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The systematic investigation of the coordination chemistry of a-aminoisobutyric acid (H-Aib-OH) and Aib-based small peptides is continued. The solid complexes [Zn3(H-Aib-O)6]MeCOOHH2O (1MeCOOHH2O), {[Zn(H-Aib-L-Ala-O)2]H2O}n (2H2O) and [Zn(H2-Aib-Aib-Aib-O)4](ClO4)25.8H2O (35.8H2O) have been isolated and characterized by single-crystal X-ray crystallography. In the structure of complex 1MeCOOHH2O, three ZnII ions and six H-Aib-O ligands have assembled to form a trinuclear cluster. All three ZnII centers are in a very distorted trigonal bipyramidal coordination. The trinuclear units assemble through a network of hydrogen bonds to form a 2D framework with a (3.6.3.6) topology, while the lattice acetic acid and water molecule connect the layers to create a 3D framework with a fcu topology. Complex 2H2O is a two-dimensional coordination polymer. The deprotonated dipeptide behaves as a g1:g1:g1:l2 ligand binding one ZnII atom through its amino nitrogen and peptide oxygen, and an adjacent ZnII atom through one of its carboxylate oxygen. In the crystal lattice, the layers are con- nected in the third direction through hydrogen bonds and the resulting framework conforms to a tfa net. Complex 35.8H2O consists of mononuclear [Zn(H2-Aib-Aib-Aib-O)4]2+ cations, CLO4 and lattice water molecules. The tripeptide ligands are in their zwitterionic form and coordinate through one of the carbox- ylate oxygen atom to the metal ion, while they are participating in a network of intra- and intermolecular hydrogen bonds forming a 3D framework that adopts the bcu network.