Crystal Structure of the Complex of β-Cyclodextrin with Bithiophene and Their Oxidative Polymerization in Water

Takashima, Yoshinori; Oizumi, Yoshihumi; Sakamoto, Kazuya; Miyauchi, Masahiko; Kamitori, Shigehiro; Harada, Akira

doi:10.1021/ma049763n

Cited by 40 publications

(31 citation statements)

References 20 publications

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“…Under heating, it is expected that the hydrogen bonds are cleaved and the hydrophobic nature becomes the stronger effect. [9,17] In particular, TMbCD behaves as a more hydrophobic host molecule than b-CD, and TMbCD complexes in water are more stabilized at higher temperatures, which leads to advantageous conditions for crystal growth. However, when 2,6-dimethyl- ), but they are smaller by two orders of magnitude than those of TMbCD.…”

Section: Resultsmentioning

confidence: 99%

Supramolecular Dye Inclusion Single Crystals Created from 2,3,6‐Trimethyl‐β‐cyclodextrin and Porphyrins

Tsuchiya¹,

Shiraki²,

Matsumoto³

et al. 2011

Chemistry A European J

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In Nature, chromophoric groups play various roles, such as oxygen carriers, electron donors, light sensitizers, which are achieved in many cases by control of their aggregation modes in proteins. Host-guest chemistry between cyclodextrins and porphyrins has attracted great interest from supramolecular chemists because of their unique structures and functions that mimic those of proteins with chromophoric prosthetic groups. To mimic Nature's contrivances, the host-guest systems between cyclodextrins and porphyrins have frequently been studied. It is really surprising, however, that to date no detailed structural information of these complexes has been obtained from single-crystal analysis. In 2011, we reported the first successful isolation of a dye inclusion single crystal (DISC) between 2,3,6-trimethyl-β-cyclodextrin (TMβCD) and 5,10,15,20-tetrapyridylporphyrin (TPyP), and analyzed its X-ray crystal structure. The crystal structure revealed not only the real complex mode but also the attractive orientation of TPyP in the DISC. Herein, we present new strategies to prepare DISCs of TMβCD for several porphyrins and provide crystal structures, details of the complex modes, and optical properties. We believe that the present study has various important implications not only for the basic crystal analysis of inclusion complexes but also for potential applications that use these single crystals.

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Section: Resultsmentioning

confidence: 99%

Supramolecular Dye Inclusion Single Crystals Created from 2,3,6‐Trimethyl‐β‐cyclodextrin and Porphyrins

Tsuchiya¹,

Shiraki²,

Matsumoto³

et al. 2011

Chemistry A European J

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“…17 It may be a little curious that crystallization of the TM¢CD-based hostguest complex is performed at high temperature. 9,18,19 In general, ¢-CD and its derivatives are strongly solvated in aqueous solution through hydrogen bonding with water molecules. Under heating, however, the hydrogen bonds are cleaved and as a result, the hydrophobic nature of ¢-CD and its derivatives can emerge strongly.…”

Section: ¹1mentioning

confidence: 99%

Single-crystal Structure of Porphyrin Bicapped with Trimethyl-β-cyclodextrins: A Novel Dye-oriented Material

Tsuchiya¹,

Yamano²,

Shiraki³

et al. 2010

Chemistry Letters

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Complexes formed between porphyrins and cyclodextrins are among the most fascinating targets of hostguest complexes. So far, the structural details have been discussed on the basis of the solution properties. However, the real complex structure determined from single-crystal analysis is not known up to the present. In this paper, we report the first successful example for formation of a single crystal and its X-ray analysis. We believe that the resultant dye-oriented crystalline material would lead to novel hostguest chemistry applicable to new photo and electronic devices.It is well-known that porphyrin derivatives act as important players in various new photo-and electrochemical research fields. Particularly, their role in the design of solar cells mimicking the natural photosynthetic system is a conspicuous example.1 In fact, many researchers have so far constructed various artificial light-harvesting systems and charge separation systems utilizing functionalized porphyrins and their assemblies.2,3 Through these studies, it is now well-established that to control the aggregation mode of porphyrins is a decisive factor to achieve high light-harvesting efficiency. In solution phase, however, regular control is rather difficult because of the predominantly strong ³³ stacking force among the porphyrin rings, which in most cases governs the resultant aggregation mode. It thus occurred to us that the crystal phase is a potential alternative to realize a variety of new porphyrin aggregation modes. The first idea was to separate the distance among porphyrin rings through formation of inclusion complexes. In this study, we have succeeded in isolating each porphyrin in the single crystal utilizing hostguest complex formation with methylated ¢-cyclodextrin (¢-CD) (Figure 1). Over a long period, hostguest complexes of CDs have been studied extensively. 49 In particular, the interaction between porphyrin and ¢-CD is interesting from the viewpoint of a biomimetic model for hemoproteins. It has been proposed that porphyrins form bicapped hostguest complexes with ¢-CDs in solution.10,11 However, their complex structures have been discussed only on the basis of the spectral properties and theoretical calculations. It is really surprising that so far nobody analyzes the single-crystal complex structures, although the complexation modes have frequently been discussed in the references. 1016 Here, we report the first example of the crystal structure of porphyrin bicapped with ¢-CDs.2,3,6-Trimethyl-¢-cyclodextrin (TM¢CD) was selected to isolate a single crystal from aqueous solution, because TM¢CD has higher inclusion ability for meso-aryl groups of tetraarylporphyrins (K µ 10 6 M ¹1) than other ¢-CD derivatives. 1216 As for a guest porphyrin, we selected 5,10,15,20-tetrapyridin-4-ylporphyrin (TPyP), because the water solubility of this compound can be adjusted by solution pH and the compound disperses well in acidic aqueous solution. Basically, there is scarce interaction between meso-tetrapyridiniumporphyrin and the ¢-CD c...

