dc.contributor.author |
Lamprecht, Zandria
|
|
dc.contributor.author |
Van Jaarsveld, Nina Alletta
|
|
dc.contributor.author |
Bezuidenhout, Daniela Ina
|
|
dc.contributor.author |
Liles, David C.
|
|
dc.contributor.author |
Lotz, Simon
|
|
dc.date.accessioned |
2016-03-11T07:20:29Z |
|
dc.date.issued |
2015-10-13 |
|
dc.description.abstract |
Access to multicarbene complexes of a fused thienothiophene substrate was obtained by the use of the
tetrabrominated thieno[2,3-b]thiophene precursor in a lithium–bromide exchange reaction, followed by
nucleophilic attack on metal hexacarbonyls (M = Cr, W). Subsequent alkylation afforded unique triscarbene
complexes [M(CO)4{{C(OEt)}2C6H1S2C(OEt)}M(CO)5] (M = Cr 12, W 13) featuring three non-equivalent
carbene ligands on a single thiophene linker, as well as the bischelated tetracarbene complexes
[M(CO)4{{C(OEt)}2C6S2{C(OEt)}2}M(CO)4] (M = Cr 14, W 15). The triscarbene complexes 12 and 13 are the
first examples of multi-alkoxycarbene complexes featuring three non-equivalent carbene ligands. The
reaction also afforded the chelated mononuclear biscarbene complexes [M(CO)4{C(OEt)}2C6H2S2] (M =
Cr 10, W 11) in low yields. Similarly, employing tetrabromothiophene as precursor yielded the mononuclear
chelate biscarbene complexes [M(CO)4{C(OEt)}2C4H2S] (M = Cr 6, W 7) and the dinuclear tetracarbene
complexes [M(CO)4{{C(OEt)}2C4S{C(OEt)}2}M(CO)4] (M = Cr 8, W 9). Modification of the classic
Fischer carbene synthetic methodology to a process of stepwise additions of lithiating agent and metal
carbonyls to thieno[2,3-b]thiophene, facilitates the formation of the mixed metal biscarbene complex
[W(CO)5C(OEt){C6H2S2}C(OEt)Cr(CO)5] 5, as analogue of the homonuclear biscarbene complexes
[M(CO)5C(OEt){C6H2S2}C(OEt)M(CO)5], (M = Cr 3, W 4). The monocarbene complexes [M(CO)5{C(OEt)-
C6H3S2}], (M = Cr 1, W 2) were also obtained in high yields, and the molecular structures of the tungsten
complexes, with the exception of 9 and 11, were confirmed by single crystal X-ray diffraction studies. |
en_ZA |
dc.description.embargo |
2016-10-13 |
|
dc.description.librarian |
am2015 |
en_ZA |
dc.description.sponsorship |
The
National Research Foundation (NRF) of South Africa with
grants to SL (no. 73679 and 77079) and DIB (no. 87890 and
92521). |
en_ZA |
dc.description.uri |
http://www.rsc.org/dalton |
en_ZA |
dc.identifier.citation |
Lamprecht, Z, Van Jaarsveld, NA, Bezuidenhout, DI, Liles, DC & Lotz, S 2015, 'Synthesis and properties of mono- and dimetal Fischer multicarbene complexes derived from thiophene and thieno[2,3-b]thiophene', Dalton Transactions, vol. 44, pp. 19218-19231. |
en_ZA |
dc.identifier.issn |
1477-9226 (print) |
|
dc.identifier.issn |
1364-5447 (online) |
|
dc.identifier.other |
10.1039/c5dt03555d |
|
dc.identifier.uri |
http://hdl.handle.net/2263/51786 |
|
dc.language.iso |
en |
en_ZA |
dc.publisher |
Royal Society of Chemistry |
en_ZA |
dc.rights |
© The Royal Society of Chemistry 2015 |
en_ZA |
dc.subject |
Nucleophilic attack |
en_ZA |
dc.subject |
Multicarbene complexes |
en_ZA |
dc.subject |
Fischer |
en_ZA |
dc.subject |
Monocarbene complexes |
en_ZA |
dc.title |
Synthesis and properties of mono- and dimetal Fischer multicarbene complexes derived from thiophene and thieno[2,3-b]thiophene |
en_ZA |
dc.type |
Article |
en_ZA |