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Development of multipurpose adsorbents for highly efficient separation of acetylene (C2H2) from carbon dioxide (CO2) and ethylene (C2H4) is of great importance but highly challenging due to their very similar sizes and physical properties. While many adsorbents have been developed to show efficient separation of either C2H2/CO2 or C2H2/C2H4, multipurpose materials with high selectivities for both gas mixtures are elusive. Herein, we developed an anion-pillared metalloporphyrin SIFSIX material (termed ZJUT-6) as a multipurpose adsorbent for highly efficient separation of C2H2 from CO2 and C2H4. Unlike routine SIFSIX materials with strong fluorine binding sites for gas separations, the use of metalloporphyrin as a building block enables ZJUT-6a to create unique sandwich-like binding sites with dual open metal sites, which can more optimally interact with the C2H2 molecule over CO2 and C2H4. ZJUT-6a thus exhibits large C2H2 capture capacities and simultaneous high C2H2/CO2 (8.9) and C2H2/C2H4 (12.2) selectivities under ambient conditions. Theoretical simulations reveal that the oppositely adjacent copper(II) centers and porphyrin groups from metalloporphyrin ligands in ZJUT-6a can construct a sandwich-type adsorption site to offer dually stronger interactions with C2H2 over CO2 and C2H4. Dynamic breakthrough experiments on ZJUT-6a demonstrate its highly efficient separation of C2H2 from actual C2H2/CO2 (50/50) and C2H2/C2H4 (1/99) gas mixtures. [ABSTRACT FROM AUTHOR]

Microporous hydrogen-bonded organic frameworks (HOFs) have been considered promising materials for ethane/ethylene (C2H6/C2H4) separation owing to their native nonpolar pores. However, the absence of functional binding sites on nonpolar pore surfaces commonly limits their separation performance. Herein, we report and construct a novel HOF material (termed as ZJU-HOF-60a) by incorporating electron-rich alkynyl groups into its pore surfaces to achieve highly efficient C2H6/C2H4 separation. The incorporated alkynyl groups not only serve as functional binding sites to provide multiple supramolecular interactions with the C2H6 molecule, but also do not participate in the formation of any hydrogen bonds in order to obtain the desired HOF framework. Alkynyl-functionalized ZJU-HOF-60a thus exhibits both a top-tier C2H6 uptake capacity of 3.79 mmol g−1 and C2H6/C2H4 uptake ratio of 1.58 at 296 K and 1 bar, surpassing most of the previously reported C2H6-selective HOFs. Theoretical calculations indicate that the incorporated alkynyl groups combined with the surrounding carboxylic groups provide stronger and more number of C–H⋯π and C–H⋯O interactions to bind with C2H6 over C2H4, thus accounting for efficient C2H6/C2H4 separation. The actual separation performance of ZJU-HOF-60a was confirmed using breakthrough experiments for 50/50 (v/v) C2H6/C2H4 gas mixtures, affording a highly pure C2H4 productivity of 7.8 L kg−1 under ambient conditions. [ABSTRACT FROM AUTHOR]

Metal–organic compound derived composites are promising multi-functional materials owing to their adjustable composition, tunable shape and porous structure. However, it is very attractive but challenging to design light and thin composites derived from metal–organic compounds with broad and strong electromagnetic-wave absorption (EWA). Herein, we designed and synthesized a series of urchin-like porous structures (CoO/C-450, CoO/C-500, Co/C-550 and Co/C-600) with wideband and strong EWA performance through heat treatments on a Co-based metal–organic precursor at different temperatures. The three-dimensional urchin-like porous structure can not only promote electromagnetic wave propagation and attenuation, but also enhance surface polarization relaxation. As a result, this kind of urchin-like morphology leads to exceptional interface polarization loss and impedance matching, affording a wide absorption bandwidth exceeding 7 GHz over X and Ku bands. Among these materials, Co/C-550 demonstrates an outstanding performance, affording an effective absorption bandwidth of 7.92 GHz with a low thickness of 2.5 mm and a minimum reflection loss of −51.2 dB. The remarkable EWA performance was mainly attributed to the synergistic effect of the urchin-like morphology, porous structure, and dielectric and magnetic losses. This work provides some guidance for the design of light and thin electromagnetic wave absorption materials with a wide absorption bandwidth. [ABSTRACT FROM AUTHOR]

