Dalton Transactions

doi: 10.1039/D2DT90121Hpmid: N/A

doi: 10.1039/D2DT90122Fpmid: N/A

Yang, Xin; Liu, Yan; Guo, Ruike; Xiao, Jiafu

doi: 10.1039/d2dt01394kpmid: 35730677

Heteroatom doping plays a crucial role in improving the electrocatalytic performance of catalysts towards water splitting. Owing to the existence of RuO moieties, Ru is thus emerging as an ideal dopant for promoting the electrocatalytic performance for water splitting by modifying the electronic structure, introducing extra active sites, improving electronic conductivity, and inducing a strong synergistic effect. Benefitting from these advantages, Ru-doped nanomaterials have been widely investigated and employed as advanced electrocatalysts for water splitting, and many excellent Ru-doped electrocatalysts have been successfully developed. In an effort to obtain a better understanding of the influence of Ru doping on the electrocatalytic water splitting performance of nanocatalysts, we herein summarize the recent progress of Ru-doped electrocatalysts by focusing on the synthesis strategies and advantageous merits. Applications of these new materials in water electrolysis technology are also discussed with emphasis on future directions in this active field of research.

Li, Yang; Pelzer, Katrin; Sechet, Damien; Creste, Geordie; Matt, Dominique; Braunstein, Pierre; Armspach, Dominique

doi: 10.1039/d2dt01553fpmid: 35861279

The presence of a permethylated α-cyclodextrin (α-CD) cavity in a chelating P,N ligand promotes exclusive formation of 1 : 1 ligand/metal complexes. In MX2 complexes, one of the two halido ligands is forced to reside inside the CD hollow while the second one is pointing outside. Unlike its cavity-free analogue, a Ni(II) complex of the CD ligand is a highly selective precatalyst for ethylene dimerisation (96% C4 selectivity with up to 95% of 1-butene within the C4 fraction).

Wang, Hua-Rui; Tian, Xu-Ke; Zhang, Ji-Rui; Wen, Meng-Yao; Yang, Xiao-Gang

doi: 10.1039/d2dt01649dpmid: 35880646

A novel metalorganic framework (MOF) hostguest material [Cd3(EtOIPA)4(HAD)2]H2O has been successfully synthesized by the reaction of 5-ethoxyisophthalic acid (EtOIPA), acridine (AD) and Cd(ii) salts under hydrothermal conditions. Structurally, the title MOF possesses a trinucleate Cd(ii) based 2D double-layer with the protonated AD cations as the template encapsulated into the grids. The combination of experiments and theoretical calculations reveals that the orderly arrangement of EtOIPA dimers, protonated AD cations and trinucleate Cd(ii) clusters generates highly delocalized -electron channels with a prolonged exciton lifetime. The MOF powders show bright yellow emission with a long lifetime of 50.63 ns. Photoelectrochemical measurements reveal a high photocurrent density ratio of 290 between light and dark conditions at 0 V bias potential, making it a perfect self-driven photodetector. By coating the yellow phosphor on a commercially available blue LED, a high performance white LED with CIE, CCT and CRI values of (0.325, 0.336), 88.2 and 5844 K, respectively can be obtained.

Chen, Jiawei; Ye, Zhi; Chen, Peican; Hu, Huihui; Zhang, Shuhong; Xu, Han; Cao, Lingyun; Wang, Cheng

doi: 10.1039/d2dt01239apmid: 35822837

Metalorganic layers (MOLs), a category of two-dimensional materials, have attracted wide interest due to their molecular tunability and the ease of surface modification. Herein, we reported the synthesis and structural determination of a free-standing MOL, {[Hf6O8H4(HCOO)2(H2OOH)4]3[Hf12O16H8(HCOO)6.8(H2OOH)11.2](TPO)8}n, constructed from Hf6-oxo and Hf12-oxo clusters as secondary building units (SBUs) and the tris(4-carboxylphenyl)phosphine oxide (TPO) ligand. We establish a structure model of this new MOL based on the combined information from different characterization methods.

Gradiski, Matthew V.; Rennie, Benjamin E.; Lough, Alan J.; Morris, Robert H.

doi: 10.1039/d2dt01556kpmid: 35731231

A variety of transition metal complexes bearing aminoquinoline PNHH-R ligands R = Ph (L1H), Cy (L2H) and their amido analogues are reported for rhodium(i) ([Rh(L1H)(PPh3)]+1 and Rh(L1)(PPh3) 2), cobalt(ii) (Co(L2)(Cl) 3), and iron(ii) ([Fe(L1H)2]2+5, Fe(L1)26, and [Fe(C5Me5)(L1H)]PF67). The acidbase and redox properties of the amido complexes 2, 6, and their protio parent complexes 1, and 5 permit the determination of the pKa and bond dissociation free energy (BDFE) of their NH bonds while the ligand scaffold is coordinated to metal centres of square planar and octahedral geometry, respectively. From relative concentrations obtained by the use of 31P{1H} NMR spectroscopy, a pKaTHF value of 14 is calculated for rhodium complex 1, 6.4 for iron complex 5, and 24 for iron complex 7. These data, when combined with elecrochemical potentials obtained via cyclic voltammetry, allow the calculations of BDFE values for the NH bond of 69 kcal mol1 for 1, and of 55 kcal mol1 for 5.

