Trans-bis(sodium pyridine-p-sulphoiiate)tetracarbonylmolybdenum(0) complex, (trans-Mo(CO)(4)(p-PySO3Na)(2), (1)) was used as a catalytic precursor for the 1-hexene hydroformylation reaction, in biphasic toluene/water medium (T = 100 degrees C, syngas total pressure = 600 psi, pH(2)/PCO = 1). Complex ( 1) showed good activity favoring the linear aldehyde. Likewise as other organic olefin substrates and with synthetic and real naphtha, good conversions to oxygenated products were obtained.