Propylene/propane (C3H6/C3H8) separation represents one of the most challenging and energy-intensive processes in the petrochemical industry due to their very similar sizes and physical properties. Most of the reported physisorbents still face the challenge of achieving simultaneously high C3H6 uptake and selectivity with moderate adsorption enthalpy. Herein, we realize an efficient propylene nano-trap in a microporous MOF (ZJUT-2, Ni(pyz-SH)2SiF6) for highly efficient C3H6/C3H8 separation. This MOF-based propylene nano-trap features a suitable pore cavity decorated with dual functionalities (–SH and SiF62−) to optimally interact with the C3H6 molecule, affording both large C3H6 capture capacity (123.5 cm3 cm−3 at 296 K and 0.5 bar) and high C3H6/C3H8 selectivity of 17.2 achieved with moderate C3H6 adsorption enthalpy (45 kJ mol−1). Theoretical calculations revealed that the appropriate pore cavity and dual functionalities synergistically construct an efficient nano-trap to match better with the C3H6 molecule and thus provide stronger multipoint interactions with C3H6 over C3H8. Actual breakthrough experiments demonstrated that this material can efficiently capture C3H6 from C3H6/C3H8 mixtures (50/50 and 10/90, v/v) under ambient conditions, affording both top-tier C3H6 capture amount (2.6 mmol g−1) and dynamic selectivity of 10. [ABSTRACT FROM AUTHOR]

Gas separation is a crucial process for the production of many highly valuable chemical feedstocks in the petrochemical industry. Traditional separation technologies, including cryogenic distillation, chemisorption, and solvent extraction, are energy-intensive or environmentally unfriendly. The development of new separation technologies with low energy consumption and high efficiency is of significant importance for adapting to the increasing industrial demands. Adsorptive gas separation based on solid porous adsorbents has made much progress over the past few decades, benefiting from low cost, high efficiency, and environment friendliness. In this regard, porous metal–organic frameworks (MOFs), as a novel class of crystalline porous materials featuring adjustable structures and finely tunable pore metrics, have shown great promise to address various gas separation challenges. Furthermore, the highly crystalline nature of MOFs endows this kind of material with a unique advantage, providing an in-depth understanding of the structure–property relationship, which is crucial and meaningful to guide the design of separating materials for gas separation. Herein, we summarize the main advancements achieved in the last five years of developing MOFs as physisorbents for various critical gas separations, including but not limited to the separation of light hydrocarbons, C2H2/CO2, and Xe/Kr, and CO2 capture, and the separation mechanisms are also highlighted in each section. Finally, some challenges and perspectives in the design of MOFs for gas separation and industrial applications are outlined. [ABSTRACT FROM AUTHOR]

Electromagnetic (EM) wave absorption materials with a light weight and low-cost are in urgent need, because of the increasing radiation interference and pollution by EM. Although a large number of carbon materials have been explored as EM wave absorbers, most of them exhibit a quite limited EM wave absorption performance because of their unstable structure, low permittivity and poor impedance matching. To overcome this limitation, a series of NiCo@nanoporous carbon@carbon fiber nanocomposites (NiCo@NPC@CF-x, x = 600, 700 or 800) composed of a micro-to-nano hierarchical porous carbon structure and flower-like NiCo@C particles using Ni/Co-MOF particles and biomass cotton as precursors, are fabricated. Benefiting from the participation of biomass cotton, the minimum reflection loss (RLmin) of hierarchical NiCo@NPC@CF is dramatically enhanced to −46.5 dB with a wide effective absorption bandwidth (EAB) of 10.0 GHz at a thickness of 3.5 mm. The total shielding effectiveness (SET) value of NiCo@NPC@CF-800 is 30.58 dB, suggesting that the sample is sufficient to shield more than 99.99% of incident EM waves. The carbonized 1D CFs facilitated the microwave energy dissipated by electron transportation and improved the impedance matching. The improvement of the wave absorption capacity was mainly attributed to the synergistic effect of the hierarchical pore structure, better impedance matching and a larger attenuation constant. Therefore, this work provides a feasible strategy to design and synthesize excellent EM wave absorbers and shielding materials by using the combination of MOFs and biomass materials as precursors. [ABSTRACT FROM AUTHOR]

