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Solution-state characterization of sec-butyllithium in [D8]toluene was conducted by utilizing a variety of NMR spectroscopic experiments including diffusion-ordered NMR spectroscopy (DOSY) with diffusion-coefficient-formula-weight correlation analyses and other one- and two-dimensional NMR spectroscopic techniques. These results suggest that sec-butyllithium exists primarily as a tetramer/hexamer mixture in hydrocarbon solvents. However, the presence of roughly 2-5 % (by mol ratio) lithium sec-butoxide in both commercially available and laboratory-synthesized sec-butyllithium solutions due to the reaction with adventitious dioxygen will lead to the formation of a 1:5 sec-butoxide/ sec-butyllithium mixed hexamer. A sec-butoxide/ sec-butyllithium mixed octamer will emerge when the proportion of butoxide to butyllithium increases. [ABSTRACT FROM AUTHOR]

The article presents a study which discusses m/p-cresol-based novolac resin synthesis in di-tert-butyl dicarbonate (t-BOC) using multidimensional nuclear magnetic resonance (NMR) spectroscopy. The study uses Bruker 400 MHz Avance instrument to record the NMR spectra in 400.13 megahertz (MHz) frequency. Results show that polymer macrostructure leads the signal in the NMR spectrum in the range of molecular weights.