A rare example of in situ linker generation with the formation of soft porous Zn- and Co-MOFs (IFP-9 and -10, respectively) is reported. The flexible ethoxy groups of IFP-9 and -10 protrude into the 1D hexagonal channels. The gas-sorption behavior of both materials for H₂, CO₂ and CH₄ showed wide hysteretic isotherms, typical for MOFs having a flexible substituent which can give rise to a gate effect.