A modular synthetic approach is reported for the synthesis of heterometallic metalorganic complex arrays (MOCAs). Modules of four metal centers containing three different metals copper(II), nickel(II), platinum(II), or ruthenium(II) are prepared using a solid-phase polypeptide synthesis technique and then linked in solution to make MOCAs of eight metal centers as linear, T-branched, and H-branched compounds. The MOCA molecular topologies thus have specific unique linear and branched sequences of metals along the peptide backbone.