Tris‐Functionalized Hybrid Anderson Polyoxometalates: Synthesis, Characterization, Hydrolytic Stability and Inversion of Protein Surface Charge. Issue 12 (10th February 2015)

• Record Type: Journal Article
• Authors: Blazevic, Amir; Al‐Sayed, Emir; Roller, Alexander; Giester, Gerald; Rompel, Annette
• Is Part Of: Chemistry. Volume 21:Issue 12(2015)
• Page Start: 4762
• Page End: 4771
• Publication Date: 2015-02-10
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201405644
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Single‐ and double‐sided functionalized hybrid organic–inorganic Anderson polyoxomolybdates with Ga<sup>III</sup> and Fe<sup>III</sup> positioned as central heteroatoms have been synthesized in a mild, two‐step synthesis in an aqueous medium. Compounds <bold>1</bold>–<bold>4</bold> were isolated as hydrated salts, [TBA]<sub>3</sub>[GaMo<sub>6</sub>O<sub>18</sub>(OH)<sub>3</sub>{(OCH<sub>2</sub>)<sub>3</sub>CCH<sub>2</sub>OH}]×12 H<sub>2</sub>O (<bold>1</bold>) (TBA=tetrabutylammonium), Na<sub>3</sub>[FeMo<sub>6</sub>O<sub>18</sub>{(OCH<sub>2</sub>)<sub>3</sub>CCH<sub>2</sub>OH}<sub>2</sub>]×11 H<sub>2</sub>O (<bold>2</bold>), [TMA]<sub>2</sub>[GaMo<sub>6</sub>O<sub>18</sub>(OH)<sub>3</sub>{(OCH<sub>2</sub>)<sub>3</sub>CNH<sub>3</sub>}]×7 H<sub>2</sub>O (<bold>3</bold>) (TMA=tetramethylammonium), and Na[TMA]<sub>2</sub>[FeMo<sub>6</sub>O<sub>18</sub>(OH)<sub>3</sub>{(OCH<sub>2</sub>)<sub>3</sub>CNH<sub>3</sub>}](OH)×6 H<sub>2</sub>O (<bold>4</bold>). All the compounds were characterized based on single‐crystal X‐ray diffraction (SXRD), FTIR, UV/Vis, thermogravimetric, ESI‐MS, NMR, and elemental analyses. Compound <bold>1</bold> was also crystallized with two smaller organic cations, giving [TMA]<sub>3</sub>[GaMo<sub>6</sub>O<sub>18</sub>(OH)<sub>3</sub>{(OCH<sub>2</sub>)<sub>3</sub>CCH<sub>2</sub>OH}]×<italic>n</italic> H<sub>2</sub>O (<bold>5</bold>) and [GDM]<sub>3</sub>[GaMo<sub>6</sub>O<sub>18</sub>(OH)<sub>3</sub>{(OCH<sub>2</sub>)<sub>3</sub>CCH<sub>2</sub>OH}]×<italic>n</italic> H<sub>2</sub>O (<bold>6</bold>) (GDM=guanidinium) and were characterized based on UV/Vis, NMR, FTIR, and elemental analyses. The use of these compounds as additives in macromolecular crystallography was investigated by examining their hydrolytic stability by using ESI‐MS in a pH range of 4 to 9. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) analysis showed that BSA remains intact in a solution containing up to 100 equivalents of <bold>1</bold> or <bold>4</bold> over more than four days at 20 °C. Zeta potential measurements demonstrate that <bold>1</bold>–<bold>4</bold> induce charge inversions on the positively charged surface of BSA (1 mg mL<sup>−1</sup>) with concentrations starting as low as 1.29 m<sc>M</sc> for compounds <bold>1</bold> and <bold>2</bold>, which have the highest negative surface charge.</p> </abstract>