A small series of alkali metal aminotroponiminates (ATIs), [M(ATIPh/Ph)(thf)n], have been synthesized and fully characterized (M = Li, Na, K). All of these compounds adopt coordination modes that differ from those reported for derivatives with a slightly varied substitution pattern at the ATI ligand (one or two of the N-bound Ph groups substituted by iPr groups). This leads to an unprecedented ATI coordination mode for the potassium compound [K(ATIPh/Ph)] and an unusual Li···Ph interaction for the lithium compound [Li(ATIPh/Ph)]. The influence of the substitution pattern at the ATI ligand on the shape and energy of the frontier orbitals of its sodium complexes has been rationalized by theoretical methods and correlated with experimental results. Analytical techniques applied in this work include NMR spectroscopy, single crystal X-ray diffraction, and DFT calculations.