Development of Metal–Organic Nanotubes Exhibiting Low-Temperature, Reversible Exchange of Confined “Ice Channels”

Nanotubular materials have unique water transport and storage properties that have the potential to advance separations, catalysis, drug delivery, and environmental remediation technologies. The development of novel hybrid materials, such as metal–organic nanotubes (MONs), is of particular interest, as these materials are amenable to structural engineering strategies and may exhibit tunable properties based upon the presence of inorganic components. A novel metal–organic nanotube, (C₄H₁₂N₂)_0.5[(UO₂)­(H<i>ida</i>)­(H₂<i>ida</i>)]·2H₂O (<b>UMON</b>) (<i>ida</i> = iminodiacetate), that demonstrates the possibilities of these types of hybrid compounds has been synthesized via a supramolecular approach. Single-crystal X-ray diffraction of the compound revealed stacked macrocyclic arrays that contain highly ordered water molecules with structural similarities to the “ice channels” observed in single-walled carbon nanotubes. Nanoconfinement of the water molecules may be the cause of the unusual exchange properties observed for <b>UMON</b>, including selectivity to water and reversible exchange at low temperature (37 °C). Similar properties have not been reported for other inorganic or hybrid compounds and indicate the potential of MONs as advanced materials

Development of Metal–Organic Nanotubes Exhibiting Low-Temperature, Reversible Exchange of Confined “Ice Channels”

Nanotubular materials have unique water transport and storage properties that have the potential to advance separations, catalysis, drug delivery, and environmental remediation technologies. The development of novel hybrid materials, such as metal–organic nanotubes (MONs), is of particular interest, as these materials are amenable to structural engineering strategies and may exhibit tunable properties based upon the presence of inorganic components. A novel metal–organic nanotube, (C₄H₁₂N₂)_0.5[(UO₂)­(H<i>ida</i>)­(H₂<i>ida</i>)]·2H₂O (<b>UMON</b>) (<i>ida</i> = iminodiacetate), that demonstrates the possibilities of these types of hybrid compounds has been synthesized via a supramolecular approach. Single-crystal X-ray diffraction of the compound revealed stacked macrocyclic arrays that contain highly ordered water molecules with structural similarities to the “ice channels” observed in single-walled carbon nanotubes. Nanoconfinement of the water molecules may be the cause of the unusual exchange properties observed for <b>UMON</b>, including selectivity to water and reversible exchange at low temperature (37 °C). Similar properties have not been reported for other inorganic or hybrid compounds and indicate the potential of MONs as advanced materials

Development of Metal–Organic Nanotubes Exhibiting Low-Temperature, Reversible Exchange of Confined “Ice Channels”

Nanotubular materials have unique water transport and storage properties that have the potential to advance separations, catalysis, drug delivery, and environmental remediation technologies. The development of novel hybrid materials, such as metal–organic nanotubes (MONs), is of particular interest, as these materials are amenable to structural engineering strategies and may exhibit tunable properties based upon the presence of inorganic components. A novel metal–organic nanotube, (C₄H₁₂N₂)_0.5[(UO₂)­(H<i>ida</i>)­(H₂<i>ida</i>)]·2H₂O (<b>UMON</b>) (<i>ida</i> = iminodiacetate), that demonstrates the possibilities of these types of hybrid compounds has been synthesized via a supramolecular approach. Single-crystal X-ray diffraction of the compound revealed stacked macrocyclic arrays that contain highly ordered water molecules with structural similarities to the “ice channels” observed in single-walled carbon nanotubes. Nanoconfinement of the water molecules may be the cause of the unusual exchange properties observed for <b>UMON</b>, including selectivity to water and reversible exchange at low temperature (37 °C). Similar properties have not been reported for other inorganic or hybrid compounds and indicate the potential of MONs as advanced materials

Development of Metal–Organic Nanotubes Exhibiting Low-Temperature, Reversible Exchange of Confined “Ice Channels”

