J Nanosci Nanotechnol
July 2008
Density functional calculations at the B3LYP/6-31G* level were performed for Si nanoclusters of ca. 1 nm in size. The structural, energetic, electronic as well as the estimated absorption spectra by the time-dependent DFT (TDDFT) calculations using varied functionals and basis sets for the representative cluster models are all in favor of the formation of most probable Si35H36 nanocluster in recent electrochemical etching experiments.
View Article and Find Full Text PDFExperimental verification of the mechanism of metallotropic migrations in cyclooctatetraeneosmiumtricarbonyl (3) by means of 2D EXSY NMR spectroscopy confirmed the mechanism of [1,2]-Os shifts with low activation barrier (E(A) = 5.9 +/- 0.2 kcal mol(-1), ln A = 32 +/- 1).
View Article and Find Full Text PDFJ Chem Theory Comput
May 2006
Density functional calculations were performed at the B3LYP level using combined basis sets for the NO and bromine interactions with the Pt(111) surface mimicked by the two-layer Pt10 cluster model. It explains well an attractive bonding interaction not only for bromine and Pt(111) but also for all three adsorption modes of NO on the Pt(111) surface. In accordance with the experimental observations, the calculations predict that the first peak in the IR spectra appears at around 1515 cm(-)(1) at the initial stage of low NO coverage, while it would shift to 1707 cm(-)(1) at high NO coverage.
View Article and Find Full Text PDFStructures and properties of CdSe quantum dots (clusters) up to a diameter of approximately 2 nm were investigated by combining experimental absorption, photoluminescence (PL), and X-ray diffraction (XRD) spectroscopies as well as ab initio DFT calculations. These CdSe clusters were nucleated and grown from solutions containing respective cadmium and selenium precursors following the hot-injection technique that allows one to obtain size-controlled CdSe clusters having PL efficiency up to 0.5.
View Article and Find Full Text PDFThe present study discusses the results of theoretical calculations obtained at the B3LYP/ 6-31G level on the structural, electronic, and energetic properties of Ti-silicalites. Particularly, the relevance of 5T cluster models, either H- or OH-terminated, in large-scale calculations has been critically considered. It was shown that an open surface structure with one OH group and a closed-bulk structure with no bonded OH group at the Ti site are responsible for the observed UV-vis properties of Ti-silicalite materials.
View Article and Find Full Text PDF