Near-IR photoconductivity of poly(1,1′-dihexylferrocenylene)-TCNE CT complex

Nishihara, Hiroshi; Kurashina, Mamoru; Aramaki, Kunitsugu; Kubo, K.

doi:10.1016/s0379-6779(98)01188-6

Cited by 14 publications

(6 citation statements)

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“…Studies of model mixed valence biferrocenes by Dong et al has shown the intricate dependency of rates of electron-transfer delocalization to the degree of ring-tilt in these structures, the nature of the counterion, and the type of substitution at the cyclopentadienyl ring. In this work, we have found that the quadrapolar splitting, Δ E q , and the isomer shifts, δ, of the new polymers 3b and 3c (listed in Table ) and their oxidized counterparts are typical of other neutral or oxidized ferrocenes, oligoferrocenes, and the polyferrocenylene 3a . As shown from the representative Mössbauer spectra in Figure , when the polymer 3c is partially oxidized with either approximately half or 1 equiv of TCNE respectively, the oxidized polymer 5c was found to not delocalize on the Mössbauer time scale (10 -7 s -1 ).…”

Section: Resultsmentioning

confidence: 76%

Copper-Mediated Polycondensations of Substituted Diiodoferrocenes and Bis(stannyl)ferrocenes: Synthesis and Properties of Soluble Polyferrocenylenes Containing Trimethylsilyl or Methyl Groups

2002

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Low to moderate molecular weight substituted polyferrocenylenes [(η 5 -C5H3X)Fe(η 5 -C5H3X)]n (where 3a-3c, X ) H, SiMe3, Me) were prepared from the Ullmann coupling reaction of the diiodoferrocenes, (η 5 -C5H3XI)2Fe (2a-2c), with an excess of copper metal or alternatively CuCl-facilitated coupling of the bis(stannyl)ferrocene, (η 5 -C5H3SiMe3SnBu3)2Fe (1b). The new monomers were characterized by 1 H and 13 C NMR spectroscopy, elemental analysis and mass spectrometry. A single-crystal X-ray diffraction study (η 5 -C5H3SiMe3I)2Fe (2b) shows the disubstituted cyclopentadienyl rings are eclipsed with the substituents staggered by 20°. The molecular weights (Mw) for the soluble homopolymers 3b and 3c were estimated by gel permeation chromatography in THF vs polystyrene standards and were found in the range from 2.0 × 10 3 to 1 × 10 4 with generally broad polydispersities (PDI > 2). Polymers 3b and 3c were characterized by 1 H and 13 C NMR spectroscopy and elemental analysis. The polymer thermal transition behavior and morphology of 3a-3c were examined by differential scanning calorimetry (DSC) and by powder X-ray diffraction (PXRD). The amorphous nature of the disubstituted polymers 3b and 3c was evident by the presence of weak glass transitions and the absence of any melt transitions. In contrast, the semicrystalline nature of the largely insoluble polyferrocenylene 3a led to the presence of a strong melt transition by DSC in addition to three sharp peaks in its the PXRD spectrum. The polymers 3b and 3c as well as their I 2 and TCNE oxidized products (4b, 4c and 5b, 5c) were characterized by UV/vis/NIR spectroscopy. The neutral polymers 3b and 3c showed only weak d-d visible transition centered near λ ) 480 nm, while the partially oxidized derivatives showed strong charge-transfer peaks in the visible λ ) 630-700 nm) and broad intervalence charge-transfer transitions between λ ) 850 and 1900 nm. Cyclic voltammetry of the neutral polymers 3b and 3c showed two well-separated oxidation waves with ∆E 1/2 values of 485 and 460 mV s -1 respectively and were consistent with substantial interaction between neighboring metal centers. Mo ¨ssbauer data of the partial oxidized dimethylferrocene polymer 5c with TCNE at room temperature indicates that electron transfer is valence trapped with distinct Fe 2+ and Fe 3+ sites.