Nanotubular materials have unique water transport and storage properties that have the potential to advance separations, catalysis, drug delivery, and environmental remediation technologies. The development of novel hybrid materials, such as metal–organic nanotubes (MONs), is of particular interest, as these materials are amenable to structural engineering strategies and may exhibit tunable properties based upon the presence of inorganic components. A novel metal–organic nanotube, (C₄H₁₂N₂)_0.5[(UO₂)­(H<i>ida</i>)­(H₂<i>ida</i>)]·2H₂O (<b>UMON</b>) (<i>ida</i> = iminodiacetate), that demonstrates the possibilities of these types of hybrid compounds has been synthesized via a supramolecular approach. Single-crystal X-ray diffraction of the compound revealed stacked macrocyclic arrays that contain highly ordered water molecules with structural similarities to the “ice channels” observed in single-walled carbon nanotubes. Nanoconfinement of the water molecules may be the cause of the unusual exchange properties observed for <b>UMON</b>, including selectivity to water and reversible exchange at low temperature (37 °C). Similar properties have not been reported for other inorganic or hybrid compounds and indicate the potential of MONs as advanced materials

Use of Charge-Assisted Hydrogen Bonding in the Supramolecular Assembly of Hybrid Uranyl Materials

Supramolecular assembly of U­(VI) materials can be limited by the passivation of the uranyl oxo group and the propensity of the metal center to hydrolyze, resulting in the formation of extended two-dimensional (2D) structures. To overcome these barriers, the use of charge-assisted H-bonding was explored using amino acids (glycine [Gly] and l-alanine [Ala]), resulting in the formation of three novel compounds {[(UO₂)₃(Gly)₂(O)₂(OH)₂]­(H₂O)₆ <b>(1)</b>, [(UO₂)₅(Gly)₄(O)₃(OH)₃]­(NO₃)­(H₂O)₁₂ <b>(2)</b>, and [(UO₂)₃(Ala)₂O­(OH)₃]­(NO₃)­(H₂O)₃ <b>(3)</b>} that have been characterized by X-ray diffraction, elemental analysis, TGA, and vibrational spectroscopy. Hydrolysis of the uranyl cation (UO₂²⁺) chelated by bridging zwitterionic amino acids results in the formation of infinite chains when synthesized from mildly acidic aqueous solutions. While positively charged chains form densely packed structures, the neutral UO₂-glycine chains support a nanoporous (internal diameter ∼1.35 nm) supramolecular architecture through multifurcated charge-assisted hydrogen bonding. These interactions occur directly between the protonated amine of glycine and the uranyl’s oxo moiety, representing a unique supramolecular synthon for the assembly of hybrid porous uranyl materials. The zwitterionic glycine ligands also assist in the helical assembly of water molecules that are hydrogen bonded to the interior walls of the nanopores, resulting in the formation of an empty 0.85 nm channel through the pore space

Patient characteristics and surgery-related factors associated with patient-reported recovery at 1 and 6 months after colorectal cancer surgery

Predictors for postoperative recovery after colorectal cancer surgery are usually investigated in relation to length of stay (LoS), readmission, or 30-day morbidity. This study describes patient characteristics and surgery-related factors associated with patient-reported recovery 1 and 6 months after surgery. In total, 153 consecutively included patients who were recovering from colorectal cancer surgery reported their level of recovery using the Postoperative Recovery Profile. Multiple logistic regression analysis was used to calculate associations with recovery, defined as good or poor, divided into five recovery dimensions: physical symptoms, physical functions, psychological, social and activity. Better preoperative health predicted good recovery regarding three dimensions 1 month after surgery. Regarding all dimensions 1 month after surgery, poor recovery was predicted by a poor recovery on the day of discharge within corresponding dimensions. Higher age was associated with good recovery 6 months after surgery, while chemotherapy showed negative associations. Overall, a majority of factors had a negative impact on recovery, but without any obvious relation to one specific dimension or point in time. Those factors were: high Body Mass Index, comorbidity, abdominoperineal resection, loop ileostomy, colostomy and LoS. This study illustrates the complexity of postoperative recovery and a need for individualised follow-up strategies

