A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes.

Described here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.

Reactivity of vinyl phosphonate containing diazoesters: formation, reactivity, and utility.

Treatment of diazo vinyl phosphonate with alcohols, amines, and thiols in the presence of Rh(II) results in the chemo- and stereoselective generation of enol ethers, enamines and vinyl sulfides via an X-H insertion process. The utility of the products from these reactions was demonstrated through their conversion into quaternary substituted heterocycles including furans and oxetanes as highlighted by the generation of a bicyclic phosphonate analogue of neodysiherbaine.

Electrical Current Signatures of DNA Base Modifications in Single Molecules Immobilized in the α-Hemolysin Ion Channel.

Nanopore technology holds high potential for next-generation DNA sequencing. This method operates by drawing an individual single-stranded DNA molecule through a nanoscale pore while monitoring the current deflections that occur as the DNA passes through. Individual current levels for the four DNA nucleotides have been established by immobilization of an end biotinylated strand in the pore in which the nucleotide of interest is suspended at the most sensitive region of the ion channel.

Exceptionally Long (> or =2.9 A) CC bonding interactions in pi-[TCNE]2(2-) dimers: two-electron four-center cation-mediated CC bonding interactions involving pi* electrons.

Three groups of singlet ground state [TCNE](2) (2-) (TCNE=tetracyanoethylene) dimers with characteristic intradimer CC separations (r) and dihedral angles (d) [i.e., group S(t) (r approximately 1.

Exceptionally Long (≥2.9 Å) C-C Bonds between [TCNE] Ions: Two-Electron, Four-Center π*-π* C-C Bonding in π-[TCNE].

Attractive interaction with the cation overcomes the electrostatic repulsion between two tetracyanoethylene radical anions, [TCNE] , and leads to the formation of a diamagnetic dimer [TCNE] , for example, in [K(glyme)] [TCNE] . The bonding is described as two-electron, four-center bonding arising from π*-π* overlap. Crystallographic as well as spectroscopic (IR and UV/Vis) features of this bonding are observed.

Template and Guest Effects on the Self-Assembly of a Neutral and Homochiral Helix.

Coordination-driven assembly based on manganese(II) centers and flexible 1,3-bis(4-pyridyl)propane leads to the solid-state formation of electronically neutral, self-templated homochiral helices, closed ring structures, and racemic mixtures of helices depending upon the presence or absence of guests such as benzene and 1,2-diphenylethane.

Mn [Mn (CN) ]-A Magnetic Interpenetrating Three-Dimensional Diamondlike Solid.

Three-dimensional extended diamondlike networks containing four-coordinate metal centers can be constructed from [Mn (CN) ] building blocks. Besides the title compound, which was prepared and its magnetic properties studied in detail, other novel magnetic solids might be able to be synthesized.

Structure and Properties of Tetracyanomanganate(II), [Mn (CN) ] , The First Paramagnetic Tetrahedral Cyanometalate Complex.

A place in the sun for solutions of [(Ph P) N] [Mn(CN) ] provides-by photochemical degradation-[Mn (CN) ] ions, the only homoleptic cyanide complex ion that is high spin (structure depicted on the right). Magnetic measurements indicate a high-spin A ground state (S=5/2), and the cyanide ligands are virtually entirely σ donors, without significant binding contributions from d-π* back-bonding.

Decomposition of thiosulphate in acidified oxidants.

The Wollack procedure has been used to study the competition between oxidant and acid for the thiosulphate ion. In concentrated hydrochloric acid solutions of iodine, iodate and chloramine-T, polythionates are the chief products, whereas in acid permanganate substantial amounts of other products occur. Both the concentration of the acid and the acid anion affect the course of the reaction in these solutions.

Comparison of the X-ray crystallography of undecafluorocyclohexane, C(6)HF(11), with that of dodecafluorocyclohexane, C(6)F(12).

A comparison of undecafluorocyclohexane and dodecafluorocyclohexane shows that both exist at 23 degrees in face-centred cubic cells with edges a(0) = 10.00 +/- 0.02 A for C(6)HF(11) and a(0) = 10.