In:
Zeitschrift für anorganische und allgemeine Chemie, Wiley, Vol. 635, No. 13-14 ( 2009-11), p. 2302-2308
Abstract:
Four new inorganic‐organic hybrid polyoxometalate compounds based on the {Mo 6 P 4 } unit have been hydrothermally synthesized from the reaction of MoO 3 , Co(CH 3 COO) 2 · 4H 2 O, triethylenetetramine (TETA) and 50 % phosphorus acid, and characterized by IR, TG, ICP and single‐crystal X‐ray diffraction. Compound 1 (H 4 TETA) 2 [(Co II TREN) 2 Co II Mo V 12 P 8 O 52 (OH) 10 ] · 4H 2 O [TREN = tris(2‐aminoethyl)amine], which is obtained at pH = 8.9, represents a {Mo 6 P 4 } unit supported transition metal complex, in which the Co II atom is pentacoordinate by four nitrogen atoms from TREN and one oxygen atom from PO 4 tetrahedron, and the other Co II atom joins two {Mo 6 P 4 } units together to form a dimer by sharing six μ 3 ‐O atoms. Compound 2 (H 4 TETA) 2 (C 6 H 18 N 3 ) 2 [Co II Mo V 12 P 8 O 54 (OH) 8 ] · 5H 2 O [C 6 H 15 N 3 = N ‐(2‐aminoethyl)piperazine] obtained at pH = 6.4 shows a dimer anion [Co II Mo V 12 P 8 O 54 (OH) 8 ] 14– , two fully protonated TETA and two protonated N ‐(2‐ A minoethyl)piperazine. Compounds 3 [H 4 TREN] 4 [Co II Mo V 12 P 8 O 56 (OH) 6 ] · 4H 2 O and 4 [H 4 TETA] 2 [Co II Mo V 12 P 8 O 48 (OH) 14 ] · 4H 2 O obtained from lower pH conditions (4.5 for 3 and 3.1 for 4 ) exhibit the same dimer anion as compound 2 only different cations. As the secondary building unit, the discrete dimer anions in compound 1 – 4 and the TETA (or its derivatives) construct 3D structures by hydrogen bonding interaction. The guest water molecules are filled in the channels, and also involved in the hydrogen bonding with oxygen atoms from inorganic‐organic hybrid framework, which makes the structures more stable. The catalytic properties of the four compounds are also tested in the styrene oxidation with H 2 O 2 .
Type of Medium:
Online Resource
ISSN:
0044-2313
,
1521-3749
DOI:
10.1002/zaac.v635:13/14
DOI:
10.1002/zaac.200801336
Language:
English
Publisher:
Wiley
Publication Date:
2009
detail.hit.zdb_id:
201094-X
detail.hit.zdb_id:
1481139-X
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