New SO2 iron-containing cluster compounds [PPN](2)[Fe-3(CO)(9)(mu(3),eta(2)-SO2)],[PPN](2)[Fe-3(CO)(8)(mu-SO2)mu(3)-S], [PPN](2)[Fe-3(CO)(8)(mu-SO2)(mu(3)-CCO)], and [PPN](2)[Fe-2(CO)(6)(mu-SO2)(2)] from heterometal precursors

Sulfur dioxide reacts with [PPN](2)[MFe3(CO)(14)] (M = Cr, Mo, VV) (PPN = b istriphenylphosphenium iminium) to produce [PPN](2)[Fe-3(CO)(9)(mu(3),eta(2 )-SO2)] (I) and [PPN](2)[Fe-3(CO)(8)(mu-SO2)mu(3)-S] (II), which were chara cterized by infrared spectroscopy,C-13 NMR, and X-ray crystallography. Furt her reaction of I with sulfur dioxide results in the formation of II in 48% yield. Reaction of SO2 with [PPN](2)[Fe-4(CO)(13)] yields [PPN](2)[Fe-2(CO )(6)(mu-SO2)(2)] (III) which was characterized by infrared spectroscopy, C- 13 NMR, mass spectrometry, and X-ray crystallography. ;One equivalent of su lfur dioxide with [PPN](2)[MFe3(CO)(14)C] (M = Cr, W) produces [PPN](2)[Fe- 3(CO)(8)(mu-SO2)(mu(3)-CCO)] (IV), which on further reaction with SO2 gives the known cluster [PPN](2)[Fe-3(CO)(7)(mu-SO2)(2)(mu(3)-CCO)] (V). An exce ss of sulfur dioxide with [MFe3(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 identifie d product. Crystallographic data for I.0.5CH(2)Cl(2): monoclinic, Cc (no. 9 ), a = 29.7648(3) Angstrom, b = 14.6496(1) Angstrom, c = 21.7620(3) Angstro m, beta = 123.397(1)degrees, V = 7922.3 Angstrom(3); Z = 4. Crystallographi c data for III.NCCH3: monoclinic P2(1) (no. 4), a = 10.0295(5) Angstrom, b = 26.356(1) Angstrom, c = 14.1032(7) Angstrom, beta = 94.691 degrees, V = 3 715.6(3) Angstrom(3); Z = 4.