Optical-based distance measurements are essential for tracking biomolecular conformational changes, drug discovery, and cell biology. Traditional Förster resonance energy transfer (FRET) is efficient separation distances up to 100 Å. We report the first successful application of a dipole-surface type from molecular dipole nanometal surface that more than doubles traditional range (220 Å) follows 1/R4 dependence. appended 1.4 nm Au cluster 5' end one DNA strand as acceptor fluorescein (FAM)...

Microwave reactor methodologies are unique in their ability to be scaled-up without suffering thermal gradient effects, providing a potentially industrially important improvement nanocrystal synthetic methodology over convective methods. Synthesis of high-quality, near monodispersity nanoscale InGaP, InP, and CdSe have been prepared via direct microwave heating the molecular precursors rather than solvent. dielectric not only enhances rate formation, it also material quality size...

The fluorescence behavior of molecular dyes at discrete distances from 1.5 nm diameter gold nanoparticles as a function distance and energy is investigated. Photoluminescence luminescence lifetime measurements both demonstrate quenching consistent with 1/d(4) separation dye to the surface nanoparticle. In agreement model Persson Lang, all experimental data show that transfer metal dominant mechanism, radiative rate unchanged throughout experiment.

We show that the luminescence from CdSe quantum dot monolayers can be strongly influenced by interaction of water molecules adsorbed on surface. Light-induced alterations in surface states following adsorption water, results quasi-reversible changes dot. The excitonic QY increases a factor 20 during first 200 s illumination air (post vacuum) and then steadily decreases to level 6 times vacuum reference after 5000 s. exciton emission exhibits an exponential blue shift nearly 16 nm (60 meV)...

Eu(III)-doped Y(2)O(3) nanocrystals are prepared by microwave synthetic methods as spherical 6.4 ± 1.5 nm with a cubic crystal structure. The surface of the nanocrystal is passivated acetylacetonate (acac) and HDA on Y exposed facet nanocrystal. presence acac gives rise to strong S(0) → S(1) (π π*, acac) Ln(3+) ligand metal charge transfer (LMCT) transitions at 270 370 nm, respectively, in Eu:Y(2)O(3) Excitation into π*) or LMCT transition leads production white light emission arising from...

Molecular inorganic clusters, which are stable under ambient conditions, can be used as convenient single-source precursors for controlled preparation of 2−9-nm CdSe and CdSe/ZnS nanocrystals 2−5-nm ZnSe. The use a cluster-based precursor allows nanomaterial growth to initiated at low temperature without the pyrolytic step nucleus formation traditionally required lyothermal processes. elimination greater synthetic control, slow thermodynamic lower temperatures, high crystallinity, reaction...

We report the experimental observation of intrinsic dynamically localized vibrational states in crystals highly nonlinear halide-bridged mixed-valence transition metal complex ${[\mathrm{Pt}(\mathrm{en}{)}_{2}][\mathrm{Pt}(\mathrm{en}{)}_{2}{\mathrm{Cl}}_{2}]({\mathrm{ClO}}_{4}{)}_{4}}$, where $\mathrm{en}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\mathrm{ethylenediamine}$. These are identified by distinctive structure and strong redshifts they impose upon overtone resonance Raman...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesigned Synthesis of Mononuclear Tris(heteroleptic) Ruthenium Complexes Containing Bidentate Polypyridyl LigandsPeter A. Anderson, Glen B. Deacon, Klaus H. Haarmann, F. Richard Keene, Thomas J. Meyer, David Reitsma, Brian W. Skelton, Geoffrey Strouse, Nicholas C. Thomas, and Cite this: Inorg. Chem. 1995, 34, 24, 6145–6157Publication Date (Print):November 1, 1995Publication History Published online1 May 2002Published inissue 1 November...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfluence Of Electronic Delocalization In Metal-to-Ligand Charge Transfer Excited StatesGeoffrey F. Strouse, Jon R. Schoonover, Richard Duesing, Stephen Boyde, Wayne E. Jr. Jones, and Thomas J. MeyerCite this: Inorg. Chem. 1995, 34, 2, 473–487Publication Date (Print):January 1, 1995Publication History Published online1 May 2002Published inissue 1 January...

Nanometal surface energy transfer (NSET) is a molecular ruler technique that has been utilized to optically probe long distances in biomolecular structures. We investigate the useful spectral range of donor dyes and importance overlap between localized plasmon resonance (LSPR) photoluminescence (520−780 nm) provide comprehensive study R0 values for NSET processes from 2 nm Au NP (gold nanoparticle). The distance-dependent quenching results experimental evidence efficiency curve slope, value,...

In this study, we report structural, vibrational, and magnetic data providing evidence of random ion displacement in the core CdSe quantum dots on Cd(2+) sites by Co(2+) ions (between x = 0 0.30). Structural for doping is obtained analyzing powder X-ray diffraction (pXRD), which exhibits a linear lattice compression with increasing concentration, accord Vegard's law. Correlated pXRD shift, hardening longitudinal optical phonon mode new local vibrational are observed track concentration....

