New experimental and theoretical data show that the previously reported planar tetracoordinate Sn complexes [Sn(Ph₂P(Se)N(Se)PPh₂)₂] (1-sq) and [Sn(iPr₂P(Se)N(Se)PiPr₂)₂] (2-sq) were not isolated and rather confused with the selenium complexes [Se(Ph₂P(Se)N(Se)PPh₂)₂] (3-sq) and [Se(iPr₂P(Se)N(Se)PiPr₂)₂] (4-sq), respectively.