David B. McConville

A novel tandem bicyclization to form an indenopyran ring system

Abstract A new palladium-copper catalyzed intramolecular acetylene-zipper type bicyclization between alkyne and hydroxy functionality of an alkynyl hydroquinone has been observed to give a highly conjugated ring system.

Crystal and molecular structure of 1-chloro-1,2-benziodoxolin-3(1H)-one·tetra-n-butylammonium chloride

AbstractThe title compound,6, a novel 1∶1 complex of 1-chloro-1,2-benziodoxolin-3(1H)-one (5) andtetra-n-butylammonium chloride, was prepared from tetra-n-butylammoniumo-iodoxybenzoate (7) and acetyl chloride. A single crystal of6 was subjected to X-ray analysis: triclinic, space group

Vanadium(IV) Complexes with Mixed O,S Donor Ligands. Syntheses, Structures, and Properties of the Anions Tris(2-mercapto-4-methylphenolato)vanadate(IV) and Bis(2-mercaptophenolato)oxovanadate(IV)

P\bar 1;

Rigid-Rod Polyimides Based on Noncoplanar 4,4‘-Biphenyldiamines: A Review of Polymer Properties vs Configuration of Diamines

a=10.239(2),b=11.518(2),c=11.523(3)Å; α=73.20(2); β=87.85(2), γ=87.72(2)°; R1=0.0326. The most notable structural feature of crystalline6 is the existence of a “secondary” bond [I· ·Cl(2), 2.943(1)Å] between the chloride ion and the iodine atom of the chlorobenziodoxolinone moiety. Further coordination at iodine includes three primary bonds: I−C [2.115(4) Å], I−O [2.145(3) Å], I−Cl(1) [2.454(1) Å]. The entire 1-chlorobenziodoxolinone-chloride sub-structure is planar and exhibits iodine-centered bond angles of 78.8(1)° [C−I−O], 92.0(1)° [C−I−Cl(1)], 97.6(1)° [Cl(2)−I−O] and 91.6(1)° [Cl(2)−I−Cl(1)]. The unit cell of6 contains two loosely packed formula units. The chlorobenziodoxolinone-chloride sub-structures occupy a common plane and exhibit a centrosymmetric relationship, while the tetra-n-butylammonium ions are situated one above and one below the plane. Bonding at the iodine atom in6 is more consistent with a 10-I-3 species electrostatically associated with the chloride ion than a 12-I-4 species such as the tetrachloroiodate ion.