Coordinating ability of phenylenediamines

Mederos, Alfredo; Domı́nguez, Sixto; Hernández-Molina, Rita; Sanchiz, Joaquı́n; Brito, Felipe

doi:10.1016/s0010-8545(99)00084-3

Cited by 96 publications

(78 citation statements)

References 206 publications

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“…Such an observation might be attributable to the difference of basicities between phenylenediamine and ethylenediamine. 22 The average distance of C-C in the sixmembered chelate rings was 1.420 Å similar to those of benzene (1.40 Å), reflecting some it's aromaticity. On the other hand, the bond length of C (20) …”

Section: Notesmentioning

confidence: 82%

Synthesis of Asymmetric Dibenzoylated Tetraazacyclo[14]annulenepalladium(II) Complexes: Structure of 3,10-Di(p-methylbenzoyl)-2,4,9,11-tetramethyl-1,5,8,12-monobenzotetraazacyclo[14]annulenepalladium(II)

Shin¹,

Kim²,

Lee³

et al. 2007

Bulletin of the Korean Chemical Society

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Several tetraazaannulenenickel(II) complexes have been synthesized by a one-step template method in a high yield. The replacement of the central metal atom, by other transition metals, is possible only by demetallating nickel complexes. These complexes have been known to possess different chemical and thermal stabilities and electrocatalytic activities by substituents at the methine sites such as psubstituted benzoyl chloride, nicotinyl chloride and acetyl chloride, etc.1-5 These tetraazaannulene complexes were mostly symmetric nickel(II) complexes with substituents at methine sites, while the examples of asymmetric complexes were rarely reported. 3,[5][6][7][8][9] In previous papers we have reported on the reaction, spectral and electrochemical properties and crystal structures of the asymmetric monobenzotetraaza- [14]annulenenickel(II) complexes with five types of psubstituted benzoyl or thiophenecarbonyl groups at the methine sites.10-12 Also, we have studied the crystal structures of asymmetric monobenzotetraaza [14]annulenepalladium(II) and -copper(II) complexes. 13,14 On the other hand, no one has investigated on the reaction, property and crystal structure of the asymmetric palladium(II) complex with para substituted benzoyl groups at the methine sites, as π-conjugated electron system.In the present work, we report that the synthesis and characterization of new asymmetric 3,10-dibenzoylmonobenzotetraaza[14]annulenepalladium(II) complexes, also the electronic effects of the substituents of the p-Xbenzoyl group (X = CH 3 , H, Cl and NO 2 ) on the infrared, electronic absorption and NMR spectra and cyclovoltammograms for the complexes. The structure of complex 2 is identified by X-ray diffraction analysis. Experimental SectionMaterials and measurements. The solvents such as methanol, ethanol, acetonitrile and dichloromethane were refluxed over calcium hydride or sodium metal under nitrogen, and checked for purities by GC just before use. Tetraethylammonium perchlorate (TEAP) used as a supporting electrolyte, was prepared and purified by the method described by Kolthoff and Coetzee. 15

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Section: Notesmentioning

confidence: 82%

Synthesis of Asymmetric Dibenzoylated Tetraazacyclo[14]annulenepalladium(II) Complexes: Structure of 3,10-Di(p-methylbenzoyl)-2,4,9,11-tetramethyl-1,5,8,12-monobenzotetraazacyclo[14]annulenepalladium(II)

Shin¹,

Kim²,

Lee³

et al. 2007

Bulletin of the Korean Chemical Society

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“…We releaved that the o-quinones readily react with MHA to give the corresponding bis-oximes, and the reaction can be pushed to completion if an excess of hydroxylamine is used [30]. The presence of different peaks in the mass spectrum of TBBC-D9 after the derivatization with MHA can be explained taking into account the redox equilibria which quinones and related molecules undergo by simple monoelectronic transfer [31]; indeed the mass peaks that were observed correspond to the TBBC-D9 dioxime, TBBC-D9 semiquinonedihydroxylamine and TBBC-D9 quinonedihydroxylamine which coexist in equilibrium (Figure 3).…”

Section: Figure 2 Gc Chromatogram and Ei-ms Spectrum Of The Three Stmentioning

confidence: 99%

Polymerization Inhibitors and Promoters for Unsaturated Polyester Resins; Use of Solid Phase MicroExtraction and Gas Chromatography Coupled to Mass Spectrometry for the Determination of 4-tert-Butyl Catechol and Acetylacetone

Dugheri¹,

Gentili²,

Bonari³

et al. 2017

Eurasian J Anal Chem

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This paper reports a contribution of three on-sample derivatization sampling techniques for acetylacetone, 4-tert-butyl catechol and its oxidated derivatives 4-tert-butyl-1,2-benzoquinone determination in unsaturated polyester resins. The use of O- (2,3,4,5,6, pentafluorobenzyl)-hydroxylamine, trimethyloxonium tetrafluoroborate and O-methylhydroxylamine is combined with automated head space/solid phase microextraction and gas chromatography/mass spectrometry analysis. For an innovative powerful meaning in high-throughput routine, the generality of the structurally informative mass spectrometry fragmentation patterns together with the chromatographic separation are also investigated. The detection limits for these polymerization inhibitors and promoters are less than 27 pg for one mg of unsaturated polyester resin. In this study a new autosampler platform is proposed by using the Multi Fiber Exchange device in a xyz robotic system. We promote these methods as the analytical reference in the polyester resin field. The introduction of dedicated, automated, and robotic systems allowed a friendly use of MS apparatus for high-throughput screening and it reduces the costs of monitoring campaigns.