The in situ pyrolysis of metal–organic-frameworks (MOFs) is an effective strategy to prepare magnetic metal nanoparticle (NP) doped porous carbon materials. These composite materials have shown great potential as high performance electromagnetic wave (EMW) absorption materials. So far, the precise control of composite composition and structure has remained a major challenge in constructing highly porous composites with uniformly distributed NPs. In this work, we report a facile route to synthesize tuneable Co NPs embedded in porous nitrogen-doped carbon (Co/NC) nanorods through the direct thermolysis of the bimetal–organic framework (CoZn–ZIF) precursor. By adjusting the proportion of Co2+ in the MOF precursor, the content and distribution of Co NPs in the composite absorber change accordingly. When the molar ratio between Co2+ and Zn2+ is 3 : 1, the carbonized composites exhibit the largest external surface area and the best EMW absorption performance. With a filler mass loading of merely 15 wt%, the minimum reflection loss (RLmin) reaches −52.3 dB at 10.1 GHz with a thin layer thickness of 2.5 mm. The largest effective absorption bandwidth (EAB) of 5.0 GHz (11.1–16.1 GHz) is achieved in a 2.0 mm thick sample. The qualified bandwidth can be up to 14.5 GHz (3.5–18.0 GHz) with the integrated thickness from 1.0 mm to 5.5 mm. The enhanced conductive/magnetic losses, strong interfacial/dipolar/defect polarization, hierarchical pore structure and the geometric effect endow the Co/NC absorber with improved impedance matching and enhanced attenuation of EMW. This work provides a good direction for the future study of MOF-derived lightweight and efficient EMW absorbing materials. [ABSTRACT FROM AUTHOR]

Separation of acetylene (C2H2) from ethylene (C2H4) and carbon dioxide (CO2) is of great importance in the petrochemical industry but remains a daunting challenge due to their very similar sizes and physical properties. Although a number of porous materials have been developed as promising adsorbents for either C2H2/C2H4 or C2H2/CO2 separation, few materials exhibit simultaneously high selectivities for both gas mixtures. Herein, we report the use of a four-connected N-donor organic linker to construct a novel water-stable SIFSIX-type material, [Cu(TPB)SiF6]n (termed ZJU-280, TPB = 1,2,4,5-tetra(pyridin-4-yl)benzene). This material features suitable rhombic pores and functional surfaces to interact optimally with C2H2 molecules, affording high C2H2 capture capacity and simultaneously high C2H2/CO2 (18.1) and C2H2/C2H4 (44.5) selectivities under ambient conditions. Theoretical calculations indicate that the suitable rhombic pores and functional sites can provide a multipoint binding environment to not only preferentially interact with C2H2 but also enable the dense packing of C2H2 molecules within the framework. Actual breakthrough experiments demonstrate that ZJU-280a can efficiently separate C2H2 from C2H2/CO2 (50/50, v/v) and C2H2/C2H4 (1/99 and 50/50) mixtures, respectively. [ABSTRACT FROM AUTHOR]

A novel expanded metal–organic framework (UTSA-111a) with functional pyrimidine sites exhibits simultaneously high gravimetric and volumetric methane storage working capacities of 309 cm3 (STP) g−1 and 183 cm3 (STP) cm−3 at 298 K and 5.8–65 bar. [ABSTRACT FROM AUTHOR]

In this work, we show that precise control of the pore size and functionality in an ultramicroporous metal–organic framework platform can finely tune the adsorption selectivity between acetylene and carbon dioxide at will. [ABSTRACT FROM AUTHOR]

Capturing carbon dioxide (CO2) from flue gases with porous materials has been considered as a viable alternative technology to replace traditional liquid amine adsorbents. A large number of microporous metal–organic frameworks (MOFs) have been developed as CO2-capturing materials. However, it is challenging to target materials with both extremely high CO2 capture capacity and gas selectivity (so-called trade-off) along with moderate regeneration energy. Herein, we developed a novel porous material, [Cu(dpt)2(SiF6)]n (termed as UTSA-120; dpt = 3,6-di(4-pyridyl)-1,2,4,5-tetrazine), which is isoreticular to the net of SIFSIX-2-Cu-i. This material exhibits simultaneously high CO2 capture capacity (3.56 mmol g−1 at 0.15 bar and 296 K) and CO2/N2 selectivity (∼600), both of which are superior to those of SIFSIX-2-Cu-i and most other MOFs reported. Neutron powder diffraction experiments reveal that the exceptional CO2 capture capacity at the low-pressure region and the moderate heat of CO2 adsorption can be attributed to the suitable pore size and dual functionalities (SiF62− and tetrazine), which not only interact with CO2 molecules but also enable the dense packing of CO2 molecules within the framework. Simulated and actual breakthrough experiments demonstrate that UTSA-120a can efficiently capture CO2 gas from the CO2/N2 (15/85, v/v) and CO2/CH4 (50/50) gas mixtures under ambient conditions. [ABSTRACT FROM AUTHOR]

