2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68552We propose a generalisation of a recent work of M. Aguiar and J.-L. Loday on Quadri-algebras, called Ennea-algebras. In this second version, this paper has been extended. We show that the augmented free Ennea-algebra is a connected Hopf algebra and construct explicit formal deformations of dendriform dialgebras, quari-algebras and ennea-algebras via Baxter operators.30 pagesQuantum AlgebraCombinatorics17A30; 18D50text