lithium-chloride and pyridine

Various sodium bacterial cellulose sulfates (SBCS) were prepared via the homogeneous sulfation of bacterial cellulose (BC) with a SO3/pyridine (Py) complex in a dimethyl acetamide/lithium chloride solution. The SBCSs were characterized using Fourier transform infrared spectroscopy, X-ray diffraction (XRD), carbon nuclear magnetic resonance spectroscopy, gel permeation chromatography, elemental analyses, and thermal gravimetric analyses. A variety of conditions (including various amounts of SO3/Py, temperatures, and reaction times) were utilized to obtain SBCSs with DS values that ranged from 0.10 to 1.50. The XRD profiles indicated that the SBCSs had a cellulose II analog polymorphous structure. The differences between BC and microcrystalline cellulose (MC) were studied in their respective reactions. BC is more reactive than MC in both the sulfation and depolymerization processes. The order of reactivity for COH is C6>C2>C3 for both BC and MC. Cellulose sulfates with DS values >0.31 were soluble in deionized water.

Topics: Acetamides; Bacteria; Cellulose; Chemistry Techniques, Synthetic; Drug Stability; Lithium Chloride; Molecular Weight; Pyridines; Solubility; Sulfur Oxides; Temperature; Water

The tosylation of cellulose in ionic liquids (ILs) was studied. Due to the beneficial effect of different co-solvents, the reaction could be performed at 25°C without the need of heating (in order to reduce viscosity) or cooling (in order to prevent side reactions). The effects of reaction parameters, such as time, molar ratio, and type of base, on the degree of substitution (DS) with tosyl- and chloro-deoxy groups as well as on the molecular weight were evaluated. Products with a DStosyl≤1.14 and DSCl≤0.16 were obtained and characterized by means of NMR- and FT-IR spectroscopy in order to evaluate their purity and distribution of functional groups within the modified anhydroglucose unit (AGU). Tosylation of cellulose in mixtures of IL and a co-solvent was found to result in predominant substitution at the primary hydroxyl group. Size exclusion chromatography (SEC) revealed only a moderate degradation of the polymer backbone at a reaction time of 4-8h. Finally, the nucleophilic displacement (SN) of tosyl- and chloro-deoxy groups by azide as well as recycling of the ILs was studied.

Topics: Acetamides; Allyl Compounds; Cellulose; Chromatography, Gel; Dimethyl Sulfoxide; Ethylamines; Imidazoles; Ionic Liquids; Lithium Chloride; Magnetic Resonance Spectroscopy; Organophosphates; Pyridines; Solvents; Spectroscopy, Fourier Transform Infrared; Tosyl Compounds

6-Azafulleroid-6-deoxy-2,3-di-O-myristoylcellulose (3) was synthesized from 6-azido-6-deoxycellulose (1) by two reaction steps. The myristoylation of compound 1 with myristoyl chloride/pyridine proceeded smoothly to give 6-azido-6-deoxy-2,3-di-O-myristoylcellulose (2) in 97.0% yield. The reaction of compound 2 with fullerene (C(60)) was carried out by microwave heating to afford compound 3 in high yield. It was found from FT-IR, (13)C NMR, UV-vis, differential pulse voltammetry (DPV), SEC analyses that compound 3 was the expected C(60)-containing polymer. Consequently, maximum degree of substitution of C(60) (DS(C60)) of compound 3 was 0.33.

Topics: Acetamides; Cellulose; Chromatography, Gel; Fullerenes; Lithium Chloride; Microwaves; Pyridines; Spectrophotometry; Thermogravimetry