a stereochemical model is proposed to elucidate the mode of enantioface-differentiating hydrogenation of prochiral ketones over TA–MRNi.
Aryl Rearrangement on the Photolysis of 2-Aryl-2-ethoxy-2-phenylethyl Cobaloxime
Authors: Tada Masaru , Inoue Kunimi , Okabe Masami 
Published: July 2006

Abstract
The photolysis of 2-aryl-2-ethoxy-2-phenylethyl cobaloxime followed by hydrolysis gave two kinds of substituted 1,2-diphenylethanones arising via phenyl or substituted-phenyl migration. The substituent effect on the aryl rearrangement is similar to that on the reported neophyl rearrangement, and the rearrangement takes place by a radical mechanism without the deep involvement of cobaloxime(II).
Syntheses of Polyoxathia[n]ferrocenophanes and Its Extraction Ability with Metal Cations
Authors: Akabori Sadatoshi , Habata Yoichi , Sato Masaru , Ebine Seiji 
Published: July 2006

Abstract
Mononuclear polyoxathia[n]ferrocenophanes (8a–d) and binuclear polyoxadithia[n,n]ferrocenophanes were synthesized by the reaction of 1,1′-bis(ω-chloropolyethyleneoxy)ferrocene with sodium sulfide in N,N-dimethylformamide and the complexing ability of 8a–d with alkali and transition metal cations was measured by an extraction method. Compound 8d extracts a thallium ion specifically, the extraction efficiency of several ions being in the order: Tl+&gt;&gt;Rb+&gt;K+&gt;Cs+&gt;Na+&gt;Li+.
The Synthesis of Tetrakisdehydrotetraazaannulenes. Tetramethyl[36]-, -[48]annulene, and Their Benzoannelated Derivatives
Authors: Ojima J\={u}ro , Kirita Mitsuru , Murosawa Yoshiko , Nakada Tetsuya 
Published: July 2006

Abstract
The conjugated mono-, di-, tri-, and tetraene, containing a terminal acetylene group were converted into a variety of symmetrical and unsymmetrical conjugated azines on treatment with aqueous hydrazine in ethanol. Oxidative couplings of these azines were attempted using anhydrous copper(II) acetate in pyridine and ether. Each of unsymmetrical azines, 3,16-dimethyl-8,9-diaza-3,5,7,9,11,13,15-octadecaheptaene-1,17-diyne and 1,10-bis(o-ethynylphenyl)-4,5-diaza-1,3,5,7,9-decapentaene, gave the corresponding two isomeric cyclic dimers: The former gave 7,12,25,30-tetramethyl-8,10,26,28-tetrakisdehydro-1,2,17,18-tetraaza[36]annulene and 7,12,25,30-tetramethyl-8,10,26,28-tetrakisdehydro-1,2,19,20-tetraaza[36]annulene, and the latter gave 6,7:12,13:24,25:30,31-tetrabenzo-8,10,26,28-tetrakisdehydro-1,2,17,18-tetraaza[36]annulene and 6,7:12,13:24,25:30,31-tetrabenzo-8,10,26,28-tetrakisdehydro-1,2,19,20-tetraaza[36]annulene, although only in poor yields. Coupling of symmetrical azines, 3,22-dimethyl-12,13-diaza-3,5,7,9,11,13,15,17,19,21-tetraeicosadecaene-1,23-diyne and 1,16-bis(o-ethynylphenyl)-8,9-diaza-1,3,5,7,9,11,13,15-hexadecaoctaene, furnished cyclic dimers, 11,16,35,40-tetramethyl-12,14,36,38-tetrakisdehydro-1,2,25,26-tetraaza[48]annulene and 10,11:16,17:34,35:40,41-tetrabenzo-12,14,36,38-tetrakisdehydro-1,2,25,26-tetraaza[48]annulene, respectively, in moderate yields. Examination of 1H NMR spectra indicates that these tetraazaannulenes are atropic.
Base-induced Oxygenation and Chemiluminescence of 10-Methylacridinium and 1-Methylquinolinium Salts in Dimethyl Sulfoxide
Authors: Suzuki Nobutaka , Kazui Yoshihiko , Tsukamoto Toshio , Kato Masahiro , Izawa Yasuji 
Published: July 2006

