F. Demirhan et al., SYNTHESIS AND COORDINATION CHEMISTRY OF DICOBALT-COMPLEXED THIACYCLOALKYNES, Journal of the Chemical Society. Dalton transactions, (18), 1993, pp. 2765-2773
The reactions of bis(2-mercaptoethyl) sulfide or bis(2-mercaptoethyl)
ether with (Co2(mu-HOCH2C= CCH2OH)(CO)6] in the presence of HBF4.OEt2
afford (Co2{mu-C2(CH2SCH2CH2)2X}(CO)6] (X = S or O) respectively toget
her with dimeric products. The structure of the monomer [Co2Pmu-C2(CH2
SCH2CH2)2S}-(CO)6] has been established by X-ray crystallography and c
omprises a hexacarbonyldicobalt unit transversely bridged via the alky
ne functionality of 1,4,7-trithiacycloundec-9-yne which has an exodent
ate conformation. Proton NMR studies of the bis(2-mercaptoethyl) sulfi
de derivatives reveal that the SCHCH2S linkages are predominantly anti
in solution. The monomers undergo carbonyl substitution by bis(diphen
ylphosphino)methane (dppm) to afford [Co2{mu-C2(CH2SCH2CH2)2X}(mu-dppm
)(CO)4] (X = S or O) which react with [Mo(CO)3(eta-C6H3Me3-1,3,5)] to
afford products in which the macrocycles face cap Mo(CO)3 fragments. R
eaction of [Co2{mu-C2(CH2SCH2CH2)2S}(CO)6] with AgBF4 and PPh3 yields
[Co2{mu-C2(CH2SCH2CH2)2S)(CO)6{Ag(PPh3)}]BF4 for which an X-ray crysta
llographic study revealed that the Ag(PPh3)+ fragment is co-ordinated
by all three sulfur atoms of the ring which adopts an endodentate conf
ormation. Reaction of [Co2{mu-C2(CH2SCH2CH2)2S}(CO)6] with [Cu(MeCN)4]
PF, affords [Co2{mu-C2(CH2SCH2CH2)2S)(CO)6{Cu(MeCN)}]PF6 containing a
labile acetonitrile ligand which undergoes substitution by phosphines.
The dimeric compound [(OC)6Co2{mu-(CCH2SCH2-CH2SCH2CH2SCH2C)2}Co2(CO)
6] produces a 1:1 adduct when treated with AgBF4. X-Ray crystallograph
y reveals that the silver ion is co-ordinated by four of the six avail
able thioether groups.