Fluorinated antimony(v) derivatives: strong Lewis acidic properties and application to the complexation of formaldehyde in aqueous solutions

Abstract

Lewis acidic fluorinated organoantimony(v) derivatives have been combined with phosphines for the complexation and colourimetric sensing of formaldehyde in biphasic water/CH2Cl2 mixtures.

Interaction between Spirosilanes and Lewis Bases: from Coordination to Frustration

“…Unfortunately,t he Lewis acidp artners 1 and even more acidic 4 provedt ob ei nefficient for the activation of H 2 and CO 2 in the presence of hindered bases. Nevertheless, activation of formaldehyde [20] was possible with the sterically encumbered IPr NHC and triisopropylphosphine. In these cases,t he three-componentz witterionic adducts 7-10 could be isolated (Scheme 7).…”

Activation of an Au−Cl Bond by a Pendent SbIII Lewis Acid: Impact on Structure and Catalytic Activity

“…The short Sb−P separation, along with the contracted Sb‐C(1)‐C(6) and P‐C(6)‐C(1) angles of 114.4(2)° and 113.7(2)° along the ortho ‐phenylene backbone suggest significant donation from the phosphine group into a Sb−Cl σ* orbital. Altogether, the core structure of L Cl is close to that of ( o ‐(PPh 2 )C 6 H 4 )Sb( o ‐O 2 C 6 Cl 4 )(C 6 H 5 ) 2 , a compound featuring a P→Sb interaction of 3.0268(12) Å . The stibine moiety of L Cl engages a neighboring stibine in a short intermolecular Sb−Cl contact of 3.261(2) Å, further demonstrating the Lewis acidity of the dichloroarylstibine functionality.…”

“…Sb interaction of 3.0268 (12) . [11] The stibine moiety of L Cl engages an eighboring stibine in as hort intermolecular SbÀCl contact of 3.261(2) ,f urther demonstrating the Lewis acidity of the dichloroarylstibine functionality.S imilar short intermolecular contacts are observed in the solid state structures of the related RSbCl 2 species PhSbCl 2 (SbÀCl ' = 3.443(2) ) [12] and p-tolylSbCl 2 (SbÀCl' = 3.433 (2) ). [13] In order to probe how the antimony-bound chloride ligands affect the ligand characteristics and coordination behavior of L Cl ,t he knownt riarylstibine derivative (o-(PPh 2 )C 6 H 4 )SbPh 2 [14] (L Ph ), was also structurally characterized ( Figure 1).…”

Nitrenium Salts in Lewis Acid Catalysis

“…Traditional examples of main-group Lewis acid catalysts involve group 13 and 14 elements as the central locus of reactivity,a stheyf eature al ow-lying orbital for substrate activation. [1] Over the last decade there has been increasing interest in studying pnictogens,o ften considered Lewis basic given the availability of an energetically accessible lone pair, in this unconventional role.T his work has been expanded to include compounds of phosphorus, [2][3][4][5][6][7][8][9][10][11] arsenic, [12] antimony, [13][14][15][16][17][18][19][20] and bismuth. [21][22][23] By contrast, the reactivity of nitrogen-containing compounds as Lewis acids has been investigated to am uch lesser extent, largely due to the dearth of such species.C hloramines,n itrenes,d iazocarboxylates,azides,and diazonium salts have been shown to possess N-centered electrophilic behavior.…”