We report the synthesis of a new phthalocyanine-molecular mixed crystal, TPP[CrxCo1-x(Pc)(CN)(2)](2), by an electrochemical method using a dilute solution. For the whole range of x, the chemical composition of the obtained single crystals is homogeneous and nearly equal to the nominal one in the dilution solution, as revealed by energy-dispersive X-ray spectroscopy. We have found that the concentrations of the starting materials play a vital role in the homogeneous growth of mixed crystals. (C) 2018 Elsevier B.V. All rights reserved.