Anion recognition by a disiloxane-1,3-diol in organic solvents

Synthesis of Structurally Varied 1,3‐Disiloxanediols and Their Activity as Anion‐Binding Catalysts

“…Monosilanols and silanediols (e.g., 11 – 13 ) exhibited lower catalytic activity compared to 1,3‐disiloxanediol catalysts (Table , entries 9–11), indicating the importance of the arrangement of the two silanol groups of 1,3‐disiloxanediols for effective anion binding. The low concentration utilized in this reaction (i.e., 5.0 m m ) is consistent with previous reports for anion‐binding applications of 1,3‐disiloxanediols (5.0–0.625 m m ) . Furthermore, the low concentration utilized in this reaction suggests that supramolecular assembly is not a key factor required for substrate activation, and activation proceeds through a monomeric disiloxanediol.…”

“…The low concentration utilized in this reaction( i.e.,5 .0 mm)i sc onsistent with previous reports for anion-binding applications of 1,3-disiloxanediols (5.0-0.625 mm). [8] Furthermore, the low concentrationu tilized in this reactions uggests that supramolecular assembly is not ak ey factor required for substrate activation, and activation proceeds through am onomeric disiloxanediol. Increasing the reactionc oncentration to 50 mm, in which the catalyst still exists as am onomer,h ad little impacto nt he observed NMR yield (76 vs 83 %, entries 1v s1 3).…”

“…To gain evidence for anion‐binding, we measured binding constants ( K a ) for disiloxanediols 1 a , 1 b , and 1 f using 1 H NMR titration with tetrabutylammonium chloride ( n Bu 4 NCl) (Table ), following previously reported procedures . Upon addition of n Bu 4 NCl, a significant downfield silanol chemical shift was observed for all disiloxanediols (see the Supporting Information), providing evidence for a favorable formation of a receptor–anion complex between the silanol and chloride anion in solution.…”

Anion coordination chemistry using O–H groups

“…27) containing two silicon atoms and two hydroxy groups was able to bind anions in CDCl3 and CD3CN, and the disiloxane tetrols 73 and 74 showed high binding affinities in CD3CN (Ka > 10 3 M -1 ). 84,85 A downside of receptors 72-74 is that they are susceptible to base-induced condensation to form polysiloxanes, so binding of acetate could not be determined. Subsequently, Kondo reported an anion sensor 75, which contains two pyrene motifs attached to a silanediol core.…”

Theoretical and experimental study of organic nano-material for acetate anion based on 1, 10-phenanthroline

“…The above observations suggested the solvent, hydrogen-bond donor, destroyed the binding between compound 1 and AcO -and also demonstrated the binding between host and guest was hydrogenbond interaction in essence. 34,35 The addition of F -also induced the spectral change of compound 1, however the spectral change was not as sensitive as the addition of acetate ion (Fig. 4).…”