Tetraphenylcyclopentadienone Research Articles

Rational design of soluble intrinsic black polyimide containing tetraphenylcyclopentadienone-based chromophore

Black polyimide shows growing demand in optoelectronic apparatus instead of yellow transparent polyimide. However, the most used black polyimide filled with carbon black suffers from the deterioration of electrical and mechanical properties. In this work, a soluble intrinsically black polyimide (TPCPPPPI) with exceptional electrical and mechanical performances was designed and prepared by the polycondensation of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and a new diamine (TPCPPPDA), which bears tetraphenylcyclopentadienone (TPCP) linked with four benzene rings. Introduction of TPCP-based chromophore into PI molecular chain greatly red-shifted the absorption scope, thus achieving absorption of whole visible light. The resulted TPCPPPPI exhibited highly opaque and black color, with a cut-off wavelength (λcut) up to 698 nm and CIE (Commission Internationale de l'Eclairage) color parameter L* low to 1.41. Simulation calculation suggested that the highly black color of TPCPPPPI was primarily ascribed to the electrons transitions from the highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO) in the chromophore-bearing diamines, in which the charges chiefly migrated from the 2,5-position aryl groups to the middle cyclopentadienone. Meanwhile, TPCPPPPI exhibited exceptional solubility, mechanical and electric performance. The intrinsically black PI accompanying with exceptional performance and organosoluble feature has attractive potential application in optoelectronic field.

Design, synthesis, and properties of soluble intrinsic black polyimide bearing tetraphenylcyclopentadienone units

AbstractBlack polyimides (BPIs) have gained increasing attention because of their growing demands in optoelectronic areas. However, the commonly used BPI containing carbon black suffers from the decreases of mechanical and electrical performances. In this work, a soluble intrinsic BPI (TPCPDFPPI) was prepared by the reaction of 4,4′‐(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and a new diamine (TPCPDFPDA) bearing tetraphenylcyclopentadienone (TPCP) connected with benzene and fluorene units. TPCP grafted with benzene and fluorene units acted as a chromophore that shifted the absorption range of PI toward the long‐wave direction. The resulting TPCPDFPPI possessed whole visible‐light absorption characteristic and therefore exhibited high blackness and opacity. Additionally, TPCPDFPPI displayed superior solubility, mechanical and electrical performance. Theoretical calculations exhibited that the visible‐light absorption responsible for the blackness of TPCPDFPPI was chiefly ascribed to the HOMO to LUMO electron transition in the diamines, where the electrons were primarily migrated from the 2,5‐position aryl groups to the cyclopentadienone. This work offers a promising strategy for improving the overall properties of BPIs for photo‐electronic areas.

Enhanced blackness and solubility of polyimide via introducing propeller-shaped chromophore

The rapid development of optoelectronic devices presents significant challenges to the comprehensive performances of black polyimide (BPI). In order to cope with these challenges, in this work, a soluble intrinsic black polyimide (TPCPPPI) is designed and synthesized through the polymerization of a new diamine (TPCPPDA) bearing tetraphenylcyclopentadienone (TPCP) chromophore with 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA). The resulted TPCPPPI showed a cutoff wavelength (λcut) of 627 nm and Commission International de l'Eclairag LAB (CIE-LAB) parameter L* of 5.73. Theoretical calculation was performed with respect to the electronic transitions of TPCPPPI. The results showed that the excellent light absorption property of TPCPPPI was principally ascribed to the electronic excitation from HOMO to LUMO orbital which occurred in the chromophore unit, where the electrons chiefly moved from the aryl groups at 2- and 5-positions to the cyclopentadienone centre. Furthermore, TPCPPPI also possessed superior mechanical, electrical and thermal performance as well as outstanding solubility due to the rational structural design. This study contributes to the development of soluble intrinsic BPI with superior overall property and promotes the application of BPI in modern electronic devices.

