| Autor: |
Pal A; School of Science, Constructor University, Campus Ring 1, Bremen 28759, Germany., Bhattacharya S; School of Science, Constructor University, Campus Ring 1, Bremen 28759, Germany.; Department of Chemistry, BITS Pilani K. K. Birla Goa Campus, Zuarinagar 403726 Goa, India., Ma X; School of Science, Constructor University, Campus Ring 1, Bremen 28759, Germany.; Fujian Provincial Key Laboratory of Advanced Inorganic Oxygenated Materials, College of Chemistry, Fuzhou University, Fuzhou 350108 Fujian, China., Ben Kiran A; Department of Chemistry, Supramolecular Organic and Organometallic Chemistry Centre (SOOMCC), Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, 11 Arany Janos, Cluj-Napoca 400028, Romania., Silvestru C; Department of Chemistry, Supramolecular Organic and Organometallic Chemistry Centre (SOOMCC), Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, 11 Arany Janos, Cluj-Napoca 400028, Romania., Kortz U; School of Science, Constructor University, Campus Ring 1, Bremen 28759, Germany. |
| Abstrakt: |
We report on the synthesis and structural characterization of six novel arylarsonate-containing polyoxomolybdates with fluorinated-functionalities in the para position of the phenyl ring. The reaction of the various arylarsonic acids, RAsO 3 H 2 [ R = 4-F-C 6 H 4 (H 2 L F ), 4-F 3 C-C 6 H 4 (H 2 L CF3 ), 4-F 3 CO-C 6 H 4 (H 2 L OCF3 )] with Na 2 MoO 4 ·2H 2 O in aqueous pH 3 solution resulted in the heteropoly-6-molybdates [{(4-F-C 6 H 4 )As} 2 Mo 6 O 24 (H 2 O)] 4- ( 1 ), [{(4-F 3 C-C 6 H 4 )As} 2 Mo 6 O 24 ] 4- ( 2 ) and [{(4-F 3 CO-C 6 H 4 )As} 2 Mo 6 O 24 (H 2 O)] 4- ( 3 ), which were isolated as guanidinium salts. When the reaction was performed in aqueous pH 1 solution the inverted-Keggin type heteropoly-12-molydates [{(4-F-C 6 H 4 )As} 4 Mo 12 O 46 ] 4- ( 4 ), [{(4-F 3 C-C 6 H 4 )As} 4 Mo 12 O 46 ] 4- ( 5 ) and [{(4-F 3 CO-C 6 H 4 )As} 4 Mo 12 O 46 ] 4- ( 6 ), were obtained and isolated as sodium salts. The 6-molybdates 1 - 3 and the 12-molybdates 4 - 6 can be easily interconverted reversibly in solution as a function of pH (3 vs 1). Polyanions 1 and 3 are isostructural and they exhibit a bent hexamolybdate ring, whereas the ring is flat for 2 . The inverted-Keggin polyanions 4 - 6 are isostructural and the metal-oxo core is capped by four arylarsonate groups. All six polyanions have been characterized in the solid state by single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, and hermogravimetric analysis as well as in solution by multinuclear NMR ( 1 H, 19 F). The synthetic procedures for the arsonic acids (4-F 3 C-C 6 H 4 )AsO 3 H 2 (H 2 L CF3 ) and (4-F 3 CO-C 6 H 4 )AsO 3 H 2 (H 2 L OCF3 ) are reported for the first time. |
