The present investigation uses a dual approach to study the copper (II) complex [Cu(phen)3]. (ClO4)2.HL.CH3CN (1) and its cationic complex- [Cu(II)(phen)3]2+ (1 a), where, HL = 4-Bromo-2((Z) -(naphthalene-4-ylimino)methyl)phenol, phen=1,10-phenanthroline. The complex (1) crystallized in the triclinic system of the space group P-1 with two molecules in the unit cell and reveals a distorted octahedral geometry. Inspiring by recent developments to find a potential inhibitor for the COVID-19 virus, we have also performed molecular docking study of [Cu(phen)3]+2 to see if our novel complex shows an affinity for the main protease (Mpro) of COVID-19 spike protein. Interestingly, the results are found quite encouraging where the binding affinity and inhibition constant were found to be −8.400 kcal/mol and 0.661 μM, respectively, for the best-docked confirmation of [Cu(II)(Phen)3]+2 complex with Mpro protein. This binding affinity is reasonably well as compared to recently known antiviral drugs. For instance, the binding affinity of [Cu(II)(Phen)3]+2 complex is found to be better than recently docking results of chloroquine (−6.293 kcal/mol), hydroxychloroquine (−5.573 kcal/mol) and remdesivir (−6.352 kcal/mol) with Mpro protein. Thus, we believe the broad-spectrum functional properties of our complex will provoke not only the interest of material chemists in materials designing but also incite the drug designing community.