Linked Life Data

19911809

Source:http://linkedlifedata.com/resource/pubmed/id/19911809

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2009-12-22
pubmed:abstractText
CdS magic-sized nanocrystals (MSNs) exhibiting both band gap absorption and emission at 378 nm with a narrow bandwidth of approximately 9 nm and quantum yield (QY) of approximately 10% (total QY approximately 28%, in hexane) were synthesized via a one-pot noninjection approach. This CdS MSN ensemble is termed as Family 378. It has been acknowledged that magic-sized quantum dots (MSQDs) are single-sized, and only homogeneous broadening contributes to their bandwidth. The synthetic approach developed is ready and highly reproducible. The formation of the CdS MSQDs was carried out at elevated temperatures (such as 90-140 degrees C) for a few hours in a reaction flask containing bis(trimethylsilyl)sulfide ((TMS)(2)S) and Cd(OAc)(OA) in situ made from cadmium acetate dihydrate (Cd(OAc)(2).2H(2)O) and oleic acid (OA) in 1-octadecene (ODE). Low OA/Cd and high Cd/S feed molar ratios favor this formation, whose mechanism is proposed to be thermodynamically driven. (13)C solid-state cross-polarization magic-angle spinning (CP/MAS) nuclear magnetic resonance (NMR) demonstrates that the capping ligands are firmly attached to the nanocrystal surface via carboxylate groups. With the cross-polarization from (1)H of the alkyl chains to surface (113)Cd, (113)Cd NMR is able to distinguish the surface Cd (471 ppm) bonding to both -COO(-) and S and the bulk Cd (792 ppm) bonding to S only. DOSY-NMR was used to determine the size of Family 378 ( approximately 1.9 nm). The present study provides strategies for the rational design of various MSNs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1936-086X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
22
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3832-8
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
CdS magic-sized nanocrystals exhibiting bright band gap photoemission via thermodynamically driven formation.
pubmed:affiliation
Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't