Question

Suggest possible solid state precursors for the formation of the following compounds by pyrolysis reactions: (a) \(\mathrm{BiCaVO}_{5} ;(\mathrm{b})\) the Mo(VI) oxide \(\mathrm{CuMo}_{2} \mathrm{YO}_{8}\) (c) \(\mathrm{Li}_{3} \ln \mathrm{O}_{3} ;(\mathrm{d}) \mathrm{Ru}_{2} \mathrm{Y}_{2} \mathrm{O}_{7}\)

Short answer

Possible precursors are oxides and carbonates matching the elements in each compound.

Step-by-step solution

Understanding Solid State Precursors

In solid-state reactions, precursors are compounds that supply the necessary elements for the formation of the desired compound through pyrolysis. In this step, we identify potential precursors based on the elements present in each target compound.

Determine Precursors for BiCaVO5

The compound, \(\mathrm{BiCaVO}_{5}\), requires bismuth, calcium, vanadium, and oxygen. Possible precursors include \(\mathrm{Bi}_{2}\mathrm{O}_{3}\) (bismuth oxide) for bismuth, \(\mathrm{CaCO}_{3}\) (calcium carbonate) for calcium, \(\mathrm{V}_{2}\mathrm{O}_{5}\) (vanadium pentoxide) for vanadium, and the inclusion of oxygen will be maintained through oxides.

Determine Precursors for CuMo2YO8

The compound, \(\mathrm{CuMo}_{2} \mathrm{YO}_{8}\), requires copper, molybdenum, yttrium, and oxygen. Appropriate precursors are \(\mathrm{CuO}\) (copper oxide) for copper, \(\mathrm{MoO}_{3}\) (molybdenum trioxide) for molybdenum, \(\mathrm{Y}_{2}\mathrm{O}_{3}\) (yttrium oxide) for yttrium, combined to ensure adequate oxygen.

Determine Precursors for Li3InO3

For the compound, \(\mathrm{Li}_{3} \mathrm{InO}_{3}\), lithium, indium, and oxygen are required. Suitable precursors include \(\mathrm{Li}_{2}\mathrm{CO}_{3}\) (lithium carbonate) for lithium, \(\mathrm{In}_{2}\mathrm{O}_{3}\) (indium oxide) for indium, with oxygen retained through the oxides.

Determine Precursors for Ru2Y2O7

The compound, \(\mathrm{Ru}_{2}\mathrm{Y}_{2} \mathrm{O}_{7}\), requires ruthenium, yttrium, and oxygen. Potential solid-state precursors are \(\mathrm{RuO}_{2}\) (ruthenium dioxide) for ruthenium, \(\mathrm{Y}_{2}\mathrm{O}_{3}\) (yttrium oxide) for yttrium, ensuring oxygen included through these oxides.

Key concepts

pyrolysis reactions

Pyrolysis reactions are chemical processes where materials decompose under high temperatures without the presence of oxygen. This method is particularly useful for producing inorganic compounds in a solid-state form. When performing pyrolysis, the heat-induced decomposition of complex materials results in smaller molecules or even elements, which then combine to form new compounds. Pyrolysis is often utilized in solid-state chemistry to synthesize ceramics, oxides, and other complex compounds.
In the context of forming compounds like \(\text{BiCaVO}_5\), \(\text{CuMo}_2\text{YO}_8\), \(\text{Li}_3\text{InO}_3\), and \(\text{Ru}_2\text{Y}_2\text{O}_7\), pyrolysis involves selecting solid-state precursors that decompose to provide the necessary elements. For example, bismuth oxide \(\text{(Bi}_2\text{O}_3)\) and calcium carbonate \(\text{(CaCO}_3)\) can undergo pyrolysis. When heated, these compounds break down, release carbon dioxide or other by-products, and the leftover metals and oxygen are able to react to form complex structures. This process efficiently enables the production of pure and precise compound structures.

inorganic compounds

Inorganic compounds are primarily composed of elements outside the realm of organic (carbon-hydrogen based) chemistry. These commonly include metals, metal oxides, salts, and minerals. They are typically characterized by their ionic properties, high melting points, and stable crystalline structures.
In preparing compounds such as \(\text{BiCaVO}_5\), \(\text{CuMo}_2\text{YO}_8\), \(\text{Li}_3\text{InO}_3\), and \(\text{Ru}_2\text{Y}_2\text{O}_7\), the focus is on selecting the right inorganic precursors.

• Bismuth oxide \(\text{(Bi}_2\text{O}_3)\), used in \(\text{BiCaVO}_5\), is a typical oxide providing metallic ions and oxygen.
• Copper oxide \(\text{(CuO)}\) and molybdenum trioxide \(\text{(MoO}_3)\), supporting the formation of \(\text{CuMo}_2\text{YO}_8\).
• Lithium carbonate \(\text{(Li}_2\text{CO}_3)\), common for forming lithium-containing compounds such as \(\text{Li}_3\text{InO}_3\).
• Ruthenium dioxide \(\text{(RuO}_2)\) plays a major role in forming \(\text{Ru}_2\text{Y}_2\text{O}_7\).

Understanding the properties and behaviors of these compounds during pyrolysis is crucial to achieving precise chemical reactions in solid-state synthesis.

solid-state reactions

Solid-state reactions refer to chemical reactions between solids that occur at high temperatures. Unlike reactions in liquid or gaseous states, these reactions do not involve the movement or dissipation of the reactants in a solvent medium. They are necessary for forming compounds with a crystalline structure or high stability.
To prepare oxides like \(\text{BiCaVO}_5\), \(\text{CuMo}_2\text{YO}_8\), \(\text{Li}_3\text{InO}_3\), and \(\text{Ru}_2\text{Y}_2\text{O}_7\), solid-state reactions utilize precursors that must align correctly to produce the desired compound under elevated temperatures.

• Elements diffuse and merge during the reaction process.
• The compounds need to endure high heat to facilitate these reactions without melting.
• Resulting reactions usually yield robust, structured compounds vital in material science and technology.

The success of solid-state reactions largely depends on optimal temperature control and the physical arrangement of the precursors to ensure homogenous mixing and reaction.

chemical elements in compounds

Chemical elements are the fundamental components of compounds. Each element contributes specific properties to a compound, defining its chemical behavior and usefulness. When synthesizing compounds through pyrolysis, understanding the role and behavior of individual elements is essential.
For example, in forming \(\text{BiCaVO}_5\):

• Bismuth provides heavyweight metal ions.
• Calcium ensures structural integrity.
• Vanadium offers oxidation properties.
• Oxygen completes and stabilizes the compound.

Similarly, in \(\text{CuMo}_2\text{YO}_8\):

• Copper helps in electrical conductivity.
• Molybdenum provides hardness.
• Yttrium offers durability.
• Again, oxygen binds and stabilizes.

By considering the role of each element, scientists can effectively choose the right precursors. This knowledge is foundational for successful inorganic synthesis through solid-state and pyrolytic methodologies.