Abstract. Starting with a pair F : A B : G of additive contravariant functors which are adjoint on the right, between abelian categories, and with a class U, we define the notion of (F, U)-coplex. Considering a reflexive object U of A with F(U ) = V projective object in B, we construct a natural duality between the category of all (F, add(U ))-coplexes in A and the subcategory of B consisting in all objects in B which admit a projective resolution with all terms in the class add(V ).Mathematics Subject Classification (2010): 16E30, 16D90.