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Section: Resultsmentioning

confidence: 76%

Copper-Mediated Polycondensations of Substituted Diiodoferrocenes and Bis(stannyl)ferrocenes: Synthesis and Properties of Soluble Polyferrocenylenes Containing Trimethylsilyl or Methyl Groups

2002

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“…Recently, a layer-by-layer electrostatic self-assembled photovoltaic device employing a cationic poly( p- phenylenevinylene) species bearing ruthenium−polypyridyl complexes in the backbone was reported . Photoconductivity in thin films of oxidized oligomeric and polymeric ferrocene-based materials has been reported recently in lateral conduction modes. ,,, Herein, we report photoconductive and photovoltaic effects in solid-state devices made with PFS/fullerene composite thin films.…”

Section: Introductionmentioning

confidence: 88%

Photoconductivity in Donor−Acceptor Polyferrocenylsilane−Fullerene Composite Films

et al. 2005

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Organometallic polymer-based solid-state photoconductive and photovoltaic devices using thin films of blends of poly(ferrocenylmethylphenylsilane) (PFMPS) and fullerenes as the active layers were fabricated. Buckminsterfullerene C 60 and [6,6]-phenyl C 61 butyric acid methyl ester (PCBM) fullerene derivative were investigated as electron acceptors in the devices, in the range of 5-18 mol % relative to the ferrocenyl electron donor in PFMPS. The devices show a predominantly UV spectral response. The short circuit currents were on the order of nanoamperes under white light illumination of ca. 160 mW/ cm 2 , and the open circuit voltage was found to vary from ca. 0.3 V for devices with C 60 to ca. 0.45 V for devices with PCBM.

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“…Nishihara et al have reported that doping of oligoferrocenylenes with tetracyanoethylene (TCNE) gives charge-transfer complex-bearing materials that exhibit photoconductivity, though the molecular weights of the materials studied were all under 5 000. [37,38] Ferrocene-containing conducting polymers [39] and self-assembled materials [40] have recently shown promise in photovoltaic applications. Thus, the photooxidation of PFSs in the presence of CHCl 3 represents an interesting technique, offering the potential of photopatterning and optical control of the electrical properties, to prepare (photo)conducting organometallic polymeric materials.…”

Section: Conductivity Measurements On Photooxidized Pfmps Filmsmentioning

confidence: 99%

Photooxidation and Photoconductivity of Polyferrocenylsilane Thin Films

Cyr¹,

Tzolov²,

Manners³

et al. 2003

Macro Chemistry & Physics

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Irradiation of thin films of poly(ferrocenylmethylphenylsilane) ([Fe(η5‐C5H4)2SiMePh]n) cast from chloroform solution with UV light leads to photooxidation of ferrocene centers in the polymer main chain. The extent of the polymer oxidation can be controlled in the range ca. 0–5% by the duration of the irradiation exposure and by the concentration of chloroform. The photooxidized polyferrocenylsilane material is conductive, with an increased conductivity of greater than three orders of magnitude relative to the unoxidized material. In addition, the photooxidized polymers have been found to be photoconductive. The photooxidation process can be reversed by means of chemical reduction using hydrazine or decamethylferrocene, leading to the regeneration of the neutral polymers. However, substantial molecular weight decline was detected during the photooxidation/reduction process, presumably as a result of chain cleavage reactions induced by the anionic or radical chlorinated photoproducts. Methylation of the cyclopentadienyl rings of the ferrocene moiety in the polymer was found to lead to materials which are significantly more stable.Time trace of the current at constant applied voltage of 100 V for a PFS film upon illumination. The ON and OFF states were created by using a mechanical shutter.magnified imageTime trace of the current at constant applied voltage of 100 V for a PFS film upon illumination. The ON and OFF states were created by using a mechanical shutter.

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Near-IR photoconductivity of poly(1,1′-dihexylferrocenylene)-TCNE CT complex

Cited by 14 publications

References 5 publications

Copper-Mediated Polycondensations of Substituted Diiodoferrocenes and Bis(stannyl)ferrocenes: Synthesis and Properties of Soluble Polyferrocenylenes Containing Trimethylsilyl or Methyl Groups

Copper-Mediated Polycondensations of Substituted Diiodoferrocenes and Bis(stannyl)ferrocenes: Synthesis and Properties of Soluble Polyferrocenylenes Containing Trimethylsilyl or Methyl Groups

Photoconductivity in Donor−Acceptor Polyferrocenylsilane−Fullerene Composite Films

Photooxidation and Photoconductivity of Polyferrocenylsilane Thin Films

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