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A set of 1,3-propanediamine derivatives connected to carbohydrates (5) has been prepared in four steps from peracetylated sugar and 1,3-dibromo-2-propanol in 60-73% yields. D-Glucose, D-mannose, D-galactose, D-xylose, D-ribose, and maltose are utilized as sugar molecules in this work. The diamine moiety was connected to the C1 carbon of the glycopyranose ring via an O-glycoside bond. All of the anomeric configurations and sugar puckering conformations, except in the D-maltose derivative, were determined by X-ray crystallography of the diazido or dibromo precursors. While glycosidation of peracetylated galactopyranose with 1,3-dibromo-2-propanol in the presence of boron trifluoride afforded both anomers, the neighboring group participation of the 2-acetoxy group yielded a single anomer for the other substrates. This method has been used to synthesize a library of sugar-pendant diamines including an OH-protected derivative (6), and an N,N'-diisopropyl-substituted derivative (7). A similar series of reactions using 2,3-dibromo-1-propanol gave ethylenediamine-type derivatives (11), and bis(bromomethyl)bis(hydroxymethyl)methane (12) gave bisglucose-pendant derivatives (16).

Shape-persistent and tough cellulose hydrogels were fabricated by a stepwise solvent exchange from a homogeneous ionic liquid solution of cellulose exposure to methanol vapor. The cellulose hydrogels maintain their shapes under changing temperature, pH, and solvents. The micrometer-scale patterns on the mold were precisely transferred onto the surface of cellulose hydrogels. We also succeeded in the spinning of cellulose hydrogel fibers through a dry jet-wet spinning process. The mechanical property of regenerated cellulose fibers improved by the drawing of cellulose hydrogel fibers during the spinning process. This approach for the fabrication of tough cellulose hydrogels is a major advance in the fabrication of cellulose-based structures with defined shapes.

For three sugar-appended diamine compounds (1,3-diamino-2-propyl β--glucopyranoside (2-β--Glc-pn), (2S)-2,3-diaminopropyl β--glucopyranoside (1-β--Glc-pn) and 1,3-diamino-2-propyl α--mannopyranoside (2-α--Man-pn)), acidity constants and stability constants with Ni 2ϩ , Cu 2ϩ and Zn 2ϩ have been measured (I = 0.16 M NaCl, 25 ЊC). The two acidity constants of each of the three sugar-diamines differ by 10 1.65 to 10 3.09 , indicating that removal of the proton from HL ϩ species is more difficult than deprotonation from the fully protonated dication H 2 L 2ϩ . Statistical and polar effects, as well as the formation of an intramolecular hydrogen bond, may cause this increased stability of the HL ϩ species. The strength of the hydrogen bond and the degree of its formation (percentage) were estimated. The sugar ring has only a small influence on the intramolecular hydrogen bond formation. For the different metal ion-ligand systems, the predominating species in solution are quite different. In the Cu 2ϩ -1-β--Glc-pn system, the dominant species are always CuL 2ϩ and CuL 2 2ϩ in the pH range 4 to 10, where the total ligand concentration is larger than total metal ion concentration. For Ni 2ϩ , NiL 3 2ϩ is also important under these same conditions; however, for Zn 2ϩ , the hydrolysis species ZnL 2 (OH) ϩ and ZnL 2 (OH) 2 predominate in the high pH region. All possible species in the system were included during the calculations, and the corresponding stability constants were determined. The hydrolysis of the metal ions themselves is important in some cases and all possible hydrolysis species were included in the fitting calculation. The stability constant plots log K versus pK yielded straight reference lines for 1,3-diamine or 1,2-diamine ligands, reflecting the complete absence of sugar oxygen atoms in the metal ion coordination. The linkage between the metal ion and the diamine residue depends solely on the basicity of the ligand.

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