sentences:  It is prepared by treatment of an aqueous solution of rhodium trichloride with activated copper metal under an atmosphere of CO.
  
  Alternatively, the compound can be prepared by treatment of a methanolic solution of RhCl3(H2O)3 with CO to afford H[RhCl2(CO)2], followed by carbonylation in the presence of sodium citrate.The cluster undergoes thermal substitution with phosphorus ligands, L