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Defects in solution-processed perovskite films can trap photoinduced carriers, facilitate ion migration, and accelerate degradation of perovskites, thus posing a major threat to the performance of perovskite solar cells (PSCs). To address these issues, we rationally proposed a multifunctional sulfonium salt molecule, namely diphenyl-(trifluoromethyl)-sulfonium trifluoromethanesulfonate (TFS-TFMS), which was designed to chelate the detrimental defects of perovskite films using a cost-effective post-treatment method. Theoretical and experimental evidence indicated that defects on the surface and grain boundaries of perovskite films, including uncoordinated Pb2+, volatile organic cations and mobile ionic vacancies, were synergistically anchored by S＝O, –CF3 and TFS+ groups in the TFS-TFMS molecule via Lewis acid–base coordination, hydrogen bonds and electrostatic interactions, respectively. The carrier dynamic behavior and energy level alignment at the interface between perovskites and hole-transportation-layers were also significantly improved. Consequently, the power conversion efficiency (PCE) of PSCs was boosted from 21.99% to 23.56% upon the introduction of TFS-TFMS, along with a diminished hysteresis index. In addition, the TFS-TFMS modified devices without encapsulation can retain 86% and 80% of their initial PCEs under aging conditions of 40–60% relative humidity (1752 h) or heating at 85 °C (504 h), respectively. It is expected that this synergistical design strategy of fluorine-rich sulfonium salt molecules can inspire more potential multifunctional modulators for efficient and stable PSCs towards commercialization in the future. [ABSTRACT FROM AUTHOR]

Self-assembled monolayers (SAMs) have been successfully employed to enhance the efficiency of inverted perovskite solar cells (PSCs) and perovskite/silicon tandem solar cells due to their facile low-temperature processing and superior device performance. Nevertheless, depositing uniform and dense SAMs with high surface coverage on metal oxide substrates remains a critical challenge. In this work, we propose a holistic strategy to construct composite hole transport layers (HTLs) by co-adsorbing mixed SAMs (MeO-2PACz and 2PACz) onto the surface of the H2O2-modified NiOx layer. The results demonstrate that the conductivity of the NiOx bulk phase is enhanced due to the H2O2 modification, thereby facilitating carrier transport. Furthermore, the hydroxyl-rich NiOx surface promotes uniform and dense adsorption of mixed SAM molecules while enhancing their anchoring stability. In addition, the energy level alignment at the interface is improved due to the utilization of mixed SAMs in an optimized ratio. Furthermore, the perovskite film crystal growth is facilitated by the uniform and dense composite HTLs. As a result, the power conversion efficiency of PSCs based on composite HTLs is boosted from 22.26% to 23.16%, along with enhanced operational stability. This work highlights the importance of designing and constructing NiOx/SAM composite HTLs as an effective strategy for enhancing both the performance and stability of inverted PSCs. [ABSTRACT FROM AUTHOR]

Developing porous materials for the efficient capture of I2 is relevant to the sequestration and storage of radioactive iodine towards clean nuclear energy. In this work, three topologically identical two-dimensional (2D) metal–organic frameworks (MOFs) [Cd3(BTB)2(Pz)4]·xSol. (2), [Cd3(BTB)2(3-PyCN)2(H2O)2]·xSol. (3), and [Cd3(BTB)2(4-PyCN)4]·xSol. (4) have been prepared by ligand exchange with [Cd3(BTB)2(DEF)4]·2(DEF)0.5 (1) via single-crystal to single-crystal transformations (H3BTB = benzene-1,3,5-tribenzoic acid; DEF = diethylformamide; Pz = pyrazine; 3-PyCN = 3-cyanopyridine; 4-PyCN = 4-cyanopyridine; xSol. = guest solvates). MOFs 1–4 feature linear Cd3 cluster secondary building units (SBUs) interconnected by BTB ligands, with each Cd3 unit also associated with four terminally bonded ligands bearing halogen bonding sites, viz. N(DEF) for 1, N(Pz) for 2, –C≡N(3-PyCN) for 3, and –C≡N(4-PyCN) for 4. MOFs 1–4 adsorbed I2 in the sequence 2 > 3 > 4 > 1 with a maximum uptake of 54.1 mg g−1 for 2. [ABSTRACT FROM AUTHOR]

