118523-82-3Relevant academic research and scientific papers
A new synthesis of 3-fluoro- and 3-chlorocyclobutenes from dihalocyclobutanes. The five isomers of chlorofluorocyclobutane
Craig, Norman C.,Borick, Steven S.,Fisher, Michael A.,Tucker, Thomas R.,Xiao, Yong-Zhuang
, p. 215 - 224 (2007/10/02)
3-Fluorocyclobutene (1) and 3-chlorocyclobutene (2) have been obtained by simpler syntheses and in higher yield than previously reported.One of the synthetic steps involves a three-phase-transfer-catalysis technique that could be of wider utility.New examples are cited of applying AgF2, an underutilized reagent, as a fluorinating agent near room temperature.Compounds 1 and 2 have been characterized by mass, NMR and vibrational spectroscopies.The NMR spectra have been fully analyzed.Useful group frequencies in the vibrational spectra of halocyclobutenes have been identified.The five monochloromonofluorocyclobutane precursors of fluorocyclobutenes have also been separated and characterized.From NMR coupling constans, conformer mixtures have been identified for three of the isomers.
Vibrational Spectra and Assignments for 1-Fluoro- and 1-Chlorocyclobutenes. Revised Assignment for Cyclobutene
Craig, Norman C.,Borick, Steven S.,Tucker, Thomas R.,Xiao, Yong-Zhuang
, p. 3549 - 3558 (2007/10/02)
Gas-phase infrared spectra and liquid-phase Raman spectra are presented for 1-chlorocyclobutene and 1-fluorocyclobutene.Complete assignments of vibrational fundamentals are proposed for these molecules of Cs symmetry.For 1-chlorocyclobutene (cm-1): (a') 3090, 2947, 2940, 1595, 1452, 1434, 1250, 1197, 1165, 1120, 916, 891, 869, 493, 299; (a'') 2980, 2966, 1140, 1070, 1016, 854, 751, 395, 211.For 1-fluorocyclobutene (cm-1): (a') 3111, 2954, 2948, 1667, 1464, 1437, 1306, 1214, 1189, 1154, 972, 911, 866, 651, 412; (a'') 2982, 2969, 1142, 1076, 1020, 855, 764, 436, 264.Frequencies of CH-rich modes correlate closely for these isotopomer-like molecules.These results along with a Raman spectrum of liquid cyclobutene near -100 deg C have provided evidence for assigning five unsettled vibrational fundamentals of cyclobutene.These modes in cm-1 are (a2) ν9 = 2944, ν11 = 1011, and ν12 = 846 and (b1) ν19 = 903 and ν20 = 888.Ring-puckering frequencies for a variety of halogen-substituted cyclobutenes are compared and found to follow an understandable pattern.
