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.