Syntheses, structures, and mesomorphic properties of two series of oxovanadium(IV) salen and salpn complexes with 4-substituted long alkoxy chains

Abe, Yuriko; Nakabayashi, Kyoko; Matsukawa, Nahoko; Takashima, Hiroshi; Iida, Masayasu; Tanase, Tomoaki; Sugibayashi, Makiko; Mukai, Hidetomo; Ohta, Kazuchika

doi:10.1016/j.ica.2006.04.047

Cited by 40 publications

(30 citation statements)

References 36 publications

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“…Figure 4 shows the X-ray patterns for the enantiotropic mesophase of 7 (n=14) The X-ray crystal structures for 4 and 6 can be available for the discussion on the liquid crystal states since 4 and 6 show the mesomorphic property at high temperature. The molecular assemblies of the prototypes of the complexes exhibit notable features when the crystalline phase transforms into the liquid crystalline phase [17,27]. The molecular packing of 6 is consisted of one-dimensional polymeric stacking formed by van der Waals interaction of 3.3-3.5 Å with the face-to-face between the salen cores as described above (Figure 2).…”

Section: Mesomorphic Properties Of 4 (N=8) -10 (N=20)mentioning

confidence: 99%

“…However, to date there has been no systematic investigation concerning molecular assemblies and metallomesogens of metal-salen (salen=N,N'-ethylenebi(salicylideneiminato)) complexes substituted by two long alkoxy chains at the 4-positions though the metal-salen complexes with 5-substituted alkoxy or alkyl chains usually show smectic A (S A ) mesophases at higher temperature [11][12][13][14][15]. In the previous papers, we prepared two series of the VO(IV) and Ni(II) salen complexes with two long alkoxy chains introduced at the 4-positions, [VO((4-C n H 2n+1 O) 2 salen)] [16][17] and [Ni((4-C n H 2n+1 O) 2 salen)] [18] (n=3-20), and found new mesomorphism of the VO(IV) salen complexes with n=16-20 , which was unambiguously elucidated in relation to the bilayer crystal structure assembled by the VO(IV) complex. The Ni(II) salen complexes with longer alkoxy chains of n=14 -20 showed an unusual metallomesogen of a lamello-columnar (ColL) mesophase.…”

Section: Introductionmentioning

confidence: 99%

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Syntheses, Structures, and Mesomorphism of a Series of Cu(II) Salen Complexes with 4-Substituted Long Alkoxy Chains

Nakazima

Tanase

Katano

et al. 2007

Molecular Crystals and Liquid Crystals

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A series of copper(II) salen complexes containing 4-substituted alkoxy chains of aromatic rings, [Cu((4-C n H 2n+1 O) 2 salen)] (n = 3 (1), 4 (2), 6 (3), 8 (4), 10 (5), 12 (6), 14 (7), 16 (8), 18 (9), and 20 (10) ) and salen=N, N'-ethylenebis(salicylideneiminato)) has been prepared and single crystal structures of 2 H 2 O, 4, and 6 by an X-ray crystallographic analysis have been revealed. Complexes 4 and 6 form tetrahedrally distorted square planer structure with onedimensional polymeric stacking by van der Waals interaction between the dramatically distorted salen moieties. Complexes 1 -3 did not exhibit any mesophases, but complexes 4-10 with longer alkoxy chains of n=8-20 showed the metallomesogen of a lamellocolumnar (ColL) mesophase in the smectic layers with the nearly constant stacking distances, 2 irrespective of the variation of the alkoxy chain lengths by the X-ray diffraction measurements, which show similar behaviors to the corresponding Ni(II) complexes of n=14-20. The molecular assemblies and mesomorphic properties in relation to the single crystal structures of 4 and 6 with the liquid crystals at higher temperature are discussed. KeywordsCu(II) complexes, salen ligand with 4-substituted long alkoxy chains, crystal structure, metallomesogen

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Section: Mesomorphic Properties Of 4 (N=8) -10 (N=20)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Syntheses, Structures, and Mesomorphism of a Series of Cu(II) Salen Complexes with 4-Substituted Long Alkoxy Chains

