Draw a mechanism that explains how the nitro-substituted aromatic products observed in your reaction were formed. My sample was nitrodiphenylmethane and three peaks were observed using GC/MS. I wasn't sure how to determine what the peaks meant exactly. We had to use SDBS and this gave me p-benzylnitrobenzene when typing in the molecular formula C13H11NO2. Therefore, I assumed I had p-nitrodiphenylmethane as a product, but didn't know how to determine the other product? Any help would be greatly appreciated. I know you can't show the mechanism on here, but any explanation or site you think would help me would be great.
To determine the other product formed in your reaction, it is important to analyze the three peaks observed in the GC/MS analysis.
First, let's start by understanding the structure of nitrodiphenylmethane. Nitrodiphenylmethane has two phenyl groups attached to a central methylene (CH2) group, with a nitro group (-NO2) substitution on one of the phenyl groups. It can exist in two isomeric forms: ortho (o-) and para (p-). Since you referred to the product as p-nitrodiphenylmethane, let's assume it's the para isomer.
Now, let's focus on the other two peaks observed in the GC/MS analysis. To determine the structures of these products, it's necessary to compare their fragmentation patterns with known compounds.
You mentioned using SDBS (Spectral Database for Organic Compounds) to analyze one of the products. SDBS is a valuable resource that provides spectroscopic data for various compounds, including MS spectra. By entering the molecular formula C13H11NO2 in SDBS and obtaining p-benzylnitrobenzene, you've likely identified one of the products correctly.
To identify the remaining product, you can employ different tools and techniques:
1. Analyze the MS spectra: Examine the mass spectrum of the compound associated with the second peak. Look for characteristic peaks and fragmentation patterns that can give you clues about its structure. Compare these patterns with known compounds in databases like NIST Mass Spectral Library or Wiley Registry of Mass Spectral Data.
2. Utilize chemical databases: Besides MS spectra, you can use other chemical databases like PubChem, ChemSpider, or Reaxys. These databases provide information on chemical structures, properties, and reactions, allowing you to search for compounds matching the molecular formula and spectral information of the unknown product.
3. Draw potential isomeric structures: Based on the molecular formula of the unknown compound, you can draw various isomeric structures and consider their plausibility. Evaluate if the possible structures align with the observed peaks and potential reaction mechanisms.
4. Consult literature: Sometimes, similar reaction systems or substrates have been previously studied, and their products and mechanisms may have been reported in scientific literature. Searching for papers related to the reaction you performed or similar reactions can provide insights into possible products and mechanisms.
Remember, identifying the exact structure of an unknown compound requires a combination of techniques, including spectral analysis, databases, logical deduction, and sometimes experimental confirmation.