Electrically Conductive Photoluminescent Porphyrin Phosphonate Metal-Organic Frameworks

Herein, the design and synthesis of a highly photoluminescent and electrically conductive metal–organic framework [Zn{Cu-p-H6TPPA}]⋅2 [(CH3)2NH] (designated as GTUB3), which is constructed using the 5,10,15,20-tetrakis [p-phenylphosphonic acid] porphyrin (p-H8TPPA) organic linker, is reported. The bandgap of GTUB3 is measured to be 1.45 and 1.48 eV using diffuse reflectance spectroscopy and photoluminescence (PL) spectroscopy, respectively. The PL decay measurement yields a charge carrier lifetime of 40.6 ns. Impedance and DC measurements yield average electrical conductivities of 0.03 and 4 S m−1, respectively, making GTUB3 a rare example of an electrically conductive 3D metal–organic framework. Thermogravimetric analysis reveals that the organic components of GTUB3 are stable up to 400 °C. Finally, its specific surface area and pore volume are calculated to be 622 m2 g−1 and 0.43 cm3 g−1, respectively, using grand canonical Monte Carlo. Owing to its porosity and high electrical conductivity, GTUB3 may be used as a low-cost electrode material in next generation of supercapacitors, while its low bandgap and high photoluminescence make it a promising material for optoelectronic applications

Guest-Induced Gate Opening and Breathing Phenomena in Soft Porous Crystals: Building Thermodynamically Consistent Isotherms

INGENIERIE+MPE:DFAMetal organic-frameworks (MOFs) have emerged as a novel and fascinating family of porous materials offering promising perspectives for designing tailor-made adsorbents and catalysts. Particularly, great attention has been paid to flexible nanoporous MOFs (or Soft Porous Crystals) displaying structural phase transitions promoted by external stimuli. This is the case of guest-induced structural transitions upon adsorption being at the origin of the striking gate opening and breathing phenomena. We present here a short overview of the formulation of thermodynamic isotherms for describing S-shaped adsorption/desorption curves typical of such phenomena, as well as recent thermodynamic methods for estimating phase transition energies. These methods might be valuable for the rational design of gate opening/breathing MOFs