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The two CeIV MOFs [Ce6O4(OH)4(TzTz)6] (Ce_TzTz) and [Ce6O4(OH)4(TzTz)4(PyPy)2] (Ce_TzTz_PyPy; H2TzTz = [2,2′‐bithiazole]‐5,5′‐dicarboxylic acid, H2PyPy = 2,2′‐bipyridine‐5,5′‐dicarboxylic acid) are prepared starting from a pre‐formed [Ce6] glycinate‐capped cluster. N2 isotherms collected at 77 K revealed BET specific surface areas of 1136 and 238 m2 g−1, respectively. Their CO2 and N2O adsorption capacity is assessed at T = 273 and 298 K and p = 1 bar. Ce_TzTz shows the highest gas uptake (7.9 and 9.7 wt% at 298 K and 11.5 and 12.5 wt% at 273 K for CO2 and N2O, respectively). More interestingly, this homo‐linker MOF possesses a higher capacity, thermodynamic affinity [(Qst)CO2 = 18.2 kJ mol−1 vs (Qst)N2O = 25.4 kJ mol−1] and selectivity (IAST SN2O/CO2 = 1.6 at T = 273 K) toward N2O than the mixed‐linker sample. At variance, Ce_TzTz_PyPy shows a slightly higher capacity, thermodinamic affinity [(Qst)CO2 = 29.5 kJ mol−1 vs (Qst)N2O = 26.4 kJ mol−1] and selectivity (IAST SCO2/N2O = 1.4 at T = 298 K) toward CO2. DFT optimizations carried out on the [N2O@Ce_TzTz] and [CO2@Ce_TzTz_PyPy] systems revealed that the primary adsorption sites are the cerium ions of the [Ce6] metallic node for N2O and the thiazole N‐atoms on the TzTz linker for CO2, respectively. [ABSTRACT FROM AUTHOR]

Covalent triazine frameworks (CTFs) represent a sub‐class of Porous Organic Polymers showing high chemical/thermal stability, large permanent porosity and intrinsically high N‐content. All these features make them ideal candidates for Carbon Capture and Storage (CCS) applications. Herein, a novel CTF has been prepared under ionothermal conditions through cyclotrimerization of a newly designed dicyano‐building block with high N/C ratio (2,6‐Dicyano‐1,5‐naphthyridine, 4). The as prepared CTF‐Napht showed remarkable carbon dioxide uptake at ambient conditions, with a loading of 3.93 mmol/g (17.3 wt. %) at 1 bar and 298 K that outperforms many benchmark CTF systems from the literature. The ad‐hoc designed dicyano building unit together with a judicious choice of synthetic conditions have imparted to CTF‐Napht an outstanding affinity towards CO2 confirmed by its isosteric heat of adsorption (Qst) as high as 39.6 KJ/mol that ranks among the highest reported so far for CTF‐based polymers. [ABSTRACT FROM AUTHOR]

Neutral ZrIV and HfIV alkyl/amido complexes stabilized by a tridentate N ligand that contains a "rolling" heterodentate benzoimidazole fragment have been prepared and characterized. The ultimate nature of the ligand denticity, the electronic properties of the ligand binding pocket and the metal coordination environment are controlled by the protection/deprotection of the benzoimidazole NH group. The metal precursor used [MIV(Bn)4 or MIV(NMe2)4] also has an influence on the final coordination sphere of the complex; indeed, a permanent central pyridine dearomatization occurs in the presence of dimethylamido ancillary groups. DFT calculations on the real system have been used to elucidate the mechanism. Selected alkyl species from this series have been scrutinized for the tandem hydrosilylation of CO2 to CH4 in combination with the strong Lewis acid B(C6F5)3 using a variety of hydrosilanes. A positive effect of the hardness modification of the ligand donor atom set is observed in the catalytic outcomes. Indeed, κ3{N−,N,N−}ZrIV(Bn)2 catalyzes the process to methane selectively with a turnover frequency as high as 272 h−1 (at 96 % substrate conversion) almost twice as much as that claimed for the benchmark κ3{O−,O,O−}ZrIV(Bn)2 complex under similar experimental conditions. Working in tandem: ZrIV/HfIV alkyl coordination compounds stabilized by a N ligand that contains a "rolling" heterodentate benzoimidazole fragment are prepared and employed with B(C6F5)3 for mild CO2 hydrosilylation to methane. The modification of the hardness of the ligand donor atom set translates into a better catalytic performance with respect to that of the benchmark catalytic system. [ABSTRACT FROM AUTHOR]

