Single-source precursor synthesis of colloidal CaS and SrS nanocrystals

Colloidal CaS and SrS nanocrystals were prepared by thermal decomposition of calcium- and strontiumdiisopropyldithiocarbamate complexes in oleylamine. The diameter of the nanocrystals was 8-10 nm with a narrow size distribution, showing that this single source precursor method gives access to monodisperse nanocrystals of small size. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved

Molecular and solid state structure of 4,4 '-bis(tetrahydrothiopyranyl)

<p>Single crystal X-ray diffraction reveals that 4,4'-bis(tetrahydrothiopyranyl) crystallizes in an equatorial-equatorial geometry with a gauche conformation along the central carbon-carbon bond. B3LYP/6-311G** and MP2/6-311G** calculations show that the antiperiplanar conformation is higher in energy than the gauche one because of sulfur induced stretching and widening of the cyclohexane-like rings. Calculations at various levels of theory suggest that in the antiperiplanar region the twisting coordinate of 4,4'-bis(tetrahydrothiopyranyl) exhibits a very shallow double-well potential. The gauche molecular structure of 4,4'-bis(tetrahydrothiopyranyl) thwarts efficient packing of its molecules in the solid state. Crown Copyright 2012 Published by Elsevier B.V. All rights reserved.</p>

Organometallic benzylidene anilines : donor-acceptor features in NCN-pincer Pt(II) complexes with a 4-(E)-[(4-R-phenyl)imino]methyl substituent

A series of organometallic 4,4'-substituted benzylidene aniline complexes 4-ClPt-3,5-(CH2NMe2)(2)C6H2CH=NC6H4R'-4', abbreviated as PtCl[NCN(CH=NC6H4R'-4']-4], with R' = NMe2, Me, H, Cl, CN (1-5, respectively), was synthesized via a Schiff-base condensation reaction involving reaction of PtCl[NCN(CH=O)-4] (7) with the appropriate 4-R'-substituted aniline derivative (6a-e) in toluene. The resulting arylplatinum(n) products were obtained in 75-88% yield. Notably, product 2 was also obtained in 68% yield from a reaction in the solid state by grinding solid 7 with aniline 6b. The structures of 2, 4, and 5 in the solid state (single crystal X-ray diffraction) showed a non-planar geometry, in particular for compound 5. The electronic interaction between the donor benzylidene fragment PtCl(NCN-CH) and the para-R' aniline substituent through the azomethine bridge was studied with NMR and UV/Vis spectroscopy. Linear correlations were found between the azomethine H-1, the Pt-195 NMR and various C-13 NMR chemical shifts, and the substituent parameters sigma(F) and sigma(R) of R' at the aniline site. In common with organic benzylidene anilines, the azomethine H-1 NMR chemical shift showed anomalous substituent behavior. The Pt-195 NMR chemical shift of the platinum center can be used as a probe for the electronic properties of the delocalized pi-system of the benzylidene aniline framework, to which it is connected. The dual substituent parameter treatment of the azomethine C-13 NMR shift gave important insight into the unique behaviour of the Pt-pincer group as a substituent. Inductively, it is a very strong electron-withdrawing group, whereas mesomerically it behaves like a very strong electron donating group

Organometallic benzylidene anilines : donor-acceptor features in NCN-pincer Pt(II) complexes with a 4-(E)-[(4-R-phenyl)imino]methyl substituent

A series of organometallic 4,4'-substituted benzylidene aniline complexes 4-ClPt-3,5-(CH2NMe2)(2)C6H2CH=NC6H4R'-4', abbreviated as PtCl[NCN(CH=NC6H4R'-4']-4], with R' = NMe2, Me, H, Cl, CN (1-5, respectively), was synthesized via a Schiff-base condensation reaction involving reaction of PtCl[NCN(CH=O)-4] (7) with the appropriate 4-R'-substituted aniline derivative (6a-e) in toluene. The resulting arylplatinum(n) products were obtained in 75-88% yield. Notably, product 2 was also obtained in 68% yield from a reaction in the solid state by grinding solid 7 with aniline 6b. The structures of 2, 4, and 5 in the solid state (single crystal X-ray diffraction) showed a non-planar geometry, in particular for compound 5. The electronic interaction between the donor benzylidene fragment PtCl(NCN-CH) and the para-R' aniline substituent through the azomethine bridge was studied with NMR and UV/Vis spectroscopy. Linear correlations were found between the azomethine H-1, the Pt-195 NMR and various C-13 NMR chemical shifts, and the substituent parameters sigma(F) and sigma(R) of R' at the aniline site. In common with organic benzylidene anilines, the azomethine H-1 NMR chemical shift showed anomalous substituent behavior. The Pt-195 NMR chemical shift of the platinum center can be used as a probe for the electronic properties of the delocalized pi-system of the benzylidene aniline framework, to which it is connected. The dual substituent parameter treatment of the azomethine C-13 NMR shift gave important insight into the unique behaviour of the Pt-pincer group as a substituent. Inductively, it is a very strong electron-withdrawing group, whereas mesomerically it behaves like a very strong electron donating group

A simple and convenient method for the hydrolysis of styrene-maleic anhydride copolymers to styrene-maleic acid copolymers

Styrene-maleic acid (SMA) copolymers are increasingly gaining attention in the membrane protein field due to their ability to solubilize lipid membranes into discoidal nanoparticles. The copolymers are synthesized as styrene-maleic anhydride (SMAnh), and need to be converted to the free acid form (SMA) before they are capable of solubilizing membranes. This hydrolysis reaction is traditionally performed under rather cumbersome reflux conditions. Here we report an alternative method for the hydrolysis reaction using simple and readily available equipment found in virtually all biochemical laboratories, namely an autoclave. Based on the results we propose an optimum set of standard conditions for the hydrolysis reaction, that should make the method easily accessible to a wide scope of researchers