Rational design and coloration mechanism of soluble intrinsic black polyimide with high comprehensive performance for black flexible copper clad laminates

With the development of flexible printed circuit boards (FPCBs) and photoelectric devices, the demand for black polyimide (BPI) is increasing, but the existing BPIs have some problems, such as poor electrical properties, mechanical performance, masking ability and solubility. To solve these problems, a novel diamine monomer (TPCPOHPDA) containing tetraphenylcyclopentadienone (TPCP) grafted with hydroxyl groups and benzene rings was customized, and then TPCPOHPDA was polymerized with 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) to obtain polyimide (TPCPOHPPI). TPCP had a broad UV–visible light absorption range (250–600 nm). Appending benzene rings and auxochrome (hydroxyl groups) on the TPCP skeleton extended the conjugated π-electron system and enhanced the mobility of electrons in the large π bonds, respectively. These structural modifications further extended its light absorption range, and the resulting TPCPOHPPI was dark black with a cutoff wavelength (λcut) of 680 nm and Commission International Eclairage (CIE) lab color parameter L* of 0.7. Simulation calculations indicated that the visible-light absorption that caused the black appearance of TPCPOHPPI was mainly due to the electron transition from HOMO to LUMO occurring within the TPCP-containing diamine moieties, in which the charge mainly transferred from the aryl moieties in positions 2 and 5 to the central cyclopentadienone core. Further investigation showed that TPCPOHPPI had excellent thermal, electrical and mechanical performances and high solubility. The TPCPOHPPI-based two-layer black flexible copper clad laminate (2L-FCCL) possessed good dip soldering resistance and peeling strength. This work provides a new idea for the design and synthesis of soluble intrinsic black polyimide with excellent comprehensive performance.

Rational design of high-performance soluble intrinsic black polyimide with full absorption of visible light

With the rapid development of photoelectric devices, the demand for black polyimide (BPI) with excellent masking ability is growing, but existing BPI doped with black substrates has serious insulation and mechanical performance deficiencies. To solve the problem, the intrinsic BPI with excellent comprehensive performance is highly desirable. In this work, tetraphenylcyclopentadienone (TPCP) was chosen as a chromophore, a novel diamine (TPCPtPPDA) containing TPCP grafted with biphenyl groups was synthesized, and TPCPtPPDA was then polymerized with 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) to obtain a black polyimide (TPCPtPPPI). The TPCPtPPPI showed full absorption of visible light with cutoff wavelength (λcut) high to 713 nm and Commission International Eclairage (CIE) lab color parameter L* of 0.82. By calculating the frontier molecular orbitals and the nature of electron transitions, the excellent light absorption property was attributed to the electron transition from HOMO to LUMO occurring in the diamine moieties, with the charge transfer mainly from the terphenyl moieties in 2 and 5 positions to the central cyclopentadienone core. Meanwhile, TPCPtPPPI also had excellent thermal, electrical and mechanical performances and solubility by introduction of rigid non-planar propeller-shaped structure. This work provides a promising strategy for constructing high-performance soluble intrinsic BPI and related polymers with full absorption of visible light.

Generation of ROS mediated by mechanical waves (ultrasound) and its possible applications

The thermal decomposition of 9,10 diphenylanthracene peroxide (DPAO2) generates DPA and a mix of triplet and singlet molecular oxygen. For DPAO2 the efficiency to produce singlet molecular oxygen is 0.35. On the other hand, it has shown that many thermal reactions can be carried out through the interaction of molecules with ultrasound. Ultrasound irradiation can create hydrodynamic stress (sonomechanical process), inertial cavitation (pyrolitic process) and long range effects mediated by radicals or ROS. Sonochemical reactions can be originated by pyrolytic like process, shock mechanical waves, thermal reactions and radical and ROS mediated reactions. Sonolysis of pure water can yield hydrogen or hydroxyl radicals and hydrogen peroxide (ROS). When DPAO2 in 1,4 dioxane solution is treated with 20 or 24kHz and different power intensity the production of molecular singlet oxygen is observed. Specific scavengers like tetracyclone (TC) are used to demonstrate it. The efficiency now is 0.85 showing that the sonochemical process is much more efficient that the thermal one. Another endoperoxide, artemisinin was also studied. Unlike the concept of photosensitizer of photodynamic therapy, in spite of large amount of reported results in literature, the term sonosensitizer and the sonosensitization process are not well defined. We define sonosensitized reaction as one in which a chemical species decompose as consequence of cavitation phenomena producing ROS or other radicals and some other target species does undergo a chemical reaction. The concept could be reach rapidly other peroxides which are now under experimental studies. For artemisinin, an important antimalarian and anticancer drug, was established that ultrasound irradiation increases the effectiveness of the treatment but without any explanation. We show that artemisinin is an endoperoxide and behaves as a sonosensitizer in the sense of our definition.

