The First Generation Grubbs Catalyst is a ruthenium-based complex, specifically Cl2(PCy3)2Ru=CHPh, where PCy3 stands for tricyclohexylphosphine and CHPh denotes a benzylidene ligand. The ruthenium center is coordinated to two chloride ions and two tricyclohexylphosphine ligands, with the benzylidene ligand forming a double bond with the ruthenium.
