Abstract: | The 1H nmr spectra of phenanthro9′,10′:4,5]thieno2,3-c]quinoline, benzof]phenanthro-9′,10′:4,5]thieno2,3-c]quinoline and benzoh]phenanthro9′,10′:4,5]thieno2,3-c]quinoline are highly congested. For each compound, all protons abide in an aromatic environment complicated by pseudo-symmetric regions which result in multiple overlap of the different spin systems these molecules contain. We illustrate here the utility of the HMQC-TOCSY experiment to identify spin systems when the proton spectrum is highly congested. To complete the assignment of the 1H and 13C nmr spectra of each compound the HMBC experiment is used to assign the quaternary carbons. |