The synthesis of a number of new phosphino-and arsinobenzenechromium tricarbonyl ligands ER2C6H5Cr (CO) 3 (ER2= PEt2, PPri2, PBu t 2, PPh2, AsPh2 AsMe2), ER [C6H5Cr (CO) 3] 2 (ER= PEt, PBu t, PPh, AsPh) has been achieved by reacting lithium derivatives of benzenechromium tricarbonyl with appropriate chlorphosphines or iodoarsines. The spectroscopic properties of these ligands are described. The structure of Pri2PC6H5Cr ( ...