Conformational preferences for some 3,3-bis[(4′-substituted phenylsulfanyl)]1-methyl-2-piperidinones through spectroscopic and theoretical studies - Olivato, Paulo Roberto; Junior, Carlos R. Cerqueira; Contieri, Bruna; Santos, Jean Miguel Mansera; Zukerman Schpector, Júlio (Journal of Sulfur Chemistry, 2013)