Einfluß verschiedenartig substituierter cyclopentadienylliganden auf die chemie schwefelreicher organometallkomplexe mit metallen der 6. Nebengruppe

Abstract

The reaction of the differently substituted cyclopentadienyl complexes LzM,(CO), with sulfur is investigated with respect to the ligand L (etmcp = ethyltetramethylcyclopentadienyl, tbcp = tbutylcyclopentadienyl, ipcp = isopropylcyclopentadienyl) and the metal M (Cr, MO, W). For M = Cr the only isolated product is etmcp,Cr,S,. For M = MO three isomers A, D, E of composition LzMo,S, (L = ipcp, etmcp) are formed whereas only two isomers (A, D) exist for L = tbcp. Only two isomers (D, E) of composition LzWzS, are formed in the system LzWz(CO), /S,, a further product is LzWz(CO)zS, for L = etmcp. Structural characterisation of all compounds was achieved by IR, 'H, and 95Mo NMR spectroscopy, whereas the structures of ryn-etmcp,M&-S),S, (M = MO, W) were determined by X-ray crystallography, the result of which allows the correction of a previous structure assignment. It is further shown that a thermal equilibrium exists between L,Mo,(~,gZ-S,X~-S), (A) and syn-L,Mo& S&S, (D) which depends strongly on the ligands.

Reactions of the Unsaturated Hydroxo Complex [W2Cp2(OH)(μ-PPh2)2(CO)]BF4 with Mono- and Bidentate Ligands Having E–H bonds (E = O, S, N)

“…To overcome the latter drawback we checked the potential of the thiolato complex 5 as a synthetic equivalent of 2. Although no reaction was observed upon addition of a great excess of a poor ligand as catechol to a solution of complex 5, the addition of a strong base as DBU to these solutions caused the immediate formation of the diolato complex [W 2 Cp 2 (μ-PPh 2 ) 2 (O,O′-O 2 C 6 H 4 )(CO)] (14) in excellent yield (Chart 4).…”

“…The W(2)–S(1) bond length of 2.303(3) Å is intermediate between the figures typically found for complexes displaying formally double MS bonds (ca. 2.14 Å in the sulfide complexes syn -[M 2 Cp′ 2 (μ-S) 2 (S) 2 ] (M = Mo, W; Cp′ = C 5 EtMe 4 ), [W 2 Cp* 2 (μ-S) 2 (S)(CO) 2 ] (Cp* = C 5 Me 5 ) or cis -[W 2 Cp* 2 (μ-S) 2 (S) 2 ]) and those with single M–S bonds (ca. 2.45 Å for the bridging thiolato ligands in [Mo 2 Cp 2 (μ-SMe) 3 (CO) 2 ]Br·H 2 O, [Mo 2 Cp* 2 (μ-SMe) 2 (μ-SH)(CO) 2 ]BF 4 , and [Mo 2 Cp 2 (μ-SPh) 2 (NCMe)(CO) 3 ](BF 4 ) 2 , or for the one electron donor terminal benzenethiolato ligand in [MoCp 2 (SPh){NC(4-C 6 H 4 NMe 2 }]PF 6 ) .…”