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Stereoselective [2 + 2] photocycloaddition provides a desirable synthetic route for target cyclobutane compounds yet remains challenging. In this issue of Chem Catalysis, Weiss and coworkers diligently apply CdSe quantum dots to photocycloaddition reactions and gain nearly quantitative yields of syn-aryl-conjugated vinylcyclobutanes.

This review summarizes the syntheses, crystal structures and applications of metal complexes with a specific zwitterionic thiolate ligand, 4-(trimethylammonio)benzenethiolate (Tab). The chemistry of Tab with transition metals (Fe, Co, Ni, Pd, Cu, Ag, Au, Zn, Cd, Hg), main group metals (In, Pb, Bi) and in heterometallic systems is described. The most significant structural features of the metal/Tab complexes are summarized and trends are discussed as a function of nuclearity and coordination numbers. The reactivity of specific metal/Tab complexes towards N- and P- donor ligands, organic acids, inorganic anions and metal ions is discussed. The luminescence and dielectric properties of the metal/Tab complexes and their applications as fluorescent biosensors and precursors to metal nanoparticles and catalysts for organic transformations are also illustrated.

We have investigated the structures of zinc and copper complexes of malonamide-linked bisporphyrin. Two porphyrin moieties adopt anti-configurations in both complexes. The linker (malonamide) plays important roles: it is involving in both coordination bonds and hydrogen bonds with coordinated water in zinc complex; it is involving in both inter- and intra-molecular hydrogen bonds in copper complex. Those supramolecular interactions lead to dimeric structures in both complexes. The dimerization constant of the zinc species has been evaluated by NMR method.

Chirality transfer has been investigated with an m-phthalic diamide-linked zinc bisporphyrinate as host and chiral monoalcohols with different alkyl substituents as guests. The substituent of the guest alcohol had a significant effect on chirality transfer. An increase in the number of carbon atoms from one to three resulted in circular dichroism (CD) sign inversion for the corresponding host-guest complexes. The crystal structures of these zinc bisporphyrinate-monoalcohol complexes revealed two types of orientation for the phenyl ring of the guests: one with the phenyl ring facing the porphyrin plane, and the other with the phenyl ring towards the linker. The chirality transfer mechanism was further studied by DFT and revealed that adjusting the chain length of the alkyl substituent could control the steric interaction between the alkyl group and the porphyrin plane, resulting in different chirality transfer outcomes. © 2018 Elsevier Ltd

Solvothermal reaction of Zn(NO3)2·6H2O with 1,4-bis(2-(pyridin-4-yl)vinyl)benzene (1,4-bpeb) and 1,3,5-benzenetricarboxylic acid (1,3,5-H3BTC) (molar ratio = 1:1:3) at 120 °C in CH3CN/H2O (v/v = 1:2) produced a one-dimensional (1D) coordination polymer {[1,4-bpebH2][Zn(H2O)(1,3,5-HBTC)(μ-1,3,5-HBTC)]·2H2O}n (1; [1,4-bpebH2]2+ = 4,4′-(-1,4-phenylenebis(ethene-2,1-diyl))bis(pyridin-1-ium)) in 64% yield. Heating 1 at 160 °C for 5 h gave rise to another 1D coordination polymer {[1,4-bpebH2][Zn(1,3,5-HBTC)(η,η,η,-μ3-1,3,5-HBTC)]·1.5H2O}n (2) in a quantitative yield. Compounds 1 and 2 were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. Compound 1 consists of [Zn(H2O)(1,3,5-HBTC)] units which are interlinked by μ-1,3,5-HBTC2− ligands to form a 1D [Zn(H2O)(1,3,5-H2BTC)(μ-1,3,5-HBTC)]n2n– anionic chain with [1,4-bpebH2]2+ cations located in-between these chains. Compound 2 contains [Zn2(1,3,5-HBTC)2] units which are interconnected to yield a 1D ladder-type [Zn(1,3,5-HBTC)(η,η,η-μ3-1,3,5-HBTC)]n2n– with [1,4-bpebH2]2+ cations positioned in-between these chains. Upon heating, the anionic single chain structure of 1 undergoes a single-crystal-to-single-crystal topological transformation into the anionic ladder-shaped chain structure of 2 by replacing the coordinated water molecules in one chain via one μ-1,3,5-HBTC2− ligand in the other chain in 1. Both compounds exhibit excellent sorption performance towards Congo Red (CR) in water at room temperature with the maximum absorption capacity of 2020 mg g−1 (1) or 2320 mg g−1 (2). Compound 1 as a representative example can selectively absorb CR from its combination with selected cationic dyes in water.

