Synthesis, crystal structure, and spectra of 9(E)-phenanthrene-9,10-dione[(1Z)-3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]hydrazone and its cation-anion complex with copper(I) bromide

The reaction of 1-hydrazino-3,3-dimethyl-3,4-dihydroisoquinoline with 9,10-phenanthrenequinone gave (9 E )-phenanthrene-9,10-dione[(1 Z )-3,3-dimethyl-3,4-dihydroisoquinolin-1(2 H )-ylidene]hydrazone (L). The reaction of L with copper(II) bromide gave the complex (LH)[CuBr 2 ]. The crystal structures of the monohydrate L · H 2 O ( I ) and the isolated complex (LH)[CuBr 2 ] ( II ) were determined by X-ray diffraction. The structural units of I are pseudo-centrosymmetric dimers in which the L and water molecules are combined by strong hydrogen bonds. The active H atom is located at the N(1) atom of the isoquinoline fragment of the L molecule. The L molecule occurs in the crystal as the cis, trans isomer with respect to exocyclic C=N bonds at the isoquinoline and phenanthrenequinone fragments, respectively. Complex II has a cation-anion structure. The LH + cation as the cis, cis isomer is protonated at N(2) and stabilized by two intramolecular hydrogen bonds. In the CuBr 2 − anion, the copper atom in the oxidation state +1 has a linear coordination, the C-Br bond length is 2.185(4) ± 0.005 Å, and the BrCuBr angle is 179.8(4)°. The main ion-ion interactions in structure II are shortened contacts involving bromine atoms, which combine cations and anions into a three-dimensional framework.