Introducing 2,3-dimethyl-1H-imidazol-3-ium iodide (Dmim) as a monodentate ligand during the preparation of ZIF-8 yields ZIF-8 + (50) and ZIF-8 + (38) with cationic 'missing linker' defects. ZIF-8 + (38) adsorbs 125I2 and the resulting radioactive host–guest complex exhibits in vitro cytotoxicity comparable to that of Na125I against colon cancer cell line CT26. [ABSTRACT FROM AUTHOR]

The treatment of a 3D perovskite film with 2D perovskite segments has been recognized as a promising approach to improve the device performance of perovskite solar cells (PSCs), which have received much less attention in methylammonium (MA)-free devices than that in the MA-containing counterparts. We explored a novel fluorine-containing aromatic ammonium salt, 4-trifluorophenylammonium iodide (TFPAI) to form a 2D/3D junction on top of a Cs/FA-based perovskite. It was found that the hole and electron transport were more balanced for the 2D/3D configuration than for the pristine one, leading to a boosted fill factor (FF) and decreased hysteresis in the resultant devices. The formation of the 2D layer further increased the PL intensity, prolonged the carrier lifetimes, and significantly suppressed nonradiative recombination. Consequently, an impressive power conversion efficiency (PCE) of 22.7% was delivered for TFPAI modified devices with 2D/3D heterostructures, which is among the most efficient Cs/FA-based PSCs. Owing to the inherent hydrophobic characteristics of the 2D capping segment, the resultant PSCs exhibited remarkable moisture tolerance and thermal stability. This study provides an insight into the molecule design to deliver an efficient 2D/3D junction for high-performance PSCs. [ABSTRACT FROM AUTHOR]

Secondary building units (SBUs) in metal–organic frameworks (MOFs) are essential from both a structural and performance perspective. While a variety of SBUs, such as paddlewheel Cu II2 , triangular Cr III3 , tetrahedral Zn II4 , and octahedral Zr IV6 have been extensively studied, the linear trinuclear SBUs (herein denoted as M3), though frequently encountered, are rarely discussed as a class. A literature survey reveals that M3 clusters are ubiquitous in discrete molecular entities as well as in MOFs. Unlike most other cluster types, however, they have an unprecedented metal diversity and ligand tolerance. The single-crystals of some M3-based MOFs are also sufficiently robust upon guest removal and exchange or multi-step post-modifications to enable catalytic mechanism elucidation. Some of these M3-based SBUs endow MOFs with stability under demanding conditions necessary, for example, in flue gas separation. Herein we review MOFs sustained by this common but under-appreciated class of SBUs and discuss applications of the resulting MOF motifs. [ABSTRACT FROM AUTHOR]

Four coordination polymers (CPs) Mn-TMPP (1), Zn-TMPP (2), Mn-THPP (3), and Zn-THPP (4) have been synthesized and characterized (H2TMPP = meso-tetrakis (6-methylpyridin-3-yl) porphyrin; H2THPP = meso-tetrakis (6-(hydroxymethyl) pyridin-3-yl) porphyrin). The one-dimensional (1D) chain compound 1 is formed via a head-to-tail connection of the Mn-TMPP unit, wherein the central Mn2+ features a square pyramidal geometry coordinated by four N atoms from the porphyrin skeleton and one additional N atom from an adjacent Mn-TMPP unit. Compound 2 features an octahedral Zn2+ center associated with four N atoms from the porphyrin skeleton to define the equatorial plane and two additional N donors at the axial positions to give a two-dimensional (2D) CP. The 1D chain of 1 and the 2D layer of 2 possess distinctive molecular structures but nearly identical molecular arrangements in their unit cells viewed along all three crystallographic axes. By contrast, Mn- and Zn-based CPs 3 and 4 supported by the THPP ligand share both identical molecular connectivities and crystal packing. In 3/4, each Mn/Zn center is chelated by four N donors of the porphyrin interior to define the equatorial plane of an octahedron, whose axial sites are occupied by two alcoholic OH groups from a pair of trans-located pyridinemethanol moieties. The third-order nonlinear optical properties of 1–4 investigated using the Z-scan technique at 532 nm revealed reverse saturable absorption and self-focusing effects for all four CPs, with hyperpolarizability values (γ) in the range 1.42 × 10−28 esu to 7.64 × 10−28 esu. These high γ values are comparable to the best porphyrin-based molecular assemblies, demonstrating potential for these materials in optical limiting applications. [ABSTRACT FROM AUTHOR]