Nakazima

Tanase

Katano

et al. 2007

Molecular Crystals and Liquid Crystals

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“…Such polar order is quite significant in the context of novel ferroelectric/piezoelectric and NLO materials [12]. Despite the inherent difficulties in synthesizing mesogenic vanadyl(IV) complexes, a number of vanadyl(IV) liquid crystalline complexes have been documented [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Rich but complex mesomorphism exhibited by the salicylaldimines and their metal complexes including vanadium has attracted considerable interests.…”

mentioning

confidence: 99%

“…Four coordinated Ni(II), Cu(II)-salen complexes with 5-substituted long alkoxy chains forming a linear rod like (1-D) structure also show SmA mesophases [33][34][35]. In contrast, metallomesogens of Schiff bases with long alkoxy chain at 4-position have been sparsely investigated [14,15,19]. Abe et al reported a series of vanadyl complexes, possessing an aliphatic (-CH 2 ) n rigid core showing an unusual rectangular (Col r ) columnar mesophase [15].…”

mentioning

confidence: 99%

“…Abe et al reported a series of vanadyl complexes, possessing an aliphatic (-CH 2 ) n rigid core showing an unusual rectangular (Col r ) columnar mesophase [15]. Complexes with shorter alkoxy substituent, [VO(4-C n H 2n+1 O) 2 salen)]ClO 4 (n = 3, 8, 10) with (-CH 2 ) 2 -rigid core lacked liquid crystalline behavior [14,15,19]. Metallomesogens exhibiting Col l mesophase are not ubiquitous [19,36].…”

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Lamellar columnar mesomorphism in a series of oxovanadium(IV) complexes derived from N, N/-di-(4-n-alkoxysalicylidene)diaminobenzene

Bhattacharjee¹,

Das²,

Mondal³

et al. 2011

Inorganic Chemistry Communications

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An Efficient Approach for Immobilizing the Oxo‐Vanadium Schiff Base onto Polymer Supports using Staudinger Ligation

Jain

Sain

2008

Adv Synth Catal

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The present paper describes the use of Staudinger ligation as an efficient and high-yielding approach for the immobilization of oxo-vanadium Schiff base on polymeric supports via covalent attachment under mild conditions. The described strategy is simple in use, versatile, highly efficient with respect to better catalyst loading and proceeds under mild, metal-free conditions. The catalytic potential of the prepared polymer immobilized oxovanadium Schiff bases was tested for the oxidation of sulfides using aqueous tert-butyl hydroperoxide (TBHP) as oxidant. The polymer-supported catalysts could easily be recovered from the reaction mixture and reused for four runs without loss in activity and no metal leaching was observed during this course.Keywords: oxidation; oxo-vanadium Schiff base; Staudinger ligation; sulfides; supported catalyst Immobilization of metal complexes to polymeric support is an area of intensive research as these immobilized complexes offer a number of advantages over traditional solution-phase chemistry.[1] These supported complexes can easily be recovered from the reaction mixture, do not contaminate the product, can be recycled and enhance selectivity. The methods which are hitherto known for the immobilization of metal complexes onto the polymer support either involve the synthesis of polymer-bound ligands followed by complexation [2] or the direct reaction of the preformed metal complex with a functionalized polymer.[3] However, these methods suffer from certain drawbacks such as need for excess metal complex and reagents, slow reactions of metal complexes with polymer support, lower catalyst loading and harsh reaction conditions. To circumvent the limitations associated with the known methods, we focused our attention towards a new coupling strategy, calling only for the stoichiometric use of ligands or metal and providing high catalyst loading under mild reaction conditions.Staudinger ligation, [4] a metal-free coupling strategy between an azide and appropriately substituted carboxylic acid mediated by trialkyl-or triarylphosphine in which a chemically stable amide bond is formed, proceeds under mild reaction conditions, almost quantitatively and without noticeable formation of side products. While Staudinger ligation has extensively been used for the immobilization of bioactive molecules, [5] to the best of our knowledge there is no literature report on its use for the preparation of polymerbound metal catalysts.The present paper describes an efficient, high-yielding approach for the immobilization of oxo-vanadium Schiff base on the polymer supports via covalent attachment with better catalyst loading using Staudinger ligation (Figure 1).In the present study, azidomethyl-polystyrene and azidomethyl-MeOPEG 5000 , easily accessible from commercially available Merrifield resin and MeO-PEG 5000 , respectively, were employed as model supports. The immobilization of oxo-vanadium Schiff base 2 was carried out by using the Staudinger ligation coupling strategy as depicted in Scheme 1....

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Syntheses, structures, and mesomorphic properties of two series of oxovanadium(IV) salen and salpn complexes with 4-substituted long alkoxy chains

Cited by 40 publications

References 36 publications

Syntheses, Structures, and Mesomorphism of a Series of Cu(II) Salen Complexes with 4-Substituted Long Alkoxy Chains

Syntheses, Structures, and Mesomorphism of a Series of Cu(II) Salen Complexes with 4-Substituted Long Alkoxy Chains

Lamellar columnar mesomorphism in a series of oxovanadium(IV) complexes derived from N, N/-di-(4-n-alkoxysalicylidene)diaminobenzene

An Efficient Approach for Immobilizing the Oxo‐Vanadium Schiff Base onto Polymer Supports using Staudinger Ligation

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