Mixed ligand complexes of CoII, NiII and CuII with cysteine and 4-substituted thiosemicarbazides (l
1–l
3) have been synthesized. The elemental analyses, molar conductance, spectra [electronic, i.r., 1H-n.m.r., mass] and thermal studies were used to characterize the isolated complexes. Cyclic voltammetry was used to study
the electrochemical behaviour of the NiII complexes. The i.r. and 1H-n.m.r. showed that cysteine is deprotonated in the complex and acts as a binegative ligand coordinating through thiol sulphur
and COOH groups. Also, thiosemicarbazides act as a bidentate ligand, coordination via NH2 and (C=S) groups. Square-planar geometry has been proposed for CoII, NiII and CuII ternary complexes. 相似文献
The present work aims to investigate the feasibility of oxalic acid-choline chloride deep eutectic solvent (OA-ChCl DES), which serves as a promising green solvent that utilized in the acidic deep eutectic solvent (DES) hydrolysis. Oxalic acid-choline chloride DES cellulose nanocrystal (OA-ChCl DES CNC) was isolated from the bleached DES treated pulp (BP) through the acidic DES hydrolysis using 1:1 molar ratio of OA-ChCl DES. The functional groups, crystallinity index, morphological structure, particle size, zeta potential, thermal stability and surface chemistry of the OA-ChCl DES CNC were compared with the sulphuric acid cellulose nanocrystal (SA-CNC) that prepared via sulphuric acid hydrolysis. The findings revealed the presence of negatively charged carboxyl groups on OA-ChCl DES CNC surface after the acidic DES hydrolysis. The physicochemical analyses verified that the OA-ChCl DES CNC was in nano-sized range with polydispersity index (PdI) of 0.56, indicating slightly monodispersed nanoparticles. A stable OA-ChCl DES CNC colloidal suspension with zeta potential value of ?52.1?±?5.2 mV was obtained. The OA-ChCl DES CNC outweighed the SA-CNC in term of thermal stability (288 °C) despite having a slightly lower crystallinity index (76.7%). In fact, the OA-ChCl DES CNC with a yield of 55.1% was achieved through the acidic DES hydrolysis, suggesting that the OA-ChCl DES was capable of promoting efficient cleavage of strong hydrogen bonds in BP.
A one‐pot synthesis of 2,4,5‐trisubstituted imidazoles from 1,2‐diketone or α‐hydroxy ketone, aldehyde and ammonium heptamolybdate tetrahydrate in an inexpensive and readily available ionic liquid, tetrabutylammonium iodide (TBAI) in molten state using catalytic amounts of p‐TSA has been described. 相似文献
The -ene reactions of propellanes containing an anhydride ring or a methylimide ring undergo secondary orbital control. In attack by 1O2 only the syn-products are obtained. In the corresponding lactone or ether steric hindrance plays a more important role in the direction of attack. 相似文献