Page 54 - Annual Report_21-22

spectra, one at 464 nm and another at 271 nm. In the MO. However, no degradation for the MO was observed
presence of the W O cluster compound under UV light, under the sunlight and visible light in the presence of
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6
both the peaks in UV-Visible spectra got vanished after W O cluster material.
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6
120 minutes showing the complete degradation of the

Figure: Structure and colour of Methyl Orange.

DMF
Na2WO4 + Acetic Anhydride W6O19
HCl
100 C
o
Scheme 1: Synthesis of W6O19 cluster material.

Figure: UV-Visible Spectra of MO (black), W O (red), and W O in MO (blue) (left); Colour of the solutions (MO,
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W O , and W O in MO) before and after UV exposure for 120 minutes (right).
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Development of phosphonium hexatungstate complexes
The reaction of sodium tungstate with tetramethyl- methyltriphenyl-, allyltriphenyl-, butyltriphenyl- and
and tetrabutyl-phosphonium bromide in the benzyltriphenyl-phosphonium bromides to yield four
presence of hydrochloric acid afforded phosphonium phosphonium hexatungstate compounds (CH Ph P) W O ,
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2
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3
3
hexatungstate compounds ((CH ) P) W O 19 and (CH CHCH Ph P) W O , (CH CH CH CH Ph P) W O ,
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19
2
3
2
2
3
2
2
6
19
3
2
6
2
3 4
2
((CH CH CH CH ) P) W O , respectively (Figure). Under and (C H CH Ph P) W O 19 respectively.
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6
2
2
3
2
2
2 4
3
5
2
6
similar conditions, sodium tungstate reacted with
Figure: Single crystal X-Ray diffraction structures of ((CH ) P) W O , ((CH CH CH CH ) P) W O , and (CH Ph P) W O .
2
2
2
19
6
6
2
19
3
6
2
2 4
3 4
3
19
3
52 ANNUAL REPORT 2021-22