Control of Interpenetration in Two-Dimensional Metal–Organic Frameworks by Modification of Hydrogen Bonding Capability of the Organic Bridging Subunits

Six coordination polymers were prepared
by linking Mn­(SCN)2 units by three different bis­(4-pyridyl)
substituited hydrazone
derivatives (L) in three different solvents (methanol,
ethanol, and acetonitrile) in order to study the effect of the hydrogen
bonding ability of L on the formation of solvates rather
than interpenetrated solvent-free interpenetrated structures. When
the ligand L which cannot act as a hydrogen donor was
used, in all three solvents the same product was obtained. This was
a [Mn­(SCN)2L2]n metal–organic framework, consisting of two-dimensional
(2D) networks, each interpenetrating two neighboring ones. When the
bridging ligands L have additional functional groups
capable of acting as hydrogen donors or acceptors, synthesis from
acetonitrile yields non-interpenetrating 2D [Mn­(SCN)2L2]n networks with
solvent molecules occupying the voids of the network. Other solvents
were found to yield interpenetrated solvent free networks, or they
replaced some of the L ligands, forming one-dimensional
coordination polymers.