Synthesis, conformational studies, and inclusion properties of tris[(2-pyridylmethyl)oxy]hexahomotrioxacalix[3]arenes

1998 ◽  
Vol 76 (7) ◽  
pp. 989-996 ◽  
Author(s):  
Takehiko Yamato ◽  
Mitsuteru Haraguchi ◽  
Jun-Ichi Nishikawa ◽  
Seiji Ide ◽  
Hirohisa Tsuzuki
Keyword(s):  
Alkylation Reaction ◽  
Alkali Metal Cations ◽  
Template Effect ◽  
Two Phase ◽  
Conformational Studies ◽  
Preferential Formation ◽  
H Nmr ◽  
Inclusion Properties ◽  
Partial Cone

O-Alkylation of the flexible macrocycle 1 with 2-(chloromethyl)pyridine in the presence of Cs2CO3 resulted in the preferential formation of partial-cone-2. The cone-to-partial-cone ratio of 2 increased in the presence of K2CO3, and led to almost equal in the presence of NaH. The template effect of the alkali metal cations plays an important role in this O-alkylation reaction. The structural characterization of these products is also discussed. The two-phase solvent extraction data indicated that tris[(2-pyridylmethyl)oxy]hexahomotrioxacalix[3]arenes 2 show moderate extractability for n-butylammonium ion and high extractability for Ag+. The 1H NMR titration of cone-2 with AgSO3CF3 clearly demonstrates that a 1:1 complex is formed, which is stable on the NMR time scale. Thus, the synergism of cyclophane moiety and two or three lower-rim side chains with pyridyl groups play a significant role on the complexation of tris[(2-pyridylmethyl)oxy] derivatives cone-2 and partial-cone-2 with Ag+ ion and n-butylammonium ion.Key words: macrocycles, calixarenes, O-alkylation, ionophores, cation-N interaction.

The Metal Template Effect on O-Alkylation of Hexahomotrioxacalix[3]arene with 4-(chloromethyl)pyridine to afford tris[(4-pyridylmethyl)oxy]hexahomotrioxacalix[3]arenes and their conformational studies

2000 ◽  
Vol 2000 (1) ◽  
pp. 10-12 ◽  
Author(s):  
Takehiko Yamato ◽  
Fenglei Zhang ◽  
Tomoki Sato ◽  
Seiji Ide
Keyword(s):  
Alkali Metal ◽  
Template Effect ◽  
Cone Conformation ◽  
Conformational Studies ◽  
Alkali Metal Carbonates ◽  
Metal Carbonates ◽  
Partial Cone

O-Alkylation of the flexible macrocycle 1 with 4-(chloromethyl)pyridine gave di- and tri- O-alkylated products with cone or partial-cone conformation which ratio was affected by NaH or alkali metal carbonates used as a base.

The metal template effect on O-alkylation of tetrahydroxy[3.1.3.1]metacyclophane with 4-(chloromethyl)pyridine to afford tetrakis- [(4-pyridylmethyl)oxy][3.1.3.1]metacyclophanes and their conformational studies

2001 ◽  
Vol 79 (10) ◽  
pp. 1422-1430 ◽  
Author(s):  
Takehiko Yamato ◽  
Kenji Kumamaru ◽  
Hirohisa Tsuzuki
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Pyridine Ring ◽  
Benzyl Bromide ◽  
Major Product ◽  
Template Effect ◽  
Substitution Product ◽  
Conformational Studies ◽  
No Formation

An attempted O-alkylation of the flexible macrocycle tetrahydroxy[3.1.3.1]metacyclophane (1) with 4-(chloromethyl) pyridine (2a) in the presence of NaH under THF reflux gave 1,3-di-O-substitution product distal-3a as a major product. In contrast, tetraol 1 was O-alkylated with 2a in the presence of Cs2CO3 to afford a mixture of two conformers of tetra-O-alkylated product 4a in a ratio of 77:23 (1,4-alternate-4a:partial-cone-4a) in 95% yield. No formation of the cone conformer in the reaction of the tetraol 1 with 2a, in comparison with those with 2-(chloromethyl) pyridine (2b) or benzyl bromide (2c) in the presence of NaH or K2CO3, which predominantly afforded cone-conformer, might be attributable to the absence of contributions derived from cation–N interactions as well as cation–π interactions. The latter effect might be much smaller because of the decreased π-density of the pyridine ring compared to that of the benzene ring. The structural characterization of these products in solution as well as solid state is also discussed.Key words: macrocycles, calixarenes, cyclophanes, [3.1.3.1]metacyclophanes, O-alkylation, conformation, crystal structure, cation–N interaction.

