Linked Life Data

19156274

Source:http://linkedlifedata.com/resource/pubmed/id/19156274

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2009-1-21
pubmed:abstractText
The syntheses and structures of hafnium(iv) and zirconium(iv) complexes with Keggin tri-lacunary polyoxometalates (POM) [A-alpha-PW(9)O(34)](9-), i.e., (Et(2)NH(2))(7)H(2)[Hf(3)(micro-OH)(3)(A-alpha-PW(9)O(34))(2)].11H(2)O (Et(2)NH(2)-) and (Et(2)NH(2))(7)H(2)[Zr(3)(micro-OH)(3)(A-alpha-PW(9)O(34))(2)].12H(2)O (Et(2)NH(2)-) are described. The two POMs, Et(2)NH(2)- and Et(2)NH(2)-, were obtained as analytically pure, colorless crystals in 30.0 and 40.9% yields, respectively, by 1:3-molar ratio reactions of [A-PW(9)O(34)](9-) with Hf(SO(4))(2) and Zr(SO(4))(2), respectively, in aqueous solutions at 80-90 degrees C, followed by refluxing. The two POMs were characterized by elemental analysis, TG/DTA, FTIR, solution ((31)P and (183)W) NMR and X-ray crystallography. X-Ray structure analysis of Et(2)NH(2)- revealed that in polyoxoanion , the three 6-coordinate prismatic Hf(IV) ions linked with the three bridging OH groups, i.e., the [Hf(3)(micro-OH)(3)](9+) cluster cation was sandwiched between two alpha-Keggin tri-lacunary POMs. The molecular structure of was isostructural with that of polyoxoanion in Et(2)NH(2)-. X-Ray crystallography also showed that the crude crystals of Et(2)NH(2)- and Et(2)NH(2)-, which were first formed without refluxing, contained the two isomeric crystalline species in a 7:3 ratio with the alpha,alpha- and alpha,beta-junctions of the two Keggin tri-lacunary POMs. These facts were also confirmed by (31)P NMR in D(2)O. By refluxing the solutions containing the crude crystals, only the alpha,alpha-isomers of Et(2)NH(2)- and Et(2)NH(2)- were finally isolated.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1477-9226
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
805-13
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Sandwich-type Hf(IV) and Zr(IV)complexes composed of tri-lacunary Keggin polyoxometalates: structure of [M(3)(mu-OH)(3)(A-alpha-PW(9)O(34))(2)](9-) (M = Hf and Zr).
pubmed:affiliation
Department of Materials Science, Faculty of Science, Kanagawa University, Hiratsuka, Kanagawa 259-1293, Japan.
pubmed:publicationType
Journal Article