The best use of a set of tools for a structure elucidation are those that have a general target or goal in mind. Random experiments for the sake of collecting data are a sure sign of inexperience. With that said, Infrared (IR) spectroscopy is a great tool for identifying or confirming a functional group(s). It is an under utilized tool that can complement information from NMR and MS.
The IR, NMR and MS spectra for butane-1-sulfonyl chloride are shown below.
Sulfonyl chloride exhibits strong characteristic bands in the IR region of 1410-1370 and 1204-1166 cm-1. The alkane CH stretching bands appear around 3000-2800 cm-1.
The MS illustrates two ions at m/z 57 and 99. The ion peak at m/z 57 is characteristic of a hydrocarbon chain. The ion peak at m/z 99, although weak, is characteristic for a sulfonyl chloride group and exhibits an A+2 peak at m/z 101 due to the 37Cl isotope.
The 1H NMR spectrum exhibits 4 distinct multiplets attributed to the hydrocarbon chain. The deshielded multiplet at 3.68 ppm indicates the presence of a strong-electron withdrawing atom or group.
Using any 2 of the 3 techniques can facilitate the elucidation process and assist in confirming the structure.
Hi Arvin,
ReplyDeleteBrilliant blog...I was trying to characterize aryl sulfonyl chloride but I really dont know which solvent to use for NMR..compound is highly reactive..could you please let me know which solvent you used for the sample prep..cheers Marto
Hello Marto,
ReplyDeleteI have limited experiences working with aryl sulfonyl chloride compounds. All I can say is the sample for 1H NMR spectrum was prepared in anhydrous deuterated chloroform.