Despite tremendous efforts, precise control in the synthesis of porous materials with ideal nanocages for desired gas separation applications still remains a challenge. Microporous metal–organic frameworks (MOFs) have provided rich chemistry to enable precise control and design of structures, pore cavities, and functionalities at the molecular level. Here, we propose and design a microporous MOF (termed as ZJUT-1, ZJUT = Zhejiang University of Technology) with a fine-tuned nanocage, exhibiting the desired size, shape, and functionalities that are suitable for trapping a single propyne (C3H4) molecule. Adsorption and computational studies indicate that such optimized nanocages can not only reduce the uptake of propylene (C3H6), but also strengthen the C3H4–host interactions through multiple hydrogen-bonding between SiF62−/–NH2 and C3H4 molecules. This material thus shows remarkably different C3H4 and C3H6 adsorption capacities, with the largest uptake ratio of 3.06 at 1 bar and 298 K, affording a very high selectivity (up to 70) for C3H4/C3H6 (1/99) separation. The actual breakthrough experiments demonstrate that ZJUT-1 can efficiently remove trace amounts of C3H4 from the important raw C3H4/C3H6 mixtures under ambient conditions with 0.19 mmol g−1 C3H4 uptake capacity to produce 99.9995% pure C3H6. [ABSTRACT FROM AUTHOR]

Heterodimetallic Ru–Fe complexes [(tppz)(PPh3)2RuL](ClO4) (L = C≡CFc, [1](ClO4); C≡C–C6H4–C≡CFc), [2](ClO4); C≡C–C6H4–C6H4–C≡CFc, [3](ClO4)) were synthesized by the reactions of [(tppz)(PPh3)2RuCl](ClO4) (tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine) with ferrocence-acetylide ligands and characterized by ESI-MS, and 1H and 31P NMR spectroscopies. The structure of [1](PF6) was determined by X-ray crystallography. The electrochemical studies show that compounds [1](ClO4)–[3](ClO4) possess two widely separated anodic peaks, ascribable to one-electron oxidation of Fc and RuII, respectively. This assignment is further corroborated by the results of UV-vis-NIR, XPS, and theoretical calculation studies. Compound [1](ClO4) exhibits significant Ru…Fe metal–metal interactions across the Ru–C≡C–Fc backbone. As revealed by electrochemical, spectroscopic and theoretical computational studies, one-electron oxidized species [1a](ClO4)2 is between the electronically delocalized and valence-trapped state and shows a typical Robin–Day class II mixed-valence behavior. [ABSTRACT FROM AUTHOR]

Two triphosphine-participated PtAu2 heterotrinuclear complexes with phenothiazine functionalized acetylides were prepared. The crystal structural determination indicates that because of a short Pt–Au distance of 2.9549(4) Å, the PtAu2 heterotrinuclear array supported by double triphosphine ligands exhibits substantial Pt–Au intermetallic contact. The PtAu2 complexes show moderate phosphorescent emission in fluid solution and the powder state, but intense orange and yellow phosphorescence in doped poly(methyl methacrylate) films with quantum yields of 73.7% and 48.9%, respectively. The phosphorescence arises from an admixture of 3[π(phenothiazine–acetylide) →π*(triphosphine)] 3LLCT and 3[π(phenothiazine–acetylide) → p/s(PtAu2)] 3LMCT triplet excited states. Utilizing blended host materials composed of both hole-transport TAPC and electron-transport OXD-7 doping with 8% phosphorescent PtAu2 complex as emitting layer, solution-processed organic light-emitting diodes (OLEDs) gave orange electroluminescence with the highest current efficiency of 35.4 cd A−1 and external quantum efficiency of 18.7%. [ABSTRACT FROM AUTHOR]