Synthesis and Structural Characterization of Hydrolysis Products within the Uranyl Iminodiacetate and Malate Systems

The interplay of hydrolysis and chelation by organic ligands results in the formation of novel uranium species in aqueous solutions. Many of these molecular complexes have been identified by spectroscopic and potentiometric techniques, but a detailed structural understanding of these species is lacking. Identification of possible uranyl hydrolysis products in the presence of organic functional groups has been achieved by the crystallization of molecular species into a solid-state compound, followed by structural and chemical characterization of the material. The structures of three novel molecular complexes containing either iminodiacetate (<i>ida</i>) (Na₃[(UO₂)₃(OH)₃(ida)₃]·8H₂O (<b>1</b>)) or malate (<i>mal</i>) (K­(<i>pip</i>)₂[(UO₂)₃O­(<i>mal</i>)₃]·6H₂O (<b>2a</b>) (<i>pip</i> = C₄N₂H₁₂), (<b>2b</b>) (<i>pip</i>)₃[(UO₂)₃O­(<i>mal</i>)₃]·H₂O, and (<i>pip</i>)₆[(UO₂)₁₁(O)₄(OH)₄(<i>mal</i>)₆(CO₃)₂]·23H₂O (<b>3</b>)) ligands have been determined by single-crystal X-ray diffraction and have been chemically characterized by IR, Raman, and NMR spectroscopies. A major structural component in compounds <b>1</b> and <b>2</b> is a trimeric 3:3 uranyl <i>ida</i> or <i>mal</i> species, but different bridging groups between the metal centers create variations in the structural topologies of the molecular units. Compound <b>3</b> contains a large polynuclear cluster with 11 U atoms, which is composed of trimeric and pentameric building units chelated by <i>mal</i> ligands and linked through hydroxyl groups and carbonate anions. The characterized compounds represent novel structural topologies for U⁶⁺ hydrolysis products that may be important molecular species in near-neutral aqueous systems

Synthesis and Structural Characterization of Hydrolysis Products within the Uranyl Iminodiacetate and Malate Systems

The interplay of hydrolysis and chelation by organic ligands results in the formation of novel uranium species in aqueous solutions. Many of these molecular complexes have been identified by spectroscopic and potentiometric techniques, but a detailed structural understanding of these species is lacking. Identification of possible uranyl hydrolysis products in the presence of organic functional groups has been achieved by the crystallization of molecular species into a solid-state compound, followed by structural and chemical characterization of the material. The structures of three novel molecular complexes containing either iminodiacetate (<i>ida</i>) (Na₃[(UO₂)₃(OH)₃(ida)₃]·8H₂O (<b>1</b>)) or malate (<i>mal</i>) (K­(<i>pip</i>)₂[(UO₂)₃O­(<i>mal</i>)₃]·6H₂O (<b>2a</b>) (<i>pip</i> = C₄N₂H₁₂), (<b>2b</b>) (<i>pip</i>)₃[(UO₂)₃O­(<i>mal</i>)₃]·H₂O, and (<i>pip</i>)₆[(UO₂)₁₁(O)₄(OH)₄(<i>mal</i>)₆(CO₃)₂]·23H₂O (<b>3</b>)) ligands have been determined by single-crystal X-ray diffraction and have been chemically characterized by IR, Raman, and NMR spectroscopies. A major structural component in compounds <b>1</b> and <b>2</b> is a trimeric 3:3 uranyl <i>ida</i> or <i>mal</i> species, but different bridging groups between the metal centers create variations in the structural topologies of the molecular units. Compound <b>3</b> contains a large polynuclear cluster with 11 U atoms, which is composed of trimeric and pentameric building units chelated by <i>mal</i> ligands and linked through hydroxyl groups and carbonate anions. The characterized compounds represent novel structural topologies for U⁶⁺ hydrolysis products that may be important molecular species in near-neutral aqueous systems