The title phosphine oxide-phosphine, 0.43C(17)H(16)NOP.0.57C(17)H(16)NP, (I)/(II), was obtained as a 0.861 (6):1.139 (6) cocrystallized mixture. Hydrogen bonding between the two constituents leads to the formation of 2:2 solid-state assemblies. Instead of forming the expected simple N,P-chelated system via loss of the N-bound H atom, reaction of 2-(diphenylphosphinomethyl)pyrrole, (II), with TiCl(4) leads to the formation of the title titanium(IV) complex, [TiCl(4)(C(17)H(16)NP)], (IV), containing a rearranged neutral ligand in which the N-bound H atom moves to one of the pyrrole C atoms, giving a partially unsaturated ring.