Zn(II), Cd(II) and Hg(II) complexes of 8-aminoquinoline.: Structure, spectra and photoluminescence property

Abstract

The reaction of 8-aminoquinoline (8-aq) with M(NO 3) 2 and M(ClO 4) 2 (where M = Zn, Cd and Hg) has synthesized complexes of the composition [M(8-aq) 2(H 2O) 2](X) 2 (X = NO 3, ClO 4) whereas MCl 2 has isolated M(8-aq)Cl 2 type non-ionic compounds. The reaction of M(OAc) 2, 8-aq and NaN 3/NH 4CNS in a 1:1:2 mole ratio has separated polynuclear complexes of the composition [M(8-aq)(Y) 2] n (Y = N 3, NCS). The complexes have been characterized by spectroscopic data and have been structurally confirmed by single crystal X-ray diffraction study in some representative cases. The X-ray structure of [Zn(8-aq) 2(H 2O) 2](NO 3) 2 shows C–H– π, and π– π interactions and forms a H-bonded sheet (with interactions between the oxygen of NO 3 and C(9)–H of 8-aq/coordinated H 2O). A novel one-dimensional cadmium(II) azido complex, [Cd(8-aq)(N 3) 2]n ( 9), in which the azido takes on an end-on (EO) bridging mode, has been synthesized and characterized. The presence of π– π interactions result in a supramolecular two-dimensional behaviour for the structure. The complexes are photoluminescent at room temperature.