Hitherto unknown squaric acid difluoride (3, 4-difluoro-3-cyclobutene-1, 2-dione)(1a) has been synthesized in 71% yield by gas phase fluorination of squaric acid dichloride (1c) with KF at 250° C.(1a) has been characterized by multinuclear NMR, mass, IR and Raman spectra. The IR spectrum is in excellent agreement with its ab initio prediction (MP2, 6-311+ G (2d, p)). The vacuum thermolysis of (1a) at 700° C does not yield the expected ...
