Development of an impedimetric sensor based on carbon dots and chitosan nanocomposite modified electrode for Cu(II) detection in water

Journal of Solid State Electrochemistry - The fast and sensitive detection of copper ions would be essential for water monitoring. Herein, we report a novel development of an impedimetric sensor...     

Radiation pasteurised oil palm empty fruit bunch fermented with Pleurotus sajor-caju as feed supplement to ruminants

In solid state fermentation, Pleurotus sajor-caju has been found to be able to degrade at least 30% oil palm empty Fruit Bunch (EFB) fibre leaving 70 % useful materials. Conditions under which fermentation carried out were investigated. It was found that, in the temperature range between 25– 28 °C, relative ph between 6–8, moisture between 60–70 % and medium composition of CaCO₃: rice bran 2 %: 5 % were the optimum conditions. The results showed in fermented products that, there were substantial reduction in cellulosic component such as Crude Fiber (CF, 18 %); Acid Detergent Fibre (ADF, 45 %), Neutral Detergent Fibre (NDF, 61 %) and Acid Detergent Lignin (ADL, 14 %). However, Crude Protein (CP, 10%) increased resulted from single cell protein enrichment of mycelial microbial mass. The mass reductions of substrate in fermentation process corresponds to the CO₂ released during fermentation. Hence, attributable to the decreased in content of CF, ADF, NDF, and ADL. The digestibility study has also been carried out to determine the useful level of this product to ruminant. Aflatoxin content was detected low in both the initial substrates and products. Based on nutritional value and low content of aflatoxin, the product is useful as a source of roughage to ruminant.     

One-pot diastereoselective synthesis of α-aminonitriles from aldehydes, chiral amines, and trimethylsilyl cyanide under solvent-free conditions

Treatment of aliphatic and aromatic aldehydes with chiral amines and trimethylsilyl cyanide in the absence or in the presence of Lewis acids (including lithium perchlorate) under solvent-free conditions afforded the corresponding α-aminonitriles in good yields and with a diastereoselectivity of 68 to 86%. Published in Russian in Zhurnal Organicheskoi Khimii, 2006, Vol. 42, No. 1, pp. 56–59. The text was submitted by the authors in English.     

A novel and efficient method for the synthesis of α-aminonitriles by the reaction of aminals with trimethylsilyl cyanide catalyzed by iodine

Iodine, was found to be a practical and novel catalyst for the reaction of aminal and trimethylsilyl cyanide under mild and neutral reaction condition to afford the corresponding α-aminonitriles in high yields and short reaction times. Trimethylsilyl iodide derived in situ from elemental iodine and trimethylsillyl cyanide catalyzed this conversion.     

A mild, rapid and highly regioselective ring-opening of epoxides and aziridines with acetic anhydride under solvent-free conditions using ammonium-12-molybdophosphate

A highly regioselective ring opening of epoxides and aziridines can be carried out efficiently with acetic anhydride to form the acetates of the corresponding 1,2-diols and 2-amino-alcohols, respectively, using ammonium-12-molybdophosphate (AMP) as a heterogeneous catalyst, at room temperature, in the absence of solvent.     

Enantioselective conjugate addition to α,β-unsaturated esters and amides mediated by lithium perchlorate

An efficient method for the enantioselective 1,4-conjugate addition of amines to α,β-unsaturated esters containing an inexpensive chiral auxiliary, such as (S)-2-methyl-1-butanol and fenchyl alcohol, in solvent-free conditions mediated by solid lithium perchlorate is reported. Over 12 examples of the products are generated in excellent yields, accompanied by moderate enantioselectivity. The concentrated solution of LiClO₄ in a diethyl ether system works well for the enantioselective 1,4-addition of organolithium compounds to α,β-unsaturated amides without any side reactions.     

Theoretical and experimental vibrational spectroscopy study of K3Ln(PO4)2 phosphates

The monoclinic phosphates with K3Ln(PO4)2 (Ln=rare earth) formula were synthesized. Their infrared and Raman spectra have been reported and analysed. The results of a force field calculation for K3Nd(PO4)2 are presented.     

Synthesis and structural characterization of trivalent amino acid derived chiral phosphorus compounds

Reaction of the N-toluenesulfonyl derivatives of (S)-alanine, phenylalanine, and valine (4-6) with PhPCl(2) gave in high yield the 4-methyl, benzyl, and isopropyl derivatives (7-9) of 2-phenyl-1-p-toluenesulfonyl-1,3,2-oxazaphospholidin-5-one. The ratios of the (2S,4S)/(2R,4S) diastereomers (cis/trans isomers) were 1:1, 2:1, and 10:1 for the methyl, benzyl, and isopropyl derivatives 7a,b, 8a,b, and 9a,b, respectively. For 7a,b, both isomers could be crystallized, but for the others only the major isomers were isolable. The X-ray crystal structure of 9a shows that the isopropyl and phenyl groups are mutually cis and that the tolyl moiety is oriented s-trans to both the isopropyl and phenyl groups. Reaction of 6 with Cl(2)PCH(2)CH(2)PCl(2) (10) gave a 56:38:7 mixture of the cis/cis, cis/trans, and trans/trans diphosphorus heterocycles 11a-c. The major isomer could be crystallized and isolated free of the other diastereomers. Reaction of 6 with EtPCl(2) gave a 6:1 mixture of cis/trans isomers of the ethyl-substituted heterocycles 12a,b as an inseparable oil but allowed confirmation of the structure of 11a. Slow epimerization at phosphorus may occur by inversion but more likely by ring opening/closure, since 7b, 9a, and 11a give rise upon standing in solution to mixtures containing starting material and 7a, 9b, and 11b, respectively, along with the free amino acid derivatives 4 and 6. The NMR spectra, and in particular the coupling constants between the alpha-hydrogen atom of the amino acid moiety and phosphorus, were used to establish the identities of the cis and trans isomers. Reaction of 9a with (THF)W(CO)(5) gave the phosphorus-ligated adduct (9a)W(CO)(5) (13), and the IR spectrum of this complex shows that 9a is a strongly electron-withdrawing ligand. The geometry of the sulfonamide moiety is discussed in detail, as are the (1)H NMR coupling constants. The data are consistent with the presence of little steric interaction between the cis isopropyl and phosphorus substituent in 9a, 11a, and 12a and orientation of the tolyl moiety s-cis to the isopropyl group in 9b, 12b, and 13.