Sunita Goyal

Synthesis, Spectral and Biological Studies of Organosilicon(IV) Complexes of Schiff Bases Derived from Amino Acids

Abstract Several new organosilicon(IV) complexes of the type Me3Si(L/L′) [where L/L′ = anions of the Schiff bases derived from the condensation of 2-methoxyben-zaldehyde (HL) or acetophenone (HL′) with glycine (HL-1/HL′-l), L-leucine (HL-2/HL′-2), L-methionine (HL-3/ HL′-3), DL-α-alanine (HL-4/HL′-4) and L-valine (HL-5/HL′-5)] have been synthesized and characterized by elemental analyses, molar conductance, electronic, infrared and multi-nuclear magnetic resonance (1H and 13C) studies. All the complexes are non-electrolytes. A penta-coordinate, trigonal-bipyramidal geometry is suggested for all of the complexes. The in vitro antimicrobial activity of the trimethyl- and triphenylsilicon(IV) complexes has also been screened against bacteria (E. coli, Rhizobium meliloti, Aeromonas formicans, Pseudomonas putida. Staphyllococcus aureus) and fungi (Penicillium notatum. Verticllium dahliae, Aureobasidium pullulans and Aspergillus niger), and the complexes were found to be active in this respect.

Synthesis, Characteristic Spectral Studies and in Vitro Antimicrobial Activity of Organosilicon(IV) Complexes of N-(2-Hydroxynaphthalidene)-Amino Acid Schiff Bases

Fifteen new organosilicon(IV) complexes formulated as R 3 Si[2-HOC 10 H 6 CH=NCH(X)COO] and Me 2 Si[2-OC 10 H 6 CH=NCH(X)COO] (where X = H[H 2 L 1 ], --CH 2 CH(CH 3 ) 2 [H 2 L 2 ], --CH 2 CH 2 -SCH 3 [H 2 L 3 ], --CH 3 [H 2 L 4 ] and --CH(CH 3 ) 2 [H 2 L 5 ] were prepared and characterized by 1 H and 13 C NMR, IR, electronic spectral studies, and elemental analysis. All of the complexes are nonelectrolytes. The spectral studies suggested a distroted trigonal-bipyramidal geometry around the silicon atom. Antimicrobial activity screening for all of the complexes was carried out against various bacteria [ Escherichia coli, Aeromonas formicans, Pseudomonas putida-2252, and Staphylococcus aureus-740 ] and fungi [ Aureobasidium pullulans-1991, Penicillium chrysogenum-1348, Verticillium dahliae-2063, and Aspergillus niger ORS-4 ]. The complexes showed good activity.

TRIPHENYLSILICON(IV) DERIVATIVES OF SCHIFF BASES DERIVED FROM AMINO ACIDS

Abstract New organosilicon(IV) complexes of the type PhSi(L) [where I. - anions of the Schiff bases derived froin the condensation of 3-methoxybenzaldetiyde or acetophenone with glycine (IIL1/HL6). I.-leucine (HI2/HL7). L-niethioninc (HL2/HL8), DI-α-alanine (HL4/HI20) and I -valine (HL5/HL10)] have been synthesized and characterized by elemental analyses, molar conductancc. electronic. intiarcd and rnultinuclear magnetic resonance (1Hand 15C) studies All the complexes are non-electrolyte On the basis of the spectral studies a penta-coordinated trigonal bipyramidal geometry is suggested for all the compleses

SYNTHESIS AND SPECTROSCOPIC PROPERTIES OF MIXED GLYCOLATE-SALICYLALDIM INATE DERIVATIVES OF ARSENIC(III)

Mixed glycolate-salicylaldiminate derivatives of arsenic(III) of the type OC6H4CH˭NAr have been prepared by the reactions of equimolar amounts of Cl [G=CH2CH2 (G1), CHMeCHMe (G2), CMe2CMe2 (G3), CHMeCH2CMe2 (G4), CMe2CH2CH2CMe2 (G5)] with N-arylsalicylaldimines (HOC6H4CH˭NC6H5 (HL1), HOC6H4H4CH˭NC6H3Me2-2,6 (HL2), HOC6H4CH˭NC6H3Et2-2,6 (HL3) and HOC6H4CH˭NC6H3(Pr-i)2-2,6 (HL4); in benzene using Et3N as a proton acceptor. These new derivatives have been characterized by elemental analyses, molecular weight measurements and spectroscopic [IR, NMR (1H and 13C)] studies.

Synthesis and Spectroscopic Properties of Mixed Aryloxide-Glycolate Derivatives of Arsenic(III)

The reaction in 1:1 molar ratio of {\gg4}OGOAsCl , where G = CH 2 CH 2 , CHMeCHMe, CMe 2 CMe 2 , CHMeCH 2 CMe 2 , and CMe 2 CH 2 CH 2 CMe 2 , and substituted phenols ArOH (Ar = C 6 H 3 Me 2 -2,6; C 6 H 3 Pr i -5-Me-2; C 6 H 3 Pr i -2-Me-5 and C 6 H 3 Pr i 2 -2,6), in the presence of one equivalent of triethylamine in benzene afford volatile colorless liquids of the type {\gg4}OGOAsOAr . All these derivatives have been characterized by elemental analyses, molecular weight measurements, and spectroscopic [IR, NMR( 1 H and 13 C)] studies.

PREPARATION AND SPECTROSCOPIC CHARACTERIZATION OF FOUR-COORDINATE MIXED GLYCOLATE-SALICYLALDIMINATE DERIVATIVES OF ALUMINIUM(III)

ABSTRACT Reactions of equimolar quantities of aluminium triisopropoxide, glycols (GH2= HOCMe2CMe2OH (G1H2), HOCHMeCHMeOH (G2H2), HOCHMeCH2- Me2OH (G3H2), HOCMe2CH2CH2CMe2OH (G4H2)) and N-arylsalicylaldimines (LH = HOC6H4CH˭NC6H3Me2−2,6 (L1H); HOC6H4CH˭NC6H3Et2−2,6 (L2H); and 2-HOC6H4CH˭NC6H3(Pr-i)2−2,6 (L3H) in benzene afford new mixed glycolate-salicylaldiminate derivatives of aluminium(III). All of these derivatives have been characterized by elemental analyses, molecular weight determinations, and spectroscopic [IR, NMR (1H and 27Al)] studies.

Dimethylsilicon(IV) Derivatives of Amino Acids

Reactions of dichlorodimethylsilane with the sodium salt of amino acids in 1:2 molar ratio led to the formation of a new series of dimethylsilicon(IV) complexes of general formula, Me 2 SiL 2 [L = anion of amino acids, viz. glycine (HGly), L-methionine (L-MethH), DL- f -alanine (DL- f -AlaH) L-leucine (L-LeuH), L-valine (L-ValH) and D-phenylalanine (D-PheH)]. The complexes have been characterized by elemental analyses, molar conductance, and electronic spectra, and the bonding in these complexes is discussed in terms of their infrared, 1 H and 13 C NMR spectra. A distorted octahedral structure with trans methyl groups has been tentatively suggested for the complexes. The complexes, found soluble in DMSO, have been tested in vitro against various bacteria, viz. Escherichia coli , Pseudomonas putida-2252 , Aeromonas formicans , Staphylococcus aureus-740 , and fungi, viz. Aspergillus niger ORS-4, Aureobasidium pullulans-1991 , Verticillium dahliae-2063 , and Penicillium notatum-1348 .