Tropylium tetrafluoroborate is an organic compound with the formula . Containing the tropylium cation and the non-coordinating tetrafluoroborate counteranion, tropylium tetrafluoroborate is a rare example of a readily isolable carbocation. It is a white solid.

This compound may be prepared by the reaction of cycloheptatriene with phosphorus pentachloride, followed by tetrafluoroboric acid.

See also Triphenylmethyl chloride, also known as trityl chloride.

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