An N,N′-diethylformamide solvent-induced conversion cascade within a metal-organic framework single crystal

Crystals of a two-dimensional (2D) metal-organic framework (MOF) [Cd-3(BTB)(2)(DEF)(4)]center dot 2(DEF) 0.5 (1; BTB = benzene-1,3,5-tribenzolate; DEF = N,N'-diethylformamide) immersed in a solution of trans1,2-bis(4-pyridyl)ethylene (BPEE) yields an interpenetrated threedimensional (3D) MOF of [Cd-3(BTB)(2)(BPEE)(H2O)(2)]center dot(BPEE)center dot xSol (2). Crystals of MOF 2, in turn, undergo a cascade conversion when immersed in DEF, yielding [Cd-3(BTB)(2)(BPEE)(1.8)(DEF)(0.9)(H2O)(0.8)]center dot xSol (3a) over 100 seconds and [Cd-3(BTB)(2)(BPEE)(2)(DEF)(2)]center dot xSol (4) after one hour, before finally shuttling back to MOF 1 after six hours.