New Di- and Triorganotin(IV) Tyrosylalaninates as Models for Metal—Protein Interactions: Synthesis, Structural Characterization, and Potentiometric Studies of Tyrosylalanine, Glycyltyrosine, and Glycylisoleucine with Di- and Trimethyltin(IV) Moieties in Aqueous Medium

Figure 5

Possible geometrical structures of the complex species: M or Me₂Sn(H₂O)₄²⁺ (a); isomers of M(HL) (b1)/(b2); M(HL) or M(OH) (c); isomers of M(HL)(OH) (d)/(e); MLH₋₁ (f).