Premium
Controlling Nucleation and Crystal Growth of a Distinct Polyoxovanadate Cluster: An In Situ Energy Dispersive X‐ray Diffraction Study under Solvothermal Conditions
Author(s) -
Antonova Elena,
Seidlhofer Beatrix,
Wang Jing,
Hinz Michael,
Bensch Wolfgang
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201202107
Subject(s) - piperazine , crystallization , amine gas treating , nucleation , chemistry , crystallography , nuclear chemistry , organic chemistry
The formation of the antimonato polyoxovanadates [V 14 Sb 8 (C 6 H 15 N 3 ) 4 O 42 (H 2 O)] ⋅ 4H 2 O ( 1 ), (C 6 H 17 N 3 ) 2 [V 15 Sb 6 (C 6 H 15 N 3 ) 2 O 42 (H 2 O)] ⋅ 2.5H 2 O ( 2 ), {C 6 H 15 N 3 } 4 [V 16 Sb 4 O 42 ] 2H 2 O ( 3 ) (C 6 H 15 N 3 =1‐(2‐aminoethyl)piperazine, AEP) has been studied under solvothermal conditions by using in situ energy dispersive X‐ray diffraction (EDRXD). The syntheses were performed with an identical ratio for Sb 2 O 3 and NH 4 VO 3 . If the reactions slurries are not stirred during the solvothermal reaction and by applying 70–75 % amine concentration, the products contain all three compounds, whereas 3 is observed at 80 %. Under stirring conditions, variation of the concentration of AEP led to crystallization of the three different compounds at distinct concentrations, that is, 1 is formed at 75 %, 1 and 2 between 75 and 80 % and 3 at 80 %. At an amine concentration of 77.5 %, first reflections of 2 occurred and at later stages, compound 1 started to crystallize. The sample with the lowest number of V IV species was formed at the lowest amine concentration, whereas crystallization of 3 required the highest concentration. The formation of the compounds occurred without crystalline intermediates and/or precursors. With increasing reaction temperature, the incubation time was significantly reduced.