| 19697947 |
Adams H, Bancroft MN, Morris MJ, Riddiough AE: Sequential construction of one, two, or three dithiolene ligands from alkynes and sulfur in dinuclear cyclopentadienyl molybdenum complexes. Inorg Chem. 2009 Oct 5;48(19):9557-66.
This paper describes the sequential assembly of up to three dithiolene ligands from alkynes and elemental sulfur at a dimetal center. The dimolybdenum mu-alkyne complexes [Mo (2)(mu-R (1) C [triple bond] CR (2))(CO)(4) Cp (2)] (1a-c; Cp = eta-C (5) H (5), R (1) = R (2) = H, CO (2) Me; R (1) = H, R (2) = CO (2) Me) undergo oxidative decarbonylation on reaction with elemental sulfur in refluxing toluene to give good to excellent yields of the terminal dithiolene complexes [Mo (2)(S)(mu-S)(2)(SCR (1)=CR (2) S) Cp (2)] (2a-c). Further reaction of these complexes with 1 equiv of an alkyne R (3) C [triple bond] CR (4) (R (3) = R (4) = H, CO (2) Me; R (3) = H, R (4) = CO (2) Me) followed by oxidation with elemental sulfur produces the bis (dithiolene) complexes [Mo (2)(mu-S)(2)(SCR (1)=CR (2) S)(SCR (3)=CR (4) S) Cp (2)] (4a-d). Two examples, [Mo (2)(mu-S)(2)(S (2) C (2) H (2))(2) Cp (2)] and [Mo (2)(mu-S)(2){S (2) C (2)(CO (2) Me)(2)}(2) Cp (2)], have been structurally characterized. Reaction of 2 with an excess of an activated alkyne R (5) C [triple bond] CR (6) (R (5) = R (6) = CO (2) Me) and sulfur, or of 4 with the alkyne alone, affords good yields of the tris (dithiolene) complexes [Mo (2)(SCR (1)=CR (2) S)(SCR (3)=CR (4) S)(SCR (5)=CR (6) S) Cp (2)] (6a-e). The degree of control over the substituents in these complexes is demonstrated by the synthesis of [Mo (2)(S (2) C (2) H (2)){mu-S (2) C (2)(CO (2) Me)(2)}{mu-S (2) C (2)(CO (2) Et)(2)}Cp (2 )] (6e), which contains three different dithiolene ligands, as a single isomer. |
31(0,1,1,1) |