Sucrose, carbons prepared from

Fig. 4.17 Plot of log,o(n/(mmol g ) against logfo (p7p) for the adsorption of benzene at 20°C on a series of progressively activated carbons prepared from sucrose. (Courtesy Dubinin.)...

Having access to protected sucroses 10, 11, 12, and 14 we proposed an efficient method of the preparation of various derivatives such as amines (15), uronic acids (16), or higher sucroses i.e. compounds homologated at the desired terminal position by functionalized carbon unit e.g. 17) examples are shown in Fig. 2. The most complex derivative representing higher sucroses was prepared from phosphonate 18 and di-acetonogalactose aldehyde 19 which - under mild phase transfer conditions - provided enone 20 converted further into polyol 21. ... 

Carbons prepared from sucrose have surface areas up to 1500 m g , and pore volumes up to 1 cm g (Table 1). These carbons also have micropore volumes of around 0.210 cm g, which is likely related to the intrinsic microporosity of the carbon precursor. For both samples a capillary condensation occurs in the p/po range between 0.1-0.4 and 0.3-0.6, which clearly indicates that the structural porosity of the silica framework is replicated in the carbon. The pore size distributions for these carbons are very narrow with peak maxima at 1.2 nm and 1 nm, for T30 SUC and T60 SUC, respectively. Additionally, a slight development of complementary mesoporosity (estimated from the amount of nitrogen adsorbed at p/po > 0.7) can be seen, accounting for 6 % and 7 % of the total pore volume. 

The pores of the silica template can be filled by carbon from a gas or a liquid phase. One may consider an insertion of pyrolytic carbon from the thermal decomposition of propylene or by an aqueous solution of sucrose, which after elimination of water requires a carbonization step at 900°C. The carbon infiltration is followed by the dissolution of silica by HF. The main attribute of template carbons is their well sized pores defined by the wall thickness of the silica matrix. Application of such highly ordered materials allows an exact screening of pores adapted for efficient charging of the electrical double layer. The electrochemical performance of capacitor electrodes prepared from the various template carbons have been determined and are tentatively correlated with their structural and microtextural characteristics. 

E. Buiel and J. R. Dahn, Reduction of the irreversible capacity in hard-carbon anode materials prepared from sucrose for Li-ion batteries, J. Electrochem. Soc., 145 (1998) 1977-1981. 

Different carbon monoliths were prepared from a sucrose coating [8,43], a polyfurfuryl coating [9], a furan coating [44] via the dipcoating method, and from methane [14,35] via the CVD method over deposited Ni. Ruthenium was loaded on furan-based monoliths by impregnation from [RuCls H20] in diluted hydrochloric acid, and lipase was loaded on the other monoliths by physical adsorption from a phosphate buffer (pH 7). 

Several monolithic enzyme biocatalysts were prepared and characterized with carbon coatings consisting of carbonized sucrose, carbonized polyfurfuryl alcohol, and carbon nanofibers. The coated carbon monoliths were also compared with an integral (composite) carbon monolith. A lipase from Candida antarctica was adsorbed on the monolithic supports. Adsorption on carbon coatings can be very effective, depending on the carbon microstructure. For a high lipase loading. 

A dextransucrase preparation from Leuconostoc mesenteroides NRRL B-1375 has been shown to transfer -D-glucopyranosyl groups from unlabelled sucrose to the anomeric position of carbon-14 labelled n-fruo-tofuranose (see reaction 2). The rate at which the carbon-14 labelled... 

Somewhat similar data of Winsor and Pollard (1956), in which sucrose and ammonium sulfate were added to a garden soil are shown in Fig.6.4, prepared from their data by Allison and Klein (1962). With this substrate, maximum immobilization occurred in 2 days instead of 20 days as with straw in Fig.6.3, and immobilization corresponded to 3.7% of the weight of the sugar in contrast to 1.7% with straw. Again immobilization was closely correlated with biological activity as evidenced by carbon dioxide evolution. 

Our first paper dealing with this problem, tried to answer the question how long should be the linker connecting both terminal positions of two subunits of sucrose We have found that minimum four carbon atom unit is able to connect the 6,6 -positions. Reaction of 13a with 1,4-di-iodobutane afforded macrocycle 39. Both terminal positions (C-6 and C-eQ could be also connected via the RCM approach which is shown in Scheme 9. Di-allyl derivative 40, easily prepared from diol 22, was converted into macrocycle 41 with the Grubbs catalyst. Alternatively, reaction of diol 22 with pentenoyl acid chloride afforded di-ester 42, which also underwent the RCM reaction to afford olefin 43. We were able to deprotect the sucrose backbone and obtain the corresponding free polyhydro)ylated macrocyclic derivatives (Scheme 9). 

The production of nanostructured carbon materials by hydrothermal processes from natural precursors is one of the most attractive subjects in material science today. Carbon materials prepared from hydrothermal process are currently being used in various fields of research including environmental, electrical, chemical, and biomedical fields. In environmental application, carbon is mainly used as a sorbent material for the removal of heavy metal ions (CrO/, Pb +, and Cd +) from water and wastewater [116,117]. Carbon nanocoils prepared from saccharides (sucrose, glucose, and starch) with a support of Pt/Ru nanoparticles exhibit a high catalytic activity for the electro-oxidation of methanol in an acid medium [150]. Similarly, electro-oxidation of ethanol and methanol was carried out with electro catalysts, such as Pd/CHC (coin-like hollow carbon), Pt/ HCS (hard carbon spherules), and Pt/Pd/CMS (carbon microspheres) in acidic and alkaline media... 

Deoxynojirimycin has been prepared from sucrose in 35% overall yield by successive treatment with triphenylphosphine-carbon tetrachloride, sodium azide and acid resin to give 6-azido-6-deoxy-D-glucose and 6-azido-6-deoxy-D-fructose in which the former could be converted to more of the latter by use of polymer supported glucose isomerase. Hydrogenation of the fructose derivative gave DNJ. ... 

Methylfurfural may be prepared by a modification of this method, which is more rapid but gives lower yiddsd A solution of 800 g. of sucrose in i 1. of hot water is allowed to flow slowly into a boiling solution of 500 g. of stannous chloride crystals, 2 kg. of sodium chloride, and 4 1. of 12 per cent sulfuric acid in a 12-I. flask. The aldehyde distils ofl as rapidly as it is formed and is steam-distilled from the original distillate after rendering it alkaline witlr sodium carbonate. The product is isolated by benzene extraction of the second distillate and distillation under reduced pressure. The yield is 27-35 g- (10-13 per cent of the theoretical amount). 

The following process description is taken from U.S. Patent 2,987,449. An appropriate S. aureofaciens strain such as mutant S1308 (ATCC No. 12,748) is grown aerobically in a suitable inoculum medium. A typical medium used to grow the primary inoculum is prepared according to the following formula sucrose, 20.0 g corn steep liquor, 16.5 ml ammonium sulfate, 2.0 g calcium carbonate, 7.0 g and water to 1,000 ml. 

---