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“…[77,78] Für den Komplex (2T) 3 ·(b-CD) 2 liegt überdies eine Kristallstrukturanalyse vor. [79] Die Cyclodextrine bilden darin wasserstoffverbrückte Kopf-Kopf-Kanäle (Abbildung 4 b); im Inneren eines Cyclodextrins befindet sich je ein Molekül 2T, und ein drittes 2T-Molekül wird zwischen den 2,3-Rändern zweier b-CD-Einheiten eingelagert. Lagrost und Mitarbeiter erhielten Pseudopolyrotaxane, indem sie 2T in Gegenwart von HP-b-CD in wässriger Lösung elektrochemisch polymerisierten (Schema 8).…”

Section: Angewandte Chemieunclassified

“…Harada und Mitarbeiter stellten ein ähnliches Pseudopolyrotaxan her, das als violetter Niederschlag bei der Oxidation wässriger Lösungen von 2T&b-CD oder 2T&DM-b-CD mit FeCl 3 ausfiel. [79] Der Mechanismus dieser oxidativen Polymerisationen wurde durch Blitzlichtphotolyse (in Lösung) [80] und mithilfe einer Quarzmikrowaage untersucht (an der Anodenoberfläche). [81] Vermutlich verläuft die Reaktion über eine diffusionskontrollierte Dimerisierung von Radikalkationen mit anschließen-dem Auffädeln der Cyclodextrine auf die wachsenden Polythiophenketten.…”

Section: Angewandte Chemieunclassified

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Isolierte molekulare Drähte

2007

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In den erstaunlich unterschiedlichen Strukturen, die bisher als “isolierte molekulare Drähte” (insulated molecular wires, IMWs) beschrieben wurden, zeigt sich, wie vielfältig die Ansätze zur elektrisch‐chemischen Isolierung auf molekularer Ebene sind. Gemeinsam verdeutlichen diese Systeme die Bedeutung von Einkapselungsstrategien bei der Entwicklung optoelektronischer Materialien und organischer Halbleiter. Dieser Aufsatz beleuchtet die Synthese und die strukturelle Charakterisierung von IMWs. Struktur‐Eigenschafts‐Beziehungen sollen zudem erklären, wie eine Isolierung die Leistungsmerkmale eines molekularen Drahtes verbessern kann. Wir konzentrieren uns auf drei IMW‐Arten: Polyrotaxane, polymerumhüllte π‐Systeme und dendronisierte Polymere. Die Eigenschaften dieser Systeme werden mit denjenigen von konjugierten Polymeren verglichen, die in mesoporöse Netzwerke und Zeolithe eingefädelt sind. Der Einschluss molekularer Drähte verstärkt so unterschiedliche Eigenschaften wie Lumineszenz, elektrische Transportgrößen und die chemische Beständigkeit, sodass Anwendungen in Elektrolumineszenzdisplays, Sensoren und der photochemischen Wasserstofferzeugung denkbar werden.

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Crystal Structure of the Complex of β-Cyclodextrin with Bithiophene and Their Oxidative Polymerization in Water

Cited by 40 publications

References 20 publications

Supramolecular Dye Inclusion Single Crystals Created from 2,3,6‐Trimethyl‐β‐cyclodextrin and Porphyrins

Supramolecular Dye Inclusion Single Crystals Created from 2,3,6‐Trimethyl‐β‐cyclodextrin and Porphyrins

Single-crystal Structure of Porphyrin Bicapped with Trimethyl-β-cyclodextrins: A Novel Dye-oriented Material

Isolierte molekulare Drähte

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