This paper describes the identification of specific host−guest interactions between basic gases (NH 3 , CD 3 CN, and pyridine) and four topologically similar 2-dimensional (2D) metal− organic frameworks (MOFs) comprising copper and nickel bis(diimine) and bis(dioxolene) linkages of triphenylene-based ligands using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance spectroscopy (EPR), and powder X-ray diffraction (PXRD). This contribution demonstrates that synthetic bottom-up control over surface chemistry of layered MOFs can be used to impart Lewis acidity or a mixture of Brønsted and Lewis acidities, through the choice of organic ligand and metal cation. This work also distinguishes differences in redox activity within this class of MOFs that contribute to their ability to promote electronic transduction of intermolecular interactions. Future design of structure−function relationships within multifunctional 2D MOFs will benefit from the insights this work provides.

The surface reactivity of TiO 2 is often governed by hydroxyl groups. Fourier transform infrared (FTIR) spectroscopy is the most commonly used method to study surface hydroxyls. However, interpretation of the observed bands of powder samples is not straightforward. In this work, we propose a facet-specific assignment of the surface hydroxyls of pyrogenic TiO 2 (commonly known as P25 and P90) by comparison between experimentally observed FTIR bands of P90, rutile, and anatase with calculated vibrational frequencies for welldefined surface facets using density functional theory. Titania was calcined for extended periods in extremely dry O 2 to remove carbonates and water for diffuse reflectance infrared spectroscopy measurements of the most thermally stable hydroxyls remaining in the 300−400 °C range. Reactions of the dehydroxylated surfaces with H 2 (D 2 ) provided further insight into hydroxyl formation. Theoretical assignments of hydroxyls were based on the calculated thermal stability of hydroxyls to dehydroxylation, agreement with calculated frequencies [scaled to be consistent with the experimental bridging hydroxyl frequency on rutile TiO 2 (110)], and the thermodynamic stability of the specific facets. Our assignments, combined with previous results, show that terminal and bridging hydroxyl frequencies overlap; therefore, the common assumption that terminal hydroxyls vibrate at higher frequencies is not valid.

This paper describes a novel synthetic approach for the conversion of zero-valent copper metal into a conductive two-dimensional layered metal–organic framework (MOF) based on 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) to form Cu3(HHTP)2. This process enables patterning of Cu3(HHTP)2 onto a variety of flexible and porous woven (cotton, silk, nylon, nylon/cotton blend, and polyester) and non-woven (weighing paper and filter paper) substrates with microscale spatial resolution. The method produces conductive textiles with sheet resistances of 0.1–10.1 MΩ/cm2, depending on the substrate, and uniform conformal coatings of MOFs on textile swatches with strong interfacial contact capable of withstanding chemical and physical stresses, such as detergent washes and abrasion. These conductive textiles enable simultaneous detection and detoxification of nitric oxide and hydrogen sulfide, achieving part per million limits of detection in dry and humid conditions. The Cu3(HHTP)2 MOF also demonstrated filtration capabilities of H2S, with uptake capacity up to 4.6 mol/kgMOF. X-ray photoelectron spectroscopy and diffuse reflectance infrared spectroscopy show that the detection of NO and H2S with Cu3(HHTP)2 is accompanied by the transformation of these species to less toxic forms, such as nitrite and/or nitrate and copper sulfide and S x species, respectively. These results pave the way for using conductive MOFs to construct extremely robust electronic textiles with multifunctional performance characteristics.