Ligand environment and the structure of schiff base adducts and tetracoordinated metal-chelates

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

Coordinative interactions of Ph2SnCl2, Me2SnCl2 and PhSnCl3 with 2-hydroxy-1-naphthalideneanilines containing different substituents in the aniline fragment have been studied. The newly synthesized adducts of 1:2 stoichiometry [organotin(IV) chloride: Schiff base] have been characterized by elemental analysis, thermogravimetric and infrared spectral data. Conductance measurements and electronic spectra indicate considerable dissociation of the compounds in solution.

Coordination Compounds of Organotin(IV) Chlorides with the Schiff Bases Derived from 2-Hydroxy-1-naphthaldehyde

Coordinative interactions of tin(II) chloride, bromide and isothiocyanate with Schiff bases derived by the condensation of 2-hydroxy-1-naphthaldehyde with aniline having different substituents have been studied. The newly synthesised adducts of 1:2 stoichiometry (tin(II) halides and isothiocyanate: Schiff base) have been characterised by elemental analysis and IR spectral data. The compounds were examined for antibacterial and antifungal activity. The compounds have moderate antimicrobial activity. Conductance measurements indicate considerable dissociation of the compounds in solution.

Coordination Compounds of Tin(II) Chloride, Bromide and Isothiocyanate with Schiff Bases Derived from 2-Hydroxy-1-naphthaldehyde

Equimolar and bimolar reactions of zirconium isopropoxide with bibasic tridentate azomethine (AZH2) having the donor system ONO have been carried out and derivatives of the type Zr(OPr1)2(AZ) and Zr(AZ)2 [Where AZ2− is the anion of the azomethine molecule] have been isolated The labile nature of the isopropoxy groups in 1∶1 derivatives has been shown by carrying out exchange reactions with equimolar amount of 2-methylpentane-2,4-diol All the newly synthesized derivatives have been characterized on the basis of elemental analysis, conductance measurements, molecular weight determinations and infrared, ultraviolet, visible and proton magnetic resonance spectral studies

Spectral studies of the newly synthesized azomethine derivatives of zirconium(IV)

The 1∶2 molar reactions of tin(IV) chloride with the Schiff bases, CH3C(OH):CHC(CH3):NR and 2 HOC10H6CH:NR′ (where R=C2H5,n-C3H7 orn-C4H9 and R′=C6H5, C2H5,n-C4H9 ort-C4H9) have resulted in the synthesis of SnCl4·(SBH)2 type derivatives (whereSBH represents the Schiff base molecule). These have been characterized by elemental analysis, conductivity measurements and IR spectral studies.

Tin(IV) complexes of schiff bases derived from pentane-2,4-dione or 2-hydroxy-1-naphthaldehyde

1∶1 and 1∶2 molar reactions of tin(IV) chloride with theSchiff bases, HO−C6H4CH∶NROH [where R=−(CH2)2−, −CH2−, −CH(CH3)−, −(CH2)3−, and −CH(C2H5)CH2−] have been studied in different stoichiometric ratios and derivatives of the type SnCl4(SBH2) and SnCl4(SBH2)2 (whereSBH2 represents theSchiff base molecule) have been isolated. These have been characterised by elemental analysis, conductivity measurements and I.R. spectral studies.

Tin(IV) complexes ofSchiff bases derived from salicylaldehyde and aminoalcohols

2-Diphenylphosphinato-1,3,2-dioxaborolanes and -borinanes of the type

(whereG = -CH2CHMe-, -CH2CH2CH2-, -CH2CH2CHMe-,-CMe2CMe2-, -CMe2CH2CHMe-,-CH2CMe2CH2-, -CH2CEt2CH2-, and -C6H4-) are obtained by the reaction of diphenylphosphinic acid with the corresponding 2,2′-oxo-bis-1,3,2-dioxaborolanes and-borinanes. The products are white crystalline solids, which have sharp melting points and are hydrolytically stable. They have been characterized by elemental analysis, IR and multinuclear NMR (11B,31P, and119Sn) studies. The data suggest structures with monodentate phosphinato moieties and 3-coordinated boron atoms.

O. P. Singh

Papers

Tin(IV) complexes of schiff bases derived from pentane-2,4-dione or 2-hydroxy-1-naphthaldehyde

Tin(IV) complexes ofSchiff bases derived from salicylaldehyde and aminoalcohols

Syntheses and spectroscopic studies of diphenylphosphinato derivatives of boron