In this paper we define two infinite families of graphs called C- graphs and -graphs and prove that -graphs satisfy delta conjecture. Also we see that C- graphs family contains the complements of -graphs. Finally we give a list of C- graphs and the relationship with the minimum semidefinite rank of these graphs.
Palabras clave: delta conjecture, simple connected graphs, minimum semidefinite rank, -graph, C-graphs, orthogonal representation