Controlling nanomaterial growth via the "specific microwave effect" can be achieved by selective heating of chalcogenide precursor. The high polarizability precursor allows instantaneous activation and subsequent nucleation leading to synthesis CdSe CdTe in nonmicrowave absorbing alkane solvents. Regardless desired size, narrow dispersity nanocrystals isolated less than 3 min with quantum efficiencies elliptical morphologies. reaction does not require a temperature injection step, solvent...

The interaction of a fluorescent molecule with gold nanoparticle is complex and can lead to excited-state enhancement or quenching. Many attempts have been made explain the observed when in close proximity metal surface; yet no single model has capable explaining observations. In this work, we show that by accurately describing terms an induced image dipole modified within size-dependent changes absorptivity dielectric constant, oscillator be fully described surface-moderated interaction....

Triplet sensitization of rubrene by bulk lead halide perovskites has recently resulted in efficient infrared-to-visible photon upconversion via triplet–triplet annihilation. Notably, this process can occur under solar relevant fluxes, potentially paving the way toward integration with photovoltaic devices. In order to further improve efficiency, fundamental photophysical pathways at perovskite/rubrene interface must be clearly understood maximize charge extraction. Here, we utilize ultrafast...

The local structure and composition of Cu ions dispersed in CdSe nanocrystals is examined using soft X-ray absorption near edge spectroscopy (XANES). Using L-edge XANES photoelectron measurements (XPS), we find that the exist Cu(I) oxidation state. We also observed signal directly proportional to molar percent present our final material. Se indicates changes density states with doping, due a chemical bonding effect, supports statistical doping mechanism. Photoluminescence (PL) indicate may...

Solid-state NMR analysis on wurtzite 2-nm hexadecylamine-capped CdSe nanocrystals (CdSe-HDA) provides evidence of discrete nanoparticle reconstruction within the Se sublattice nanomaterial. The cadmium and selenium atoms are probed with 1H−113Cd 1H−77Se cross-polarization magic angle spinning (MAS) experiments, which demonstrate five ordered sites in that can be assigned to contributions arising from different surface a site one layer down surface. Intriguingly, these materials both HDA...

Mn ion doping of CdSe and other semimagnetic quantum dot (QDs) alloys has been an area active speculation for over a decade. We report evidence Mn(II) grown from cubic single source precursor that is superparamagnetic (SPM) with blocking temperature 40 K following thermal annealing. Prior to annealing the 4 nm Mn/CdSe (1% Mn) QDs exhibit mainly paramagnetic behavior between 300 2 K, weak antiferromagnetic exchange. Following sample, high-temperature ferromagnetic exchange observed in...

We report a systematic investigation about the mechanism of pH sensing using SnO2 nanobelt field effect transistors (FETs). The FETs, based on single nanobelts, are channel-limited and with proper contact passivation; was conducted sodium phosphate solutions through integrated microfluidics. responses FET channel conductance to were measured at different gate voltages: linear dependence observed in transport "on" state, while an exponential subthreshold regime. Measurements same but ion...

Colloidal gold nanoparticles can be isolated from excess citric acid buffer by electrolyte-induced precipitation water solutions through the addition of oxyanions. This allows nanomaterials to as freely soluble powders that readily redissolved in or solution for other applications, such biolabeling. Analysis UV−vis and FTIR spectroscopy direct analysis oxyanion interaction at surface Au nanomaterial. For a series oxyanions, order thermodynamic stability is CO32- < H2PO41- SO42, while shift...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBlack MLCT AbsorbersPeter A. Anderson, Geoffrey F. Strouse, Joseph Treadway, Richard Keene, and Thomas J. MeyerCite this: Inorg. Chem. 1994, 33, 18, 3863–3864Publication Date (Print):August 1, 1994Publication History Published online1 May 2002Published inissue 1 August 1994https://pubs.acs.org/doi/10.1021/ic00096a007https://doi.org/10.1021/ic00096a007research-articleACS PublicationsRequest reuse permissionsArticle...

In solution, CdSe quantum dot exciton recombination is composed of an intrinsic band edge decay and a photoinduced charged exciton, which produces the observation biexponential dynamics. The nearly identical radiative lifetimes both extrinsic decays scale with cube size, nonradiative rate for follows energy gap law, while exhibits strong lattice perturbations arising from Frölich coupling to optical phonons. arises in particle that has photo-induced trapped carrier temporally resolved Stark...

Charge-lattice fluctuations are observed in the layered perovskite manganite LaSr2Mn2O7 by Raman spectroscopy as high 340 K and with decreasing temperature they become static form a charge ordered (CO) phase below TCO=210 K. In regime, superlattice reflections through neutron x-ray diffraction propagation vector (h+1/4,k-1/4,l). Crystallographic analysis of CO state demonstrates that degree orbital ordering this is weaker than three dimensional manganites. A TN=170K type-A antiferromagnetism...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFormation of thin polymeric films by electropolymerization. Reduction metal complexes containing bromomethyl-substituted derivatives 2,2'-bipyridineSharon Gould, Geoffrey F. Strouse, Thomas J. Meyer, and B. Patrick SullivanCite this: Inorg. Chem. 1991, 30, 14, 2942–2949Publication Date (Print):July 1, 1991Publication History Published online1 May 2002Published inissue 1 July...