Double Betaine Research Articles

Very strong hydrogen bonds in hydrated 1:1 adducts of an olefinic double betaine with perchloric and nitric acids: L·HClO4·H2O and L·HNO3·H2O [L=cis-(p-Me2N+C5H4N)2C2(COO−)2

The hydrated 1:1 adducts of an olefinic double betaine with perchloric and nitric acids, L·HClO4·H2O I and L·HNO3·N2O2 [L=cis-(p-Me2N+C5H4N)2C2(COO−)2], have been shown to be nearly isostructural by X-ray crystallography and infrared spectroscopy. The common cationic unit HL+ of both compounds exhibits significant semi-quinonoid character and possesses symmetrym, ist two coplanar carboxylate groups being linked by a very strong, nearly linear intramolecular O−H−O hydrogen bond [O...O 2.397(9)A and O−H−O 167.1° for1; 2.388(7)A and 167.4° for2]. The HL+ units are further connected by intermolecular O−H...O hydrogen bonds between the exocyclic carboxyl oxygen atoms and the water molecules to generate polymeric zigzag chains running parallel to thec axis, and the disordered ClO4 or NO3− anions occupy channels running parallel to thea axis in the resulting host lattice.

Flexible double betaines: molecular structures and hydrogen bonding in their crystalline hydrates

Abstract Crystalline hydrates of three flexible double betaines, −OOCCH2N+Me2−(CH2)n−N+Me2CH2COO− (1n = 2; 2n = 3; 3n = 4) have been isolated and characterized by single-crystal X-ray analysis. 1·2H2O crystallizes in the monoclinic space group C2/c with Z = 4; 2·3H2O and 3·2H2O are both triclinic, space group P 1 , with Z = 2 and 1, respectively. The site symmetries of 1, 2 and 3 are C2, C1 and Ci, respectively. The formation of hydrogen bonds generated by water molecules bridging neighboring carboxy oxygen atoms in different modes leads to polymeric zigzag chains in the dihydrates of 1 and 3, and a layer structure in the trihydrate of 2.

Electrostatic Control of the Molecular and Crystal Structure of an Olefinic Double Betaine

AbstractNo Absract.

IR spectroscopic study of the structure of solid neodymium hexamethylenediaminetetraacetates

1. By IR spectroscopy the authors have studied hexamethylenediaminetetraacetic acid (HMTA, H4G), its potassium salts, and its complex compounds with neodymium having the compositions Nd2(H2G)3, NdHG, KNdG, K5NdG2, K9NdG3, and Nd2G(OH)2. 2. HMTA and its salt K2H2G have the structure of a double betaine. 3. The compound Nd2(H2G)3 is an acid salt, not a complex compound. 4. In the protonated complex NdHG, one of the iminodiacetate groups has the betaine structure. 5. The complex compounds KNdG, K5NdG2, K9NdG3, and Nd2G(OH)2 have an “open” structure; in these complexes the bonds are mainly ionic.