[Letter from Paul B. Diederich]

Diederich, Paul B.

doi:10.2307/811064

Cited by 8 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a measurement tool, however, it is not clear that the profiles that result yield psychometrically useful information (Hill, 2001). Diederich's (1974) suggestion was to use the traits for socializing raters to a common standard, and then to drop the traits and focus on total scores.…”

Section: The Issue: What Aspects Of Writing Achievement Should Be Mea...mentioning

confidence: 99%

Chapter 4. The Misuse of Writing Assessment for Political Purposes

White

2024

Considering Students, Teachers, and Writing Assessment: Volume 1, Technical and Political Contexts

View full text Add to dashboard Cite

show abstract

Section: The Issue: What Aspects Of Writing Achievement Should Be Mea...mentioning

confidence: 99%

Chapter 4. The Misuse of Writing Assessment for Political Purposes

White

2024

Considering Students, Teachers, and Writing Assessment: Volume 1, Technical and Political Contexts

View full text Add to dashboard Cite

show abstract

“…All commercially available reagents (Fluka, Acros Organics) were used without further purification. 15,19 ]octacosa-1(25),3,5,7(28), 9,11,13(27), 15,17,19(26),21,23dodecaene- 4,6,10,12,16,18,22,24-octol (= 5,11,17,23-Tetranitroresorcinarene; 1). To a soln.…”

Section: Experimental Partmentioning

confidence: 99%

“…Crystals for X-ray structure analysis were obtained from a conc. 1,1',1'',1'''- (4,6,10,12,16,18,22,3.1.1 3,7 .1 9,13 .1 15,19 ]octacosa-1(25),3,5,7(28), 9,11, 13(27), 15,17,19(26),21,23-dodecaene-5,11,17,23-tetrayl)tetrakis [ethanone] (= 5,11,17,2). As descirbed as for 1, with 2-acetylresorcinol (15.2 g, 0.1 mol), NaOH (8 g, 0.2 mol) and formaldehyde (3 g, 0.1 mol).…”

Section: Experimental Partmentioning

confidence: 99%

“…TG and DSC (heating 108/min from 25 to 4008): À 7.03% from 100 to 1508, 52.12 J/g; À 13.21% from 150 to 2808, 116.1 J/g; À 20.21% from 280 to 4008, 388.72 J/g. 5,11,17,3.1.1 3,7 .1 9,13 .1 15,19 ]octacosa-1(25), 3,5,7(28), 9,11,13(27), 15,17,19(26),21,6,10,12,16,18,22,11,17,5). To a soln.…”

Section: Experimental Partmentioning

confidence: 99%

“…The particular shape of resorcinarenes is suitable for encapsulating small chemical entities such as solvent molecules or metal ions [5]. Such a compound becomes pincer-like at the nanoscale level owing to a change of conformation which is dependent on pH [6]. Cavitands and carcerands, prepared from resorcinarenes, are very interesting synthons for supramolecular chemistry [7 -11].Standard preparation of resorcinarenes is performed in alcoholic acidic medium.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Synthesis of New Resorcinarenes Under Alkaline Conditions

Bourgeois

Stœckli-Evans

2005

Helvetica Chimica Acta

View full text Add to dashboard Cite

The preparation of functionalized resorcinarenes is described. Thus, 2-nitroresorcinol (= 2-nitrobenzene-1,2-diol), 2-acetylresorcinol (= 1-(2,6-dihydroxyphenyl)ethanone), and 2,6-dihydroxybenzoic acid were treated with formaldehyde in alkaline medium to give the corresponding resorcinarenes 1 -3 (Scheme 1). This method is also applicable for resorcinol (= benzene-1,3-diol) itself, but the yields are poorer. In this case, the molecule formed is the simplest resorcinarene 4 on which a number of substituents can be inserted between the two OH groups. Thus, bromation of 4 yields 5 (Scheme 2). Some properties and conformations of these new products are discussed, and the X-ray crystal structures of the nitro and bromo compounds 1 and 5, respectively, are presented.Introduction. -Resorcinarenes are well known molecules, and a number of reports appear each year on this subject [1 -4]. The particular shape of resorcinarenes is suitable for encapsulating small chemical entities such as solvent molecules or metal ions [5]. Such a compound becomes pincer-like at the nanoscale level owing to a change of conformation which is dependent on pH [6]. Cavitands and carcerands, prepared from resorcinarenes, are very interesting synthons for supramolecular chemistry [7 -11].Standard preparation of resorcinarenes is performed in alcoholic acidic medium. An aldehyde (except formaldehyde) and resorcinol (= benzene-1,3-diol) are refluxed together with hydrochloric acid for several hours to permit the formation of the most stable stereoisomer. Therefore, all resorcinarenes have an alkyl group at the C-junction of the aromatic moieties. Under these acidic conditions, formaldehyde will form a copolymer with resorcinol. With 2-methylresorcinol, however, excellent yields of resorcinarene were achieved [12].All other attempts to synthesize substituted resorcinarenes in acidic medium were unsuccessful. Thus, treatment of 2-nitroresorcinol with formaldehyde gave only dimeric compounds [8]. Reaction of 2,6-dihydroxybenzoic acid with formaldehyde gave polymeric compounds. On changing the reaction conditions, it was quickly realized that basic medium is very convenient for formaldehyde and those resorcinols that bear an electron-attracting group at position 2, such as 2-nitroresorcinol (= 2-nitrobenzene-1,2-diol), 2-acetylresorcinol (= 1-(2,b-dihydroxyphenyl)ethanone), and 2,6-dihydroxybenzoic acid. The reactions are clean and rapid with yields of ca. 50%. The only real problem of this new method is the tedious preparation of the 2-substituted resorcinols. Usually, isolation and purification of resorcinarenes (this is also true for calixarenes) are very difficult for two reasons: these products have several conformations [13] [14], and they form different supermolecular complexes with different solvents, which excludes the use of mixed solvents for crystallization. Fortunately, the new tetranitroresorcinarene 1 was not soluble in either H 2 O or in MeOH, and so it was isolated, in good purity, by simply washing with these solvents. The dry red p...

show abstract

The Reception of the Third New International Dictionary

Haebler¹

1989

dic

View full text Add to dashboard Cite

[Letter from Paul B. Diederich]

Cited by 8 publications

References 0 publications

Chapter 4. The Misuse of Writing Assessment for Political Purposes

Chapter 4. The Misuse of Writing Assessment for Political Purposes

Synthesis of New Resorcinarenes Under Alkaline Conditions

The Reception of the Third New International Dictionary

Contact Info

Product

Resources

About