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Article: Synthesis, structural characterization and thermal reactivities of Osmium Carbonyl clusters containing 4,6-dimethylpyrimidine-2-thione

TitleSynthesis, structural characterization and thermal reactivities of Osmium Carbonyl clusters containing 4,6-dimethylpyrimidine-2-thione
Authors
Issue Date1995
PublisherRoyal Society of Chemistry. The Journal's web site is located at http://www.rsc.org/dalton
Citation
Journal of the Chemical Society Dalton Transactions, 1995, n. 6, p. 1047-1057 How to Cite?
AbstractThe reaction of the labilized cluster [Os3(CO)10(MeCN)2] and bis(4,6-dimethylpyrimidin-2-yl) disulfide affords two major products [Os3(CO)10(µ-dmpymt)2]1(36%) and [Os3(CO)10(µ-SH)(µ-dmpymt)]2(19%)(dmpymt = 4,6-dimethylpyrimidine-2-thione). Cluster 2 is formed from C–S bond cleavage of one of the dmpymt ligands at ambient conditions. Thermolysis of cluster 1 in n-heptane (98 °C) for 1 h produces an isomeric cluster of 1, [Os3(CO)10(µ-dmpymt)2]3(62%), which contains two dmpymt ligands co-ordinated across the same non-bonding Os Os edge. Thermolysis of cluster 3 in n-heptane for 2 h affords the cluster [Os3(CO)9(µ-dmpymt)(µ3-η2-dmpymt)]4 as the major product (42%) in addition to a minor product [Os3(CO)8(µ-η2-dmpymt)(µ3-η2-dmpymt)]5(9%). Cluster 4 contains two dmpymt moieties co-ordinating in µ and µ3-η2 modes respectively. Cluster 5 has two dmpymt moieties bonding in the µ3-η2 modes respectively. Further thermolysis of cluster 4 in n-octane (125 °C) leads to a much higher yield of cluster 5(60%) at the expense of cluster 4. Chemical activation of cluster 1 using Me3NO in CH2Cl2 at –78 °C also produces clusters 4 and 5 in 20 and 15% yield respectively. A new, orange product (31%) is also formed but remains uncharacterized. When cluster 4 is allowed to stand under ambient conditions over a period of ten days, it isomerizes to the cluster [Os3(CO)9(µ-dmpymt)(µ-η2-dmpymt)]6 in almost quantitative yield (87%). Cluster 6 contains one dmpymt ligand co-ordinating in the µ-η2 five-electron donating mode. Cluster 5 undergoes carbonylation to form cluster 4(62%) under a CO atmosphere in CH2Cl2 while cluster 4 also changes back to cluster 3(47%) in refluxing n-hexane (69 °C) under a CO atmosphere. Formation of clusters 3–5 is thus reversible. Mechanisms for the formation of 3, 4 and 6 have also been proposed. All the clusters 1–6 isolated have been fully characterized by conventional spectroscopic methods as well as single-crystal X-ray analyses.
Persistent Identifierhttp://hdl.handle.net/10722/69691
ISSN
2002 Impact Factor: 3.023
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorAu, YKen_HK
dc.contributor.authorCheung, KKen_HK
dc.contributor.authorWong, WTen_HK
dc.date.accessioned2010-09-06T06:15:58Z-
dc.date.available2010-09-06T06:15:58Z-
dc.date.issued1995en_HK
dc.identifier.citationJournal of the Chemical Society Dalton Transactions, 1995, n. 6, p. 1047-1057en_HK
dc.identifier.issn1472-7773en_HK
dc.identifier.urihttp://hdl.handle.net/10722/69691-
dc.description.abstractThe reaction of the labilized cluster [Os3(CO)10(MeCN)2] and bis(4,6-dimethylpyrimidin-2-yl) disulfide affords two major products [Os3(CO)10(µ-dmpymt)2]1(36%) and [Os3(CO)10(µ-SH)(µ-dmpymt)]2(19%)(dmpymt = 4,6-dimethylpyrimidine-2-thione). Cluster 2 is formed from C–S bond cleavage of one of the dmpymt ligands at ambient conditions. Thermolysis of cluster 1 in n-heptane (98 °C) for 1 h produces an isomeric cluster of 1, [Os3(CO)10(µ-dmpymt)2]3(62%), which contains two dmpymt ligands co-ordinated across the same non-bonding Os Os edge. Thermolysis of cluster 3 in n-heptane for 2 h affords the cluster [Os3(CO)9(µ-dmpymt)(µ3-η2-dmpymt)]4 as the major product (42%) in addition to a minor product [Os3(CO)8(µ-η2-dmpymt)(µ3-η2-dmpymt)]5(9%). Cluster 4 contains two dmpymt moieties co-ordinating in µ and µ3-η2 modes respectively. Cluster 5 has two dmpymt moieties bonding in the µ3-η2 modes respectively. Further thermolysis of cluster 4 in n-octane (125 °C) leads to a much higher yield of cluster 5(60%) at the expense of cluster 4. Chemical activation of cluster 1 using Me3NO in CH2Cl2 at –78 °C also produces clusters 4 and 5 in 20 and 15% yield respectively. A new, orange product (31%) is also formed but remains uncharacterized. When cluster 4 is allowed to stand under ambient conditions over a period of ten days, it isomerizes to the cluster [Os3(CO)9(µ-dmpymt)(µ-η2-dmpymt)]6 in almost quantitative yield (87%). Cluster 6 contains one dmpymt ligand co-ordinating in the µ-η2 five-electron donating mode. Cluster 5 undergoes carbonylation to form cluster 4(62%) under a CO atmosphere in CH2Cl2 while cluster 4 also changes back to cluster 3(47%) in refluxing n-hexane (69 °C) under a CO atmosphere. Formation of clusters 3–5 is thus reversible. Mechanisms for the formation of 3, 4 and 6 have also been proposed. All the clusters 1–6 isolated have been fully characterized by conventional spectroscopic methods as well as single-crystal X-ray analyses.-
dc.languageengen_HK
dc.publisherRoyal Society of Chemistry. The Journal's web site is located at http://www.rsc.org/daltonen_HK
dc.relation.ispartofJournal of the Chemical Society Dalton Transactionsen_HK
dc.titleSynthesis, structural characterization and thermal reactivities of Osmium Carbonyl clusters containing 4,6-dimethylpyrimidine-2-thioneen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=1472-7773&volume=No6&spage=1047&epage=1057&date=1995&atitle=Synthesis,+structural+characterisation+and+thermal+reactivities+of+Osmium+Carbonyl+clusters+containing+Bis-4,6-dimethylpyrimidin-+2-yl+disulphide+(DmpymSSdmpym)en_HK
dc.identifier.emailCheung, KK: kkcheung@hkucc.hku.hken_HK
dc.identifier.emailWong, WT: wtwong@hku.hken_HK
dc.identifier.authorityWong, WT=rp00811en_HK
dc.identifier.doi10.1039/DT9950001047-
dc.identifier.scopuseid_2-s2.0-37049078674-
dc.identifier.hkuros14553en_HK
dc.identifier.issue6-
dc.identifier.spage1047-
dc.identifier.epage1057-
dc.identifier.isiWOS:A1995QN86000022-
dc.publisher.placeUnited Kingdom-

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