Green synthesis of new lawsone enaminones and their Z/E(CC)-isomerization induced by organic solvent

The synthesis of a new class of lawsone enaminone derivatives by using lawsone, triethyl orthoformate and aromatic amines in the presence of guanidinium chloride under solvent-free conditions has been developed.

Interaction strength of osmolytes with the anion of a salt-bridge determines its stability

In order to understand the role of osmolytes in regulating physicochemical behavior of proteins, we investigated the influence of protein destabilizing (urea and guanidinium chloride) and stabilizing osmolytes (TMAO, glycerol,...

Stable Polymer Bilayers for Protein Channel Recordings at High Guanidinium Chloride Concentrations

Use of chaotropic reagents is common in biophysical characterization of biomolecules. When the study involves transmembrane protein channels, the stability of the protein channel and supporting bilayer membrane must be considered. In this letter we show that planar bilayers composed of poly(1,2-butadiene)-b-poly(ethylene oxide) diblock copolymer are stable and leak-free at high guanidinium chloride concentrations, in contrast to diphytanoyl phosphatidylcholine bilayers which exhibit deleterious leakage under similar conditions. Further, insertion and functional analysis of channels such as α-hemolysin and MspA are straightforward in these polymer membranes. Finally, we demonstrate that α-hemolysin channels maintain their structural integrity at 2M guanidinium chloride concentrations using blunt DNA hairpins as molecular reporters.

Derivatives of the triaminoguanidinium ion, 6. Aminal-forming reactions with aldehydes and ketones

Cyclic aminals (N,N-acetals) could be prepared by the reaction of N,N′,N″-triaminoguanidinium sulfate, N,N′,N″-tris(benzylamino)guanidinium chloride or N,N′,N″-tris(benzylamino)guanidine with formaldehyde or acetone. In all cases, 1,2,4,5-tetrazinane derivatives were obtained, which were structurally confirmed by X-ray crystal structure determinations. In two cases, 1:1 cocrystals of two different tetrazinane products were isolated. On the other hand, the reaction of N,N′,N″-tris(benzylamino)guanidinium chloride with benzaldehyde yielded a 3-(2-benzylidenehydrazin-1-yl)-1H-1,2,4-triazole.

Effect of guanidinium chloride in eliminating O2− electron extraction barrier on a SnO2 surface to enhance the efficiency of perovskite solar cells

The charge transfer hindrance of adsorbed oxygen species on SnO2 is successfully reduced by modifying it with guanidinium chloride, improving the power conversion efficiency from 15.33% to 18.46% (after modification) with maximum fill factor of 80%.

Orthoamide und Iminiumsalze, XCVI. Push-pull-substituierte 1,3,5-Hexatriene aus Orthoamiden von Alkincarbonsäuren und Birckenbach-analogen Acetophenonen

From acetone and the orthoamide of phenylpropiolic acid (21b) N,N-dimethyl-phenylpropiolic acid amide (24) is formed. In contrast, the reaction of chloroacetone (28) with 21b results in the vinylogous guanidinium chloride 29. Unexpectedly, the Birckenbach-analogoue ethyl methyl ketone (34) reacts with the orthoamide 21b to give the push-pull-substituted butadiene 36. In contrast to this observation, the reaction of the Birckenbach-analogous acetophenones 30 with the orthoamides 21a–c delivers the push-pull-substituted 1,3,5-hexatrienes 31a–j.