Two Zn-based metal–organic frameworks (MOFs) of pyridinemethanol–carboxylate conjugated ligands, namely, [Zn(L1)]n xSol (1, 3D) and [Zn(L2)2]n (2, 1D) (H2L1 = 4-(6-(hydroxymethyl)pyridin-3-yl)benzoic acid; H2L2 = 3-(6-(hydroxymethyl)pyridin-3-yl)benzoic acid) have been synthesized and structurally characterized. The dimensionalities of 1 and 2 are defined by the deprotonation states of the ligands. Specifically, the 3D MOF 1 features a rod-shaped Zn–O/COO chain as the secondary building unit (SBU) which effectively hinder network interpenetration, whereas the 1D chain of 2 mimics an edge-sharing octahedron with each Zn center serving as the vertex. MOF 1 reversibly uptakes CO2 and exhibits a Brunauer–Emmett–Teller (BET) surface of 345 m2 g−1, and remains crystalline upon activation, an indication of permanent porosity.

Summary Efficient oxygen reduction reaction (ORR) catalysts are key for the development of high-performance fuel cells. Palladium (Pd) is a promising catalyst system for ORR given its potential to replace platinum (Pt); however, it usually exhibits lower activity than Pt. Here, we report a class of ordered Pd 3 Pb tripods (TPs) with predominantly {110} facets and show that they achieve extremely high ORR performance in alkaline medium. In contrast to the knowledge that the excellent ORR activity of Pt catalyst is caused by its partially filled d orbital, our first-principle calculations suggest that the strong charge exchange between Pd-4 d and Pb-( sp ) orbitals on the Pd 3 Pb TPs {110} facet results in a Pd-Pb local bonding unit with an orbital configuration similar to that of Pt. Consequently, Pd 3 Pb TPs exhibit much higher ORR activities than commercial Pt/C and commercial Pd/C. Pd 3 Pb TPs are endurable and sustain over 20,000 potential cycles with negligible structural and compositional changes.

Cyanide (CN) assumes a unique role in the development of coordination chemistry, with the first CN-based coordination polymer dye Prussian blue as a milestone example. In this review, we discuss the structures of a rich class of Mo(W)–Cu–S clusters, cluster-based oligomers, 1D, 2D and 3D coordination polymers bearing CN ligands. The stable Mo(W)–Cu–S cluster skeletons in conjugation with the strong Cu–CN linkages offer enhanced stability of these cluster species, making them good nonlinear optical materials.

One palladium dichloride adduct of a phosphine-pyridine ligand N-diphenylphosphanyl-2-aminopyridine (L1) [(L1)PdCl2] (1) has been prepared and structurally characterized. Compound 1 can be used as an effective catalyst for the Suzuki-Miyaura cross-coupling reactions of unreactive aryl chlorides with aryl boronic acids, and worked much better than its mono- or bidentate phosphine ligands. The reactions with a wide scope of substrates proceeded to give desired products in good to excellent yields.

A green protocol for the synthesis of quinoxalines has been developed from catalytic oxidative cyclization of deoxybenzoins with 1,2-phenylenediamines in water. The optimal conditions are involved in the use of a water-soluble mononuclear copper(II) complex of a zwitterionic calix[4]arene [Cu(II)L(H 2 O)]I 2 ( 1 , H 4 L = [5,11,17,23–tetrakis (trimethylammonium)–25,26,27,28–tetrahydroxycalix[4]arene]) as a catalyst in alkali solution after refluxing for 15 h in O 2 . The target quinoxaline and its derivatives were obtained in good yields (up to 88%). The procedure described in this paper is simple, practical and environmentally benign.

