Synthesis, spectroscopic, and magnetic studies of new alkoxy and allied bimetallic derivatives of nickel(II) with aluminium

Abstract

Nickel(II) tetraisopropoxyaluminate undergoes alcoholysis reactions with various alcohols and acetylacetone to yield products with the composition: Ni[Al(OR)4]2 (when ROH = methanol, ethanol, 2,2,2-trifluoroethanol, 2,2,2-trichloroethanol, n-butanol, and 1,3-dichloro-2-propanol); Ni[Al(O-i-Pr)(O-t-Bu)3]2 (with tertiary butyl alcohol); Ni[Al(O-i-Pr)2(O-t-Am)2]2 (with tertiary amyl alcohol); and Ni[Al(O-i-Pr)2(acac)2] (with acetylacetone). On the basis of their visible reflectance and infrared spectra along with molecular weights and magnetic susceptibilities, and octahedral geometry is tentatively suggested for these complexes in the solid state with indications of an equilibrium between tetrahedral and octahedral forms in solution. The alkoxy ligands have also been fitted into the spectrochemical and nephelauxetic series.

CoGa2O4 Nanoparticles and Films Using a Single Molecular Source

“…Solvents were purified by standard methods and stored over appropriate desiccating agents. The hetero-bimetallic precursor, [CoGa 2 (OtBu) 8 ], was obtained by a salt-elimination reaction between anhydrous cobalt chloride and sodium tetra-alkoxogallate [Equation (1)] as described by Singh and Mehrotra [19].…”

“…The hetero-bimetallic precursor, [CoGa 2 (OtBu) 8 ], was obtained by a salt-elimination reaction between anhydrous cobalt chloride and sodium tetra-alkoxogallate as reported by Singh and Mehrotra [19]. The crystals of [CoGa 2 (OtBu) 8 ] were found to be unsuitable for single-crystal X-ray diffraction anal- , whose distributions in the gas phase were found to be temperature dependent [24].…”

“…Although molecule-to-material transformation processes are not well-studied, the competitive edge of molecule-based synthesis is sufficient by homogeneous chemical compositions and more importantly the ability to synthesize metastable phases. Among transition metal ternary oxides, metal gallates are promising materials for optical [16][17][18] and catalytic applications [19]. CoGa 2 O 4 spinel is mainly used as oxidic semiconductor as well as color pigment.…”

Metal-Oxygen-Metal' Ring Formation in Metal Alkoxide Systems

“…12 ' It is interesting to record that [Fe(OMe) 2 (O 2 CCH 2 Cl] 10 adopts an interesting structure termed by Lippard' 131 as a molecular ferric wheel, some possible modifications of which have been suggested by Mehrotra and Singh" 4 ' X-ray structural study of the yttrium methoxyethoxide [Y(OC 2 H 4 OMe) 3 ] 10 shows' 15 ' a centrosymmetric cyclic arrangement of 10 yttrium atoms, each in a seven coordinate environment attaining a pentagonal bipyramidal arrangement. This decameric structure of methoxyethoxide of yttrium does not appear to be in conformity withBradley's conclusion 1 ' 6 ' that metal alkoxides tend to attain the attainment of the higher coordination state of the central metal.Again a contrast is presented by the crystal structure of [Cu(OCHMe-CH 2 -NMe 2 ) 2 ] which depicts" 71 a trans square planar stereochemistry around the copper.Interestingly, the use of phosphino -alkoxide ligands has not only made accessible metal derivatives with fascinating structural features," 8201 but also stabilized novel platinum(II) alkoxide complexes' 2 ' 1 (Fig.4)which are in general kinetically unstable with respect to pnoteworthy that the stability of the chelate alkoxo complexes of the type shown inFigure 4appears to be due to the conformation of the chelate ring making P-hydrogen elimination unfavourable.Tetraalkoxoaluminate ligands function generally as bidentate'22 " 241 (Fig.5a). However, the hexacoordinated nature of nickel' 221 in [Ni{Al(OMe) 4 } 2 ] indicates that {Al(OMe) 4 }~ functions in a tridentate manner (Fig.5b) of ligated {Zr 2 (OR) 9 }~ groups in responding to the tendency of different metal atoms for achieving their preferred coordination state and geometry with the formation of |i 2 -and |i 3 -alkoxo bridges has been demonstrated in a number of publications, as summarized in a recent review by the authors.…”

Bimetallic Alkoxides of Nickel(II) with Niobium(V) and Tantalum(V)

“…Recently in our laboratories, detailed investiga tions have been carried out on nickel(II) alkoxide derivatives [4,5]. In contrast to the insoluble and polymeric nature of these derivatives, M ehrotra et al [6,7] have been able to synthesize soluble and vol atile bimetallic alkoxides of nickel with aluminium in which the [A l(O Pr')4]-unit was found to act as a tridentate ligand.…”