In the current paper the contribution of a Coulomb-like potential tensor interaction on the solution of the Dirac equation with a new generalized Morse-like potential is investigated using Feynman path integral method. Relativistic and non-relativistic energy spectra were obtained. Using the resulting non-relativistic energy eigen equations, three diatomic molecules (H2, LiH, and HCl) were investigated and their thermodynamic properties, including mean energy, free energy, entropy, and specific heat capacity were obtained. A comparison with the available literature shows that the thermodynamic plots obtained match those in the literature.