An efficient catalytic system containing [RuCl2(η6-p-cymene)]2 and one P,N ligand, N-diphenylphosphino-2-aminopyridine (L1) was loaded in catalyzing the alkylation of ketones with primary alcohols for a diverse array of substrates. Other five P,N ligands based on pyridin-2-amine and pyrimidin-2-amine were also examined in this reaction to explore the influence of steric hindrance and electronic effects. Monitoring by 1H NMR and ESI-MS reveals a stable cationic L1-coordinated ruthenium hydride intermediate, identified as [Ru(η6-p-cymene)(κ2-L1)H]+. Organic intermediates consistent with a three-step dehydrogenation, alkylation and hydrogenation pathway were also observed. The final step in this reaction, the ruthenium-catalysed transfer hydrogenation reduction of α,β-unsaturated ketone with benzyl alcohol was performed separately.

A new porphyrin with a (phenylcarbamoyl)benzoic acid group (compound A) and its iron(III) complex [Fe(A)] were successfully synthesized. The crystal structure of [Fe(A)] was characterized by X-ray crystallography, which shows a dimeric structure through iron-carboxlate coordination bonds. By using methylene blue (MB) dye as a model pollutant, we studied the photocatalytic activity of [Fe(A)] under visible light. The system of [Fe(A)]/H2O2 exhibited high efficiency for the photodegradation of MB in water. Moreover, the recycling experiments confirmed the stability and reutilization of the catalyst.

Developing stable, efficient and economical electrocatalytic materials is still challenging for hydrogen evolution reaction (HER). Hence, we develop a Pd/Ni bimetallic carbon electrocatalyst (Pd/Ni-NC) with outstanding electrocatalytic performance. The catalyst derived from Pd-doped Ni-MOF (Pd/Ni-MOF) has particles and needle-like carbon tubes on its surface and is similar in shape to setaria. Benefiting from the composition and the unique structure, Pd/Ni-NC shows excellent HER catalytic performance with 16 mV at 10 mA cm−2, superior to Pd or Ni single metal-carbon catalyst. Furthermore, it maintains stable catalytic activity under constant current for 25h. These results show the strategy that obtaining Pd and Ni bimetallic MOF by cation exchange and its corresponding bimetallic carbon material with setaria-shaped structure by calcination is powerful for high efficient HER performance.

Four anionic ligands including 1-methyl-3(or 4)-(1-(pyridin-2-yl)-1H-pyrazol-3-yl)pyridin-1-ium iodide ([3,2′-pypzpym]I, [4,2′-pypzpym]I) and 1-methyl-3(or 4)-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)pyridin-1-ium iodide ([2,3′-pypzpym]I, [2,4′-pypzpym]I) are prepared. Reaction of CuI with [3,2′-pypzpym]I affords a mononuclear complex [CuI2(3,2′-pypzpym)] (1) and a one-dimensional coordination polymer [(Cu4I6)(3,2′-pypzpym)2]n (2). Analogous reactions of CuI with [4,2′-pypzpym]I, [2,3′-pypzpym]I or [2,4′-pypzpym]I yield [Cu4I6(4,2′-pypzpym)2] (3), [CuI2(2,3′-pypzpym)] (4) and [CuI2(2,4′-pypzpym)] (5), respectively. Relative to that of CuI, complexes 1–5 exhibit enhanced catalytic activities towards the Chan–Lam cross-coupling reactions of imidazole and arylboronic acids in a H2O MeCN (v/v=2:1). This catalytic system is involved in the C N cross-coupling reaction and works for a variety of imidazole derivatives as well as arylboronic acids with different electronic properties.

Without using any additional ligands, RuCl3 efficiently catalyses the reductive N-alkylation of aryl nitro compounds with alcohols using bio-based glycerol as the hydrogen source and without the need for any added solvents. The reaction can be easily manipulated to produce either imines or secondary amines in high yields. RuCl3-catalyzed reductive N-alkylation of nitroarenes with alcohols affords the corresponding imine products in good to excellent yields. Under the same reaction conditions, the one-pot sequential reaction of nitroarenes with alcohols and glycerol also gives amines in higher yields.

A water-soluble cationic mononuclear copper(II) complex [Cu(II) L (H 2 O)]I 2 ( 1 , H 4 L = 5,11,17,23–tetrakis(trimethylammonium)-25,26,27,28-tetrahydroxycalix[4]arene) was employed as a catalyst in the oxidation of benzyl alcohols to benzaldehydes in water. In the presence of TEMPO and H 2 O 2 , complex 1 exhibited good catalytic activity towards primary benzyl alcohols with a less catalyst loading (0.25 mol%) and a lower temperature (60 °C). The isolated yields of the aldehydes achieved 63–98% within 12 h.

Reaction of AgNO 3 with one tetraphosphine ligand, 1,4- N , N , N ′, N ′-tetra(diphenylphosphanylmethyl) benzene diamine (dpppda), gave rise to a Ag(I)/tetraphosphine coordination polymer [Ag 4 (NO 3 ) 4 (dpppda)] n ( 1 ). Compound 1 has a one-dimensional (1D) chain structure in which the chair-like [Ag 4 (NO 3 ) 4 ] cores are linked by the dpppda ligands using a Z-shaped μ - η 2 : η 2 side-by-side mode. Compound 1 exhibited good catalytic activity towards the photodegradation of nitrobenzene (NB), paranitrophenol (PNP) and 2,4-dinitrophenol (2,4-DNP) in aqueous solution under UV light irradiation. The kinetics and the mechanism of such catalytic photodegradation reactions were also investigated. The present work provided some new insight into the design and preparation of new coordination polymers as catalyst for high-performance photodegradation of toxic and persistent organic species existed in industrial wastewaters.

This review summarizes the uses of Tp- and Tp*-based Mo(W) sulfido precursor compounds, namely, [Et4N][Tp*WS3] (P1), [Et4N][Tp*MoS(S4)] (P2), [Et4N][TpMoS(S4)] (P3) and [(Tp*WS2)2(μ-S2)] (P4) for the assembly of a diverse class of heterometallic clusters, predominantly Mo(W)-Cu-S clusters. Some of these clusters also feature as building blocks for cluster-supported coordination polymers to achieve enhanced third-order nonlinear optical performances.

Suzuki–Miyaura coupling reactions of arylboronic acids with aryl bromides were mediated by PdCl2 and bdppmapy (N,N-bis-(diphenylphosphanylmethyl)-2-aminopyridine) that both stabilizes and solubilizes the catalyst in predominantly ethanol as a solvent. Excellent yields for a wide variety of substrates were obtained under relatively mild conditions in this ‘green’ solvent.

An efficient approach to decarboxylative C3-acylation of benzothiophenes or benzofurans with α-oxocarboxylic acids via palladium-catalyzed C–H bond activation was developed. This method was compatible with a variety of functional groups and provided an attractive route to 3-acylbenzothiophenes and 3-acylbenzofurans in good to high yields.

Treatment of [Et 4 N][Tp ∗ MoS(S 4 )] (Tp ∗ = hydridotris(3,5-dimethylpyrazol-1-yl)borate) ( 1a ) with [Ag(MeCN) 4 ]PF 6 and PPh 3 or Agdca (dca = dicyanamide) afforded two new neutral compounds [Tp ∗ MoO(μ–O) 2 MoO(μ–O) 2 MoO(μ–O) 2 OMoTp ∗ ]·8(MeCN) 0.5 ( 2 ·8(MeCN) 0.5 ) and [Tp ∗ Mo(μ–S)(μ–S 2 )(μ–S 3 )MoTp ∗ ]·DMF ( 3 ·DMF). Reactions of [Et 4 N][Tp ∗ WS 3 ] ( 1b ) with AgX (X = SCN, NO 3 , CN) in the presence of N- or P-donor ligands formed one binuclear cluster [Et 4 N][Tp ∗ WS(μ–S) 2 EW(NCS) 2 ] (E = 0.5O + 0.5S) ( 4 ) and two W/Ag/S clusters [Tp ∗ WO(μ–S) 2 Ag(dppe)]·MeCN ( 5 ·MeCN) and [{Tp ∗ WS(μ–S)(μ 3 –S)Ag 2 (py) 2 } 2 (μ–CN) 2 ] ( 6 ). These compounds were characterized by elemental analysis, IR, UV–Vis, 1 H NMR and single-crystal X-ray crystallography. Compound 2 possesses a centrosymmetric tetranuclear structure in which two dinuclear [Tp ∗ MoO(μ–O) 2 MoO] units are linked by a pair of μ–O bridges. Compound 3 contains a dimeric structure in which two [Tp ∗ Mo] units are linked by one μ–S, one μ–S 2 and one μ–S 3 bridge. Compound 4 has another dimeric anionic structure in which one [Tp ∗ WS] unit and one [(SCN) 2 WE] unit are linked via a pair of μ–S bridges. Compound 5 has a dimeric structure in which one [Ag(dppe)] + unit is linked by two μ–S atoms of [Tp ∗ WO(μ–S) 2 ] − moiety. Compound 6 adopts a centrosymmetric hexanuclear structure in which two unique trinuclear [Tp ∗ WS(μ–S)(μ 3 –S)Ag 2 (py) 2 ] units are interconnected by a couple of μ–CN bridges. The isolation of 2 – 6 provided an insight into not only the complexity arising from reactions of 1a and 1b with Ag(I) salts in the presence or absence of N- or P-donor ligands but also the interesting assembly chemistry of the Mo(W)/Ag/S clusters.