Crystals of a two-dimensional (2D) metal–organic framework (MOF) [Cd3(BTB)2(DEF)4]·2(DEF)0.5 (1; BTB = benzene-1,3,5-tribenzolate; DEF = N,N′-diethylformamide) immersed in a solution of trans-1,2-bis(4-pyridyl)ethylene (BPEE) yields an interpenetrated three-dimensional (3D) MOF of [Cd3(BTB)2(BPEE)(H2O)2]·(BPEE)·xSol (2). Crystals of MOF 2, in turn, undergo a cascade conversion when immersed in DEF, yielding [Cd3(BTB)2(BPEE)1.8(DEF)0.9(H2O)0.8]·xSol (3a) over 100 seconds and [Cd3(BTB)2(BPEE)2(DEF)2]·xSol (4) after one hour, before finally shuttling back to MOF 1 after six hours. [ABSTRACT FROM AUTHOR]

Zwitterionic metal–organic frameworks (MOFs) of {[Cu(Cbdcp)(Dps)(H2O)3]·6H2O}n (MOF 1) and [Cu4(Dcbb)4(Dps)2(H2O)2]n (MOF 2) (H3CbdcpBr = N-(4-carboxybenzyl)-(3,5-dicarboxyl)pyridinium bromide; H2DcbbBr = 1-(3,5-dicarboxybenzyl)-4,4′-bipyridinium bromide; Dps = 4,4′-dipyridyl sulfide) quench the fluorescence of cytosine-rich DNA tagged with 5-carboxytetramethylrhodamine (TAMRA, emission at 582 nm, denoted as C-rich P-DNA-1) and yield the corresponding P-DNA-1@MOF hybrids. Exposure of these hybrids to Ag+ results in the release of the P-DNA-1 strands from the MOF surfaces as double-stranded, hairpin-like C–AgI–C (ds-DNA-1@Ag+) with the restoration of TAMRA fluorescence. The ds-DNA-1@Ag+ formed on the surface of 1 can subsequently sense biothiols cysteine (Cys), glutathione (GSH), and homocysteine (Hcy) due to the stronger affinity of mercapto groups for Ag+ that serves to unfold the ds-DNA-1@Ag+ duplex, reforming P-DNA-1, which is re-adsorbed by MOF 1 accompanied by quenching of TAMRA emission. Meanwhile, MOF 2 is also capable of co-loading a thymine-rich probe DNA tagged with 5-carboxyfluorescein (FAM, emission at 518 nm, denoted as T-rich P-DNA-2) to achieve synchronous sensing of Ag+ and Hg2+, resulting from the simultaneous yet specific ds-DNA-1@Ag+ and T–HgII–T duplex (ds-DNA-2@Hg2+) formation, as well as the distinctive emission wavelengths of TAMRA and FAM. Detection limits are as low as 5.3 nM (Ag+), 14.2 nM (Cys), 13.5 nM (GSH), and 9.1 nM (Hcy) for MOF 1, and 7.5 nM (Ag+) and 2.6 nM (Hg2+) for MOF 2, respectively. The sequential sensing of Ag+ and biothiols by MOF 1, and the synchronous sensing of Ag+ and Hg2+ by MOF 2 are rapid and specific, even in the presence of other mono- and divalent metal cations or other biothiols at much higher concentrations. Molecular simulation studies provide insights regarding the molecular interactions that underpin these sensing processes. [ABSTRACT FROM AUTHOR]

A cationic two-dimensional coordination polymer sustained by a [Ag12S12] cluster secondary building unit has been prepared from a stepwise solid-state reaction. This coordination polymer is capable of associating the anionic dye Congo Red, yielding a composite material that exhibits improved photocurrent and dielectric responses as compared to the pristine polymer. [ABSTRACT FROM AUTHOR]