Abstract
10-Methylacridinium methyl sulfate and the 1-methylquinolinium salt gave strong light emission, when oxidized with ground state oxygen in the presence of t-BuOK in DMSO, owing to the fluorescence of 10-methyl-9(10H)-acridinone and 1-methyl-1(4H)-quinolinone excited to their S1 state.
The X-Ray Structure of 2-Aminocyclohexanone Oxime Hydrochloride
Authors: Kitano Yukishige , Matsukuma Yoshihisa , Imamura Shinzo , Takagi Ryo , Ashida Tamaichi 
Published: July 2006

Abstract
The crystal structure of the title compound was determined by the X-ray method. The space group is P\bar1, with a=8.537(1), b=5.223(3), c=9.505(1) Å, α=91.04(2), β=80.58(1), γ=99.16(3)°, and Z=2. The hydroxyl group of the oxime takes the anti conformation to the amino group in the solid state. The molecules, linked together by NH···Cl and OH···Cl hydrogen bridges, form columns in the crystal.
Contribution of Quadruply Degenerate π-Electron Orbitals to London Susceptibility
Authors: Horikawa Tsuyoshi , Aihara Jun-ichi 
Published: July 2006

Abstract
A graph-theoretical formula was derived to evaluate the contribution of quadruply degenerate π-electron orbitals to London diamagnetism. This formula enables us to calculate London susceptibilities of such compounds as p-terphenyl and perylene without factorization of their secular determinants.
Catalytic Hydrogenolysis of 1,1-Difluoro-2-phenyl- and 1,1-Difluoro-3-methyl-2-phenylcyclopropane
Authors: Isogai Koji , Nishizawa Naomi , Saito Tetsuji , Sakai Jun-ichi 
Published: July 2006

Abstract
The title compounds were hydrogenolyzd over PdO or Raney nickel. The C2–C3 bond of the cyclopropane ring underwent cleavage exclusively over the both catalysts. The contribution of the fluorine substituent to the lengthening and weakening the C2–C3 bond of the cyclopropane ring seems to become a dominant factor in the regioselectivity.
Studies on Salt Hydrate for Latent Heat Storage. III. Pseudo-binary System, CH3CO2Na·3H2O–HCONH2
Authors: Wada Takahiro , Kimura Fumiko , Yamamoto Ryoichi 
Published: July 2006

Abstract
A pseudo-binary system CH3CO2Na·3H2O–HCONH2 has been studied by differential scanning calorimetry. In this system, a one to one addition compound CH3CO2Na·HCONH2·3H2O is formed. This addition compound melts congruently at 40.5 °C and its heat of fusion is 255 J/g. So, it is hopeful for solar energy storage.
Dispersibility of Magnetic and Nonmagnetic Iron(III) Oxides in 2-Butanone
Authors: Kandori Kazuhiko , Kitahara Ayao , Kon-no Kijiro 
Published: July 2006

