Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Summary 1,2-Dihydroxycyclobutene-3,4-dione (squaric acid) was polycondensed with N-ethyl- and N-(1-butyl)carbazole in polyphosphoric acid to give polymers having 36–43% of 1,2-oriented squarate units. The polymers are insoluble in organic solvents or sulfuric acid. Condensation of 1,2-dichlorocyclobutene-3,4-dione (squaryl dichloride) with N-1-butyl-carbazole in nitrobenzene gave 100% of 1,2-oriented squarate units. This polymer is soluble in most organic solvents, and the molecular weight (¯Mw) is 1900 (DP=6). The electrical conductivity was low, 〈10−9 (ohm cm)−1, and did not increase on treatment with iodine.
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