A novel method for the synthesis of highly monodispersed hydrophillic InP-ZnS nanocrystals and their use as luminescence probes for live cell imaging is reported. Hydrophobic InP-ZnS nanocrystals are prepared by a new method that yields high-quality, luminescent core-shell nanocrystals within 6-8 h of total reaction time. Then by carefully manipulating the surface of these passivated nanocrystals, aqueous dispersions of folate-conjugated nanocrystals (folate-QDs) with high photostability are prepared. By use of confocal microscopy, we demonstrate the receptor-mediated delivery of folic acid conjugated quantum dots into folate-receptor-positive cell lines such as KB cells. These folate-QDs tend to accumulate in multi-vescicular bodies of KB cells after 6 h of incubation. Receptor-mediated delivery was confirmed by comparison with the uptake of these particles in folate-receptor-negative cell lines such as A549. Efficient two-photon excitation of these particles and two-photon imaging using these particles are also demonstrated. The use of these InP-ZnS nanoparticles and their efficient two-photon excitation can be potentially useful for deep tissue imaging for future in vivo studies.

III−V semiconductor quantum dots are of considerable interest as their applications cover a broad spectrum, from optoelectronic to biomedical technology. For them to be of practical value, there is a need for a method that provides rapid and scalable production of highly monodispersed nanoparticles. This paper reports an efficient and rapid method of producing highly monodispersed InP quantum dots using a novel precursor-based colloidal synthesis in a noncoordinating solvent. The method also allows judicious control over the size of the quantum dots and can also be extended to produce other III−V quantum dots. In this paper, the synthesis and characterization of highly monodispersed InP quantum dots from newly prepared indium(III) carboxylate complexes in octadecene are detailed. When using indium(III) carboxylate as the indium precursor, no surfactant or coordinating solvents are required to prepare high-quality InP quantum dots in octadecene. The in situ formation of a surfactant upon injection of the phosphine precursor [P(SiMe3)3] helps control the growth of the resulting quantum dots. Structural and optical studies (continuous wave and time-resolved) have been performed on the as-prepared InP quantum dots. In addition, time-resolved photoluminescence has been conducted on etched InP quantum dots. The effects of the carboxylate chain length in indium(III) carboxylate and injection temperature on the growth and properties of quantum dots have been studied.

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2 , DPPBTS), to establish the stability of the platinum methyl bond in aqueous solution. From pH ) 3 to 14 there is no reaction other than ligand substitution of H 2 O or OHfor Cl -; there is no CH 3 OH elimination. At lower pH's protonolysis of the Pt-Me bond occurs, producing CH 4 . Dissolving PtMe 2 L 2 into a solution of HCl at pH ) 1 rapidly produces PtCl 2 L 2 for the bidentate ligands, but trans-Pt(Cl)(Me)L 2 is observed for the monodentate ligands. trans-PtClMe(TPPTS) 2 undergoes protonolysis very slowly, indicating an important role for geometry in protonolysis reactions. The protonolysis reactions occur stereospecifically but are sometimes accompanied by cistrans isomerization. The cis or trans thermodynamic preferences, cis-PtCl 2 L 2 , cis-PtMe 2 L 2 , cis-Pt(OH)(Me)L 2 , trans-Pt(Cl)(Me)L 2 , and trans-Pt(H 2 O)(Me)L 2 + , are not easily explained.Platinum and palladium complexes are catalysts for many reactions. [1][2][3][4] In a number of cases, the product formation involves β-hydride elimination; relatively few involve reductive elimination. A number of reactions such as hydrogenation, hydration, hydroamination, and methane to methanol could involve reductive elimination. Goldberg has shown that reductive elimination can occur from Pt(IV) complexes, with formation of carboncarbon or carbon-oxygen bonds. 5 Protonolysis reactions of Pt(II) alkyl complexes in CH 3 OH have been the subject of a few studies. Reactions of trans-Pt(Me)(X)-(PEt 3 ) 2 with triflic acid produced methane, possibly through a Pt(IV) hydride. Deuterium labeling showed extensive incorporation into the CH 4 . 6 A study of HBF 4 or HCl reaction with cis-PtR 2 (PEt 3 ) 2 in CH 3 OH showed cleavage of one Pt-R (R ) Me, Et, etc.) and a slow cis to trans isomerization. 7 In this protonolysis a 10 4 increase was shown for C 2 H 6 elimination over CH 4 . 7 Protonolysis studies on platinum(II) alkyls and aryls showed that acid strength was very important, halide sometimes had an effect, steric hindrance occurred, and aryl cleavage was slower than alkyl, but could not distinguish the site of protonolysis. 8 Florinated bidentate phosphines examined by Roddick and co-workers were much less prone to methyl protonolysis. 9 The dimethyl complexes required neat acids and the monomethyl complexes required neat acids at elevated temperatures. 9 The recent interest in water-soluble organometallic complexes as potential "green" approaches to catalysis raises questions regarding the stability of metal alkyl bonds in aqueous solutions. In this article, we use cis-PtMe 2 (TPPTS) 2 , trans-Pt(Cl)(Me)(TPPTS) 2 , PtMe 2 (LL), and Pt(Cl)(Me)(LL) (TPPTS ) P(m-C 6 H 4 SO 3 Na) 3 , LL ) (m-C 6 H 4 SO 3 Na) 2 PCH 2 CH 2 P(m-C 6 H 4 SO 3 Na) 2 , DPPETS; (m-C 6 H 4 SO 3 Na) 2 PCH 2 CH 2 CH 2 P(m-C 6 H 4 SO 3 Na) 2 , DP-PPTS; (m-C 6 H 4 SO 3 Na)PCH 2 CH 2 CH 2 CH 2 P(m-C 6 H 4 SO 3 -Na) 2 , DPPBTS) (throughout this article LL is generic for one of the three bidentate ligands and L 2 is generic for two TPPTS ligands or one of the bidentate ligands) to examin...