The formation of the planar complex increases, and the formation of the nonplanar complex, on the contrary, decreases the proton-acceptor ability of phenols in the ground state. The formation of the nonplanar complex leads to an increase in the proton-donor properties of phenols under excitation...
Consider the scheme shown here, which depicts two hypothetical acid-base conjugate pairs. Take careful note of the labeling of this diagram: the acids HA and HB areproton sourcesand the conjugate bases A–and B–areproton sinks. This "source-sink" terminology is synonymous with the "donor-ac...
Two fused-ring structures, 6-decyloxy-2-naphthoic acid C10ONA (3) and 6-dodecyloxyisoquinoline IS (8), were synthesized and utilized as proton donor and acceptor moieties to construct a series of simple mesogenic supramolecules. The other complementary hydrogen-bonded (H-bonded) moieties are ...
The OH interaction between proton donor systems phenol, substituted phenols, benzyl alcohol and cyclohexanol and proton acceptor systems benzene, toluene, m- and p-xylenes, naphthalene and anthracene have been studied by infrared spectroscopy. It is found that the strength of the OH hydrogen bonding...
1A); this distance is similar to that between D96 and the retinal Schiff base (~ 11 Å), and to that between D85 and E194-E204 (~ 12–13 Å, Fig. 1A). Similar distances between proton donor and acceptor pairs are observed in other proteins. In the mouse Hv1 structure, the ...
英语化学问题, 急用~~According to the Lewis theory of acids and bases an acid is a proton donor and a base is a proton acceptor. 这句话对不对? 还是应该according to Bronsted Lowry theory ? 急用 谢谢~~ 答案 应该是后一种 According to Bronsted Lowry theory.原因是:布朗特(Bronsted)的酸碱质子...
water molecules could mediate such an essential proton transfer.Fig. 1shows a schematic drawing of water-mediated proton transfer in the switch. In this simple scheme, a water molecule stabilizes an ion pair state between proton donor and acceptor in the active center (switch). Energy input disp...
The stepwise internal proton transfer reactions across the membrane, and the release and uptake at the surface, are the elementary steps that together constitute the transport mechanism in a proton pump. Although the proton donor and acceptor residues can be usually identified, the directionality and...
Analysis shows that proton donor is more important than proton acceptor in determining hydrogen bond formation and strength, and a clear explanation is given for this. Within one system, hydrogen bond strength, ΔH, can be calculated by ΔH = kx - α, where k and α are constants and x ...
From previous report by Parada et al., it is clear that the structural modification of HBQ significantly affects their optical properties, especially the proton donor-acceptor distance and dihedral angle between the proton donor and acceptor moieties. Therefore, in this work, the effect of geometry...