J. P. Tandon

Schiff base complexes of aluminium(III)

Abstract Schiff bases containing a functional OH group ortho to the azomethine (>CN-) group, such as o -HOC 6 H 4 C(CH 3 ):N R (where R = n -C 4 H 9 , or C 6 H 5 ) and o -HOC 6 H 4 C 4 C(CH 3 ):N(CH 2 ) n N:(CH 3 )CC 6 H 4 OH- o (where n = 2 or 3) (react with aluminum iso proposixide in the medium of anhydrous benzene liberating various moles of iso propanol depending on the stoichiometry, and yield a variety of aluminium-Schiff base derivatives. All these complexes have been synthesized in almost quantitative yields and their molecular weights determined ebullioscopically in benzene. The i.r. spectra show almost no shift in ν(CN) and ν(AlO) frequencies appear in 610–587 cm −1 region.

Synthesis of Some Novel Germanium(IV)-Schiff Base Complexes

Abstract Non-electrolytes and hexacoordinated germanium complexes of the type Ge(SB)2 (where SBH2 is the bifunctional tridentate Schiff base having the donor system, HO-N-OH) have been synthesized by the reaction between germanium tetraethoxide and the Schiff base in benzene medium. The Schiff bases used in these reactions are of the general types o-HOC6H4C(CH3):NROH and 2-HOC10H6CH:NR′OH (where R = R′ = stoichiometry are exclusively obtained in whatever molar ratio the reactants are mixed. The infrared, mass and proton magnetic resonance spectra of these complexes show the coordination of azomethine nitrogen and phenolic and alcoholic oxygens to the central germanium atom. The integral procedual decomposition temperature (IPDT) of germanium bis[2-hydroxy-1-naphthylidene-2-hydroxyethylamine] and germanium bis[2-hydroxyacetophenone-2-hydroxyethylimine] complexes has been calculated and this shows the higher thermal stability of the latter as compared to the former.

Aluminium Complexes with Sulphur Containing Ligands

Abstract Reactions of Al(OPri)3 with some sulphur containing Schiff bases having or donor system have been investigated in different molar ratios. The reaction products from equimolar (M:L) ratios are dimeric, whereas 2:3 (M:L) ratios yield monomeric reaction products in boiling benzene. Based on elemental analysis, U.V., I.R. and NMR spectral studies possible structures have been indicated for the resulting compounds.

Schiff Base Complexes of Boron: Boron Complexes of Schiff Bases of 2,4-Pentanedione

Abstract Tetra-coordinated diacetoxy-boron Schiff base derivatives of the type (AcO)2B(SB) (where SB− is the anion of the corresponding monofunctional bidentate Schiff base, SBH) have been synthesized in almost quantitative yields and in a state of sufficient purity by the equimolar ratio reactions of boric acid and Schiff bases in acetic anhydride medium. Even on mixing the reactants in higher molar ratio only 1:1 derivatives could be isolated. On the basis of elemental analyses, molecular weight determinations and conductance measurements and infrared and proton magnetic resonance spectra, the possible structures for the resulting new derivatives have been indicated.

Schiff Base Derivatives of Boron. Synthesis of Boron Derivatives of the Schiff Bases Derived from the Condensation of 1-Phenyl-1,3-butane-dione with Hydroxy Alkylamines or Arylamines

Abstract Synthesis of B(OEt)(SB) and B(SB)(SBH) types of derivatives (where SB− and SBH− are the anions of the Schiff bases, SBH2) is reported. These are formed by 1:1 and 1:2 molar reactions of boron ethoxide with the bifunctional tridentate Schiff bases such as 3-(2-hydroxyethyl)amino-1-phenyl-2-buten-1-one, 3-(2-hydroxy-n-propyl)amino-1-phenyl-2-buten-1-one and 3-(2-hydroxyphenyl)amino-1-phenyl-2-buten-1-one respectively. The labile nature of the ethoxy groups in 1:1 derivatives has been shown by carrying out exchange reactions with an excess of t-butyl alcohol. The resulting derivatives have been characterized by elemental analysis, molecular weight determinations, conductance measurements and infrared and proton magnetic resonance spectra.

