Open AccessDefect {(WVIO7)WVI4} and Full {(WVIO7)WVI5} Pentagonal Units as Synthons for the Generation of Nanosized Main Group V Heteropolyoxotungstates
Author(s) -
Elias Tanuhadi,
Nadiia I. Gumerova,
Alexander Roller,
Andreas Mautner,
Annette Rompel
Publication year - 2021
Publication title -
inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 233
eISSN - 1520-510X
pISSN - 0020-1669
DOI - 10.1021/acs.inorgchem.1c00810
Subject(s) - isostructural , chemistry , x ray photoelectron spectroscopy , crystallography , spectroscopy , thermogravimetric analysis , metal , catalysis , x ray crystallography , crystal structure , nuclear chemistry , analytical chemistry (journal) , diffraction , physics , nuclear magnetic resonance , organic chemistry , quantum mechanics , biochemistry , chromatography , optics
We report on the synthesis and characterization of three new nanosized main group V heteropolyoxotungstates K x Na y [H 2 (XW VI 9 O 33 )(W VI 5 O 12 )(X 2 W VI 29 O 103 )]· n H 2 O {X 3 W 43 } ( x = 11, y = 16, and n = 115.5 for X = Sb III ; x = 20, y = 7, and n = 68 for X = Bi III ) and K 8 Na 15 [H 16 (Co II (H 2 O) 2 ) 0.9 (Co II (H 2 O) 3 ) 2 (W VI 3.1 O 14 )(Sb III W VI 9 O 33 )(Sb III 2 W VI 30 O 106 )(H 2 O)]·53H 2 O {Co 3 Sb 3 W 42 } . On the basis of the key parameters for the one-pot synthesis strategy of {Bi 3 W 43 } , a rational step-by-step approach was developed using the known Krebs-type polyoxotungstate (POT) K 12 [Sb V 2 W VI 22 O 74 (OH) 2 ]·27H 2 O {Sb 2 W 22 } as a nonlacunary precursor leading to the synthesis and characterization of {Sb 3 W 43 } and {Co 3 Sb 3 W 42 } . Solid-state characterization of the three new representatives {Bi 3 W 43 } , {Sb 3 W 43 } , and {Co 3 Sb 3 W 42 } by single-crystal and powder X-ray diffraction (XRD), IR spectroscopy, thermogravimetric analysis (TGA), energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and elemental analysis, along with characterization in solution by UV/vis spectroscopy shows that {Bi 3 W 43 } , {Sb 3 W 43 } , and {Co 3 Sb 3 W 42 } represent the first main group V heteropolyoxotungstates encapsulating a defect {(W VI O 7 )W VI 4 } ( {X 3 W 43 } , X = Bi III and Sb III ) or full {(W VI O 7 )W VI 5 } ( {Co 3 Sb 3 W 42 } ) pentagonal unit. With 43 tungsten metal centers, {X 3 W 43 } (X = Bi III and Sb III ) are the largest unsubstituted tungstoantimonate- and bismuthate clusters reported to date. By using time-dependent UV/vis spectroscopy, the isostructural representatives {Sb 3 W 43 } and {Bi 3 W 43 } were subjected to a comprehensive study on their catalytic properties as homogeneous electron-transfer catalysts for the reduction of K 3 [Fe III (CN) 6 ] as a model substrate revealing up to 5.8 times higher substrate conversions in the first 240 min (35% for {Sb 3 W 43 } , 29% for {Bi 3 W 43 } ) as compared to the uncatalyzed reaction (<6% without catalyst after 240 min) under otherwise identical conditions.