Abstract
The dispersion stability of needlelike and octahedral iron(III) oxides of magnetic or nonmagnetic particles in 2-butanone was studied. Two kinds of copolymers of poly(vinyl acetate-vinyl chloride-maleic acid) (VAVCCOOH) and poly(vinyl acetate-vinyl chloride-vinyl alcohol) (VAVCOH) were used as dispersants. The sedimentation of dispersions, the adsorption of copolymer dispersants on the particles and zeta potentials were measured. By polymer adsorption, the dispersion of nonmagnetic needlelike iron(III) oxide was stabilized and the dispersions of magnetic needlelike iron(III) oxides were somewhat stabilized, but the dispersions of magnetic octahedral iron(III) oxides were only slightly stabilized. This characteristic behavior of the sedimentation experiment was discussed in relation to the amount of polymer adsorption and zeta potential and was correlated with the observations by an electron microscope. The magnetic attractive force operating between the two magnetic particles was calculated to illustrate the dispersibility of magnetic oxides. It was suggested from the calculation that the strength of the magnetization and the volume of a particle are the main factors affecting the flocculation of the magnetic particles.
Association of Chlorophyll with Amides on Plasticized Polyethylene Particles. II. The Isomeric N-Pyridylmyristamides
Authors: Kusumoto Yoshihumi , Seely Gilbert R , Senthilathipan Velu 
Published: July 2006

Abstract
When chlorophyll, together with certain other amphiphilic substances, is adsorbed to particles of polyethylene plasticized by incorporation of tetradecane, it is maintained in monomeric or oligomeric forms with characteristic absorption and fluorescence spectra. The present work describes the properties of chlorophyll a on such particles in the presence of the three isomeric N-pyridylmyristamides, and of the similarly shaped but not basic compound myristanilide, in an effort to ascertain the structural factors governing associations of these species. Absorption and fluorescence spectra at room temperature are resolved into minimal sets of Gaussian components, and relations between the component sets are proposed. The positions of the component bands and their relative abundance are characteristic of the amide used. The 3- and 4-pyridyl isomers bind more strongly to chlorophyll, probably by ligation of the pyridine nitrogen to Mg of the pigment. The 2-pyridyl isomer and myristanilide bind more weakly, probably through the amide carbonyl group. The association of chlorophyll into species with characteristic absorption and fluorescence bands is promoted more strongly by the 3- and 4-isomers than by the 2-isomer and myristanilide, and probably involves hydrogen bonding to chlorophyll carbonyl groups. A possible manner of association of chlorophyll in the presence of N,N-dimethylmyristamide is also presented. By way of comparison, chlorophyll adsorbed with N-dodecylpyridinium bromide, which lacks a nucleophilic function, is mainly in the microcrystalline hydrate form absorbing near 740 nm.
Gravimetric Determination of Copper(II) Using N1-Hydroxy-N1-(m-tolyl)-N2-(o-chlorophenyl)-p-toluamidine Hydrochloride
Authors: Mohabey Hemlata , Sharma Pramod Kumar , Mishra Rajendra Kumar 
Published: July 2006

Abstract
A simple, rapid, and accurate method has been developed for the gravimetric determination of Copper(II) using a new reagent N1-hydroxy-N1-(m-tolyl)-N2-(o-chlorophenyl)-p-toluamidine hydrochloride (HTCPTH). The proposed reagent reacts quantitatively with copper at 3.3–11.0 pH giving a buff coloured precipitate. The precipitated complex can be easily filtered, dried and directly weighed as (C21H18N2OCl)2Cu. The complex is thermally stable as is evident from DTA and TGA studies up to 210 °C and insoluble in many organic solvents. Most of the common ions including Ni(II), Co(II), Cr(III), Mn(II), etc. do not interfere. The interference due to iron(III) can be eliminated by masking it with tartaric acid. The method has been successfully applied for the determination of copper in some British Chemical Standards alloys.
Thermal Properties of Solid Bis(2,3-alkanedione dioximato)nickel(II). Crystal Structure Transformation
Authors: I Mikiya , Wakita Hisanobu , Masuda Isao 
Published: July 2006

