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.
The loading of a metal-organic framework (MOF), [Cu(3)(btc)(2)xH(2)O] HKUST-1, with europium β-diketonate complexes is studied with the goal to using the porous molecular framework as a photonic antenna. Whereas loading of HKUST-1 powder particles produced via the conventional solvothermal synthesis method was strongly hindered, for HKUST-1 SURMOFs, thin MOF films fabricated using the liquid phase epitaxy method, a high filling factor can be achieved. The optical properties of the HKUST-1-MOFs before and after loading were analysed with the aid of luminescence spectroscopy. Careful analysis of the absorption spectra reveals the presence of an effective energy transfer between the HKUST-1 framework and the Eu(3+) centers.
The step-by-step growth of highly oriented and continuous thin films of [Cu 2 (ndc) 2 (dabco)] (1) at 50 C was studied and compared with growth directly from solvothermal mother solution at 120 C. The substrates were bare unmodified SiO 2 , Al 2 O 3 grown by atomic layer deposition (ALD), Ta 2 O 5 and Si 3 N 4 . The deposited layers of 1 were characterized via in-plane and out-of-plane X-ray powder diffraction (PXRD) and Scanning Electron Microscopy (SEM). The stepwise film formation process was studied by the variation of the reaction conditions and washing procedures indicating an island growth mode and the importance of storage effects. The highly oriented layers obtained by the step-bystep method were used as seeds for the deposition of thicker films of 500-700 nm with the same orientation directly from solvothermal mother solution.
Self assembled monolayers (SAMs) made from an aromatic organodithiol, 2-mercaptomethylbenzenethiol (C(6)H(4)SHCH(2)SH) on Au(111) have been investigated in the context of a combined experimental and theoretical approach. The SAMs prepared by immersion of an Au-substrate in corresponding ethanolic solutions were characterized using scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), infrared reflection absorption spectroscopy (IRRAS) and thermal desorption spectroscopy (TDS). Adapted from the experimentally obtained unit cell of the SAM, density functional theory (DFT) calculations were applied to get a deeper insight into the structure of these dithiolate based SAMs. On the basis of the experimental and theoretical findings we provide a detailed structural model for this aromatic SAM consisting of the phenyl-group rigidly anchored to the substrate by two thiolate-bonds.
The vibrational spectrum of a thiolate-based self-assembled monolayer fabricated by the adsorption of benzylmercaptan on a Au(111) substrate is studied using a combined experimental and theoretical approach employing infrared reflection absorption spectroscopy and density functional theory. The vibrational spectra are derived both using a finite differences approach and from ab initio molecular dynamics simulations at various temperatures. In addition, the possibility of adsorbate-induced reconstructions of the Au(111) substrate is taken into account. It turns out that the measured spectra can only be understood by taking finite temperatures into account.
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