Three new coordination polymers, [Mn(L)(H2O)2]2·5H2O (1), [Cu(L)(4,4′-bipy)]2·H2O (2) and [Pb(L)(4,4′-bipy)0.5] (3) (H2L = 5-(pyridin-4-yl)isophthalic acid; 4,4′-bipy = 4,4′-bipyridine) have been synthesized and characterized by IR, thermogravimetric analysis, X-ray powder diffraction and X-ray single crystal diffraction. Complex 1 shows a 2D layer structure which stacks with the other ones to form 1D channels to hold 1D water chains. Complex 2 displays a 3D + 3D → 3D polycatenation network. 3 shows a unique 2D + 2D → 3D polycatenation net in which each Pb center has a hemidirected coordination geometry due to the existence of “inert pair effect”. The thermal and luminescent properties of 1–3 were also examined.

Reactions of NiCl2·6H2O or Ni(ClO4)2·6H2O with 2,2′-bipyridine (2,2′-bipy), or 2-bis(diphenylphosphino)ethane (dppe) or 1,4-bis(diphenylphosphino)butane (dppb) followed by addition of [Zn(Tab)4](PF6)2 (1) resulted in the formation of one trinuclear cationic complex [(2,2′-bipy)4Ni3(μ-Tab)4]Cl0.5(PF6)5.5 (2), one mononuclear cationic complex [Ni(Tab)2(dppe)](PF6)2 (3), and one dinuclear cationic complex [Ni2(dppb)(μ-Tab)2(Tab)2](PF6)2(ClO4)2 (4). Complexes 2–4 were characterized by elemental analysis, IR, UV–vis, 1H and 31P NMR, and single-crystal X-ray diffraction. In the [(2,2′-bipy)4Ni3(μ-Tab)4]6 + hexacation of 2, the central Ni(II) atom is connected to two [Ni(2,2′-bipy)2]2 + fragments by two pairs of μ-Tab ligands, forming a linear trinuclear cationic structure. The Ni(II) center of the dication of 3 is tetrahedrally coordinated by two S atoms from two Tab ligands and two P atoms of one dppe ligand. Complex 4 has a dimeric cationic structure in which two [(Tab)Ni]2 + species are linked by a pair of μ-Tab ligands and one dppb ligand. Complexes 2–4 displayed high catalytic activity toward the cross-coupling reactions of arylboronic acids and amines to produce N-arylated amines.

This work reported that Suzuki–Miyaura coupling reactions of arylboronic acid with aryl bromide or iodides were mediated by Pd(OAc)2 and 4-(benzylthio)-N,N,N-trimethylbenzenammonium chloride in the presence of Na2CO3 in water under the mild conditions. The corresponding Suzuki–Miyaura coupling products were obtained in good to excellent yields.

