Crystallographic report: Bis(pyrrolinedithiocarbamato)mercury(II)

The mononuclear structure of Hg(S₂CN(CH₂)₄)₂ has crystallographically imposed twofold symmetry and features chelating dithiocarbamate ligands that form asymmetric Hg? S bond distances leading to a heavily distorted tetrahedral geometry. Copyright © 2003 John Wiley & Sons, Ltd.     

Crystallographic report: (4,4′‐Bipyridine)bis[bis(N,N‐diethyldithiocarbamato)zinc(II)]

The structure of [Zn(S₂CNEt₂)₂]₂(4,4′‐bipy) shows two independent dimeric molecules, one located about a centre of inversion, the other lying on a two fold axis containing the zinc atoms. Bidentate coordination by the dithiocarbamate ligands and a distorted square pyramidal geometry are found for two of zinc atoms whereas for the third zinc atom, the geometry is intermediate between square pyramidal and trigonal bipyramidal, a result that underscores the flexibility of coordination in these systems. Copyright © 2003 John Wiley & Sons, Ltd.     

Crystallographic report: Polymeric [bis(N,N‐diethyldithiocarbamato) (trans‐1,2‐bis(4‐pyridyl)ethylene)cadmium(II)]

The linear polymeric structure of [Cd(S₂CNEt₂)₂(trans‐NC₅H₄C(H)?C(H)C₅H₄N)]_∞ shows bidentate coordination by the dithiocarbamate ligands and a distorted octahedral geometry for cadmium, defined by a trans‐N₂S₄ donor set. Copyright © 2003 John Wiley & Sons, Ltd.     

Phenyliodine(III) Bis(Trifluoroacetate) Mediated Synthesis of 2‐Aryl‐1,2‐Benzisothiazol‐3(2H)‐Ones in Ionic Liquid

Treatment of N‐aryl‐2‐(benzylthio)benzamides with phenyliodine(III) bis(trifluoroacetate) containing trifluoroacetic acid resulted in an interrupted Pummerer‐type reaction in ionic liquid 1‐n‐butyl‐3‐methylimidazolium hexafluorophosphate, [bmim][PF₆] to give 2‐aryl‐1,2‐benzisothiazol‐3(2H)‐ones rather than the normal Pummerer‐type products.     

Nested PCR in magnetically actuated circular closed-loop PCR microchip system

We demonstrate a new and sensitive amplification technique (referred to as Nested Polymerase Chain Reaction; nPCR). It based on a magnetically actuated circular closed-loop PCR microchip system. nPCR involves the use of two sets of primers in two successive PCR runs, and allows the amplification of a single locus from a minute quantity of template DNA. Two sets of primers are specially designed to a target 500-bp region of the bacteriophage lambda template DNA in the first PCR run, and a 247-bp region of the targeted 500-bp first PCR product in the second PCR run. PCR is run on the microchip system and concurrently in regular thermocycler for comparison. The products are analyzed by conventional agarose gel electrophoresis. The detection limit for the initial template DNA is 1.63?×?10⁵ copies per μL (or 8.67?pg) for the first PCR run, and 1.63 copies per μL (or 0.0867?fg) for the second run. The results are comparable to a regular thermocycler. This preliminary study opens a new gateway to future development of specialized nPCR on chip.

Crystallographic report: (2,9‐Dimethyl‐1,10‐phenanthroline)bis‐(N,N‐pyrrolidinedithiocarbamato)zinc(II) chloroform hemihydrate

The mononuclear structure of Zn(S₂C(N(CH₂)₂)₄)₂(2,9‐Me₂‐1,10‐phen) shows monodentate coordination by the dithiocarbamate ligands and a distorted tetrahedral geometry for zinc, defined by an N₂S₂ donor set, results. Copyright © 2003 John Wiley & Sons, Ltd.     

Crystallographic report: Bis(N,N‐dibenzyldithiocarbamato)zinc(II)

The structure of Zn[S₂CN(CH₂Ph)₂]₂ features, in contrast to many related analogues, a mononuclear species with two chelating dithiocarbamate ligands that form a distorted tetrahedral array around the zinc centre; the molecule has two‐fold symmetry. Copyright © 2004 John Wiley & Sons, Ltd.     

Crystallographic report: (2,2′‐Bipyridine)bis(N,N‐dibenzyldithiocarbamato)zinc(II)

The structure of Zn[S₂CN(CH₂Ph)₂]₂(2,2′‐bipy) features a distorted trigonal prismatic geometry around the zinc centre defined by an N₂S₄ donor set; the molecule has two‐fold symmetry. Copyright © 2004 John Wiley & Sons, Ltd.     

Structure Determination of Brominated Morphinan-6-ones by 13C-NMR. Spectroscopy: A novel closure of the oxygen bridge using 4-acetoxymorphinan-6-ones

Bromination of (?)-4-hydroxy-N-methylmorphinan-6-one ( 3 ), prepared from natural morphine, with 1 mol of bromine in acetic acid, afforded the 1-bromo ketone 5 . The structure of 5 was assigned by ¹³C-NMR.spectroscopy, and confirmed by X-ray diffraction analysis of its hydrobromide salt. It is suggested that monobromination of synthetic (±)-2,4-dihydroxy-N-formylmorphinan-6-one ( 7 ) takes in principle a similar course, although the ¹³C-NMR.spectrum of the primary reaction product 9 could not be measured because of insolubility in commonly used solvents. Monobromination of (?)-4-acetoxy-N-formylmorphinan-6-one ( 12 ) of the natural series, and of (±)-2,4-diacetoxy-N-formylmorphinan-6-one ( 8 ) of the synthetic series, followed by treatment of the monobrominated ketones with potassium carbonate in methanol resulted in closure of the O-bridge, and afforded after acid hydrolysis, the corresponding 4,5-epoxy-morphinan-6-ones (?)- 16 and (±)- 17 respectively. This variation of the ring closure reaction represents a novel and convenient method to convert 4-hydroxymorphinan-6-ones into their corresponding 4,5-epoxymorphinan-6-ones, without involving aromatic bromination and with only 1 mol of bromine.