Synthesis, Crystal Structure, and Spectra of the 1 : 1 Solvate of 3,3-Dimethyl-1-N-(1-phenyl-2,3-dimethyl-5-oxo-3-pyrazolin-4-yl)imino-1,2,3,4- tetrahydroisoquinolinium Triclorocobaltate(1-) with Acetone [(C22H25N4O)CoCl3] · C3H6O

The complex [(HL)CoCl3] · C3H6O (HL is 3,3-dimethyl-1-N-(1-phenyl-5-oxo-3-pyrazolin-4-yl)imino-1,2,3,4- tetrahydroisoquinolinium) was synthesized. The structure of the complex was studied by X-ray crystallography and IR and electronic absorption spectroscopy. In complex formation, the ligand remains in the same tautomeric form. The proton is attached to the exocyclic nitrogen atom, and the nascent HL+ cation coordinates the Co atom through the lone electron pair of the oxygen atom of the C=O group. As compared with the free L molecule, in the HL+ cation, the intramolecular bond is ruptured, and the antipyrine moiety turns around the C-N bond by ca. 180°.