By amide groups

The generic name given to the nylon type of polymer, which consists of short carbon chains connected by amide groups -NHCO-. See Nylon. Polybutadiene... 

In the early 1990s Hunter [49] and Vogtle [50,51] discovered independently the possibility of using hydrogen bonding interactions displayed by amide groups to template the formation of [2 ] catenanes. While studying the reaction between the... 

Polyamides are macromolecules whose constitutional repeating units are joined by amide groups, for example ... 

A derivative that stands apart in this analysis is NDI 7, in which the carboxylic acids (or esters) have been replaced by amide groups, thus allowing the possibility of a new type of hydrogen bonding interaction. The crystal structure of molecule 7 was obtained by slow evaporation of an acetone solution and the analysis showed a complex network of molecules connected via a large number of hydrogen bonds. 

Oxidative Radical Generation via Nitrogen Dioxide Dimer Conversions Induced by Amide Groups of Macromolecules... 

Macromolecule of PA consists of methylene chains coimected by amide groups, which cause vulnerability of these polymers at thermooxidative destruction. 

The second target, 4-oxo-4H-l-benzopyran-3-carboxylic acids (3) were obtained by Jones oxidation of or hydrolysis of the 3-carbonitrile derivatives ( ) described below (14). The third target, 3-(4-oxo-4H-1-benzopyran-3)acrylic acids (4) were synthesized generally by the Knoevenagel reaction of 3-carboxaldehydes (2) with malonic acid ( 1 ). In the meantime, it was found that the 3-carboxaldehydes ( ), which were able to function as P-dialdehyde compounds, were attacked by amide groups in some cases, to give 2(IH)-pyridone derivatives after condensation with malonic acid derivatives. Thus, condensation of 2 with malonodiamide in pyridine gave initially acrylamide derivatives which were converted into 3-carbamoyl-5-(2-hydroxybenzoyl)-2(IH)-pyridones ( ) (24) ... 

Amino acids are linked together into proteins by amide groups (Table 24.6) ... 

Figure 9.2 The structures of vasopressin and oxytocin. Differences are in amino acid residues 3 and 8. The normal carboxylate groups of the C-terminal residues (Gly) have been replaced by amide groups.

Conventional aliphatic polyamides, like PA-66, melt at 250 °C. By inserting aromatic rings between the amide groups, near-infusible polymers are formed. Aromatic polyamides (aramides) are known mainly in the form of fibres. Two grades of DuPont are widely used. Nomex is made from m-phenylene diamine and isophthalic acid (anhydride). In Kevlar, phenylene groups are para-substituted by amide groups,... 

Proteins and peptides (short proteins) are polymers of amino acids joined by amide groups. One feature common to the structure of many proteins is the j8 sheet, shown... 

The alpha-phase crystal structure of nylon 11, suggested by Slichter (1959), is polar. The molecular conformation of the proposed structure is all-trans, and for an odd-numbered nylon, this entails a net dipole moment per chain. Figure 4 shows the molecular sfructures of odd-numbered nylons and even-numbered nylons (Lee 1991 Su et al. 1995). As can be seen, in odd-numbered nylons, the electric dipoles formed by amide groups (H-N-C=0) with a dipole moment of 3.7 Debyes are sequenced in a way that all the dipoles are in the same direction synergistically. Therefore, the net dipole moment can be formed in one direction. While in even-numbered nylons, the amide group dipoles are in two ways if one is in one direction, the next one will be in the opposite direction, alternately. This results in an intrinsic cancellation of the dipole moments, as demonstrated schematically in the figure. 

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