Synthesis and Inclusion Properties of thiacalix[4]arene tetraamides in cone- and 1,3-alternate conformation

2007 ◽  
Vol 2007 (10) ◽  
pp. 557-560 ◽  
Author(s):  
Shofiur Rahman ◽  
Nazneen Begum ◽  
Carol Pérez-Casas ◽  
Akina Yoshizawa ◽  
Takehiko Yamato
Keyword(s):  
Hydrogen Bonding ◽  
Solvent Extraction ◽  
Alkali Metal ◽  
Metal Cations ◽  
Intramolecular Hydrogen Bonding ◽  
Alkali Metal Cations ◽  
Two Phase ◽  
Inclusion Properties ◽  
Intramolecular Hydrogen

Novel thiacalix[4]arene tetraamides in cone- and 1,3- alternate conformation were prepared, in which the cone-tetraamide shows stronger intramolecular hydrogen bonding than 1,3- alternate-tetraamide. The two-phase solvent extraction data indicated that tetraamides show no extractability for alkali metal cations, but small extractability for dichromate anion (Cr2O72-).

Characterization of flow regimes in two phase flow using wavelet analysis

2018 ◽  
Author(s):  
Munzarin Morshed ◽  
Syed Imtiaz ◽  
Mohammad Aziz Rahman
Keyword(s):  
Wavelet Analysis ◽  
Two Phase Flow ◽  
Flow Regimes ◽  
Phase Flow ◽  
Two Phase

Small angle X-ray scattering study of porosity variation in a styrene-divinylbenzene copolymer

1981 ◽  
Vol 46 (7) ◽  
pp. 1675-1681 ◽  
Author(s):  
Josef Baldrian ◽  
Božena N. Kolarz ◽  
Henrik Galina
Keyword(s):  
Small Angle ◽  
Structural Parameters ◽  
Two Phase ◽  
X Ray ◽  
Porosity Variation ◽  
Swelling Agent ◽  
X Ray Scattering ◽  
Styrene Divinylbenzene ◽  
Ray Scattering

Porosity variations induced by swelling agent exchange were studied in a styrene-divinylbenzene copolymer. Standard methods were used in the characterization of copolymer porosity in the dry state and the results were compared with related structural parameters derived from small angle X-ray scattering (SAXS) measurements as developed for the characterization of two-phase systems. The SAXS method was also used for porosity determination in swollen samples. The differences in the porosity of dry samples were found to be an effect of the drying process, while in the swollen state the sample swells and deswells isotropically.

Synthesis and characterization of novel chiral derivatizing agents containing β-keto-anthracene adducts (KAAs) by 1H-NMR: aromatic influence and chiral alcohol absolute configuration determination

2019 ◽  
Vol 17 (3) ◽  
pp. 541-554
Author(s):  
Neeranuth Intakaew ◽  
Puracheth Rithchumpon ◽  
Chanatkran Prommin ◽  
Saranphong Yimklan ◽  
Nawee Kungwan ◽  
...  
Keyword(s):  
1H Nmr ◽  
Absolute Configuration ◽  
Synthesis And Characterization ◽  
Chiral Alcohols ◽  
Chiral Alcohol ◽  
Aromatic Rings ◽  
H Nmr ◽  
Chiral Derivatizing Agents

New chiral derivatizing agents and the effect of aromatic rings were investigated for absolute configuration of chiral alcohols via1H-NMR.

scholarly journals Synthesis and characterization of different soybean oil-based polyols with fatty alcohol and aromatic alcohol

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 491-499
Author(s):  
Fukai Yang ◽  
Hao Yu ◽  
Yuyuan Deng ◽  
Xinyu Xu
Keyword(s):  
Molecular Weight ◽  
Soybean Oil ◽  
Retention Time ◽  
Ring Opening ◽  
Isoamyl Alcohol ◽  
Synthesis And Characterization ◽  
Intermolecular Force ◽  
H Nmr ◽  
Epoxy Groups

Abstract In this article, five kinds of soybean oil-based polyols (polyol-E, polyol-P, polyol-I, polyol-B, and polyol-M) were prepared by ring-opening the epoxy groups in epoxidized soybean oil (ESO) with ethyl alcohol, 1-pentanol, isoamyl alcohol, p-tert-butylphenol, and 4-methoxyphenol in the presence of tetrafluoroboric acid as the catalyst. The SOPs were characterized by FTIR, 1H NMR, GPC, viscosity, and hydroxyl numbers. Compared with ESO, the retention time of SOPs is shortened, indicating that the molecular weight of SOPs is increased. The structure of different monomers can significantly affect the hydroxyl numbers of SOPs. Due to the large steric hindrance of isoamyl alcohol, p-hydroxyanisole, and p-tert-butylphenol, SOPs prepared by these three monomers often undergo further dehydration to ether reactions, which consumes the hydroxyl of polyols, thus forming dimers and multimers; therefore, the hydroxyl numbers are much lower than polyol-E and polyol-P. The viscosity of polyol-E and polyol-P is much lower than that of polyol-I, polyol-B, and polyol-M. A longer distance between the molecules and the smaller intermolecular force makes the SOPs dehydrate to ether again. This generates dimer or polymers and makes the viscosity of these SOPs larger, and the molecular weight greatly increases.

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