A novel zinc(ii) metal–organic framework UTSA-67a with narrow one-dimensional (1D) pore channels and inner cages of moderate size has been developed for highly selective separation of C2H2/C2H4 mixtures at room temperature. [ABSTRACT FROM AUTHOR]

A new lvt-type metal–organic framework UTSA-60a with suitable pore channels and open metal sites has been developed for highly selective separation of C2H2/C2H4 at room temperature. [ABSTRACT FROM AUTHOR]

We have developed a new porous metal-organic framework (MOF) (UTSA-80) with an elongated anthracene derivative as a linker. The activated UTSA-80a has a pore volume of 1.03 cm3 g-1 and a gravimetric Brunauer-Emmett-Teller surface area of ca. 2280 m2 g-1, higher than those of PCN-14. The volumetric methane storage capacity of UTSA-80a at 35 bar and 298 K is 192 cm3 (STP) cm -- 3, which makes it one of the few porous MOFs with a storage capacity >190 cm3 (STP) cm-3 at 35 bar. The volumetric uptake of methane by UTSA-80a reaches 233 cm3 (STP) cm-3 at room temperature and 65 bar; this is 88.6% of the new volumetric target of the US Department of Energy if the packing density loss is ignored. This capacity is comparable with that of PCN-14. However, as a result of the lower methane uptake of UTSA-80a at 5 bar, it has a much higher methane storage working capacity (deliverable amount of methane between 65 and 5 bar) of 174 cm3 (STP) cm-3 compared with PCN-14 [157-160 cm3 (STP) cm-3]. This value is slightly lower than the 190 cm3 (STP) cm-3 achieved by HKUST-1, suggesting that it is a promising material for methane storage in transport applications. Such an exceptionally high working capacity can probably be attributed to the elongated anthracene derivative used as a linker within UTSA-80a, which adjusts the pore sizes/cages and interactions with the methane molecules to optimize the methane working capacity. [ABSTRACT FROM AUTHOR]

A series of platinum(ii) complexes with 1,3-bis(2-pyridylimino)isoindoline (BPI) derivatives were prepared by substitution of the coordinated Cl in the precursor complex Pt(BPI)Cl with a N-heterocyclic ligand such as pyridine, phthalazine or phenanthridine. These complexes display orange to red luminescence in fluid dichloromethane solutions and in the solid states at room temperature. The photophysical properties were tuned by introducing electron-withdrawing -NO2or electron-donating -NH2to the BPI ligand. The DFT computational studies suggest that the emission in the N-heterocyclic ligand substituted platinum(ii) complexes originates mainly from the 3[π→π*(BPI)] 3IL triplet excited state, mixed with some 3[dπ(Pt)→π*(BPI)] 3MLCT character. Compared with the precursor Pt(BPI)Cl, both the low-energy absorption and the emission in the N-heterocyclic ligand substituted platinum(ii) complexes exhibits a distinct blue-shift due to an obviously enhanced contribution from the 3IL state and a reduced 3MLCT character. [ABSTRACT FROM AUTHOR]

A platinum(ii) complex of 5,5′-bis(trimethylsilylethynyl)-2,2′-bipyridine displays unusually reversible colour and luminescence changes when exposed to specific organic vapours, correlated well with PtPt distances as well as π–π and C–H(CC) interactions in the stacking of square-planar platinum(ii) moieties. [ABSTRACT FROM AUTHOR]

In this study, we successfully synthesize palladium-decorated indium trioxide (Pd/In 2 O 3 ) hybrid nanoclusters (NCs) using an advanced dual-target cluster beam deposition (CBD) method, a significant stride in developing high-performance ethanol sensors. The prepared Pd/In 2 O 3 hybrid NCs exhibit exceptional sensitivity, stability, and selectivity to low concentrations of ethanol vapor, with a maximum response value of 101.2 at an optimal operating temperature of 260 °C for 6 at% Pd loading. The dynamic response of the Pd/In 2 O 3 -based sensor shows an increase in response with increasing ethanol vapor concentrations within the range of 50 to 1000 ppm. The limit of detection is as low as 24 ppb. The sensor exhibits a high sensitivity of 28.24 ppm -1/2 , with response and recovery times of 2.7 and 4.4 seconds, respectively, for 100 ppm ethanol vapor. Additionally, the sensor demonstrates excellent repeatability and stability, with only a minor decrease in response observed over 30 days and notable selectivity for ethanol compared to other common volatile organic compounds. The study highlights the potential of Pd/In 2 O 3 NCs as promising materials for ethanol gas sensors, leveraging the unique capabilities of CBD for controlled synthesis and the catalytic properties of Pd for enhanced gas-sensing performance.

