Crystal structure of 4-{2-[4-(dimethylamino)phenyl]diazen-1-yl}-1-methylpyridinium iodide

The mol­ecular geometry of the ionic title compound, C₁₄H₁₇N₄⁺·I⁻ or DAZOP⁺·I⁻, is essentially featureless. Regarding the crystal structure, in addition to the obvious cation–anion Coulombic inter­actions, the packing is mostly directed by non-covalent inter­actions involving both ring systems, as well as the iodide anion. It consists of cationic mol­ecules aligned along [101] and disposed in an anti­parallel fashion while linked into π-bonded dimeric entities by a stacking contact involving symmetry-related phenyl rings, with a centroid–centroid distance of 3.468 (3) Å and a slippage of 0.951 Å. The dimers are, in addition, sustained by a number of C—H⋯I and I⋯π (I⋯centroid = 3.876 Å) inter­actions involving the anion. Finally, inter­dimeric contacts are of the C—H⋯I and C—H⋯π types.

Solvatochromic and Single Crystal Studies of Two Neutral Triarylmethane Dyes with a Quinone Methide Structure

The crystal structure of two neutral triarylmethane dyes with a p-quinone methide core was determined by X-ray diffraction analysis. The spectroscopic characteristics of both compounds in 23 solvents with different polarities or hydrogen-bonding donor (HBD) abilities has been studied as a function of three solvatochromic parameters (E_T(30), π* and α). Both compounds 1 and 2 showed a pronounced bathochromic shift of the main absorption band on increasing solvent polarity and HBD ability. The correlation is better for compound 2 than for compound 1. The stronger effect and better correlation was observed for compound 2 with the increment of the solvent HBD ability (α parameter).

BODIPY dyes functionalized with 2-(2-dimethylaminophenyl)ethanol moieties as selective OFF–ON fluorescent chemodosimeters for the nerve agent mimics DCNP and DFP

Hand held sensing kits for detecting nerve agents simulants.