We created mixed triatomic clusters, AlCGe-, AlSi2-, and AlGe2-, and studied their electronic structure and chemical bonding using photoelectron spectroscopy and ab initio calculations. Excellent agreement between theoretical and experimental photoelectron spectra confirmed the predicted global minimum structures for these species. Chemical bonding analysis revealed that the AlSi2- and AlGe2- anions can be described as species with conflicting (sigma-antiaromatic and pi-aromatic) aromaticity. The AlCGe- anion represents an interesting example of chemical species which is between classical and aromatic.