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In chemistry, a polyoxometalate (abbreviated POM) is a polyatomic ion, usually an anion, that consists of three or more transition metal oxyanions linked together by shared oxygen atoms to form closed 3-dimensional frameworks. The metal atoms are usually group 6 (Mo, W) or less commonly group 5 (V, Nb, Ta) and group 7 (Tc, Re) transition metals ...
Monocryl has a low tissue reactivity, maintains high tensile strength, and has a half-life of 7 to 14 days. At 1 week, its in vivo tensile strength is at 50–60% undyed (60–70% dyed), 20–30% undyed (30–40% dyed) at two weeks, and essentially completely hydrolyzed by 91–119 days. [3]
A transition metal oxo complex is a coordination complex containing an oxo ligand. Formally O 2–, an oxo ligand can be bound to one or more metal centers, i.e. it can exist as a terminal or (most commonly) as bridging ligands. Oxo ligands stabilize high oxidation states of a metal. [1]
Tungsten(VI) oxide, also known as tungsten trioxide is a chemical compound of oxygen and the transition metal tungsten, with formula WO 3. The compound is also called tungstic anhydride , reflecting its relation to tungstic acid H 2 WO 4 .
The metal ratio in such compounds can vary over a broad range. For instance, the substitution of molybdenum and tungsten for rhenium in the complexes Re 4 O 6−y (OCH 3) 12+y allowed one to obtain complexes Re 4−x Mo x O 6−y (OCH 3) 12+y in the range 0 ≤ x ≤ 2.82 and Re 4−x W x O 6−y (OCH 3) 12+y in the range 0 ≤ x ≤ 2.
The oxide ion has an ionic radius of 1.40 Å, molybdenum(VI) is much smaller, 0.59 Å. [1] There are strong similarities between the structures of the molybdates and the molybdenum oxides, ( MoO 3 , MoO 2 and the " crystallographic shear " oxides, Mo 9 O 26 and Mo 10 O 29 ) whose structures all contain close packed oxide ions.
Aliphatic metal alkoxides decompose in water as summarized in this idealized equation: Al(OR) 3 + 3 H 2 O → Al(OH) 3 + 3 ROH. In the transesterification process, metal alkoxides react with esters to bring about an exchange of alkyl groups between metal alkoxide and ester. With the metal alkoxide complex in focus, the result is the same as for ...
Lithium oxide (Li 2 O) is the lightest alkali metal oxide and a white solid. It melts at 1570 °C. Sodium oxide (Na 2 O) is a white solid that melts at 1132 °C and decomposes at 1950 °C. It is a component of glass. Potassium oxide (K 2 O) is a pale yellow solid that decomposes at 350 °C. Rubidium oxide (Rb 2 O) is a yellow solid that melts ...