We herein report three isoreticular Tp*–W–Cu–S cluster-based one-dimensional coordination polymers, namely, [Tp*WS3Cu2(CN)2Cu](pz)0.5 (2), [Tp*WS3Cu2(CN)2Cu](bipy)0.5·0.5DMF (3), and [Tp*WS3Cu2(CN)2Cu](bpb)0.5·DMF (4), from the reaction of [Et4N][Tp*WS3] (1) with CuCN in the presence of bridging ligands pyrazine (pz), 4,4′-bipyridine (bipy), and 1,4-bis(4-pyridyl)benzene (bpb) under solvothermal conditions. In 2–4, a pair of butterfly-shaped [Tp*WS3Cu2]+ clusters are connected by two [Cu(CN)2]− units to give a macrocyclic unit, which is further strung by pz/bipy/bpb to give linear chains. Besides their rare isoreticular nature, 2–4 are also unique in that they contain a [Tp*WS3Cu2] + [Cu] combination instead of the widely acknowledged nest-shaped [Tp*WS3Cu3]2+ or cuboidal [Tp*WS3Cu3X]+ (X = Cl, Br, I) cluster skeleton. Compounds 2–4 are also characterized by FT-IR, elemental analysis, UV-vis and ESI-MS. The ESI-MS results also indicate that the pz/bipy/bpb coordination is labile in solution under harsh ionization conditions, yielding CN-ligated anionic species which are assumed as the key contributors to the enhanced NLO performance of 2–4 compared to that of the starting material 1. [ABSTRACT FROM AUTHOR]

Defects within the nanoscale UiO-66 metal–organic framework (MOF) are created to lock a hybrid phosphonoacetate ligand through Zr–O–P linkages, leaving the carboxyl group free to anchor cisplatin prodrug cis, cis, trans-[Pt(NH3)2Cl2(OH)2]. A drug loading of 256.5 mg g−1 (25.7 wt% based on cisplatin) was achieved with a Zr6 : Pt : P ratio of 1.5 : 1 : 1, which surpasses defect-free UiO-66 and several other MOF carriers. This framework exhibited a burst release of its payload in PBS solution in the first 2 h, releasing 71% of the drug, including a 50% payload release in less than 1 h. This work demonstrates that MOF defects can be intentionally engineered to achieve a high drug loading, and serves as an alternative to drug encapsulation using the pore void and through the association of the functionalized ligand. [ABSTRACT FROM AUTHOR]

A two-dimensional (2D) Co-based metal–organic framework (MOF) with porphyrinic skeleton forms crystalline plates, flower-shaped clusters, and ultrathin films under optimized conditions, including the use of polyvinylpyrrolidone (PVP) as a surfactant. Ultrathin films demonstrate the best solution-based third-order nonlinear optical properties, featuring a nonlinear transmittance (T) value of 0.54, absorption coefficient (α2) of 9.5 × 10−10 m W−1 and second hyperpolarizability (γ) value of 1.37 × 10−28 esu, which are slightly better than those of the flower-shaped clusters (T = 0.65, α2 = 7.0 × 10−10 m W−1; γ = 1.27 × 10−28 esu), but marginally better than those of the crystalline thin plates (T = 0.94, α2 = 2.4 × 10−10 m W−1; γ = 0.24 × 10−28 esu). [ABSTRACT FROM AUTHOR]

We have exploited an efficient electrostatic attraction strategy to fabricate hybrid 2D–2D heterostructures consisting of few-layered ReS2 nanosheets chemically anchored on both sides of reduced graphene oxide in vertical orientation (v-ReS2/rGO) via a one-pot hydrothermal approach. The additive hydroxylamine hydrochloride plays a critical role in reversing the negatively charged pristine rGO to positively charged rGO, which favors the electrostatic attraction of ReO4− and facilitates the subsequent growth of the few-layered ReS2 nanosheets perpendicular to the rGO substrates, where ReS2 nanosheets present a thickness of ∼3.7 nm and a height of ∼50 nm relative to the rGO scaffold. Due to the synergistic effects of the elegant 2D–2D nano-hierarchy created on graphene, the resulting v-ReS2/rGO nanocomposite exhibits reversible lithium and sodium storage with excellent specific capacity and rate capability at low potentials, making such 2D–2D materials promising candidates as anode hosts in alkali ion batteries. [ABSTRACT FROM AUTHOR]

