File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Synthesis, structural characterization, solvatochromism, and electrochemistry of tetra-osmium carbonyl clusters containing azo-ligands

TitleSynthesis, structural characterization, solvatochromism, and electrochemistry of tetra-osmium carbonyl clusters containing azo-ligands
Authors
KeywordsAzo-compounds
Cluster compounds
Electrochemistry
Osmium
Solvatochromism
Issue Date2001
PublisherWiley - V C H Verlag GmbH & Co KGaA. The Journal's web site is located at http://www.eurjic.org
Citation
European Journal Of Inorganic Chemistry, 2001 n. 12, p. 3163-3173 How to Cite?
AbstractThe reaction of [Os4(μ-H)4(CO)12] with 4-(2-pyridylazo)-N,N-dimethylaniline (PNNDA) in dichloromethane afforded the new clusters [Os4(μ-H)4(CO)11NC5H 4(N=N)C6H4NMe2}] (1) and [Os4(μ-H)4(CO)10{η2-NC 5H4(N=N)C6H4NMe2}] (2) in 34% and 15% yields, respectively. Upon heating in toluene under reflux, compound 1 converted into 2 in 80% yield. The MLCT transition of compound 2 shows strong solvent dependency, displaying unusually large positive solvatochromism in different organic solvents. Treatment of [Os4(μH)4(CO)12] with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP) in dichloromethane gives [Os4(μ H)3(CO)10{μ-η3-Et2NC 6H3(O)(N=N)C5NH3Br}] (3). The O - H bond activation is observed and the azo-ligand behaves as a five-electron donor. The clusters [Os4(μ-H)2(CO)10{μ-η 3NC5H4(N=N)C5H4N}] (4) and [Os4(μ-H)4(CO)10{μ-η 2NC5H4(N=N)C5H4N}] 2 (5) were isolated from the reaction of [Os4(μ-H)4(CO)10(NCMe)2] with 2,2′-azopyridine and 3,3′-azopyridine, respectively. In compound 4, both pyridine and azo nitrogen atoms were found to coordinate to the cluster core. Dehydrogenation was also observed in this compound. For compound 5, two tetra-osmium metal cores were connected by two azo ligands through their pyridyl nitrogen atoms to form a novel cyclic structure. The redox properties of the compounds described herein were investigated by means of cyclic voltammetry and controlled potential coulometry. Both compound 2 and 5 exhibit a reversible cathodic wave, which indicates that they undergo addition of one electron without significant structural changes. Furthermore, compound 5 displays an electronic interaction between two redox centers, the extra electrons are believed to delocalize throughout the cyclic structure.
Persistent Identifierhttp://hdl.handle.net/10722/70077
ISSN
2015 Impact Factor: 2.686
2015 SCImago Journal Rankings: 1.018
References

 

DC FieldValueLanguage
dc.contributor.authorLi, Yen_HK
dc.contributor.authorLin, ZYen_HK
dc.contributor.authorWong, WTen_HK
dc.date.accessioned2010-09-06T06:19:30Z-
dc.date.available2010-09-06T06:19:30Z-
dc.date.issued2001en_HK
dc.identifier.citationEuropean Journal Of Inorganic Chemistry, 2001 n. 12, p. 3163-3173en_HK
dc.identifier.issn1434-1948en_HK
dc.identifier.urihttp://hdl.handle.net/10722/70077-
dc.description.abstractThe reaction of [Os4(μ-H)4(CO)12] with 4-(2-pyridylazo)-N,N-dimethylaniline (PNNDA) in dichloromethane afforded the new clusters [Os4(μ-H)4(CO)11NC5H 4(N=N)C6H4NMe2}] (1) and [Os4(μ-H)4(CO)10{η2-NC 5H4(N=N)C6H4NMe2}] (2) in 34% and 15% yields, respectively. Upon heating in toluene under reflux, compound 1 converted into 2 in 80% yield. The MLCT transition of compound 2 shows strong solvent dependency, displaying unusually large positive solvatochromism in different organic solvents. Treatment of [Os4(μH)4(CO)12] with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP) in dichloromethane gives [Os4(μ H)3(CO)10{μ-η3-Et2NC 6H3(O)(N=N)C5NH3Br}] (3). The O - H bond activation is observed and the azo-ligand behaves as a five-electron donor. The clusters [Os4(μ-H)2(CO)10{μ-η 3NC5H4(N=N)C5H4N}] (4) and [Os4(μ-H)4(CO)10{μ-η 2NC5H4(N=N)C5H4N}] 2 (5) were isolated from the reaction of [Os4(μ-H)4(CO)10(NCMe)2] with 2,2′-azopyridine and 3,3′-azopyridine, respectively. In compound 4, both pyridine and azo nitrogen atoms were found to coordinate to the cluster core. Dehydrogenation was also observed in this compound. For compound 5, two tetra-osmium metal cores were connected by two azo ligands through their pyridyl nitrogen atoms to form a novel cyclic structure. The redox properties of the compounds described herein were investigated by means of cyclic voltammetry and controlled potential coulometry. Both compound 2 and 5 exhibit a reversible cathodic wave, which indicates that they undergo addition of one electron without significant structural changes. Furthermore, compound 5 displays an electronic interaction between two redox centers, the extra electrons are believed to delocalize throughout the cyclic structure.en_HK
dc.languageengen_HK
dc.publisherWiley - V C H Verlag GmbH & Co KGaA. The Journal's web site is located at http://www.eurjic.orgen_HK
dc.relation.ispartofEuropean Journal of Inorganic Chemistryen_HK
dc.subjectAzo-compoundsen_HK
dc.subjectCluster compoundsen_HK
dc.subjectElectrochemistryen_HK
dc.subjectOsmiumen_HK
dc.subjectSolvatochromismen_HK
dc.titleSynthesis, structural characterization, solvatochromism, and electrochemistry of tetra-osmium carbonyl clusters containing azo-ligandsen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=1434-1948&volume=&spage=3163&epage=3173&date=2001&atitle=Synthesis,+structural+characterization,+solvatochromism,+and+electrochemistry+of+tetra-osmium+carbonyl+clusters+containing+azo-ligandsen_HK
dc.identifier.emailWong, WT: wtwong@hku.hken_HK
dc.identifier.authorityWong, WT=rp00811en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1002/1099-0682(200112)2001:12<3163::AID-EJIC3163>3.0.CO;2-Q-
dc.identifier.scopuseid_2-s2.0-0035208501en_HK
dc.identifier.hkuros68315en_HK
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-0035208501&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.issue12en_HK
dc.identifier.spage3163en_HK
dc.identifier.epage3173en_HK
dc.publisher.placeGermanyen_HK
dc.identifier.scopusauthoridLi, Y=7502089799en_HK
dc.identifier.scopusauthoridLin, ZY=7404230177en_HK
dc.identifier.scopusauthoridWong, WT=7403973084en_HK

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats