REACTIONS OF TRISULFONATED TRIPHENYLPHOSPHINE, TPPTS, WITH COBALT CARBONYLS IN WATER

The synthesis and characterization of a series of water-soluble cobalt carbonyl complexes is described: HCo(CO)(3)(TPPTS), HCo(CO)(2)(TPPTS) (2), and [Co(CO)(3)(TPPTS)](-), where TPPTS=P(m-C6H4SO3Na)(3). Investi gation of the substitution of Co-2(CO)(8) by TPPTS shows that the reac tion proceeds via the ionic intermediate [Co(CO)(3)(TPPTS)(2)] [Co(CO) (4)], which is relatively stable in water. The hydride complexes are s table in the presence of water at low pH. Under these conditions, it i s likely that the sodium cations are replaced with protons. A variety of reaction pathways to these compounds are described. The dimer, Co-2 (CO)(6)(TPPTS)(2), undergoes base-induced disproportionation above pH 10 to yield the substituted anion [Co(CO)(3)(TPPTS)](-) as the only ca rbonyl-containing product. In the course of this investigation, crysta ls of the sodium salt of Co-2(CO)(6)(TPPTS)(2) were obtained. Crystald ata: space group C2/c, a=31.723(16)Angstrom, b=11.244(14)Angstrom, c=4 1.267(14)Angstrom, beta=107.456(35)degrees, Z = 8. Data were collected at 193 K, and a total of 5898 reflections with I > 3 sigma(I) were co llected. The sodium ions and solvent are partially disordered, and two of the sulfonate groups are disordered. This and two very long cell a xes contribute to the final residuals, R=0.0858 and R(W)=0.0997. Quali tative aspects of the structure are discussed.