Liquid crystalline polymeric phthalocyanines

Bryant, Geoffrey C.; Cook, Michael J.; Ryan, T.G.; Thorne, Andrew J.

doi:10.1039/c39950000467

Cited by 37 publications

(24 citation statements)

References 4 publications

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“…Reflection-absorption infrared spectroscopy (RAIRS) indicates that the angle between the plane of the ring and the substrate surface increases as the length of the tethering chain is increased from (CH 2 ) 3 through (CH 2 ) 8 to (CH 2 ) 11 [27]. Compounds of both series 2 and 3 have been used as precursors to more complex molecules, utilizing the hydroxyl group in esterification reactions to generate liquid crystalline Pc 'dimers', 'trimers' [28] and polymers [29], and derivatives tethering the Pc moiety to redox-active groups such as ferrocene and tetrathiafulvalene [30,31].…”

Section: :1 Phthalocyaninesmentioning

confidence: 99%

Non-uniformly substituted phthalocyanines and related compounds: alkylated tribenzo-imidazolo[4,5]- porphyrazines

Bakboord

Cook

Hamuryudan

2000

J. Porphyrins Phthalocyanines

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The synthesis and properties of ‘3:1’ phthalocyanines, in which three of the benzenoid rings are similarly substituted whereas the fourth is differently substituted or is replaced by a heteroaromatic ring, are overviewed with an emphasis on contributions from the group at the University of East Anglia. The synthesis of novel hepta-alkylated tribenzo-imidazolo[4,5]porphyrazines as metal-free derivatives by cross-condensation of 3,6-dialkylphthalonitrile and 1-alkyl-4,5-dicyanoimidazole is described. The compounds show Q band absorption at 701 and 660 nm. The Q band is thus hypsochromically shifted relative to the Q band absorption of the corresponding metal-free octa-alkylphthalocyanines and the metal-free hexa-alkylated derivatives of tribenzo-pyridino[3,4]porphyrazines, tribenzo-thiopheno[2,3]porphyrazines and tribenzo-thiopheno[3,4]porphyrazines. Examples of the tribenzo-imidazolo[4,5]porphyrazines have been deposited as smooth, even and transparent spin-coated films with broad-band absorption in the region 600-750 nm.

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Section: :1 Phthalocyaninesmentioning

confidence: 99%

Non-uniformly substituted phthalocyanines and related compounds: alkylated tribenzo-imidazolo[4,5]- porphyrazines

Bakboord

Cook

Hamuryudan

2000

J. Porphyrins Phthalocyanines

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“…The light absorbing properties of the phthalocyanines in the visible and in the infrared regions have much significance because of the present interest in the conversion of solar to electrical energy. The electrical, optical and structural properties of many of these thin films prepared by different techniques have already been reported [9][10][11][12]. It was reported earlier from our lab that the electrical, structural and optical properties of phthalocyanine thin films depend on several factors such as the substrate temperature, nature of substrate, evaporation rate, annealing, and film thickness [13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Influence of iodine on the electrical properties of magnesium phthalocyanines thin film devices

Varghese

Menon

2006

Open Physics

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Abstract:The influence of iodine on the electrical properties of sandwich structures of magnesium phthalocyanine (Mg Pc) thin films with gold and aluminium electrodes has been investigated. The various electrical properties and different electrical parameters of the iodine-doped Mg Pc thin film devices have been estimated and compared with the values of normal Mg Pc devices from the analysis of the current-voltage characteristics. Generally samples showed an asymmetric conductivity both under forward and reverse bias. From our study we found that iodine doped Mg Pc films showed an enhanced electrical conductivity of nearly ten times that of typical Mg Pc. At low voltages the films showed an ohmic conduction with a hole concentration of P 0 = 6.34 × 10 18 m −3 and hole mobility μ = 9.16 × 10 −5 m 2 V −1 s −1 , whereas at higher voltage levels the conduction is dominated by space charged limited conduction (SCLC) with a discrete trapping level of 1.33 × 10 22 m −3 at 0.63 eV above the valance band edge. The ratio of the free charges to trapped charges (trapping factor) for the doped samples was found to be 1.07 × 10 −7 . Furthermore the reverse conduction mechanisms have also been investigated. From the current limitations in the reverse condition a strong rectifying behaviour was evident which was attributed to Poole-Frankel emission with a field-lowering coefficient of value 2.24 × 10 −5 eV m 1/2 V −1/2 .

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“…The synthetic method was developed earlier by us to provide examples of homologues designed for other studies. [22][23][24][25] In the present work, the mixed cyclisation of two phthalonitrile derivatives, i.e. a 3-methyl-6-(hydroxyalkyl) phthalonitrile and a 3,6-dialkylphthalonitrile, step iii in Scheme 1, produced the desired metal-free phthalocyanine compound.…”

Section: Introductionmentioning

confidence: 99%

“…Simon's Pcs carried eight alkoxymethyl chains at the peripheral (2,3,9,10,16,17,23,24-) sites of the Pc ring. [11][12][13][14] The UEA group then reported new examples bearing eight medium length alkyl [15][16][17][18] or alkoxymethyl groups 19,20 located at the alternative non-peripheral (1, 4,8,11,15,18,22,25-) [21][22][23][24][25] All the liquid crystalline examples referred to above exhibit columnar mesophase behaviour, see Fig 2, and is discussed later. Our recent preliminary study 26 probed how a combination of particular ring substituents on the Pc core of type C metal-free compounds also promotes mesophase formation.…”

Section: Introductionmentioning

confidence: 99%

Design and synthesis of liquid crystalline phthalocyanines: combinations of substituents that promote the discotic nematic mesophase

et al. 2015

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Graphical AbstractDesign and synthesis of liquid crystalline phthalocyanines: combinations of substituents that promote the discotic nematic mesophase AbstractA homologous series of fourteen metal-free 1,4,8,11,15,18-hexakis(alkyl)-22-methyl-25-hydroxyalkylphthalocyanine derivatives has been investigated to interogate the interlay of the roles of the six alkyl chains and the length of the hydroxyalkyl chain in promoting thermotropic nematic liquid crystalline behavior. All but two of the compounds form mesophases. Eight of the remaining compounds exhibit only columnar mesophases which is common among liquid crystalline phthalocyanines. However, four examples form the rare discotic nematic mesophase. A general structural feature is deduced in that this rare phase is favoured when the number of linking atoms in the hydroxyalkyl chain exceeds twice the number of carbon atoms in any one of the six common alkyl chains, disrupting the columnar packing arrangement. In addition, zinc and copper metallated examples of one of the metal-free discotic nematic compounds were prepared of which the zinc metallated compound formed a nematic phase whereas the copper containing analogue favoured columnar mesophase formation.

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Liquid crystalline polymeric phthalocyanines

Abstract: The first examples of phthalocyanine linear mainchain polymers showing liquid crystal properties are described.

Cited by 37 publications

References 4 publications

Non-uniformly substituted phthalocyanines and related compounds: alkylated tribenzo-imidazolo[4,5]- porphyrazines

Non-uniformly substituted phthalocyanines and related compounds: alkylated tribenzo-imidazolo[4,5]- porphyrazines

Influence of iodine on the electrical properties of magnesium phthalocyanines thin film devices

Design and synthesis of liquid crystalline phthalocyanines: combinations of substituents that promote the discotic nematic mesophase

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