The reaction of [Re(CO)5Br] with the corresponding N,N′-donor polypyridyl ligands (L1–L8) leads to the formation of mononuclear tricarbonylrhenium(I) complexes having the general formula fac-[Re(L)(CO)3Br] (1–8), where L=dpt-NH2 (L1), Hbpp (L2), pypypm (L3), dppn (L4), dpp (L5), dpp3Me (L6), dppMe (L7) and bpzpy (L8). All these nitrogen donor planar ligands react with the metal precursor under nitrogen atmosphere to form tricarbonylrhenium(I) complexes [Re(N∩N)(CO)3Br] (1–8). All these metal complexes were isolated as neutral complexes and were characterized by FT-IR, 1H NMR, UV–Vis and Mass spectroscopic techniques. Complexes (1–6 & 8) were structurally determined by single-crystal X-ray diffraction technique. Single crystal X-ray crystallographic data conforms that the molecular structure of [Re(N∩N)(CO)3Br] is distorted octahedron around the rhenium atom with one Br-atom, facial arrangement of three CO groups and one polypyridyl ligand. The molecular orbital diagrams of the complexes (1–6 & 8) have been obtained from the density functional theory (DFT) method. The spin-allowed singlet–singlet electronic transitions for the metal complexes [Re(N∩N)(CO)3Br] have been calculated with the time-dependent DFT (TDDFT) method which are in good agreement with the experimental values.