Homo- and Heterometallic Complexes of Vanadium and Chromium and their Conversion into Oxide Ceramics

This dissertation specifically describes the synthesis and characterization of novel homo- and heterometallic single-source molecular precursors of vanadium and chromium and their subsequent conversion into binary and ternary oxides. Investigations and results obtained in the study are assembled in four major parts related to vanadium and chromium molecules and their application in materials synthesis.

Part 1 of this thesis demonstrates the synthesis of new air stable homoleptic and heteroleptic vanadium (III) and (IV) heteroarylalkenolates as promising precursors to selectively obtain their respective oxide materials

Part 2 gives a detail account of the synthesis and characterization of heterobimetallic and trimetallic alkoxide precursors comprising of a predefined metal-metal ratio suitable for the formation of ternary and quaternary oxide nanomaterial. The flexibility of combining lithium with vanadium in different ration with possibility for trimetallic alkoxide formation was demonstrated as a molecular structural concept in [Li2V(OtBu)4Cl(THF)2] 8, [Li2V(OtBu)4(N[Si(CH3)3]2) (THF)2] 9 and [Ti4V4Li2O2(OMe)26] 10.

Part 3 clearly demonstrated an interesting synthetic approach to achieve control over phase selective synthesis of metastable chromium oxide nanomaterials. Here, bifunctional O, N chelating ligands was used as an essential building block for a number of homoleptic chromium (II) and (III) complexes.

Finally, part 4 of this thesis demonstrates the fabrication of phase selective LiCrO2 and Li2CrO4 nanoparticles from new heterometallic chromium(III)-based alkoxide, via a facile and efficient solvothermal method. The new heterometallic chromium(III)-based alkoxide was successfully synthesized and stabilized via ligand modification using 3,3,3-trifluoro(pyridin-2-yl) propen-2-ol (H-PyCH=COCF3) and N, N' -bis(4,4,4-trifluorobut-1-en-3-on)-ethylenediamine (Tfb-en).