In enol CURC ISC is also in competition between the excited state Hydrogen transfer that can happen via the intramolecular H-bond relying the keto and enol group. This process is usually regarded as susceptible to quench ISC severely limiting its efficiency. Our SH dynamics have clearly shown the occurrence of the H-transfer via a dynamic and ultrafast equilibrium. However, it has also been shown that triplet population is still possible, even in presence of this competitive mechanism. On the other hand, triplet population leads to a significant deformation of CURC skeleton, in particular breaking its planarity.