Formation of Pt-S-Mn groups in platinum triphenylphosphine complexes with cymanthrenylthiolate ligands

Abstract

Stepwise decarbonylation of the platinum complex with cymanthrenylthiolate ligands cis (Ph 3 P) 2 Pt[(SC 5 H 4 )Mn(CO) 3 ] 2 (1) affords the cis (Ph 3 P) 2 Pt[(SC 5 H 4 )Mn(CO) 3 ] [(SC 5 H 4 )Mn(CO) 2 ] (2) and cis (Ph 3 P) 2 Pt[(SC 5 H 4 )Mn(CO) 2 ] 2 (3) complexes. The replace ment of one carbonyl group at the manganese atom with the lone electron pair of sulfur is accompanied by the formation of a new Mn-S bond giving rise to an unusual norbornane type core. Complexes 1-3 were characterized by elemental analysis and IR spectroscopy. The structures of complexes 1-3 were established by single crystal X ray diffraction.It is known that organomanganese chalcogenides can exist as unusual organometallic radicals, for examples, CpMn(CO) 2 SR, where R = Ph 1 or C(O)Ph, 2 and for mally biradical dichalcogenides [CpMn(CO) 2 ] 2 (µ X 2 ) (Х = S 2 or Sе 2,3 ), which always contain sharply short ened Mn-Х bonds.It was of interest to synthesize a platinum cis tri phenylphosphine complex containing the cymanthrenyl thiolate ligands (cymanthrenyl is C 5 H 4 Mn(CO) 3 ), use this complex for generating radicals by replacing the carbonyl group at the manganese atom with SR groups, and study delocalization of lone electrons throughout the molecule by ESR spectroscopy. However, it was unexpectedly found that only intramolecular replacements of CO by the sulfur atoms of the cymanthrenylthiolate ligands occur giving rise to new sulfide bridged heterometallic groups. Results and DiscussionThe starting platinum bis triphenylphosphine complex with cymanthrenylthiolate ligands cis (Ph 3 P) 2 Pt[(SC 5 H 4 )Mn(CO) 3 ] 2 (1) was prepared ac cording to two procedures: 1) by the reaction of bis triphenylphosphineplatinum dichloride with cymanthre nylthiolate anions and 2) by oxidative addition of dicym anthrenyl disulfide 4 to the Pt 0 tetraphosphine complex by analogy with the known insertion of the platinum atom at the S-S bond in organic disulfides 5,6 (Scheme 1).

Synthesis and structure of mixed-metal thiolate complex Cp′Cr(CO)2(μ-SBu)Pt(PPh3)2: Side-on-coordination of Cr–S double bond with platinum

“….Cr distance is 3.7105(4) Å. These parameters are similar to found in the analogous structures at R = C 5 H 4 Mn(CO) 3 [8], Ph [9] or CH 2 Ph [10]. Methylcyclopentadienyl groups adopt cis-position in respect to the Cr 2 S 2 core and n-butyl groups are in syn conformation in respect to the S. .…”

“…Recently we reported the preparation and structure of the monomeric thiolate complex CpCr(CO) 2 (SR) (R = ferrocenyl) which contains strongly shortened (2.136(1) Å) double Cr@SR bond [8]. Keeping in mind the unsaturated nature of this bond it was interesting to study the reaction of thiolate-bridged complex [CpCr-(CO) 2 (SBu)] 2 with Pt(0) complexes by analogy with Pt olefin complexes preparation.…”