In this work, we show that precise control of the pore size and functionality in an ultramicroporous metal-organic framework platform can finely tune the adsorption selectivity between acetylene and carbon dioxide at will.

A new lvt-type metal-organic framework UTSA-60a with suitable pore channels and open metal sites has been developed for highly selective separation of C2H2/C2H4 at room temperature.

Using 3-methyloxysalicylaldoxime (mosaoH2) and N-methyl diethanolamine (N-mdeaH2) as coligands, a family of heptanuclear Mn/Ln heterometallic compounds [Mn(II)Mn(III)2Ln(III)4(mosao)2(mosaoH)4(piv)4(N-mdea)4]·xMeCN [Ln = Dy(1), Tb(2) and Y(3), pivH = pivalic acid] have been prepared. The crystal structures of 1-3 were obtained, and their core consists of two Mn(III)Ln2(μ3-OR)2 (RO(2-) = N-mdea(2-)) triangles linked to a central Mn(II) atom. A dc magnetic susceptibility study reveals that single-ion effects of the Ln ions are dominant in compounds 1 and 2. As for compound 3, which contains diamagnetic Y ions, the magnetic interactions between Mn ions via oximate NO bridges are revealed to be ferromagnetic. Fitting of the χ(m)T vs. T data gives g = 1.96 and J = 1.12 cm(-1), affording a S = 13/2 ground state. All of the three compounds exhibit frequency-dependent out-of-phase ac susceptibility signals indicative of slow magnetization relaxation and potential SMM behavior. Among them, 1 and 3 display the out-of-phase χ"(m) peak maximum above 2.0 K. Fitting of the ac susceptibility data to the Arrhenius law gives an energy barrier U(eff) = 9.27/13.83 K for 1 and 3, respectively.

Exploration of the complex Ni2(MBD)4 (MBD = 2-mercaptobenzimidazole) (C1) having different coordinated Ni atoms as a photocatalyst for hydrogen evolution is made. For comparison, the bimetallic Ni2(MBT)4 (MBT = 2-mercaptobenthiazole) (C2) complex with the same coordinated Ni atoms was synthesized. Both of the complexes have been successfully constructed for photo-induced hydrogen production using organic dyes as photosensitizers and triethanolamine (TEOA) as the effective electron donor by visible light (>400 nm) in acetonitrile-water solution. The time-dependence of H2 generation and DFT computational studies demonstrate that the complex C1 is more active than C2 for H2 evolution. The mechanisms of photocatalytic hydrogen generation for C1 and C2 involve different protonation sites resulting from the differences between the two structures.

Reactions of [Mn6O2(piv)10(py)2.5(piv)1.5], Ln(NO3)3·6H2O and N-mdeaH2 in MeCN in the presence of Me3SiCl generated a family of octanuclear Mn/Ln complexes [Mn6(III)Mn(II)Ln(N-mdea)3(N-mdeaH)(piv)8O2(OH)3(NO3)(H2O)]·xCH3CN·xH2O [Ln = Gd (1), Dy (2), Er (3), pivH = pivalic acid, N-mdeaH2 = N-methyl diethanolamine]. Each complex possesses a [Mn6(III)Mn(II)Ln(μ3-O)2(μ3-OH)3](16+) core containing two butterfly-like subunits of [Mn3Ln(μ3-OH)2] and [Mn4(μ3-O)2] sharing a common vertex, and an outer Mn atom ligated to one of the subunits through a μ3-OH(-) ligand. The core topology represents a new Mn/Ln core type. The magnetic susceptibility study of 1-3 indicates the presence of dominant antiferromagnetic interactions within the complexes. For complex 1, which contains an isotropic Gd(III) atom, fitting of the obtained M/(NμB) vs. H/T data gave S = 4, g = 1.90, and D = -0.31 cm(-1). The results were further supported by ac data. Complex exhibits out-of-phase ac susceptibility signals, indicating it may be a SMM.

