4th EucheMs chemistry congress

thursday, 30-Aug 2012
s697
chem. Listy 106, s587–s1425 (2012)
inorganic Chemistry plus Young inorganic chemistry day
Young inorganic chemistry day – i
o - 4 4 5
noBLe MetALS – ContAininG
PoLyoxoMetALAteS
n. izArovA 1 , u. Kortz 1
1 Jacobs University, School of Engineering and Science,
Bremen, Germany
Polyoxometalates (POMs) [1] containing noble metals, in
particular palladium and platinum, have gained special attention
over the last years. [2-4] Incorporation of noble metal ions in POM
frameworks allows keeping the former soluble in aqueous or
organic media and at the same time encapsulated in a fully
inorganic, thermally and redox stable metal-oxo matrix. Such
features offer a distinct advantage over noble metal coordination
complexes displaying a set of organic ligands or organometallic
moieties, susceptible to oxidative degradation.
Here we report on a novel series of PdII containing
polyoxotungstates based on the monolacunary Keggin-type
[Pd (α-XW O ) ] 2 11 39 2 n- (X = PV , n = 10; [5] X = SiIV , GeIV , n = 12) and
Dawson-type [Pd (α -P W O ) ] 2 2 2 17 61 2 16- [5] polyanions comprising two
POM ligands linked via two PdII centers in square-planar
coordination environment. Several structural isomers vary by
relative orientation of POM ligands have been isolated. The
stability of the PdII containing POMs in both aqueous and organic
solutions has been investigated using 31P and 183W NMR
spectroscopy. The PtII analogue [Pt (α-PW O ) ] 2 11 39 2 10- has also been
prepared and characterized in the solid state and solution whereas
reaction of [α-PW O ] 11 39 7- with PtIV led to rather unexpected
products.
references:
1. Pope M.T., Heteropoly and Isopoly Oxometalates;
Springer-Verlag: Berlin, 1983.
2. Putaj P., Lefebvre F., Coord. Chem. Rev. 2001, 255,
1642–1685.
3. Lee U., Joo H.-C., Park K.-M., Mal S.S., Kortz U., Keita
B., Nadjo L., Angew. Chem. Int. Ed. 2008, 47, 793–796.
4. Izarova N.V., Vankova N., Banerjee A., Jameson G.B.,
Heine T., Schinle F., Hampe O., Kortz U., Angew. Chem.
Int. Ed. 2010, 49, 7807–7811.
5. Izarova N.V., Banerjee A., Kortz U., Inorg. Chem. 2011,
50, 10379–10386.
Keywords: Polyoxometalates; Noble metals; Palladium;
Platinum; NMR;
Young inorganic chemistry day – i
4 th EucheMs chemistry congress
o - 4 4 6
PoMziteS: A new CLASS of MiCroPorouS
inorGAniC frAMeworKS froM A MiniMAL
BuiLdinG BLoCK LiBrAry
t. Boyd 1 , S. MitCheLL 1 , d. GABB 1 , d. LonG 1 ,
L. Cronin 1
1 University of Glasgow, School of Chemistry, Glasgow, United
Kingdom
Email: Lee.Cronin@glasgow.uk
The crown-type heteropolyanion, [P W O ] 8 48 184 40- (hereafter
referred to as {P W }) is notable for several properties including
8 48
its high-negative charge, nanometer-sized cavity and remarkable
electrochemistry. [1] Its inherent pore space means {P W } is an
8 48
ideal candidate as a network synthon, to prepare open framework
materials with microporosity. [2] The preparation of such
“POMzite” materials, and open frameworks with designed
topologies in general, requires control of two main factors;
statistics (molar ratios of the components) and geometry
(transition metal coordination modes). Recently, such structures
have been prepared by introducing first row transition metals to
aqueous solutions of {P W }, however the desired control in
8 48
preparing {P W }-based porous frameworks remains a challenge.
8 48
In the case of {P W } assemblies, framework extension is
8 48
highly dependent on experimental conditions such as pH,
temperature and the presence of secondary cations. To understand
this, and crucially to manipulate it in the formation of targeted
networks, the binding properties of {P W } were investigated
8 48
revealing crown ether-like behaviour of the {P W } ring. 8 48 [3]
Mapping the binding sites around the ring has enabled structural
classification and comprehensive topological analysis, shedding
light on a fascinating class of porous materials. Among many
desirable properties, POMzite materials have shown remarkable
single-crystal to single-crystal transformations, tunable and
gateable guest uptake dependent on the redox state of the
framework, and great potential as radioactive sequestrants. [2]
references:
1. R. Contant, A. Tézé, Inorg. Chem., 1985, 24, 4610-4614.
2. S. G. Mitchell, C. Streb, H. N. Miras, T. Boyd, D.-
L. Long, L. Cronin, Nat. Chem., 2010, 2, 308–312.
3. T. Boyd, S. G. Mitchell, D. Gabb, D.-L. Long, L. Cronin,
Chem. Eur. J., 2011, 17, 12010-12014.
Keywords: Polyoxometalates; Supramolecular chemistry;
Microporous materials;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc