A condensation reaction between two cis-[PtCl₂(Hmtpo)₂] (where Hmtpo = 4,7-H-5-methyl-7-oxo[1,2,4]triazolo[1,5a]pyrimidine) molecules takes place in neutral aqueous media, giving [Pt₂Cu-mtpo)₄]·4H₂O (1). The X-ray structure of the recrystallization product of 1 in DMSO:EtOH (1:1) (DMSO =, dimethyl sulfoxide), namely, [Pt₂Cu-mtpo)₄]·2DMSO (2) has been determined. Compound 2 crystallizes in the orthorhombic space group Pbcn with unit cell dimensions a = 14.207(3) Å, b = 15.187(3) Å, c = 17.165(3) Å, and Z = 4. The molecular structure shows that the two Pt atoms are bridged by four mtpo ligands. Thus, it presents two face to face PtN4 units with a Pt···Pt 2.744(2) Å separation. Compound 1 has also been characterized by ¹H and ¹⁹⁵Pt NMR. The very short Pt(II)···Pt(II) contact suggests an interaction between the two metal centers, supported by the great deshielding observed for the platinum nuclei in the ¹⁹⁵Pt NMR spectrum (d = -2005 ppm) compared to a Pt(II) in a typical N-4 environment. In order to make an approach to the possible bonding nature of the Pt(II)···Pt(II) interaction, a theoretical analysis has been performed on the basis of the properties of the electronic charge density distribution, derived from ab initio MO calculations for the model compound Pt₂[NHCHN(C(CH₂)(CH₃))]₄ using RHF/LANL2DZ and B3LYP/LANL2DZ wave functions; both take into account relativistic effects and the second electronic correlation also. A significant directional interaction between the two metal centers has been found. Thus, a bond critical point appears between the two platinum nuclei, with a density of charge r(r) = 0.056, e·bohr^-3, which is half of that found for the platinum nitrogen bond. Moreover, a value of the energy density, E_d(r)<0 (E_d(r) = -0.0175 hartree·bohr^-3, at this point, shows the bonding nature of the interaction.