A series of measurements performed, highlighting the formation of entanglements of an initially disentangled melt for a range of molar masses, and probing the thermodynamically nonequilibrium melt state was discussed. Homogeneous complexes were used to meet the requirements for a single chain forming a single crystal, which are single site in nature and display uniform activity and produce linear polymers with a narrow molecular weight distribution. It was observed that disentangled chains become a fully entangled thermodynamically stable melt. Unfilled symbols at low frequencies were determined by stress-relaxation experiments which cover the low frequencies inaccessible to the dynamic experiments. The curves formed are representative of chain dynamics in the initially disentangled and fully entangled environments. The results show that entanglements formation in a disentangled melt should hold for all disentangled polymer melts.