Exploring the electrochemical behavior of screen printed graphite electrodes in a room temperature ionic liquid

Screen printed graphite electrodes (SPGEs) have been characterized in the room temperature ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate [C6MIM][PF6] by studying pertinent electrochemical parameters of the electroactive species ferrocene (Fc), 1,4-benzoquinone (BQ), 1,4-diphenyl-9,10-anthraquinone (AQ), tetracyclone (TC) and benzophenone-3 (BZ-3). Diffusion coefficients and kinetics calculations together with Digisim simulations for comparison were performed. Additionally, the reductive cyclovoltammograms of organic carbonyl containing BQ, AQ, TC and BZ-3 derivatives provided valuable information and comparison of the electrochemical reduction of the CO functional group in model molecules of different size, solubility and π-aryl aromaticity. Finally, potentialities for the electroanalytical measurement of BZ-3 at SPGEs via the room temperature ionic liquid [C6MIM][PF6] have been evaluated.

ChemInform Abstract: Reaction of 3,4,3′,4′-Tetradehydrobiphenyl (Bisbenzyne) with Tetracyclone and Acecyclone.

ChemInform Abstract: Reaction of 3,4,3′,4′-Tetradehydrobiphenyl (Bisbenzyne) with Tetracyclone and Acecyclone.

Thermal oxidation of tetracyclones (2,3,4,5-tetraarylcyclopentadienones)

Tetracyclones are transformed to a mixture of diacylstilbenes and α-pyrones, when they are heated in diphenylether saturated with oxygen.

Undergraduate Separations Utilizing Flash Chromatography

This article describes the procedures used to carry out four flash chromatography experiments: the isolation of the carotenes, chlorophylls and xanthophylls from a spinach extract; the separation of ß-carotene from tetraphenyl cyclopentadienone; the isolation of (+) and (-) carvone from caraway and spearmint oil; and the purification of benzil from benzoin. Apparatus used is nonbreakable, easy to use, and inexpensive.

Chemical mechanism of dioxygen activation by manganese(III) Schiff base compound in the presence of aliphatic aldehydes

The manganese(III) complexes with tetradentate Schiff base [H 2(L)] derived from salicylaldehyde and 2-amino-1-benzylamine [abbreviated as H 2(salabza)], ethylenedimaine and 2-hydroxybenzophenone [H 2(7-Phe-salen)], ethylenediamine and 2-hydroxyacetophenone [H 2(7-Me-salen)] showed much higher activity for degradation of tetraphenylcyclopentadienone(TCPN) the singlet oxygen ( 1 δ g) scavenger, in the presence of cyclohexanecarboxaldehyde than those of the compounds with H 2(salen) and H 2(salphen), which are derived from salicyaldehyde and ethylenediamine, and o-phenylenediamine, respectively. X-ray crystal structural determinations of the former three compounds and electrochemical data of all the compounds have given strong support for the conclusion that the active species for degradation of TCPN is an acylperoxo Mn III species coordinated by an aliphatic peracid chelate, which should be derived from aliphatic aldehyde and dioxygen, where the geometry of the tetradentate Schiff base around the Mn III ion is of cis-β-configuration. Under the same experimental conditions, the corresponding iron(III) compounds exhibited negligible activity towards the activation of the dioxygen molecule. This was explained in terms of the difference in electronic structures between the two metal ions.

Reductive substitution of nickelocene; interception of a monohydrido intermediate in the hydrogenation of 2,3,4,5-tetraphenylcyclopentadienone (tetracyclone)

Reductive substitution 1 1 For a definition of “reductive substitution” cf. the communication on p. C21–C25. of nickelocene with tetracyclone affords bis(tetracyclone)nickel(0) ( 1), η 3-1,2,3,4-tetraphenyl-5-ketocyclopentenylcyclopentadienylnickel ( 2) and trans-1,2,3,4-tetraphenylcyclopenten-1-one-5 ( 3); evidence is presented that 2 is an intermediate in the formation of 3 from 1.

