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Synthesis and characterization of tractable linear metal beta-diketone coordination polymers
Abstract
New soluble linear cobalt(III) and chromium(III) $\beta$-diketone polymers have been prepared and characterized. Attempts to prepare linear coordination polymers analogous to the synthetic organic counterparts have historically posed serious problems for chemists particularly as a result of their intractability. In this study, bis($\beta$-diketonates) of the metal were first prepared and then allowed to react with sulfur halides of the form SCl$\sb2$ or S$\sb2$Cl$\sb2$ to yield thio- or dithio-bridged polymers, with the bridging occurring through the 3-carbons of the 2,4-diones. The polymers were found to be extremely soluble, with moderate molecular weights of at least 15,000 (as determined by NMR end-group analysis and viscosity measurements). GPC results were less satisfactory; they indicated polystyrene was not good as a standard for these polymers. Characterization of the materials was accomplished by Fourier-transform infrared (FT-IR), $\sp1$H- and $\sp{13}$C-nuclear magnetic resonance (NMR), pyrolysis-gas chromatograph/mass spectroscopy (py-GC/MS) and ultraviolet-visible (UV-vis) spectroscopy. Micro-analyses, gel permeation chromatography (GPC), thermal gravimetric analysis (TGA) and viscosity measurements were also performed. The synthesized materials also showed different degrees of thermostability (to at least 250$\sp\circ$C) and volatility as shown by their thermograms. In general, the trifluoroacetyl acetonate polymers were found to yield the more volatile polymers, while the Co(III)-containing materials were generally less volatile than their Cr(III) counterparts. A secondary goal of the investigation was to establish the ability of these materials to undergo chain scission upon exposure to radiation, with the reduction in molecular weight based on GPC measurements. Upon irradiation, GPC results clearly showed degradation to lower molecular weight materials. This reduction in molecular weight is an essential characteristic and requirement for positive acting resists, a possible application for these compounds.
Subject Area
Inorganic chemistry|Polymer chemistry|Chemistry
Recommended Citation
Ochaya, Ven Oryem, "Synthesis and characterization of tractable linear metal beta-diketone coordination polymers" (1993). Doctoral Dissertations Available from Proquest. AAI9408325.
https://scholarworks.umass.edu/dissertations/AAI9408325