- Synthetic method of 2,5-dibromo-p-phenylenediamine
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The invention discloses a synthetic method of 2,5-dibromo-p-phenylenediamine. According to the method, the 2,5-dibromo-p-phenylenediamine is synthesized from a compound shown as I, namely, p-dibromobenzene serving as a starting material. By adopting the synthetic method of the 2,5-dibromo-p-phenylenediamine disclosed by the invention, the 2,5-dibromo-p-phenylenediamine can be effectively synthesized. Moreover, the synthetic method has the advantages of high synthesis efficiency, safe production, simple process operation, short production period and the like, so that the method is more suitablefor large-scale and industrialized production of the 2,5-dibromo-p-phenylenediamine.
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- Benzodipyrrole-based Donor–Acceptor-type Boron Complexes as Tunable Near-infrared-Absorbing Materials
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Benzodipyrrole-based donor–acceptor boron complexes were designed and synthesized as near-infrared-absorbing materials. The electron-rich organic framework combined with the Lewis acidic boron co-ordination enabled us to tune the LUMO energy level and the HOMO–LUMO gap (i.e.,the absorption wavelength) by changing the organic acceptor units, the number of boron atoms, and the substituents on the boron atoms.
- Nakamura, Tomoya,Furukawa, Shunsuke,Nakamura, Eiichi
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p. 2016 - 2020
(2016/07/28)
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- Synthesis of bromine- or aryl-substituted ditopic Schiff base ligands and their bimetallic iron(II) complexes: Electronic and magnetic properties
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Syntheses of three new ditopic Schiff base ligands bearing bromine, phenyl or 2-thienyl substituents are described. Bimetallic iron(II) complexes were prepared from these ligands and were characterized. Electrochemical measurements suggest no measurable electronic coupling between the metal ions in each complex. Variable temperature magnetic susceptibility measurements indicate gradual spin-crossover is operative in the complexes studied, with the low-spin state as the ground state in all cases. Density functional theory calculations corroborate these experimental observations. Attempts to electropolymerize the 2-thienyl-substituted complexes were not successful.
- Wilson, Danielle,Djukic, Brandon,Lemaire, Martin T.
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- Imine-bridged planar poly(p-phenylene) derivatives for maximization of extended π-conjugation. The common intermediate approach
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Described are two approaches to planar conjugated poly(p-phenylene) (PPP) derivatives. The first approach, involving lactam bridges, was unsuccessful due to the insolubility of the 6(5H)-phenanthridinonyl moieties. The second approach, which utilized imine bridges, worked excellently since the compounds were generally soluble and the bridge formations were highly efficient. The main PPP backbone was synthesized via Pd(0)-catalyzed coupling of an arylbis(boronic ester) with an aryl dibromide. Imine bridges, which are formed by exposure of the polymer to trifluoroacetic acid or HCl, force the consecutive units into planarity. The bridging units are sp2 hybridized, thus allowing for greater π-electron flow between the consecutive phenyl units. The polymers, upon planarization, exhibit enormous bathochromic shifts of 210-240 nm. The optical spectra of the planar systems are compared to that of the parent nonplanarized polymers, oligo(p-phenylenes), and PPP. When the bridges were n-dodecyl- or n-octylphenyl-substituted, the fully planar structures could be made into flexible free-standing films. Additionally, an improved method is described in which a common intermediate, an aryl dibromo diacyl halide, could be used to prepare both the A and B units for the AB-type step growth polymerization. In one case, a selective alkylation or arylation of the acyl portions was accomplished using lower order cyanocuprates or Pd(0)-catalyzed ketone formation. For the second monomer, a bis-Curtius rearrangement, in the presence of tert-butyl alcohol, converted both carbonyl moieties to BOC protected amines.
- Lamba, Jaydeep J. S.,Tour, James M.
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p. 11723 - 11736
(2007/10/02)
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