Relativistic calculations of the spectroscopic properties of low-lying states of ICI

Relativistic quantum calculations which include spin-orbit interactions and correlations were carried out for the low-lying states of ICl. Spectroscopic properties (R₃, ω_e, T_e) were calculated for these states. Based on the energies and wave functions both the absorption and emission spectra of ICl in the region below 45000 cm⁻¹ were interpreted. These calculations confirm the predissociation of the B0⁺ state and the existence of a second minimum (B′0⁺) in the 0⁺(II) state. Properties of the 0⁻(I)(³Π_0⁻) state which is yet to be observed were also predicted. The calculated properties for the 2(I)(³Π₂) state are in very good agreement with the properties obtained by the very recent characterization of the A′ state by optical three-photon resonance. The continuous and diffuse absorption spectra of ICl in the region below 45000 cm⁻¹ were interpreted and assigned to the appropriate electronic transitions.     

Synthesis of 3-substituted coumarins via sequential pericyclic transformations of δ-aryloxymethylacrylic acids and enophiles

A new procedure for the synthesis of 3-functionally substituted coumarins via sequential Claisen and ene reactions of δ-aryloxymethylacrylic acids and anophiles has been developed.     

Ropinirole hydro­chloride,a dopamine agonist

Ropinirole hydro­chloride, or diethyl[2‐(2‐oxo‐2,3‐dihydro‐1H‐indol‐4‐yl)ethyl]ammonium chloride, C₁₆H₂₅N₂O⁺·Cl⁻, belongs to a class of new non‐ergoline dopamine agonists which bind specifically to D2‐like receptors with a selectivity similar to that of dopamine (D3 > D2 > D4). The N atom in the ethyl­amine side chain is protonated and there is a hydrogen bond between it and the Cl⁻ ion. In the crystal structure, two cations and two anions form inversion‐related cyclic dimers via N—H⋯Cl hydrogen bonds.