Abstract
The thermal behavior in the solid state of the title complexes was investigated. Here 2,3-alkanedione dioximato is CH3–C(=NOH)–C(=NO)–R; R includes C2H5 (1), n-C3H7 (2), n-C4H9 (3), n-C5H11 (4), n-C6H13 (5), and n-C8H17 (6) groups. The complexes, 1, 2, 5, and 6, underwent thermal crystal structure transformation; the transformation was irreversible for 1 and 5, and reversible for 2 and 6. The ΔHt values, heats of transformation, were found to fall in the 5.3–32.6 kJ mol−1 range. The ΔHm values, heats of melting, were determined for the complexes, 2–6. On the basis of these data, the thermal characteristics for these complex crystals are discussed in relation to the nature of the R groups.
Studies of Bitter Peptides from Casein Hydrolyzate. III. Bitter Taste of Synthetic Analogs of BPIa (Arg–Gly–Pro–Pro–Phe–Ile–Val) Containing d-Proline or Glycine in Place of l-Proline
Authors: Miyake Ichizo , Kouge Katsushige , Kanehisa Hidenori , Okai Hideo 
Published: July 2006

Abstract
In order to elucidate the relationship between chemical structure and bitter taste of BPIa, the analogs containing d-proline or glycine in place of the l-proline in the 3- or 4-positions were synthesized. The bitter taste of [d-Pro3,4]–BPIa (ld-d), [d-Pro3]–des–Pro3–BPIa (2d), and [Gly3]–des–Pro3–BPIa lacking the l-proline residue was much weaker than that of the peptides containing the l-proline, BPIa (1l-l), 1l-d, 1d-l, and 2l. The CD curves of these analogs and BPIa were measured in water. The results suggested that the bitter taste of BPIa is caused by the spatial structure attributed to the l-proline residue.
Reaction of Secondary Aromatic Amines with Manganese(III) Acetate
Authors: Nishino Hiroshi , Kurosawa Kazu 
Published: July 2006

Abstract
The reaction of 2-(methylamino)benzophenone with manganese(III) acetate afforded 5-[(o-benzoylanilino)methyl]-2-(methylamino)benzophenone, 2-aminobenzophenone, 5-formyl-2-(methylamino)benzophenone, 2-amino-5-[(o-benzoylanilino)methyl]benzophenone, 2-formamidobenzophenone, 2-amino-5-formylbenzophenone, and 2-(N-methylformamido)benzophenone. It was found that the reaction did not cause oxidative cyclization, but dimerization and conversion of N-methyl into N-formyl groups. Characterization of the products, the detailed oxidation mechanism, and the effects of the additives are discussed.
Reactions of 2-Methylenebenzothiazolines with Methylenecyclopropenes
Authors: Tsuge Otohiko , Tanaka Minoru , Shimoharada Hiroshi , Kanemasa Shuji 
Published: July 2006

Abstract
Reactions of 2-methylene-3-phenacylbenzothiazoline and 3-benzyl-2-methylenebenzothiazoline, generated in situ from the corresponding 2-methylbenzothiazolium bromide and triethylamine, with methylenecyclopropenes gave a variety of products, cross-conjugated systems, spiro-cyclopentafurans and/or cyclopentabenzothiazines, depending on the nature of substituents of the methylenecyclopropenes. The reaction pathways for the formation of products are also described.
Electronic States of Dioxygen Heme Complex Revealed from ab Initio LCAO-SCF-MO Calculations
Authors: Nozawa Tsunenori , Hatano Masahiro , Nagashima Unpei , Obara Shigeru , Kashiwagi Hiroshi 
Published: July 2006

Abstract
Ab initio LCAO-SCF-MO calculations of a model oxyheme were carried out on several singlet, triplet and quintet states arising from the three types of configurations, (dε)6(πga)2, (dε)5(dγ)1(πga)1(πgb)1, and (dε)5(πga)2(πgb)1. The lowest states in the SCF energy are of the configuration (dε)5(πga)2(πgb)1 whose electronic structures can be also expressed as Fe(III)–O2− from the results of Mulliken’s population analysis. Calculated Mössbauer parameters of those states are in good agreement with experiments for oxyhemoglobin, oxymyoglobin and model oxyheme, while those of the closed-shell singlet state (dε)6(πga)2 are inconsistent with experiments. The Fe–O1 overlap populations indicate a bonding nature for the former states and a non-bonding nature for the latter state. These results all predict singlet states of Fe(III)–O2− structure as the main configuration of the ground state in the model oxyheme.
Electrochemical Oxidation and Reduction of Flavin–Adenine Dinucleotide Adsorbed on a Mercury Electrode Surface
Authors: Kakutani Tadaaki , Katasho Isao , Senda Mitsugi 
Published: July 2006

Abstract
The electrochemical redox reaction of flavin–adenine dinucleotide (FAD) adsorbed on a hanging mercury drop electrode was studied in a pH 6.9 phosphate buffer by means of cyclic d.c. and a.c. voltammetry. Both the oxidized and reduced forms of FAD were strongly adsorbed on the mercury electrode surface. At the surface concentrations of FAD, Γ, lower than 5.0×10−11 mol cm−2, the cyclic d.c. and a.c. voltammetric behavior of adsorbed FAD was explained by the theory for a two-step one-electron surface redox reaction. The formal redox potential, semiquinone formation constant, and charge transfer rate constant for the surface redox reaction of FAD and the interaction parameter of adsorbed FAD species were determined. Cyclic d.c. voltammetry and differential capacity measurement showed that, as Γ exceeded 5×10−11 mol cm−2, the reorientation of adsorbed FAD molecules occurred. At Γ&gt;5.8×10−11 mol cm−2, the semiquinone formation constant was very small and the behavior was interpreted by the theory of a single-step two-electron surface redox reaction. The electrochemical surface redox properties of FAD adsorbed on a mercury electrode surface appear to depend on the orientation mode of adsorbed FAD molecules.
Ylide–Metal Complexes. VII. The Preparation and Properties of IIA Group Metal(Be, Mg) and IIIA Group Metal(Al, Ga, In) Complexes of Alkylidenetriphenylphosphoranes
Authors: Yamamoto Yoshihisa 
Published: July 2006

Abstract
The reactions of (C6H5)3P=CH2 (L) with BeCl2 or MgCl2 in the mole ratio of 2 : 1 or 4 : 1 yield new dimeric compounds of di-μ-chloro-bis[(methylenetriphenylphosphorane)metal] dichloride, (Remark: Graphics omitted.) (M: Be and Mg). The configuration of these metals is trigonal. The reactions of L with AlCl3, GaCl3 or InCl3 in the mole ratio of 2 : 1 yield new compounds of di-μ-chloro-bis[bis(methylenetriphenylphosphorane)metal] tetrachloride, (Remark: Graphics omitted.) (M: Al, Ga, and In). The reactions of L with AlCl3 or GaCl3 in the mole ratio of 3 : 1 or 5 : 1 yield new compounds of μ-chloro-bis[tris(methylenetriphenylphosphorane)metal] pentachloride, [{(C6H5)3PCH2}3M–Cl–M{CH2P(C6H5)3}3]Cl5 (M: Al, Ga). These dimers, bridged by chloride anions, are thermally stable.
The Synthesis and Color of Pyrido[1′,2′ : 1,2]pyrimido[4,5-b]acridine-7,15-diones
Authors: Yokoyama Yasukazu 
Published: July 2006

Abstract
Some derivatives of pyrido[1′,2′: 1,2]pyrimido[4,5-b]acridine-7,15-diones have been synthesized, their absorption spectra have also been investigated in order to elucidate the relationship between the color and the chemical constitution in contrast to the related compounds, quinacridone and pyrido[2,1-b]pyrido[1′,2′ : 1,2]pyrimido[4,5-g]quinazoline-7,15-dione. The absorption spectra in DMSO and in concentrated sulfuric acid show a good correlation with the electronic effect of the substituents. The absorption spectra of the solid are more influenced by the position of the substituents than by the electronic effect.