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“…Transition-metal complexes having non-innocent ligands such as dioxolenes, 1 dithiolenes, 2 and benzoquinonediimines 3,4 adopting three oxidation states (L 2À : catecholate-like dianions, L À : -radical semiquinonate monoanions, or L 0 : neutral quinones) (Scheme 1), have been receiving much attention in view of the redox-activity of the ligand coupled with the central metal: e.g. valence tautomerization, 1c partial oxidation producing molecular-based conductors, 2c and so on.…”

mentioning

confidence: 99%

“…For the benzoquinonediimines, Balch 2À;1À;0 , functions as the non-innocent ligand, whereas the parent o-phenylenediamine, H 2 L, acts as an innocent ligand. 3 We focus again on the metal complexes having the noninnocent o-semibenzoquinonediimine, because its undeprotonated, innocent o-phenylenediamine forms metal complexes. 3 So far, some o-phenylenediamine metal complexes have been synthesized and structurally characterized.…”

mentioning

confidence: 99%

“…3 We focus again on the metal complexes having the noninnocent o-semibenzoquinonediimine, because its undeprotonated, innocent o-phenylenediamine forms metal complexes. 3 So far, some o-phenylenediamine metal complexes have been synthesized and structurally characterized. 5 The existence of the metal complexes with the innocent parent ligand is different from cases of the dioxolene and dithiolene compounds.…”

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confidence: 99%

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pH-Dependent Color-Change Behavior of Bis(o-phenylenediamine)platinum(II) Complex and pH-Dependent Redox of Bis(o-semibenzoquinonediimine)platinum(II) Complex

Konno¹,

Matsushita²

2006

Bulletin of the Chemical Society of Japan

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[1]Cl 2 in an aqueous solution changes from colorless either to purple or to yellow-green depending on the pH of the solution. The purple solution gave a neutral complex 2 and the yellow-green solution yielded [2 2 ]Cl 2Á 6H 2 O. In the latter complex, the monocation, [2] þ , dimerizes forming a weak Pt-Pt bond [3.0109(4) Å ] with no bridging ligands. The spectroscopy of [1]Cl 2 in the buffer solutions shows that the complex 2 is formed in the range of pH 4.6-5.8, while the complex [2] þ is generated in the range of pH 2.1-4.5. These results indicate that the one-electron redox process of [2] þ /2 depends on the pH of the solution. By adjusting the pH of the solution by adding acid or base, it is possible to reversibly control this redox process. This behavior is a kind of pH-dependent chromism because of their color being different. 2À;1À;0 , functions as the non-innocent ligand, whereas the parent o-phenylenediamine, H 2 L, acts as an innocent ligand. 3 We focus again on the metal complexes having the noninnocent o-semibenzoquinonediimine, because its undeprotonated, innocent o-phenylenediamine forms metal complexes. 3So far, some o-phenylenediamine metal complexes have been synthesized and structurally characterized. 5 The existence of the metal complexes with the innocent parent ligand is different from cases of the dioxolene and dithiolene compounds. Sharma et al. 6 have recently reported the synthesis of the bis(o-phenylenediamine)platinum(II) complex, [Pt(H 2 L) 2 ]Cl 2 , isolated as a black powder. The black color is, however, inconsistent with the general observation that most tetraamineplatinum(II) complexes are colorless to pale-yellow. The color of the solid suggests the presence of impurities, although the authors have pointed nothing out. In our study, colorless plate-like singlehave been successfully obtained by careful recrystallization. The colorless crystals are soluble in water and its solution is colorless. Interestingly, the color of the aqueous solution changes gradually from colorless to either purple or yellow-green depending on the pH of the solution.In this paper, we demonstrate that the pH-dependent colorchange behavior is ascribed to the deprotonation and oxidation of [1]Cl 2 : that is, the formation of either [Pt(L) 2 ] (2) or its oneelectron-oxidized species, [Pt(L) 2 ] þ (2 þ ), depending on the pH of the solution, where L denotes the o-semibenzoquinonediimine monoanion or neutral o-benzoquinonediimine. We also show that the one-electron redox process of [2] þ /2 depends on the pH of the solution. In the crystal, the monocations

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Coordinating ability of phenylenediamines

Cited by 96 publications

References 206 publications

Synthesis of Asymmetric Dibenzoylated Tetraazacyclo[14]annulenepalladium(II) Complexes: Structure of 3,10-Di(p-methylbenzoyl)-2,4,9,11-tetramethyl-1,5,8,12-monobenzotetraazacyclo[14]annulenepalladium(II)

Synthesis of Asymmetric Dibenzoylated Tetraazacyclo[14]annulenepalladium(II) Complexes: Structure of 3,10-Di(p-methylbenzoyl)-2,4,9,11-tetramethyl-1,5,8,12-monobenzotetraazacyclo[14]annulenepalladium(II)

Polymerization Inhibitors and Promoters for Unsaturated Polyester Resins; Use of Solid Phase MicroExtraction and Gas Chromatography Coupled to Mass Spectrometry for the Determination of 4-tert-Butyl Catechol and Acetylacetone

pH-Dependent Color-Change Behavior of Bis(o-phenylenediamine)platinum(II) Complex and pH-Dependent Redox of Bis(o-semibenzoquinonediimine)platinum(II) Complex

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