Five stable clusters sharing the cuboidal [Ni4O4] skeleton are subjected to third-order nonlinear optical (NLO) property measurements. Preliminary results suggest that the NLO property is largely defined by the cluster core skeleton and the directly coordinated atoms, with limited contribution from the heavy atoms peripherally attached to the aromatic ligands. [ABSTRACT FROM AUTHOR]

We herein report the preparation of unique heteroatom-doped and carbon-based AuAg alloy nanoparticles (NPs) via the pyrolysis of a structurally defined octanuclear heterometallic Au(i)–Ag(i) cluster [Au4Ag4(Dppy)4(Tab)4(MeCN)4](PF6)8 (2, Dppy = diphenylphosphine-2-pyridine and Tab = 4-(trimethylammonio)benzenethiolate). This cluster-precursor approach exerts a fine control over the spatial arrangement, size and uniformity of the AuAg alloy NPs as well as the doped heteroatoms (P, N, F and S). The optimized material prepared at 450 °C efficiently catalyzes the oxidative coupling of anilines to yield azobenzenes under mild conditions. [ABSTRACT FROM AUTHOR]

Reaction of [Et4N][Tp*WS3] (1) with [Cu(MeCN)4]PF6, CsCl, isonicotinic acid and CuCN, and treatment of [Et4N][Tp*WS3(CuCl)3] (2)/[Et4N][{Tp*WS3Cu3Cl}2(μ-Cl)2(μ4-Cl)] (3) with AgOTf and bpp (Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate; bpp = 1,3-di(4-pyridyl)propane) give rise to [Et4N]2[{Tp*WS3Cu3(CN)0.5}2(μ-Cl)2(μ4-Cl)]2(PF6)2 (4) and [(Tp*WS3Cu3)2(μ3-Cl)2(bpp)3]2(OTf)4 (5), respectively. Compounds 4 and 5 feature cluster-based rectangle and [2]catenane architecture, and both exhibit enhanced third-order nonlinear optical responses relative to those of 1. [ABSTRACT FROM AUTHOR]

A series of Fe(iii) complexes of β-diketonate ligands, 1-(2-pyridyl)-3-(3-pyridyl)-1,3-propanedione (L1), 1-(2-pyridyl)-3-(2-pyridyl)-1,3-propanedione (L2), 1-(2-pyridyl)-3-(4-pyridyl)-1,3-propanedione (L3), 1-(3-pyridyl)-3-(4-pyridyl)-1,3-propanedione (L4), 1-(3-pyridyl)-3-(3-pyridyl)-1,3-propanedione (L5) and 1-(4-pyridyl)-3-(4-pyridyl)-1,3-propanedione (L6), viz. [Fe(L1)3] (1), [Fe(L2)3] (2), [Fe(L3)3] (3), [Fe(L4)3] (4), [Fe(L5)3] (5) and [Fe(L6)3] (6) have been structurally characterized. All but one complex (1) catalyzed the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) in near quantitative yield at 110 °C to give polymers with relatively narrow polydispersities (PDI). The comparison of in situ reaction and a reaction with preformed 1 indicated that the latter was a better catalyst, giving a higher molecular weight. Complex 2 catalyzed this reaction in a more modest yield reflecting its greater thermal stability, shorter Fe–O bonds and minimal distortion in fold angle among the isomeric complexes, suggesting that ligand dissociation is important for catalytic activity. [ABSTRACT FROM AUTHOR]

Cuboidal [Ni4O4] clusters supported by a pyridine alkoxide ligand have been developed. One of these clusters was selected as a precursor for carbon-hosted Ni nanoparticles (NiNPs/C) which were efficient catalysts for the conversion of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) at room temperature. [ABSTRACT FROM AUTHOR]

A protonated mononuclear complex [Zn(Hbpvp)Cl3] (1) is assembled by solvothermal reaction of Zn(NO3)2·6H2O with 3,5-bis-(2-(pyridin-4-yl)vinyl)pyridine (bpvp) in DMF/H2O with a few drops of concentrated HCl added. Hydrogen-bonded zigzag chains of 1 crystallize over time to form large-size hollow hexagonal tubular crystals whose evolution from irregular crystal seeds is monitored by SEM and PXRD. Upon UV light irradiation, single crystals of 1 undergo a stereoselective [2+2] photocycloaddition while its Methyl Blue-coated crystals keep intact. [ABSTRACT FROM AUTHOR]

