Deposition of microcrystalline [Cu-3(btc)(2)] and [Zn-2(bdc)(2)(dabco)] at alumina and silica surfaces modified with patterned self assembled organic monolayers: evidence of surface selective and oriented growth

摘要

The deposition of microcrystalline, phase pure [Cu-3(btc)(2)] (1) and [Zn-2(bdc)(2)(dabco)] (2) under solvothermal conditions on alumina and on silica surfaces modified with self assembled organic monolayers has been studied. The growth of 1 is remarkably surface selective and does not take place on silica but does on alumina. In contrast the growth of 2 is not surface selective at all and densely packed coatings were obtained on silica and on alumina surfaces. Most interestingly, [Cu-3(btc)(2)] shows an oriented growth mode on both c-plane sapphire and COOH-terminated SAMs at SiO2/Si(100) wafers. The single crystals of 1 are attached to the organic surface via the (100) face, while on c-plane sapphire the crystals interact via the (100) lattice plane leading to different shapes of the crystals: pyramids on sapphire and fully developed octahedra on the COOH- SAM. The gas adsorption properties of the obtained coatings were demonstrated by reversible loading with water and with pyridine in the case of 1 and loading with [(eta(5)- C5H5) Pd( eta(3)-C3H5)] as a typical example of a MOCVD precursor for both 1 and 2 which allows the fabrication of Pd nanoparticle loaded MOF thin films.