New SO(2) Iron-Containing Cluster Compounds [PPN](2)[Fe(3)(CO)(9)(&mgr;(3),eta(2)-SO(2))], [PPN](2)[Fe(3)(CO)(8)(&mgr;-SO(2))&mgr;(3)-S], [PPN](2)[Fe(3)(CO)(8)(&mgr;-SO(2))(&mgr;(3)-CCO)], and [PPN](2)[Fe(2)(CO)(6)(&mgr;-SO(2))(2)] from Heterometal Precursors.

Sulfur dioxide reacts with [PPN](2)[MFe(3)(CO)(14)] (M = Cr, Mo, W) (PPN = bistriphenylphosphonium iminium) to produce [PPN](2)[Fe(3)(CO)(9)(&mgr;(3),eta(2)-SO(2))] (I) and [PPN](2)[Fe(3)(CO)(8)(&mgr;-SO(2))&mgr;(3)-S] (II), which were characterized by infrared spectroscopy, (13)C NMR, and X-ray crystallography. Further reaction of I with sulfur dioxide results in the formation of II in 48% yield. Reaction of SO(2) with [PPN](2)[Fe(4)(CO)(13)] yields [PPN](2)[Fe(2)(CO)(6)(&mgr;-SO(2))(2)] (III) which was characterized by infrared spectroscopy, (13)C NMR, mass spectrometry, and X-ray crystallography. One equivalent of sulfur dioxide with [PPN](2)[MFe(3)(CO)(14)C] (M = Cr, W) produces [PPN](2)[Fe(3)(CO)(8)(&mgr;-SO(2))(&mgr;(3)-CCO)] (IV), which on further reaction with SO(2) gives the known cluster [PPN](2)[Fe(3)(CO)(7)(&mgr;-SO(2))(2)(&mgr;(3)-CCO)] (V). An excess of sulfur dioxide with [MFe(3)(CO)(n)()C](x)()(-) (M = Cr, W: n =13, x = 2; M = Rh: n = 12, x = 1; M = Mn: n = 13, x = 1) produced V as the only identified product. Crystallographic data for I.0.5CH(2)Cl(2): monoclinic, Cc (no. 9), a = 29.7648(3) Å, b = 14.6496(1) Å, c = 21.7620(3) Å, beta = 123.397(1) degrees, V = 7922.3 Å(3); Z = 4. Crystallographic data for III.NCCH(3): monoclinic P2(1) (no. 4), a = 10.0295(5) Å, b = 26.356(1) Å, c = 14.1032(7) Å, beta = 94.691 degrees, V = 3715.6(3) Å(3); Z = 4.