I have my carbon NMR spectra and my product should not have any N in it but there are peaks for N-H secondary amines...the only nitrogen used was in the catalyst...this should not show up on the spectra, right? If it should not have how would I explain the occurrence of these peaks?

If your product should not have any nitrogen (N) in it, but you observe peaks for N-H secondary amines in your carbon NMR spectra, there could be a few possible explanations:

1. Contamination: It's possible that your product has been contaminated with a small amount of a compound containing secondary amines. Even a small contamination can lead to detectable peaks in your spectra.

2. Reaction byproducts: During your reaction, some side reactions might have occurred that produced compounds containing secondary amines. These reaction byproducts could be present in your final product and result in the observed peaks.

3. Incomplete removal of catalyst: If you used a catalyst containing nitrogen, such as a transition-metal complex, and if the removal of the catalyst was not thorough, trace amounts of the catalyst could be present in your product. These residual catalyst species may contribute to the appearance of N-H secondary amine peaks.

To investigate and confirm the presence of these peaks, there are a few steps you can take:

1. Conduct a blank experiment: Run a control experiment without the catalyst but with all other reaction conditions identical. Compare the NMR spectra of the product from the control experiment and your actual reaction. If the peaks for N-H secondary amines are only observed in your product sample and not in the control, it suggests that the peaks are indeed related to the catalyst or some other reaction-specific factor.

2. Perform additional characterization techniques: Use other analytical techniques, such as IR (Infrared) spectroscopy or mass spectrometry, to investigate the presence of N-H secondary amine groups. These complementary techniques can provide additional evidence of the presence of nitrogen-containing compounds in your product.

3. Optimize reaction conditions: If the presence of N-H secondary amine peaks is unwanted and affecting the purity of your product, consider optimizing your reaction conditions. This could involve modifying temperature, solvent, catalyst concentration, or reaction time, to minimize the formation of these nitrogen-containing impurities.