Organometallic polymers

Tin-containing polymers were synthesized by reaction of amino acids (4-aminobenzoic acid, ampicillin, glycylglycine and glycyl-D-phenylalanine) with organotin dichloride via the interfacial condensation technique. The products were characterized using Fourier Transform Infrared spectrometry, Ultraviolet spectrometry, light scattering photometry and mass spectral analysis. The biological activities of the products were tested against selected microorganisms and human cells.

Ruthenium-containing polymers derived from dichloro-bis(2,2-bipyridine)-ruthenium and selected dithiol or diamines have been synthesized. These polymeric products were characterized using FTIR, ultraviolet spectroscopy, light scattering photometry and mass spectral analysis. Thermal degradation studies of these products are presented.

Reaction of Group IVB metallocene dichlorides with a monoaza dye yields a polymer in which the metal is bonded to a sulfonic and a hydroxyl group. The structure and bonding of the polymer was confirmed using infrared, mass spectrometry and 1H-NMR spectroscopy. Thermo and elemental analysis was used to confirm the presence of the metal. The stability of the polydye to the monomer unit was compared employing an argon laser in the visible region.

Organotin-modified poly(vinyl alcohol) products and titanocene-containing polyethers were synthesized via the interfacial polymerization technique. The structures were determined using infrared and mass spectroscopy. Further characterization involved elemental analysis, thermal analysis, and solubility studies. For the organotin products, the biological activities towards selected microorganisms were determined. The products exhibited selective inhibition of Candida Albicans, the microorganism most responsible for yeast infections in man. The titanocene-containing polyethers exhibited flexibility when derived from longer chained polyethylene glycols, but were inflexible when shorter chained polyethylene glycols were used.

Group IVB metallocene polymers and oligomers undergo a pi-sigma rearrangement of the cyclopentadienyl moieties in DMSO based on NMR data. The sigma-Cp rings are stereochemically rigid at room temperature.

A new polymeric ligand, poly[5-(1,3-bis-(2'-pyridylimino) isoindolyloxy)ethylene], was synthesized. At same time, 1,3-bis-(2 '-pyridylimino)-5-hexadecanyloxyisoindoline was also synthesized. These two products were characterized with fourier transform infrared spectrometry, ultraviolet spectrometry, mass spectral analysis and elemental analysis. Their complexes of Cu+2 were prepared.

Cancer is the second leading cause of death in the western world. In order to treat various types of cancer, platinum-based drugs are most widely employed as metal-containing chemotherapeutic agents. However, their clinical usage is hindered by toxic side effects, and by the emergence of drug resistance. Our focus was to replace platinum with less toxic metal like tin which can give better alternatives for cancer treatment. The major aim of our study was to synthesize novel organotin polyethers (Sn-O) which can be used to combat cancer. Preliminary results from our laboratory using organotin polyethers, that were synthesized by varying the structure of diols showed growth inhibition in Balb-3T3 cells. This study directly led us to hypothesize the two structural windows, first by changing the distance between diol and second, by presence of unsaturation in diols, the biological activity of organotin polyethers (Sn-O) can be enhanced significantly. Different series of polymeric compounds were synthesized based upon these two structural windows and the formation of products was validated using standard techniques like infrared spectroscopy (IR), light scattering photometer, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and nuclear magnetic resonance (NMR). The synthesized polymers arrested the growth of cancer cell lines including bone, prostate, colon, breast, pancreas and lung cancer derived cell lines in vitro. In number of instances where chemotherapeutic index values of two and greater were found that these polymers are significantly more active against cancer cells than non-cancerous cells in culture.