The reaction of different copper(II) salts with a class of thiazole-based ligands under solvothermal conditions produces three crystalline 1D/2D coordination polymers: [Cu(κ- N-thiazole)4(SiF6)]∞ ( 1 (1D)), {Cu[μ-(κ- N:κ -COO)- L1]2⋅(H2O)}∞ ( 2 (2D); H L1=2-aminothiazole-5-carboxylic acid), and {Cu[μ-(κ- N:κ -COO)- L2]2⋅1.5 (H2O)}∞ ( 3 (2D); H L2=thiazole-5-carboxylic acid). All the materials have been characterized through common solid-state techniques: single-crystal (XRD) and (variable-temperature) powder X-ray diffraction (PXRD), infrared spectroscopy (IR), thermogravimetric analysis combined with mass spectrometry (TGA-MS), and BET surface area and pore-size distribution measurements. Polymer 3 shows a porous structure made of squared channels formed by the ordered stacking of the planar sheets along the a crystallographic axis (inner surface area equal to 15 m2 g−1, as inferred from N2 adsorption at T=77 K on the pre-activated form), and it has been exploited for CO2 physisorption at ambient temperature ( T=303 K) and pressure ( p [ABSTRACT FROM AUTHOR]

The development of functional porous samples suitable as gas-adsorption materials is a key challenge of modern materials chemistry to face with global warming or issues related to renewable energy-storage solutions. Herein, a set of five Covalent Triazine Frameworks (CTFs) featured by high specific surface area (SSA, up to 3201 m2 g−1) and N content as high as 12.2 wt% have been prepared through a rational synthetic strategy and exploited with respect to their gas uptake properties. Among CTFs from this series, CTF- p DCB/DCIHT (4) combines ideal morphological and chemico-physical properties for CO 2 and H 2 adsorption. Noteworthy, besides ranking among CTFs with the highest CO 2 adsorption capacity reported so far (up to 5.38 mmol g−1 at 273 K and 1 bar), 4 displays a H 2 excess uptake at 77 K of 2.84 and 5.0 wt% at 1 and 20 bar, respectively, outperforming all CTF materials and 2D Porous Organic Polymers of the state-of-the-art. [Display omitted] • Highly porous N-rich CTF materials are prepared by mixing different building blocks. • CTFs chemical and morphological properties are optimized for dual CO 2 /H 2 adsorption. • CTF from this series offers the highest H 2 uptake value reported for organic polymers. [ABSTRACT FROM AUTHOR]

[Display omitted] • H 2 TzPhTz has been prepared via a classical Hantzsch synthesis. • [[Zn(TzPhTz)(H 2 O) 2 ] shows 1-D chains with {ZnO 4 } nodes and bridging TzPhTz2- spacers. • [UO 2 (TzPhTz)] features {UO 2 (TzPhTz)(DMF)} 2 dimeric units along 1-D strands. • H 2 TzPhTz and [Zn(TzPhTz)(H 2 O) 2 ] emit in the blue-green visible region. The new ditopic ligand [2,2′-(1,4-phenylene)bithiazole]-5,5′-dicarboxylic acid (H 2 TzPhTz) was synthesized in ∼ 70% yield through a classical Hantzsch synthesis. Isolation of the dimethyl ester intermediate Me 2 TzPhTz as the trifluoroacetic acid adduct Me 2 TzPhTz·2CF 3 CO 2 H allowed its crystal structure determination, revealing that the constituting molecules are interconnected through an extended hydrogen-bond network. Reaction of H 2 TzPhTz with suitable ZnII and UVI salts yielded the 1-D coordination polymers [Zn(TzPhTz)(H 2 O) 2 ] (Zn_TzPhTz) and [UO 2 (TzPhTz)(DMF)]·DMF (U_TzPhTz). The former is characterized by zig-zag chains with cis -{Zn(O COO) 4 (O H2O) 2 } nodes and μ-η2:η2- TzPhTz 2- spacers, while in the latter TzPhTz -bridged {UO 2 (TzPhTz)(DMF)} 2 dimeric units form polymeric strands. In the solid state, both H 2 TzPhTz and Zn_TzPhTz emit in the blue-green visible region (λ em = 474 and 477 nm, respectively). The two coordination polymers witness the versatility of H 2 TzPhTz as a linker toward d and f metal ions, and they should be considered as the preliminary step toward the preparation of TzPhTz -based metal–organic frameworks for practical applications in the field of luminescence sensing. [ABSTRACT FROM AUTHOR]