The integration of a geometrically rigid Pd(ii), a coordinatively monotonous N-heterocyclic carbene 1,3-dimethylimidazoline-2-ylidene (IMe), and a flexible zwitterionic thiolate 4-(trimethylammonio)benzenethiolate (Tab) affords a class of Pd–IMe–Tab complexes with various nuclearities, namely, trans-[Pd(IMe)2(Tab)2](OTf)2 (2, mononuclear), cis-[Pd(IMe)2(Tab)2](OTf)(Cl) (3a, mononuclear), cis-[Pd(IMe)2(Tab)2](PF6)2·MeCN (3b·MeCN, mononuclear), [Pd2(IMe)4(Tab)2](PF6)4·2MeCN (4·2MeCN, dinuclear) and [Pd4(IMe)4(Tab)6](OTf)6(Cl)2 (5, tetranuclear). Further presence of Ag(i) in the assembly provides a heterometallic octanuclear cluster of [Pd4Ag4(IMe)8(Tab)10](PF6)12 (6). Compounds 2–6 are formed by the reaction of trans-Pd(IMe)2Cl2 (1) with various additional reagents via different reaction pathways. These compounds are characterized by means of FT-IR, 1H and 13C NMR, ESI-MS, elemental analysis and X-ray crystallography. Notably, the skeleton of compound 5 features a [Pd4S4] parallelogram wherein each of the four Pd(ii) centers bisects the edge defined by the S atoms. The main skeleton of compound 6 is an oval-shaped Pd4Ag4S10 unit, featuring an edge-fused norbornane-like (Pd2Ag4S6) framework appended by two additional PdS2 motifs at the polar positions. Compounds 5 and 6 also feature Pd…Pd (5), Pd…Ag and Ag…Ag (6) interactions. Compound 5 as a representative example is highly effective at catalyzing Suzuki–Miyaura couplings in water, highlighting the potential of applying these types of homo- and heterometallic clusters as catalysts for organic transformations in environmentally benign media. [ABSTRACT FROM AUTHOR]

Balancing the high power conversion efficiency (PCE) and long-term stability of organic–inorganic hybrid perovskite solar cells (Pero-SCs) is a challenging factor for the commercialization of solar cells. Herein, a cost-effective and widely available water-soluble additive, polyvinyl alcohol (PVA), has been adopted to improve the film quality of CH3NH3PbI3 and enhance the efficiency and long-term tolerance to humidity. A PCE of 17.4% has been achieved for the device with PVA, showing an 11.6% increase compared to those of the devices without the additive. Most importantly, the unencapsulated devices retain over 90% of their initial efficiency even after 30 days in a high humidity environment (90% relative humidity), exhibiting greater humidity tolerance and superior stability. Our studies present a simple solution-based approach to fabricate high efficiency solar cells with long-term stability under high humidity conditions, potentially revealing new methods for the mass production of Pero-SCs. [ABSTRACT FROM AUTHOR]

Cubic CuFeS2 nanocrystals (NCs) have been obtained via a facile colloidal chemistry approach and they show remarkable catalytic activity in the reduction of I3−. Dye sensitized solar cells (DSSCs) with CuFeS2 NCs as counter electrodes (CEs) display a power conversion efficiency of 8.10% comparable to that of a cell with Pt as the CE (7.74%) under the same conditions. [ABSTRACT FROM AUTHOR]

The investigation of heterometallic Mo(W)–M′–S clusters (M′ = transition metals) has its genesis in the late 1970s with the identification of the nitrogenase iron–molybdenum cofactor (FeMoco) featuring a Mo–Fe–S double-cubane cluster core. This has led to the generation of a library of cluster skeletons subsequently used as building blocks for oligomers (OGs) and polymers, merging this field with the fascinating developments in supramolecular chemistry and coordination polymers (CPs). While resembling the general metal–ligand assembly to form CPs in one-pot, cluster-based OGs or CPs are conventionally prepared from Mo(W)–S synthons and Cu(i) salts in the presence of bridging ligands. This review summarizes the synthesis of Mo(W)–Cu–S cluster-supported OGs and CPs through a two-step strategy involving preformed clusters. This stepwise approach facilitates clean conversion, and is amenable to exquisite design protocols and yields products otherwise inaccessible via a direct one-pot method. We review the synthesis of OGs and CPs by cluster core upgrading, downgrading, ligand substitution, and cluster aggregation reactions, together with the optical and host–guest properties of the products. In doing so, we demonstrate the power and generality of this strategy for assembling these unique materials and offer clues on how to adapt this less practiced method to preparing extended molecular assemblies with potentially intriguing properties. [ABSTRACT FROM AUTHOR]

