       DIAQUABIS(2-METHYLLACTATO)ZINC(II): SYNTHESIS, PROPERTIES AND REACTIVITY WITH 1,10 PHENANTHROLINE. Rosa Carballo 1 , Alfonso Castiñeiras 2 , Berta Covelo 1 , Ezequiel M. Vázquez-López 1 . 1 Departamento de Química Inorgánica. Facultade de Ciencias. Universidade de Vigo. E-36200-Vigo. España. 2 Departamento de Química Inorgánica. Facultade de Farmacia. Universidade de Santiago de Compostela. E-15706-Santiago de Compostela. España. The chemistry of α-hydroxycarboxilic acids and its complexes with metal ions is of considerable interest because of their key role in biological processes, besides metal complexes with hydrogen-bonding and π-π stacking capabilities may be used as chemotherapeutic agents[1-3]. In this work we studied the zinc(II) complex of 2-methyllactic acid and its reactivity with 1,10- phenanthroline. The complex [Zn(HmL) 2 (H 2 O) 2 ] (I) was synthesised and characterised by elemental analysis, IR spectroscopy, thermo-gravimetric analysis and X-ray diffractometry. The structure of (I) is based on neutral complex [Zn(HmL) 2 (H 2 O) 2 ] where HmL is a monoanionic O,O’-bidentate 2- methyllactato ligand that chelates the zinc(II) ion through the carboxylato and the hydroxyl oxygen atoms to form a five-membered chelate ring, and in which the two aqua ligands are cis to each other. The coordination polyhedra is a distorted octahedral (See Figure 1). Figure 1.- Crystal structure of [Zn(HmL) 2 (H 2 O) 2 ] (I). Reaction of [Zn(HmL) 2 (H 2 O) 2 ] (I) with 1,10-phenanthroline in ethanol afforded colourless single crystals of formula [Zn(HmL)(phen) 2 ][Zn(HmL)(mL)(phen)].15H 2 O (II) that were obtained by slow evaporation of the mother liquor.