Two [FeFe] hydrogenase mimics, [Fe(2)(μ-pdt)(CO)(5)L1] (L1 = PPh(2)SPhNH(2)) (Ph = phenyl) (2) and [Fe(2)(μ-pdt)(CO)(5)L2] (L2 = PPh(2)PhNH(2)) (3), and two molecular photocatalysts, [(CO)(5)(μ-pdt)Fe(2)PPh(2)SPhNHCO(bpy)(ppy)(2)Ir]PF(6) (bpy = bipyridine, ppy = 2-phenylpyridine) (2a) and [(CO)(5)(μ-pdt)Fe(2)PPh(2)PhNHCO(bpy)(ppy)(2)Ir](PF(6)) (3a), have been designed and synthesized, anchoring Ir(ppy)(2)(mbpy)PF(6) (mbpy = 4-methyl-4'-carbonyl-2,2'-bipyridine) (PS) to one of the iron centers of complexes 2 and 3 by forming amide bonds. Molecular dyads 2a, 3a and the intermolecular systems 2, 3 with PS have also been successfully constructed for photoinduced H(2) production using triethylamine (TEA) as a sacrificial electron donor by visible light (>400 nm) in CH(3)CN-H(2)O solution. The time-dependence of H(2) generation and spectroscopic studies suggest that the activity of H(2) evolution can be tuned by addition of a S atom to the phosphane ligand. The highest turnover numbers (TON) of hydrogen evolution obtained are 127, using 2a as a photocatalyst in a supramolecular system, and 138, based on catalyst 2 in a multi-component system. Density functional theory (DFT) computational studies demonstrate that the S atom in the second coordination sphere makes complex 2 accept an electron more easily than 3 and improves the activity in light-induced hydrogen production.

A diiron dithiolate complex 1o with a dithienylethene (DTE) phosphine ligand has been elaborately designed and fully investigated by spectroscopic and DFT computational studies. Upon irradiation with UV light, the DTE moiety in complex 1o undergoes an excellent photocyclization reaction to attain ring-closed state 1c in high yield (>95%), accompanied by a colour change from orange to deep blue. On the other hand, upon irradiation with visible light (>460 nm), ring-closed form 1c in CH(3)CN solution reverts perfectly into ring-open form 1o. Both 1o and 1c were characterised by IR, (1)H, (31)P, (19)F NMR and electrochemical spectroscopy. The electrochemical behaviours of both the open and closed forms were investigated by cyclic voltammetry. Upon photocyclization reaction, a 290 mV (from -2.29 V to -2.00 V) positive shift is induced in the potential of electrochemical catalytic proton reduction, due to the electron-withdrawing effect of the ring-closed DTE moiety. Consequently, complex 1 can reversibly photoswitch the potential of proton reduction on the [FeFe] moiety.

A 1,3-butadiyne-linked diruthenium complex 4 is successfully brought onto the gold surface in a lying flat mode to form self-assembled monolayers (SAMs) showing reversible multiple redox behaviors on the electrode surface. The diruthenium species with different oxidation states, particularly the Ru(2)(III,III) state which is unstable and impossible to isolate from the solution, can be detected by in situ IR spectroscopy.

A series of model complexes [(μ-pdt)Fe(2)(CO)(5)](2)M(sip)(2) (M = Fe, Ni) were synthesized as H-cluster analogues of [FeFe]-hydrogenase. Their electrochemical behaviours were investigated and it is proposed that the bridging metal bis(tris-chelate) groups act as electron transfer sites in theses mimics.

Heterotetranuclear Zn(2)Ln(2) (Ln = Nd , Eu , Sm , Er , Yb ) complexes {Zn(2)(Mq)(2)(tpyO)(2)}{(Ln(hfac)(3))(2)} (HMq = 2-methyl-8-hydroxylquinoline, tpyOH = [2,2':6'2'']terpyridin-4'-ol, hfac = hexafluoroacetylacetonate) display novel square structures ligated by bifunctional ligands tpyO (mono- and tridentate) and Mq (chelating and bridging mu-phenoxo). These compounds exhibit sensitized lanthanide emission upon photo-excitation of ZnMq/tpy antenna chromophores. By virtue of the dual luminescence with complementary colors, the ZnMq/tpyO-based cyan emission and Sm(III)-centered orange luminescence are combined to generate a white-light emission in Zn(2)Sm(2) (4) complex.