Colloidal deposition of gold nanoparticles (Au NPs) onto NH2-UiO-66 nanocrystals has been demonstrated with the resulting hybrid catalyst proving robust and versatile for one-pot, heterogeneous conversions involving the selective oxidation of primary alcohols in tandem with Knoevenagel condensation reactions. Within these systems, structure–property correlations have been established to confirm that the active sites for the oxidation and condensation reactions are intrinsically correlated with the Au NPs and pendant amine groups respectively. [ABSTRACT FROM AUTHOR]

By utilizing the coordination unsaturation of 1,2,3-benzenetricarboxylate (1,2,3-BTA) and protonated N,N′-di(3-pyridyl)succinamide (L) in the as-synthesized 1D coordination polymer (CP) of [(H2L)0.5][Zn(1,2,3-BTA)(H2O)]·2H2O (1), we successfully doped an additional half equivalent of Zn2+ and Co2+ ions to yield [Zn3L(1,2,3-BTA)2(H2O)6]·4H2O (2) and [Zn2CoL(1,2,3-BTA)2(H2O)6]·4H2O (2c). Compounds 2 and 2c are also possible through direct one-pot metal–ligand assembly. With the one-pot method, [Zn2.76Co0.24L(1,2,3-BTA)2(H2O)6]·4H2O (2a) and [Zn2.40Co0.60L(1,2,3-BTA)2(H2O)6]·4H2O (2b) are accordingly prepared to demonstrate the universality of hetero-metallic doping and for probing the doping effect on photocurrent responses. Compounds 2, 2a–2c are 2D CPs formed by linking 1,2,3-BTA-based 1D chains through L ligands. Their photocurrent responses were found to be positively related to the Co2+ percentage of the doped materials. [ABSTRACT FROM AUTHOR]

Polymorphic compounds {[Cu(dcbb)2(H2O)2]·10H2O}n (2, 1D chain), [Cu(dcbb)2]n (3, 2D layer) and their co-crystal {[Cu(dcbb)2(H2O)][Cu(dcbb)2]2}n (4) have been prepared from the coordination reaction of a 2D polymer [Na(dcbb)(H2O)]n (1, H2dcbbBr = 1-(3,5-dicarboxybenzyl)-4,4′-bipyridinium bromide) with Cu(NO3)2·3H2O at different temperatures in water. Compounds 2–4 have an identical metal-to-ligand stoichiometric ratio of 1 : 2, but absolutely differ in structure. Compound 3 features a 2D layer structure with aromatic rings, positively charged pyridinium and free carboxylates on its surface, promoting electrostatic, π-stacking and/or hydrogen-bonding interactions with the carboxyfluorescein (FAM) labeled probe single-stranded DNA (probe ss-DNA, delineates as P-DNA). The resultant P-DNA@3 system facilitated fluorescence quenching of FAM via a photoinduced electron transfer process. The P-DNA@3 system functions as an efficient fluorescent sensor selective for HIV double-stranded DNA (HIV ds-DNA) due to the formation of a rigid triplex structure with the recovery of FAM fluorescence. The system reported herein also distinguishes complementary HIV ds-DNA from mismatched target DNA sequences with the detection limit of 1.42 nM. [ABSTRACT FROM AUTHOR]

We herein report a fluorescent Zn(ii)-supported metal–organic framework (MOF) [Zn4(Hbpvp)2(BTC)3(HCOO)(H2O)2]·4H2O (1) (bpvp = 3,5-bis-(2-(pyridin-4-yl)vinyl)pyridine; H3BTC = 1,3,5-benzenetricarboxylic acid) assembled from solvothermal reactions of ZnSO4·7H2O with bpvp and H3BTC ligands. Compound 1 has a unique two-dimensional (2D) layer structure and exhibits a high sensitivity and a low limit of detection of 1.0 × 10−6 mol L−1 for both 2,4-dinitrophenol (2,4-DNP) and p-benzoquinone (p-BQ) in aqueous solutions, inferred from fluorescence quenching studies. The fluorescent intensity of 1 recovers upon removal of analytes, making it a promising recyclable dual-targeted luminescent probe for 2,4-DNP and p-BQ in water. [ABSTRACT FROM AUTHOR]

