Condensation polymers from 1,2,5‐thiadiazole‐3,4‐dicarboxylic acid

MacDonald, Robert N.; Sharkey, W. H.

doi:10.1002/pol.1973.170111008

Cited by 10 publications

(4 citation statements)

References 8 publications

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“…Whether amide groups of this kind also have a nonplanar ground-state conformation has been considered but not substantiated [4]. We are investigating structurally isomeric [5] [6] pol yamides derived from methylated piperazines and 1,2,5-thiadiazole-3,4-dicarboxylic acid [7]. In connection with these studies, we were interested in the crystal and solution conformation of the amide group derived from 2,2,6,6-tetramethylpiperidine and 1,2,5-thiadiazole-3,4-dicarboxylic acid.…”

mentioning

confidence: 99%

On the Conformation of a Sterically Congested Amide Group in the Crystalline State and in Solution

Mühlebach

Lorenzi

Gramlich

1986

Helvetica Chimica Acta

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The conformation in the crystdine state and in solution of the sterically congested tetramethylpiperidinederived arnidc group of the symmetric diamide I formed from 2,2,6,6-tetramethylpiperidine (b) and 1,2,5-thiadiarole-3,4-dicarbonyl dichloride (c), and of the mixed diamide 11 derived from b, c, and piperidine (a) has been investigated. In crystals, as observed with 11, this group is strongly bent out-of-plane at both the N-atom and the carbonyl C-atom, and there is also a sizable twisting around the amide bond. Furthermore, the amide bond is abnormally long (1.37 A). In CD2Cl2 (or CDC1,) solution, the group is apparently planar in its ground-state conformation, but the energy barrier to rotation around the amide bond is low. This conclusion is based on low-temperature 'H-NMR measurements on I, 11, and on the symmetric diamide 111 derived from a and c.

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confidence: 99%

On the Conformation of a Sterically Congested Amide Group in the Crystalline State and in Solution

Mühlebach

Lorenzi

Gramlich

1986

Helvetica Chimica Acta

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“…Schmp. 196 : 19,7,20,8 (2 CH,); 28,4 ((CH,),C); 45, 9,50,8 (CH);47,1,47,9 (CH,); 80,4 ((CH,),C); 127,6 (arom. C(2), C(6)); 132,5 (arom.…”

Section: 53unclassified

“…Als weitere einfache unsymmetrische Piperazin-Derivate kamen cis -2,6-Dimethylpiperazin (7) und 2, in Frage. Wegen der leichteren Zuganglichkeit wurden fur die folgenden Untersuchungen das bekannte 7 [8] als unsymmetrisches und 4 [9] als symmetrisches Monomer benutzt, 7 ist auch kauflich (EGA-Chemie). Dagegen ist das Copolyamid aus 7 und 4 bisher noch nicht beschrieben.…”

unclassified

Konstitutionsisomerie in Polykondensaten. Teil VI. Synthese und Eigenschaften von völlig geordneten und ungeordneten Bipolyamiden aus cis‐2,6‐Dimethylpiperazin und 1,2,5‐Thiadiazol‐3,4‐dicarbonyl‐dichlorid

Mühlebach¹,

Pino²

1990

Helvetica Chimica Acta

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The synthesis of constitutionally perfectly regular and random alternating copolyamides from the 'symmetric' monomer 1,2,5-thiadiazol-3,4-dicarbonyl dichloride (4) and the 'non-symmetric' monomer cis-2,6-dimethylpiperazine (7) by solution and interfacial polycondensation methods is described. Their constitutional regularities (s values) were determined by high-resolution I3C-NMR spectroscopy in CDCI, solutions. Ordered and random copolyamides were amorphous with Tg values of ca. 200". However, the regular head/tail and the random copolyamides with low molecular weights could be partially crystallized by annealing and showed large differences in their melting points (549. Beside other physical properties, the membrane properties of the copolyamides were carefully investigated. In H,O desalination by reverse osmosis, no differences in salt rejections and permeabilities between constitutionally regular and random copolyamides were found (within experimental errors). In contrast, the regular head/head/tail/tail-and head/tail-type copolyamides showed considerably larger separation factors in the gas separation (methane/hydrogen) than the random ones.

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“…The polymer was formed interfacially by addition of 10.15 g (0.05 mole) of isophthaloyl chloride dissolved in 120 ml of ll1,2-trich1oroethane with rapid stirring to a mixture of 8.6 g (0.05 mole) of 2,3-dioxo-5,6-dicyanopyrazinc,9 500 ml of water, 4 g of sodium hydroxide, and 4 g of tetraethylammonium chloride at a temperature of 0-2°C. The polymer (15.1 g, 100% yield) was characterized by infrared absorpt,ion at 3.27 p for =CH, 4.44 p for C=N, 5.54 and 5.83 p Tor imide carbonyl, and at 6.16, 6.28, and 6.76 p for aromatic C=C.…”

Section: Polymer From 1456-tetrahydro-56~ioxo-23-pyrazinedicarbomentioning

confidence: 99%

Polymers from intermediates obtained from hydrogen cyanide

MacDonald

Cairncross

Sieja

et al. 1974

J. Polym. Sci. Polym. Chem. Ed.

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The recent demonstration of an easy synthesis of diiminosuccinonitrile (DISN) from hydrogen cyanide and cyanogen, the reduction of DISN to diaminomaleonitrile (DAMN), and the use of these compounds to form difunctional heterocycles has made several new polyamide intermediates accessible. The 1‐ and 2‐methyl‐1,2,3‐triazole‐4,5‐dicarbonyl chlorides have been polymerized interfacially to form high‐melting polyamides of good heat stability. Interfacial polymerization of 1‐methylimidazole‐4,5‐dicarbonyl chloride and trans‐2,5‐dimethylpiperazine has given a polyamide that is water‐soluble. The 2,6‐ and 2,3‐pyrazinedicarbonyl chlorides have been similarly converted to high‐melting polyamides. 2,6‐Dicyano‐3,5‐dipiperazinylpyrazine has been prepared from tetracyanopyrazine and piperazine and reacted with toluene diisocyanate to form a strong, stiff polyurea. Polyamides were also made from 2,3‐diaminoquinoxaline, 1,4,5,6‐tetrahydro‐5,6‐dioxo‐2,3‐pyrazinedicarbonitrile, and DAMN.

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Condensation polymers from 1,2,5‐thiadiazole‐3,4‐dicarboxylic acid

Cited by 10 publications

References 8 publications

On the Conformation of a Sterically Congested Amide Group in the Crystalline State and in Solution

On the Conformation of a Sterically Congested Amide Group in the Crystalline State and in Solution

Konstitutionsisomerie in Polykondensaten. Teil VI. Synthese und Eigenschaften von völlig geordneten und ungeordneten Bipolyamiden aus cis‐2,6‐Dimethylpiperazin und 1,2,5‐Thiadiazol‐3,4‐dicarbonyl‐dichlorid

Polymers from intermediates obtained from hydrogen cyanide

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