A novel process of preparing tridentate ligands containing a diarylphosphine electron donating group are disclosed. Use of this process for preparing a combinatorial library of such tridentate ligands and of organometallic complexes containing same is also disclosed. Further disclosed are novel diarylphosphine-containing compounds that can serve as tridentate ligands (e.g., pincer ligands), combinatorial libraries of such tridentate ligands, organometallic complexes containing these ligands (e.g., pincer complexes), and combinatorial libraries of such complexes. Methods utilizing these libraries for screening for candidate organometallic catalysts are also disclosed.