Phenol–Formaldehyde Polymers

Knop, André; Böhmer, Volker; Pilato, Louis A.

doi:10.1016/b978-0-08-096701-1.00176-2

Cited by 18 publications

(28 citation statements)

References 176 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Surprisingly the temperature dependence of the signals for the methylene protons of the calix [8]arenes in CDCI, corresponds very closely to that found for the ~alix [4]arenes. '~~", "I The greater flexibility of the "eightmembered" ring is only noticeable in a solvent such as pyridine which breaks down the hydrogen bonds; here only a singlet is observed for the methylene protons at the lowest temperatures studied ( -90 C).…”

Section: Larger Calixarenes Of' Type I1supporting

confidence: 59%

“…Table 1). There is a considerable amount of evidence that the calix [4]arene is the thermodynamically most stable product (it can for example be obtained from calix [6]-or calix [8]arene under basic conditions), while calix [8]arene is formed under kinetic control. In contrast, a template effect has been suggested as an explanation for the formation of ~alix [6]arene.…”

Section: One-pot Proceduresmentioning

confidence: 99%

“…-40 "C) this singlet splits into one pair of doublets for calix [S]arenes, while in the case of calix [6]and calix [7]arenes three and seven pairs are observed, respectively. ["' Remarkably, calix [8]arenes also give rise to only one pair of doublets at low temperatures. [871 Apparently the intramolecular hydrogen bonds stabilize a highly symmetrical conformation with a regular "up and down" arrangement of the phenol units in which all the methylene bridges are equivalent, while the environment of the protons is similar to that in calix [4]arenes.…”

Section: Larger Calixarenes Of' Type I1mentioning

confidence: 99%

“…['] Macrocycles with several CH,-0-CH, bridges can however be more readily prepared by the elimination of water from doubly hydroxymethylated phenols or from ~l i g o m e r s .~'~~-~~ Macrobi-and -tricyclic compounds with CH,-0-CH, 8 bridges have been obtained from the corresponding functionalized phenol ether derivatives by Williamson synthesis. [24d1…”

Section: 33-tetramethylbutyl (-C(ch)-ch-c(ch))mentioning

confidence: 99%

“…[~"] Gutsche proposed an intramolecular reaction for the conversion of calix [8]arene into calix [4]arene."] However, experiments with a mixture of labeled and unlabeled calix [8]arene as the starting material show a rapid statistical distribution of the label in the tetramer.rgbl The conversion of calix [6]arene into calix [4]arene also argues against an intramolecular "constriction process".…”

Section: One-pot Proceduresmentioning

confidence: 99%

See 4 more Smart Citations

Calixarenes, Macrocycles with (Almost) Unlimited Possibilities

Böhmer

1995

Angew. Chem. Int. Ed. Engl.

Self Cite

1,957

885

View full text Add to dashboard Cite

The condensation reaction between p‐tert‐butylphenol and formaldehyde leads in a single step to good yields of cyclic oligomers in which, depending on the reaction conditions, either four, six, or eight phenol units are joined by methylene bridges. The beakerlike shape of the most stable conformation of the tetramer has led to their being given the name “calixarenes” (calix = chalice). Resorcinol can undergo condensation in a similar manner with a variety of aldehydes to afford cyclic tetramers with the same basic structure (the resorcarenes). In both cases the reaction does not require the use of dilution techniques, so that large quantities of product can be readily obtained. In addition, the parent compounds can be modified in various ways, in particular at the phenolic hydroxy groups or the phenyl residues; these approaches can be used separately or in combination. Calixarenes are thus ideal starting materials for the synthesis of various types of host molecules and can also act as building blocks for the construction of larger molecular systems with defined structures and functions. Their potential applications range from use as highly specific ligands for analytical chemistry, sensor techniques and medical diagnostics to their use in the decontamination of waste water and the construction of artificial enzymes and the synthesis of new materials for non‐linear optics or for ultrathin layers and sieve membranes with molecular pores.

show abstract

Section: Larger Calixarenes Of' Type I1supporting

confidence: 59%

Section: One-pot Proceduresmentioning

confidence: 99%

Section: Larger Calixarenes Of' Type I1mentioning

confidence: 99%

Section: 33-tetramethylbutyl (-C(ch)-ch-c(ch))mentioning

confidence: 99%

Section: One-pot Proceduresmentioning

confidence: 99%

See 3 more Smart Citations

Calixarenes, Macrocycles with (Almost) Unlimited Possibilities

Böhmer

1995

Angew. Chem. Int. Ed. Engl.

Self Cite

1,957

885

View full text Add to dashboard Cite

show abstract

Polymers Based on Phenols

Qiao

Caulfield

2009

Patai's Chemistry of Functional Groups

View full text Add to dashboard Cite

show abstract

Calixarene – Makrocyclen mit (fast) unbegrenzten Möglichkeiten

Böhmer

1995

Angewandte Chemie

283

View full text Add to dashboard Cite

Durch Kondensation von p‐tert‐Butylphenol mit Formaldehyd sind in einem Schritt in guten Ausbeuten cyclische Oligomere erhältlich, in denen je nach Reaktionsbedingungen vier, sechs oder acht Phenolbausteine über Methylenbrücken verknüpft sind. Die kelchartige Gestalt der stabilsten Konformation des Tetramers erklärt den Namen Calixaren (calix = Kelch). In ähnlicher Weise liefert Resorcin bei der Kondensation mit einer Vielzahl von Aldehyden cyclische Tetramere mit dem gleichen Grundgerüst (Resorcarene). In beiden Fällen erfordert die Herstellung keine Verdünnungsbedingungen, so daß auch größere Mengen leicht zugänglich sind. Überdies können die Stammverbindungen vielfältig modifiziert werden, wobei die phenolischen Hydroxygruppen und die Phenylringe zwei Ansatzpunkte bieten, die getrennt oder in Kombination genutzt werden können. Calixarene sind deshalb ideale Edukte für die Synthese der unterschiedlichsten Wirtverbindungen und Bausteine für die Konstruktion größerer molekularer Systeme mit definierter Struktur und Funktion. Die potentiellen Anwendungen reichen vom Einsatz als hochspezifische Liganden für die Analytik, die Sensortechnik und die medizinische Diagnostik über die Verwendung zur Decontaminierung von Abwässern bis hin zur Konstruktion künstlicher Enzyme und zur Herstellung neuer Materialien für die nichtlineare Optik oder für ultradünne Schichten und Siebmembranen mit molekularen Poren.

show abstract

Phenol–Formaldehyde Polymers

Cited by 18 publications

References 176 publications

Calixarenes, Macrocycles with (Almost) Unlimited Possibilities

Calixarenes, Macrocycles with (Almost) Unlimited Possibilities

Polymers Based on Phenols

Calixarene – Makrocyclen mit (fast) unbegrenzten Möglichkeiten

Contact Info

Product

Resources

About