Formation of Singlet Oxygen by Photo–excitation of Substituted Aromatic Azo Compounds in Oxygenated Solution

Irradiation into the visible adsorption band of four trans–4–dialkylamino–4′‐nitroazobenzenes not subject to azo–hydra–zone tautomerism leads to conversion of triplet oxygen to singlet oxygen. Evidence for formation of singlet oxygen is provided by characterization of cis–dibenzoylstilbene as the predominant oxidation product of tetraphenylcyclopenta–dienone and by inhibition of the oxidation by DABCO and other singlet oxygen quenchers. Addition of the same concentration of 2, 6–di–t–butyl–phenolhas essentially no effect. The rates of disappearance of the singlet oxygen scavengers bilirubin and 1, 3–diphenylisobenzofuran are also reduced in the presence of DABCO. Quantum yields of singlet oxygen formation between 0. 03–2 × W‐3 were obtained for the compounds examined in di–n–butylterephthalate. The singlet oxygen yield parallels the triplet yield obtained from the same azo compounds by laser flash photolysis.

Evidence against the ( π2 s + π2 a) mechanism for the cycloadditions of allenes

The chemoselectivities in the ( π4 s + π2 s) cycloaddition reactions of tetraphenylcyclopentadienone (TPCD) with ethyl- and 1,1-dimethylallene have been determined and are compared with those observed for reaction with maleic anhydride.

ChemInform Abstract: THE REACTION OF SULPHONYL AZIDES WITH TETRACYCLONE, O‐ AND N‐SULPHONYL‐2‐PYRIDONES

AbstractDas Sulfonylazid (I) reagiert mit Tetracyclon (II) beim Erhitzen in Cyclohexan zu dem Dehydrobenzol‐Addukt (III), den Sulfonamiden (IV) und (V) und zu Tetraphenylpyridon (VI).

II—Evidence for the Formation of Singlet Oxygen by Phototendering Vat Dyes

The reaction of tetraphenylcyclopentadienone (TPC) with singlet oxygen has been used as a probe for the photochemical formation of singlet oxygen by phototendering vat dyes. The dyes C.I. Vat Yellow 1, 2 and 26 and C.I. Vat Orange 9 sensitised the oxidation of TPC in phenol‐methylene chloride solution by the action of visible light. In each case the sole photo‐oxidation product was cis‐dibenzoylstilbene, indicating the intermediacy of singlet oxygen. Similar results were obtained when the dyes were applied to cotton fabric, although the relative efficiencies of the dyes as sensitisers differed from those observed in solution. The singlet‐oxygen‐sensitising efficiencies of the dyes on cotton parralleled their relative phototendering activities towards cellulose, providing evidence in favour of the singlet‐oxygen theory of phototendering. Quenching studies of the dye‐sensitised oxidation of TPC confirmed that the reaction proceeded by a singlet‐oxygen mechanism rather than a radical process.

On the transformation of tetraphenylcyclopentadienone to pentaphenylpyrrole in boiling nitrobenzene

On the transformation of tetraphenylcyclopentadienone to pentaphenylpyrrole in boiling nitrobenzene

Dielectric studies of mobility of polar molecules in polystyrene

Dielectric measurements (5Hz–8.5 GHz) at temperatures from –30 to 100°C have been made on polar solutes molecularly dispersed in a polystyrene matrix. Rigid molecules of varying size and shape (camphor, anthrone, cholest-4-en-3-one, tetraphenyl cyclopentadienone) and β-naphthol are considered. By 80° all the molecules show their full dipole moments in polystyrene : the apparent (Eyring) activation energies ΔH*E for molecular dipole relaxations vary from 0.9 kcal mole–1 for camphor to 130 kcal mole–1 for tetracyclone. The apparent ΔH*E over limited temperature ranges themselves reflect changes in the polymer matrix relaxations, and the 130 kcal mole–1 value may well be derived from the glass-transition process. The ΔH*E and ΔS*E correlate linearly and the former is dependent upon the molecular rotational volume. The “whole molecule” and hydroxyl group rotations are well resolved for β-naphthol with ΔH*E values of 11.2 and 0.5 kcal mole–1 respectively.

“Tetraphenylcyclobutadiene” from tetracyclone

The first page of this article is displayed as the abstract.

The Synthesis of Some Alkoxy- and Alkyl-substituted Tetraphenylcyclopentadienones

The Synthesis of Some Alkoxy- and Alkyl-substituted Tetraphenylcyclopentadienones