Instant adsorption of Congo Red (CR) by a 1D coordination polymer, [(H2L)0.5][Zn(1,2,3-BTA)(H2O)]·2H2O (1·2H2O), leads to the formation of a unique dye composite 1·0.75CR·6H2O, which demonstrates a remarkably enhanced photocurrent response compared to that of its precursor. [ABSTRACT FROM AUTHOR]

Nitrogen-doped carbon nanotubes decorated with Co and Ni metal nanoparticles were assessed as counter electrodes (CEs) of dye-sensitized solar cells (DSSCs). These composites show good electrocatalytic activity toward the counter electrode reduction reaction (I3−→ I−) in DSSCs. The resulting devices using these composites as CEs display photovoltaic performance as good as, or even better than Pt-based devices, indicating their potential for application in DSSCs. [ABSTRACT FROM AUTHOR]

A set of four metal–organic frameworks, namely, [Zn(1,3-BDC)(bmimb)]n (1), [Zn(1,4-BDC)(bmimb)]n (2), [Cd(1,3-BDC)(bmimb)]n (3), and [Cd(1,4-BDC)(bmimb)]n (4), have been prepared under solvothermal conditions (1,3-BDC = 1,3-benzenedicarboxylate; 1,4-BDC = 1,4-benzenedicarboxylate; bmimb = 4,4′-bis(4-methyl-1-imidazolyl)biphenyl). The long bmimb ligand (N…N separation of ca. 14.1 Å) induces interpenetration of 1, 2 and 4 to increase both the framework stability and the density of effective catalytic metal centers. Compounds 1, 2 and 4 are interpenetrated 3D structures while 3 features a 2D structure. Compound 1 exhibits a parallel 2D → 3D polycatenation while 2 and 4 are isomorphous and feature 3D → 3D interpenetration. Compounds 1–4 fluoresce in the range of 350–372 nm in the solid state, whereas compounds 2 and 3 catalyze the almost complete photodegradation of rhodamine B (RhB) in water within ca. 4 h and can be recycled at least five times without loss in their crystallinity. [ABSTRACT FROM AUTHOR]

Single-crystalline Cd3P2 nanowires (NWs) have been synthesized via a solution–liquid–solid (SLS) mechanism. The lengths of the resulting nanowires can be effectively tuned in the range of 180 nm and 5 μm, and the photodetectors made of the Cd3P2 nanowires exhibited a pronounced photoresponse with high stability and reproducibility. [ABSTRACT FROM AUTHOR]

The facile hydrothermal synthesis of rutile TiO2 nanorod arrays on FTO substrates without the use of acids has been developed. The morphology of the nanorods can be finely tuned by changing the growth parameters, and the potential of the as-made rutile TiO2 nanorods in perovskite solar cells was evaluated, showing power conversion efficiencies up to 11.1%. [ABSTRACT FROM AUTHOR]

Self-assembly of NiX2(X = Br or OAc) with 2-hydroxymethyl pyridine (hmpH) and 5-ethoxycarbonyl-2-hydroxymethyl pyridine (5-ehmpH) results in six new Ni(ii) complexes viz.[Ni(hmpH)2(H2O)2]Br2(1), [Ni4(hmp)4(µ-OAc)4] (2), [Ni2(µ-Br)2(5-ehmpH)4]Br2·0.33MeCN·0.67H2O (3), [Ni(5-ehmpH)3]Br2·0.33MeOH (4), [Ni4(5-ehmp)4(H2O)4Br4] (5) and [Ni4(5-ehmp)4(µ-OAc)2(OAc)2(H2O)2] (6), all of which have different chemical compositions and structures. Complexes 2, 5and 6, however, share a common cubane [Ni4O4] core in which the deprotonated alkoxypyridine serves as a bridge-chelate. The others (viz.1, 3, 4) are mono- or dinuclear with the alkoxypyridine remaining in its native acid form. [ABSTRACT FROM AUTHOR]