Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.category: chiral-catalyst. In my other articles, you can also check out more blogs about 4488-22-6
Chemistry is an experimental science, and the best way to enjoy it and learn about it is performing experiments.Introducing a new discovery about 4488-22-6, Name is [1,1′-Binaphthalene]-2,2′-diamine, category: chiral-catalyst.
The synthesis and characterization of the open-chain and cyclic sapphyrin dimers 2-4 and 7, bearing various bisamide spacers is reported. This family of receptors was shown to display excellent recognition properties for various dicarboxylate anions, as judged from mass spectrometric analyses, U-tube aqueous I/CH2Cl2/aqueous II through-model-membrane transport experiments, and equilibrium binding studies. These latter were carried out in either methanol or dichloromethane using 1H or 2H NMR and visible spectroscopic titrations. The flexible, first-generation system 2, featuring a 1,3-bisamidopropane spacer was found to display a high affinity for dicarboxylate anions even in polar solvents, such as methanol. Within a range of substrates, this receptor showed a strong preference toward linear over bent, and aromatic over aliphatic dicarboxylate anions, a fact that is readily rationalized in terms of extra, stabilizing Pi-Pi, C-H···pi or C-H···N interactions. This latter C-H···N hydrogen-binding motif was observed in the single crystal structure of the 1:1 complex formed between benzoate anion and the monoprotonated form of sapphyrin 1a. The second-generation, open-chain chiral sapphyrin dimers 3 and 4 (containing (1S,2S)-1,2-bisamidocyclohexane and (S)-2,2′-bisamido-1,1′-binaphthalene chiral auxiliaries, respectively) were found to form strong complexes with N-carbobenzyloxy-protected aspartate and glutamate anions (K(a), values are on the order of 104-105 M-1 in 19:1 (v/v) dichloromethane-methanol)), and displayed a preference for glutamate over aspartate, with receptor 4 showing a modest level of enantiomeric selectivity. The cyclic dimer 7 binds these anions less effectively, but displays excellent chiral discrimination between the D- and L-antipodal forms of N-carbobenzyloxy-protected glutamate anion.
Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.category: chiral-catalyst. In my other articles, you can also check out more blogs about 4488-22-6
Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare