Synthesis and Crystal Structure of the Azoxydichinyl Helicene,Pyrido[3,2-<Emphasis Type="Italic">f</Emphasis>]quinolino[6,5-<Emphasis Type="Italic">c</Emphasis>]cinnoline 5-Oxide Monohydrate

Abstract  

The helicene, pyrido[3,2-f]quinolino[6,5-c]cinnoline 5-oxide, was prepared by treatment of 6-hydroxylaminoquinoline with xanthine oxidase or treatment of 6-nitroquinoline with glucose in 30% NaOH and the product characterized using NMR, high resolution mass spectrometry, and X-ray crystallography. The hydrogens on carbons 7 and 12 of the terminal aromatic rings are separated by 2.495 ? creating an angle of 25.0° between the planes of the two quinoline ring systems. In the crystal, water molecules serve to link the helicenes into a one dimensional chain structure forming a hydrogen bonded bridge between N2 of one molecule and N4 of another. The molecule (C₁₈H₁₀N₄O·H₂O) crystallized in the monoclinic P2₁/n space group. Unit cell parameters for pyrido[3,2-f]quinolino[6,5-c]cinnoline 5-oxide monohydrate: a = 7.0829(12), b = 18.559(3), c = 11.0985(19) ?, β = 107.736(2)°, and Ζ = 4.     

FTIR Emission Spectra, Molecular Constants, and Potential Curve of Ground State GeO

Extensive new high-temperature, high-resolution FTIR emission spectroscopy measurements for the five common isotopomers of GeO are combined with previous diode laser and microwave measurements in combined isotopomer analyses. New Dunham expansion parameters and an accurate analytical potential energy function are determined for the ground X1Sigma+ state. Copyright 1999 Academic Press.