Isolation and Characterization of Different Homometallic and Heterobimetallic Complexes of Nickel and Zinc Ions by Controlling Molar Ratios and Solvents

Abstract

This work describes employment of two structurally similar Schiff‐base ligands (H2L and H2L‐Me) [H2L = C14H13NO3 and H2L‐Me = C15H15NO3] for the synthesis of three homo‐metallic ZnII and two hetero‐bimetallic ZnII–NiII based multinuclear complexes {[ZnII4L4(MeOH)2] (1), [ZnII5(L)5(MeOH)2]·MeOH·CH3CN (2), [(L)2ZnII4Cl2(µ3‐OMe)2(MeOH)2]·2MeOH (3), [NiII2ZnII2(L)4(MeOH)2] (4) and [Ni3Zn2(L‐Me)5(H2O)2]·MeOH·CH3CN (5)} with different interesting structural core topologies. All of these complexes (1–5) have been characterized by single‐crystal X‐ray diffraction (XRD), elemental analysis, and UV/Vis and Fourier transform infrared (FTIR) spectroscopy. The fluorescence properties of ZnII‐containing complexes have been studied by measuring fluorescence spectra in solid state and solution phase. The luminescence behavior has been further quantified by fluorescence life‐time and quantum yield measurements. Using high resolution mass spectrometry (HR‐MS), the molecular integrity of complexes in the solution phase has been demonstrated by simulating isotopic distribution of molecules with theoretically calculated molecular isotopic patterns. The magnetic properties of ZnII–NiII containing complexes (4–5) have been studied in the temperature range from 5 K to 300 K. Thermogravimetric analysis (TGA) has been carried out to study the thermal stabilities of these complexes (1–5).