Schiff Base Derivatives of Lanthanides - Synthesis of La(III), Pr(III) and Nd(III) Complexes of Alkylimines and Arylimines Derived from 2-Hydroxy-1-Naphthaldehyde

Abstract Methods of synthesis of lanthanide derivatives of the type, In(0-i-C3H7)2(2-OC10H6CH:NR) and In(0-i-C3H7) (2-OC10H6CH:NR)2 in high yields and in high purity have been described. These have been synthesized by the 1:1 and 1:2 molar reactions of the isopropoxides of lanthanides with monofunctional bidentate Schiff bases, 2-HOC10H6CH:N-n-C4H9 and 2-HOC10H6CH:NC6H5. Their exchange reactions with an excess of t-butyl alcohol have yielded the corresponding t-butyl derivatives. The resulting compounds have been characterized by elemental analyses and molecular weight determinations. Their infrared spectra have also been recorded and tentative assignments were made.

Mixed aldimine derivatives of aluminium

Abstract 1:1:1 Molar reactions of Al(OPr i ) 3 with monofunctional bidentate and bifunctional tridentate Schiff bases have yielded mixed Schiff base derivatives of the type (S′B′)Al(SB) (where S′B′ 2− and SB − are the anions of bifunctional tridentate and monofunctional bidentate Schiff bases respectively). If these complexes are monomeric, the central aluminium atom will be pentacoordinated, and this is suggested by the addition reaction with pyridine. Structures based on IR and NMR spectra have been suggested.

Schiff base complexes of gallium

Abstract Gallium Schiff base complexes of the type, Ga(OPri)(SB) and Ga2(SB)3 (where SB2− represents the anion of the bifunctional tridentate Schiff base SBH2 having the donor system HONOH) have been synthesized by the interactions of gallium isopropoxide with the Schiff bases in the medium of anhydrous benzene. Ga2(SB)3 type of derivatives are monomeric, whereas Ga(OPri)(SB) type of derivatives are dimeric and undergo interchange reactions with t-butanol giving Ga(OBut)(SB) type of compounds, which are also dimeric. Further, tetradentate Schiff base, bis(o-hydroxyacetophenone)-1,3-propylenediimine having the donor system HONNOH yeilds insoluble products. The i.r. spectra of the resulting complexes exhibit ν(GaO) frequencies in the region, 683-600 cm−1; ν(CN) frequencies remain almost unaffected on complexation. The magnetic susceptibilities of digallium tris-Schiff base complexes show them to be diamagnetic

Schiff base derivatives of lanthanons—a novel synthesis of La(III), Pr(III) and Nd(III) derivatives of fluorine containing schiff bases

Abstract 1:1 and 1:2 stoichiometric reactions of the isopropoxides of some of the lanthanons La(III), Pr(III) and Nd(III) with monofunctional bidentate Schiff bases containing fluorine such as 1, 1, 1-trifluoro-2,4-pentanedione- n -propylimine (TFAH- n -C 3 H 7 ) and 1,1,1-trifluoro-2,4-pentanedione- n -butylimine (TFAH- n -C 4 H 9 ) have led to a novel synthesis of derivatives of the type, Ln (0- i -C 3 H 7 ) 3− n (TFA-R) n (where n = 1 or 2; Ln = lanthanides; R = n -C 3 H 7 or n -C 4 H 9 and TFA- R is the anion of the corresponding Schiff base, TFAH- R ). The resulting compounds have been obtained in high yields and characterized by elemental analysis and mol. wt determinations. Their i.r. spectra have been recorded in the range of 4000-400 cm −1 and the effect of CF 3 group on the and stretching frequencies is discussed.

Potentiometric studies on stepwise mixed ligand complex formation Cu(II), Ni(II) or Zn(II)-nitrilotriacetic acid-hydroxy acid

Abstract Potentiometric studies of the interaction between copper(II), nickel(II) and zinc(II) nitrilotriacetates with certain bidentate ligands, such as salicylic acid(SA),5-sulphosalicylic acid (SSA) and 1,2-dihydroxy benzene-3,5-disulphonic acid (Tiron) are reported. Ternary complexes having a 1 : 1 : 1 molar ratio of metal ion to nitrolotriacetic acid (NTA) to be secondary ligand are formed. Their formation constants (Log K MAB ) are reported and the probable reaction mechanism is discussed. The order of stability in terms of metal ion has been found to be Cu(II) > Zn(II) > Ni(II) and in terms of secondary ligand as Tiron > SA > SSA.