Singh, Kasturi; Vaidyanathan, Sivakumar

doi: 10.1039/d2dt01042apmid: 35647652

The search for extremely narrow-band new red emitters is essential for smart displays and lighting applications. Herein, we report the synthesis of a series of red-emitting Eu3+-substituted Li3BaSrY3(WO4)8 and solid-solution (Li3BaSrY0.3Eu2.7(WO4)8y(MoO4)y) phosphors with a stratified scheelite structure and the systematic investigation of their optical properties. All the compositions show broad absorption (charge transfer (O2 M6+)) extended up to the blue region along with strong characteristic Eu3+ excitation lines. The phosphor compositions exhibit proficient narrow-band red emission (quantum yield up to 85%; full width at half maximum (FWHM) = 6 nm; CIE colour coordinates x = 0.65, y = 0.35, i.e. approaching the NTSC standard for red colour) of exceptional colour purity (94% to 98%), and this host supports heavy trivalent Eu activation (showing zero concentration quenching of the emission (Eu-rich lattice)). The dominating electric dipole (5D0 7F2, red emission) transition shows Eu3+-ion occupancy in the non-centrosymmetric site in the host lattice. The selected composition shows better absolute quantum efficiencies compared to commercial phosphors. The presently synthesized phosphors have proven to be thermally stable against the temperature quenching effect. The fabricated red LED showed excellent performance, colour purity, LER and CIE values. The excellent optical properties, quantum yield and thermal stability make the phosphor applicable as a red component in solid-state lighting devices and as a light source for plant growth applications.

Dankert, Fabian; Fischer, Malte; Hering-Junghans, Christian

doi: 10.1039/d2dt01575gpmid: 35766522

Phosphanylidenephosphoranes of the type RP(PR3), also known as phospha-Wittig reagents, can be utilized in a variety of bond activation reactions exploiting their phosphinidenoid reactivity. Herein, we thoroughly show that a facile PMe3 for H2O exchange gives access to various primary phosphine oxides of the general formula RP(H)2O (R = Mes*, MesTer, DipTer) and the molecular structure of DipTerP(O)H2 was determined. However, phosphanylidenephosphoranes are described to be highly nucleophilic as well. We show that the attachment of main group Lewis acids such as GaCl3 and GaI3 to RP(PMe3) yielded the highly sensitive, yet stable coordination compounds [(RPGaX3)PMe3] (R = Mes*, DipTer) or [(RPPMe3)2GaCl2]GaCl4 (R = MesTer). In contrast to the free phosphanylidenephosphoranes, these species reacted differently with H2O, which was demonstrated for [(Mes*PPMe3)GaI3]. Here the formation of the phosphino-phosphonium cation [Mes*P(H)PMe3]+ and different anions was observed with combined NMR spectroscopic and SC-XRD (SC-XRD = single crystal X-ray diffraction analysis) studies. This work demonstrates that the ambiphilic character of phosphanylidenephosphoranes can be utilized to manipulate the reactivity of RP(PMe3) towards water, giving primary phosphine oxides, whereas the Lewis acid adducts [(RPGaX3)PMe3] gave phosphino-phosphonium species.

Solea, Atena B.; Sudittapong, Burin; Taylor, Christopher G. P.; Ward, Michael D.

doi: 10.1039/d2dt01713jpmid: 35791857

In this work we compare and contrast the hydrolysis of two different aromatic esters using an octanuclear cubic Co8 coordination cage host as the catalyst. Diacetyl fluorescein (DAF) is too large to bind inside the cage cavity, but in aqueous solution it interacts with the exterior surface of the cage via a hydrophobic interaction with K = 1.5(2) 104 M1. This is sufficient to bring it into close proximity to the layer of hydroxide ions which also surrounds the 16+ cage surface even at modest pH values, accelerating the hydrolysis of DAF to fluorescein with kcat/kuncat (the rate acceleration for that fraction of DAF in contact with the cage surface in the equilibrium) 50. This is far smaller than many known examples of catalysis inside a cage cavity, but at the exterior surface it is potentially general with no cavity-imposed size/shape limitations for guest binding. In contrast 4-nitrophenyl acetate (4NPA) binds inside the cage cavity with K = 3.5(3) 103 M1 and as such is surrounded in solution by the hydroxide ions which accumulate around the cage surface. However its hydrolysis is actually inhibited: either because of a geometrically unfavourable geometry of the bound substrate which makes it inaccessible to surface-bound hydroxide, or because the necessary volume expansion/geometry change associated with formation of a tetrahedral intermediate cannot be accommodated inside the cavity. Any 4NPA that is free in solution as part of the equilibrium undergoes catalysed hydrolysis at the cage exterior surface in the same way as DAF, but the effect is limited by the low affinity of 4NPA for the exterior surface. We conclude that exterior-surface catalysis can be effective and potentially general; and that cavity-binding of guests can result in negative, rather than positive, catalysis.