Does anyone know the proper format to report an iso-butyl group, eg. $\ce{R-CH2-C\color{red}{H}(CH3)2}$, in $\ce{^1H}$ NMR tabulation? The proton in red should be a triplet of septets, so I've written:
δ 2.72 (d, J = 5.5 Hz, 2H), 1.80 (tsep, J = 5.5, 5.3 Hz, 1H), 1.02 (d, J = 5.3 Hz, 6 H).
Is the use of "tsep" acceptable here?