Disulfur and Diselenium as Strong Acceptor Ligands in (η⁵‐C₅H₅)Re(CO)₂S₂ and [η⁵‐C₅(CH₃)₅]Mn(CO)₂Se₂

Abstract

plify the calculation, interconversions involving Ms, M6, and M, were not considered. These minima have 1,2-cis-

[(μ‐C){Re(CO)2(η‐C5H5)}2]: A Surprisingly Simple Bimetallic Carbido Complex

“…90 % based on 3) of 4 may be obtained along with a second complex, which was identified crystallographically as the disulfur complex [Re(h 2 -S 2 )(CO) 2 (h-C 5 H 5 )] (5) previously shown by Herberhold to arise from the reaction of 2 with elemental sulfur. [14] We are therefore inclined to suspect that 4 arises from a di-or possible trinuclear intermediate with one or more extraneous {Re(CO) 2 (h-C 5 H 5 )} fragments coordinating to the thiocarbonyl ligand, though the actual mode of CS bridging in such species is open to debate (Scheme 3). In support of this we note that 1) Stone has described the reaction of 3 with [Pt(h 2 -C 2 H 4 )(PMe 3 ) 2 ] to afford [RePt(m-CS)(CO) 2 (PMe 3 ) 2 (h-C 5 H 5 )], the sulfur of which displays enhanced nucleophilic character relative to 3; [15] 2) the coordination of two rhodium centers to the selenium of a selenocarbonyl ligand has recently been reported; [16] and 3) a tetrametallic molybdenum-iridium carbido complex has recently been shown to form by insertion of iridium(I) into the CSe bond of a selenocarbonyl ligand.…”

“…In particular, the angles between the three monohapto ligands are all close to 908 and the molecule is unconstrained by any crystallographically imposed symmetry. The two almost colinear (173.3(7)8) rhenium-carbido bonds (1.882(14), 1.881 (14) ) fall within the range typical of Re À C multiple bonds; [11] for example, [Re(=CHPh)(CO) 2 (h-C 5 H 5 )] (1.95 (2) ), [11a] [Re(= C=CHPh)(CO) 2 (h-C 5 H 5 )] (1.912 (14 ), [11b] [Re(=C=C= CPh 2 )(SAd)(NtBu) 2 ] (1.898 (13 ), [11c] and [Re(CPh)(CO) 2 -(h-C 5 Me 5 )] + (1.782(4 ). [11d] For comparative purposes, complex 3 was also structurally characterized [12] and the thiocarbonyl ligand was found to have a similar Re À C bond length (1.866 (9 ).…”

“…Molecular structure of 4 from a crystal (ellipsoids set at 50 % probability). Selected bond lengths [] and angles[8]: Re1-C1 1.882(14), Re2-C1 1.881(14); Re1-C1-Re2 173.3(7), C1-Re2-C21 90.7(6), C1-Re2-C22 88.2(6), C21-Re2-C22 88.6(7), C1-Re1-C11 86.4(6), C1-Re1-C12 89.6(6), C11-Re1-C12 87.2(6); C22-Re2···Re1-C11 172.7(6), C21-Re2···Re1-C12 À11.75(6).…”

The syntheses, structures and reactivity of bis(tert-butylcyclopentadienyl)molybdenum derivatives: nitrogen alkylation of an η2-acetonitrile ligand and influence of the chalcogen on the barrier to inversion of chalcogenoether adducts

“…For example, the S-S bond length of 2.043(4) Å in (Cp Bu t ) 2 Mo(η 2 -S 2 ) is comparable to the S-S single bonds in S 8 (2.060 Å) 59 and S 2 2Ϫ (e.g. 2.08 Å in SrS 2 60 and 2.13 Å in Na 2 S 2 61 ), but is much longer than that of the S᎐ ᎐ S bond in the gas phase (1.887 Å). 61 than that of the Se᎐ ᎐ Se bond in the gas phase (2.19 Å).…”

Low-valent Organorhenium Compounds

“…The key photochemical step appears to be dissociation of the 410 In the solid-state structure of the disulfide complex, the S-S bond distance of 0.199 6(5) nm is between that for single and double bonds. The CO stretching absorptions in the IR spectrum appear at 2014(s) cm and 1945(s) cm" 1 , indicating that S 2 is a better acceptor ligand than CO. 411 The pentamethylcyclopentadienyl analogue (191) is prepared in 47% yield and undergoes 3-chloroperbenzoic acid oxidation to (192) in 50% yield. Further oxidation generates (193) which was not isolated in pure form.…”