A series of novel yttrium- and lanthanide-containing heteropolyoxopalladates have been prepared and isolated as hydrated sodium salts, Na(5)[X(III)Pd(II)(12)(AsPh)(8)O(32)]y H(2)O (X=Y (1), Pr (2), Nd (3), Sm (4), Eu (5), Gd (6), Tb (7), Dy (8), Ho (9), Er (10), Tm (11), Yb (12), Lu (13); y=15-27). The polyanions [X(III)Pd(II)(12)(AsPh)(8)O(32)](5-) consist of a cuboid framework of twelve Pd(II) ions with eight phenylarsonate heterogroups located at the vertices and a central guest ion X. The compounds 1-13 have been prepared in a simple one-pot self-assembly reaction of Pd(CH(3)COO)(2), phenylarsonic acid and the respective salt of the element X in 0.5 M aqueous sodium acetate solution (pH 6.9), and characterized in the solid state by single-crystal X-ray diffraction, elemental and thermogravimetric (TGA) analyses, and IR spectroscopy. It was demonstrated that small, medium, and also large lanthanide ions can be incorporated in the center of the novel heteropolypalladate [X(III)Pd(II)(12)(AsPh)(8)O(32)](5-). The Ln-O bond lengths follow the expected trend decreasing from left to right in the lanthanide series. This indicates that the {Pd(II)(12)O(32)} shell can adjust to the coordination requirements of the encapsulated guest cation. Compounds 3 and 5 were selected for electrochemical studies. Their cyclic voltammetry in a lithium acetate buffer at pH 5.9 showed a Pd(0) deposition process on the glassy carbon electrode surface. Coulometry indicated that all Pd(II) centers were reduced to Pd(0). The film was stable and could be taken out of the deposition medium and characterized in pure pH 5.9 buffer. Magnetic susceptibility and EPR measurements were carried out on 5 and 6. The former was confirmed to be diamagnetic and the latter strongly paramagnetic with a S=7/2 ground state. DFT calculations for some of the polyoxometalates have been also performed.

Selective oxidation of betulin to biologically active betulinic aldehyde is demonstrated for the first time over Ru/C catalyst mixed with a basic hydrotalcite and using SiO 2 as a dehydrating agent in synthetic air at 108 8C in toluene with conversion of 41 % in 24 h and 67 % selectivity to betulinic aldehyde, whereas without SiO 2 with Ru/C the corresponding conversion and selectivity values were 20 % and 66 %, respectively. Over another, acidic Ru/C catalyst even higher conversion was achieved, giving, however, allobetulin as a main product. These results indicate that basicity and absence of water are crucial for selective botulin oxidation over Ru catalysts. The conversion levels are comparative with the results in the oxidation of hydroxymathylfurfural, which contains a hydroxymethyl group attached to the heterocyclic ring.Pharmaceuticals are conventionally synthesized in multistep procedures using several organic solvents and stoichiometric reagents, therefore the E-factor, i. e. the amount of waste per formed product is very high. [1] Currently there is a high interest to develop more environmentally friendly methods for production of pharmaceuticals, moreover starting the synthesis from naturally occurring compounds. A potential compound for medical applications is betulin, which is present in the bark of some tree species, such as Betula sp. [2,3] Betulinic acid is present in birch bark or cork of cork oak (Quercus suber L.) and can be isolated and extracted, [2] whereas the stem bark of Tectona grandis contains betulinic aldehyde. [4] In this work betulin oxi-dation was investigated using heterogeneous catalysts and air as an oxidant (Figure 1).Oxidation of betulin produces both betulonic and betulinic aldehydes and acids, respectively, as products ( Figure 1). Betulinic acid has been conventionally prepared from betulin in socalled Jones oxidation process using Cr 2 O 3 as an oxidant. The formed betulonic acid can be reduced to betulinic acid with NaBH 4 in tetrahydrofuran. [18] Betulinic acid was also synthesized via oxidation of betulin using Keggin type tungstophosphoric acid together with potassium dichromate between 15-35 8C during 60 to 240 min giving betulonic acid, which is reduced to betulinic acid with NaBH 4 in an organic solvent. [19] TEMPO (2,2,6,6-teramethylpiperidine -oxyl) catalyst has also been used in the oxidation of betulin to betulinic acid with iodine or (diacetoxyiodo)benzene DIB as oxidants. 2 Furthermore, a high isolated yield of betulinic acid (86 %) was achieved, using 4-acetamido-TEMPO as a catalyst together with NaClO 2 /NaOCl at 50 8C. [20] The above-mentioned betulin derivatives exhibit several biological and medicinal properties. [5][6][7][8][9][10][11][12][13][14][15][16][17] Several examples were given from betulin oxidation with homogeneous catalysts, e. g. RuCl 2 (PPh 3 ) 3 and TEMPO as a cocatalyst in oxygen at 1 atm and 105 8C giving 15 % yield of betulinic aldehyde at 17 % conversion in 27 h and in 8 h at 100 8C under 8 bar 69 % of betulinic aldehyde, respectively...

The yttrium containing isopolytungstate [YW10O36]9− (1) has been synthesized and isolated in the form of its hydrated sodium salt Na9[YW10O36]·35H2O (Na‐1). The title compound has been structurally characterized in the solid state by single‐crystal X‐ray crystallography, IR spectroscopy, thermogravimetric analysis and in solution by 183W and 89Y NMR spectroscopy. The X‐ray analysis shows that Na‐1 crystallizes in the triclinic system, space group $P{\bar 1}$, with a = 12.7625(9), b = 13.0825(10), c = 20.496(2) Å, α = 82.856(5), β = 74.520(4), γ = 88.822(4)°, V = 3272.1(4) Å3 and Z = 2. Solution 183W NMR shows the expected 2 lines at –1.3 ppm and –14.3 ppm, respectively, with an intensity ratio of 1:4, and 89Y NMR shows a singlet at –12.9 ppm.

Aqueous reaction of (CH3)2SnCl2 with Na9[A‐α‐PW9O34] in a 3:1 ratio with [C(NH2)3]+ as structure‐directing agent resulted in three distinct assemblies of dimethyltin‐functionalized tungstophosphates depending on the pH: [{(CH3)2Sn(H2O)}{(CH3)2Sn}(A‐α‐PW9O34)]5– (1) at pH = 4.5; [{(CH3)2Sn(H2O)2}{(CH3)2Sn(H2O)}2(A‐α‐PW9O34)]3– (2) at pH = 3.0; and [{(CH3)2Sn(H2O)}3(A‐α‐PW9O34)]3– (3) at pH = 2.0. All three compounds have been characterized in the solid‐state by elemental and thermal analyses, infrared spectroscopy and single‐crystal X‐ray diffraction. The [A‐α‐PW9O34]9–trilacunary fragments have three {(CH3)2Sn}2+ groups anchored on the vacant sites via two Sn–O(W) bonds each and they are linked into guanidinium‐templated, extended architectures with dimensionalities increasing with the acidity of the reaction media. The structure of 1 consists of a 1‐dimensional arrangement of alternating [A‐α‐PW9O34]9– subunits and trans‐(CH3)2SnO4 bridging moieties, whereas compounds 2 and 3 are 2‐ and 3‐dimensional assemblies, respectively, of monomeric [{(CH3)2Sn}3(A‐α‐PW9O34)]3– building blocks connected via weak intermolecular Sn–O=W bridges.

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