Theoretical and experimental studies of indoaniline dyes. A novel relationship between absorption spectra and molecular structure

Adachi, Masafumi; Murata, Yukichi; Nakamura, Shinichiro

doi:10.1021/ja00063a059

Cited by 34 publications

(17 citation statements)

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“…46 Nakamura and coworkers have however attributed the shift to longer wavelengths to the configurational interactions of the molecule and not just a HOMO-LUMO energy gap change. 47 These data are in contrast to the UV-vis spectra of the AQ diimines in which the buckled central ring system limits the amount of extended conjugation and results in a shift to shorter wavelengths (DAQ k max ¼ 398 nm).…”

Section: Alkyl Benzoquinonimines Model Compoundsmentioning

confidence: 91%

Condensation routes to polyaniline and its analogs

Hall

Padías

Boone

2007

J. Polym. Sci. A Polym. Chem.

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To obtain polyanilines which are more structurally perfect than those obtainable by the oxidation of anilines, polycondensation procedures were investigated. Model reactions gave extensive information about yields and about the physical properties of the putative structural polymer units. Condensation of anthraquinones with aromatic diamines using titanium tetrachloride and the unique base, 1,4-diazabicyclo-[2.2.2]-octane Dabco, gave high molecular weight orange polyquinonimines. Alkoxy groups on the anthraquinone ring aided solubility and molecular weight, and appropriately positioned alkoxy groups afforded stereoregular polymers. A bisthiophene benzoquinone also polymerized successfully. Application of the same procedure to 2,5-dimethyl-p-benzoquinone gave stereoregular poly(arylene benzoquinonimines), close analogs of pernigrani line. The factors causing problems in achieving high yields and high molecular weight were identified. Recent synthetic developments in this field are discussed. Reduction of the obtained polyquinonimines proceeded smoothly to the leucoemeraldine analogs. Unlike the results from pernigraniline obtained by oxidative polymerization, no evidence for the formation of the electrically conductive emeraldine form was obtained. Keywords: conducting polymers; conjugated polymers; polyaniline; polycondensation; polyimines H. K. Hall, Jr., received his B.S. at Brooklyn Polytech, M.S. at Pennsylvania State University, and Ph.D. from the University of Illinois in 1949. Postdoctoral work followed, with Prof. P. J. Flory at Cornell and with Professors S. Winstein and W. G. Young at UCLA. After 17 years at DuPont, he moved in 1969 to the University of Arizona. His research interests have included the ring-opening polymerizations of strained bicyclic molecules, the mechanisms of reactions of donor with acceptor olefins, the polymerization of imines, and the synthesis of electrically conductive, piezoelectric, and nonlinear optical polymers.

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Section: Alkyl Benzoquinonimines Model Compoundsmentioning

confidence: 91%

Condensation routes to polyaniline and its analogs

Hall

Padías

Boone

2007

J. Polym. Sci. A Polym. Chem.

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“…The excitation spectrum was obtained using the INDO/CIS method as implemented in the ZINDO 15 program with the spectroscopic parameterization. The INDO/CIS method as implemented in ZINDO has been used with success in the analyses of the spectrum of dyes 16 and of near‐infrared absorbing dyes of the naphthoquinone methide type 17. The hyperpolarizabilities were obtained by the sum‐over‐states procedure 1 using the calculated spectrum.…”

Section: Methodsmentioning

confidence: 99%

Environmental updates

2005

Environ. Prog.

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“…Such linkage is common in indophenol dyes, [14] for which the addition of electron-donating groups [14] and an increase in the dihedral angle between aromatic groups [15,16] add further to the red shift in absorbance. Direct support for the assignment of nitrogen as the linking atom comes from model compound experiments on indophenol, solubilized in water as a cyclodextrin complex (see the Supporting Information for details).…”

Section: Europe Pmc Funders Author Manuscripts Europe Pmc Funders Autmentioning

confidence: 99%

Unusual Chromophore and Cross‐Links in Ranasmurfin: A Blue Protein from the Foam Nests of a Tropical Frog

Oke¹,

Ching

Carter³

et al. 2008

Angew Chem Int Ed

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Ranasmurfin is an unusual blue protein isolated from the nests of a Malaysian tree frog, Polypedates leucomystax, [1] showing the rich chemical diversity displayed by biomolecular foams. Many species of tropical frogs use foams to protect delicate eggs and developing embryos against environmental challenges. These nests act as miniature ecosystems containing a spectrum of novel proteins and other macromolecules with functions related to foam stabilization and adhesion, resistance to microbial degradation, predation, or dehydration, providing a biocompatible environment for embryonic development.Thisworkformspartofourwiderstudyofthe intriguing physical and chemical properties of biofoams as unusual examples of biological soft matter. [2] P. leucomystax is an abundant Rhacophorid frog that is widespread in Malaysia and surrounding regions of South-East Asia. During mating, the female produces a protein-rich fluid that she, together with the attending male, whips up into a sticky foam nest incorporating the fertilized eggs (see the Supporting Information Figure S1). The nests are usually attached to vegetation or other structures overhanging water into which the tadpoles fall when fully developed (usually after 3-4 days in the wild).[3] These nests exhibit a variety of pigmentation, usually pale creamy white/orange when first † † To whom correspondence should be addressed. naismith@st-and.ac.uk, phone 44-1334-463792, fax 44-1334-467229 alanc@chem.gla.ac.uk, phone 44-141-330 5278, fax 44-141-330 (Figure1 ), which are consistent with the presence of two ionizable moieties with pKa values of 6 and 9, and the color fades slowly (overnight) upon treatment with ethylenediaminetetraacetic acid (EDTA) and dithiothreitol (DTT; Figure S9 in the Supporting Information). The chromophore is bleached rapidly (seconds) by low concentrations (0.25 mm) of N-bromosuccinimide (NBS, Figure 1).Ranasmurfin, purified from natural material, crystallizes readily as deep blue crystals that diffract well, allowing protein structure determination to 1.16 A resolution (Figures 2 and 3; see the Supporting Information for crystallographic details). Initial X-ray diffraction experiments indicated the presence of a heavy metal in the protein, which was subsequently identified as zinc by X-ray fluorescence of the crystals (Ref.[1] and Supporting Information). Zinc was also the dominant metal detected by ICP-OES experiments on purified protein solutions (ca. 1.2 mol Zn/26 kDa). The presence of a heavy metal facilitated the structure determination. The phases from the Zn atom extended to 1.6 A and gave a well-resolved electron-density map in which two molecules per asymmetric unit could be traced. Phases were extended to 1.16 A by solvent flattening and twofold averaging. This resolution was sufficient to identify most amino acids in the polypeptide chain, even in the absence of the complete protein or encoding cDNA sequence, and minor ambiguities were resolved by comparison with peptide sequences determined denovo by mass spectrometry. T...

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Theoretical and experimental studies of indoaniline dyes. A novel relationship between absorption spectra and molecular structure

Cited by 34 publications

References 0 publications

Condensation routes to polyaniline and its analogs

Condensation routes to polyaniline and its analogs

Environmental updates

Unusual Chromophore and Cross‐Links in Ranasmurfin: A Blue Protein from the Foam Nests of a Tropical Frog

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