Influence of Hole-Sequestering Ligands on the Photostability of CdSe Quantum DotsHydrogen Bonding and OH-Stretch Spectroscopy in Water: Hexamer (Cage), Liquid Surface, Liquid, and IceHow innocent is thallium(I)? Corrected formulations of Tl2Pd14(CO)(9)(PM

Chalcogenide nanocrystals or quantum dots (QDs) such as CdSe and PbSe have great potential as absorbers for QD-sensitized solar cells, but their practical utility is limited by fast degradation when exposed to ambient environments. Here we present results showing that small organic molecules acting as hole-accepting ligands can be very effective in reducing photooxidation of CdSe QDs. The aromatic amine, 4-dimethylaminothiophenol (DMATP), is shown to be especially effective in enhancing stability of CdSe QDs when illuminated in air or in aqueous environments. Using photoluminescence and density functional theory (DFT) calculations, we show that the enhanced stability results from hole transfer from the QD to the ligand and delocalization of the resulting positive charge on the aromatic ring and amino group instead of the sulfur atom that links the molecule to the CdSe.We present a unified picture of how OH-stretch spectroscopy in water can be understood in terms of hydrogen bonding for the four systems listed in the title. To understand the strength, and hence OH-stretch frequency, of a hydrogen bond, it is crucial to consider the number of additional acceptor hydrogen bonds made by both the donor and acceptor molecules. This necessity for focusing on the hydrogen-bond environment of both donor and acceptor molecules follows from quantum chemical considerations and is related to the three-body interactions in water. Armed with this understanding we can make a detailed interpretation of the OH-stretch IR absorption spectrum of the cage conformer for HOD(D2O)(5) and the imaginary part of the ssp OH-stretch sum-frequency spectrum of the surface of liquid D2O with dilute HOD.Two previously reported cationic clusters, Au2Pd14 (1-Me) and AuPd9 (2-Ph), obtained by similar reactions of CO/PR3-ligated Pd(0) clusters with AuCl(PR3') in the presence of TlPF6 are shown to be [Tl2Pd14(CO)(9)(PMe3)(11)](2+) (1a-Me) and [TlPd9(CO)(9)(PPh3)(6)](+) (2a-Ph), respectively. These clusters ([PF6](-) counterion) were prepared without the presence of gold by reactions of either Pd-10(CO)(12)(PMe3)(6) or Pd-10(CO)(12)(PPh3)(6) with TlPF6 and characterized crystallographically and spectroscopically.Selected reaction monitoring on a triple quadrupole mass spectrometer is currently experiencing a renaissance within the proteomics community for its, as yet, unparalleled ability to characterize and quantify a set of proteins reproducibly, completely, and with high sensitivity. Given the immense benefit that high resolution and accurate mass instruments have brought to the discovery proteomics field, we wondered if highly accurate mass measurement capabilities could be leveraged to provide benefits in the targeted proteomics domain as well. Here, we propose a new targeted proteomics paradigm centered on the use of next generation, quadrupole-equipped high resolution and accurate mass instruments: parallel reaction monitoring (PRM). In PRM, the third quadrupole of a triple quadrupole is substituted with a high resolution and accurate mass mass analyzer to permit the parallel detection of all target product ions in one, concerted high resolution mass analysis. We detail th!