Deposition of Metal-Organic Frameworks by Liquid-Phase Epitaxy: The Influence of Substrate Functional Group Density on Film Orientation

Abstract

The liquid phase epitaxy (LPE) of the metal-organic framework (MOF) HKUST-1 has been studied for three different COOH-terminated templating organic surfaces prepared by the adsorption of self-assembled monolayers (SAMs) on gold substrates. Three different SAMs were used, mercaptohexadecanoic acid (MHDA), 4’-carboxyterphenyl-4-methanethiol (TPMTA) and 9-carboxy-10-(mercaptomethyl)triptycene (CMMT). The XRD data demonstrate that highly oriented HKUST-1 SURMOFs with an orientation along the (100) direction was obtained on MHDA-SAMs. In the case of the TPMTA-SAM, the quality of the deposited SURMOF films was found to be substantially inferior. Surprisingly, for the CMMT-SAMs, a different growth direction was obtained; XRD data reveal the deposition of highly oriented HKUST-1 SURMOFs grown along the (111) direction.

Comparative studies of vibrational properties and phase transitions in metal-organic frameworks of [NH4][M(HCOO)3] with M=Mg, Zn, Ni, Fe, Mn

“…[1,2]. In recent years, a group of divalent metal formats containing organic cations in the large cavities of the framework of formula [cat + ][M(HCOO) 3 ] with cat + = ammonium, dimethylammonium, guanidinium, azetidinium, formamidinium etc.…”

Minimization of Surface Energies and Ripening Outcompete Template Effects in the Surface Growth of Metal–Organic Frameworks

“…[20][21][22][23][24] In the case of coordinating head groups (e.g. [22,26,28,29] While the first class of MOFs can be formed very reliably and thus has turned out to be avery robust test system, the pillared-layer system shows al arger structural variability,and thus abroader range of potential applications, because of the basically independent choice of Land P. Aset of rules has been developed to predict the surface growth of these MOFs.W hile for the cubic HKUST-1 systems mostly the density of coordinating groups at the surface seems to determine the SURMOFs orientation, [30] in the tetragonal pillared-layer system the nature of the surface-exposed ligands is of major importance.Thus,monodentate functional groups (e.g. [13,22,25,26] Tw oclasses of MOFs,which both are based on secondary building units (SBUs) comprising dinuclear tetracarboxylate clusters [M 2 (O 2 CR) 4 ]h aving the so-called paddle-wheel symmetry,h ave been successfully deposited in the form of highly defined SURMOFs.F irst, the cubic HKUST-1 MOF (Cu 3 btc 2 ;b tc = benzene-1,3,5-tricarboxylate) and its derivatives, [13,27] and second, the tetragonal, layered MOFs of the general formula [M 2 L 2 P],w here M = Cu 2+ or Zn 2+ ,L = a rigid, linear dicarboxylate linker,and P = an optional diamine pillar.…”

“…[13,22,25,26] Tw oclasses of MOFs,which both are based on secondary building units (SBUs) comprising dinuclear tetracarboxylate clusters [M 2 (O 2 CR) 4 ]h aving the so-called paddle-wheel symmetry,h ave been successfully deposited in the form of highly defined SURMOFs.F irst, the cubic HKUST-1 MOF (Cu 3 btc 2 ;b tc = benzene-1,3,5-tricarboxylate) and its derivatives, [13,27] and second, the tetragonal, layered MOFs of the general formula [M 2 L 2 P],w here M = Cu 2+ or Zn 2+ ,L = a rigid, linear dicarboxylate linker,and P = an optional diamine pillar. [22,26,28,29] While the first class of MOFs can be formed very reliably and thus has turned out to be avery robust test system, the pillared-layer system shows al arger structural variability,and thus abroader range of potential applications, because of the basically independent choice of Land P. Aset of rules has been developed to predict the surface growth of these MOFs.W hile for the cubic HKUST-1 systems mostly the density of coordinating groups at the surface seems to determine the SURMOFs orientation, [30] in the tetragonal pillared-layer system the nature of the surface-exposed ligands is of major importance.Thus,monodentate functional groups (e.g. -OH or pyridyl), which coordinate at the apical position of the paddle-wheel SBUs, usually induce SURMOF growth in the [001] direction, while bidentate ones (typically -COO À )p romote ag rowth in either the [100] or the [010] direction, depending on the exact symmetry of the MOF system.…”

Macroscopically Oriented Porous Materials with Periodic Ordered Structures: From Zeolites and Metal–Organic Frameworks to Liquid‐Crystal‐Templated Mesoporous Materials

“…This progress report presents an overview of recent studies on the synthesis, properties, and applications of porous materials with macroscopically oriented structures ( Table 1 ). The scope of this report is limited to porous materials with nano‐ or mesoscale periodic channels constructed by supramolecular self‐assembly of atomic and/or molecular components, such as zeolites (Section ), MOFs (Section ), mesoporous oxides (Section ), and polymers based on liquid crystals (LCs) (Section ) . In other words, porous materials produced by physical processes, such as anodic aluminum oxides or porous silicones, are beyond the scope of this report.…”