An efficient method of ligand-free Cu-catalyzed oxidative decarboxylative homocoupling of aryl propiolic acids was developed. When CuI was employed as the catalyst and I 2 as the oxidant, the decarboxylative homocoupling reaction for C sp –C sp bond formation in DMSO underwent smoothly to afford the corresponding 1,4-disubstituted 1,3-dialkynes in good to excellent yields without any organic ligands. This catalytic system was applicable to aryl propiolic acids bearing different steric, electronic, and functional groups.

Hydrothermal reactions of CdCl2·2.5H2O with 2-amine-4,4′-bis(1-imidazolyl)-bibenzene (abimb) and 5-hydroxy-1,3-benzenedicarboxylic acid (5-HO-1,3-H2BDC) or 5-oxyacetate isophthalic acid (H3OAIP) afforded two 3D Cd(II) coordination polymers, [Cd(5-HO-1,3-BDC)(abimb)]n (1) and {[Cd3(OAIP)2(abimb)2(H2O)3]·H2O}n (2). Complexes 1 and 2 were characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. 1 can be considered as having a 3D doubly pillared-layer framework constructed through 2D undulated (4,4) layers and abimb pillars. 2 exhibits a 3D pillared-layer framework derived from 2D (6,3) bilayers and abimb pillars. The Schlafli symbols for the two frameworks are (412 · 63) (1) and (62 · 84)2(65 · 8) (2), respectively. The thermal and photoluminescent properties of 1 and 2 were also investigated.

Three [CunXn]-based (X = Br, I) coordination polymers, {[Cu2(μ-I)2(bimb)2]·iodobenzene}n (1), {[Cu4(μ3-I)4(bimb)2][Cu2(μ-I)2(bimb)]}n (2) and {[Cu2Br(bimb)2]Br}n (3) were prepared from solvothermal reactions of CuX (X = I, Br) with 1,4-bis(imidazol-1-yl)butane (bimb) at different temperatures. These compounds were characterized by elemental analysis, IR, and single crystal X-ray diffraction. Compound 1 contains a rhombic [Cu2(μ-I)2] dimer that acts as a planar four-connected node to link four equivalent ones via bimb bridges to form a 2D (4,4) network. Each layer is further stacked by π–π interactions to form a 3D structure with 1D rhombic channels occupied by the guest iodobenzene molecules. Compound 2 consists of [Cu2(μ-I)2] dimers and [Cu4(μ3-I)4] tetramers which are interconnected by bimb bridges to generate another 2D network. Compound 3 contains [Cu2Br(bimb)2]+ cations that are linked by bimb ligands to form a 1D cationic chain. We also investigated the solid state photoluminescent properties of 1–3 at ambient temperature. The results provide an interesting insight into how reaction temperatures exert a great effect on the assembly of [CunXn]-based coordination polymers.

Cobalt(II) complexes (5 mol% Co) bearing phosphine-free N˄N˄N pincer ligands efficiently catalyze C–C coupling of secondary and primary alcohols to selectively form α-alkylated ketones with a good functional group compatibility using NaOH (20 mol%) as a base at 120 °C. The NH group on the N˄N˄N–Co(II) precatalyst controls the activity and selectivity. This simple catalytic system is involved in the synthesis of quinolones via the dehydrogenative annulation of 2-aminobenzyl alcohols with secondary alcohols.

Reactions of Zn(NO3)2∙ 6H2O with 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (titmb) in the presence of 1,4-benzenedicarboxylic acid (1,4-H2BDC) or 1,3-benzenedicarboxylic acid (1,3-H2BDC) under hydrothermal conditions afforded one 1D and one 2D coordination polymers [Zn3(titmb)2(1,4-BDC)3(H2O)6] (1) and [Zn2(titmb)(1,3-BDC)2(H2O)] (2), respectively. Similar reactions of Zn(NO3)2∙ 6H2O with 1,3-bis(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (bitmb) and 1,4-H2BDC gave rise to one 2D coordination polymer [Zn2(bitmb)2(1,4-BDC)2] (3). Compound 1 has a 1D linear chain formed from linking 24-membered [Zn2(titmb)2] metallamacrocycles and [Zn(1,4-BDC)(H2O)2] units via imidazolyl groups of titmb ligands. Compound 2 has a 2D network assembled from connecting spiral [Znn(1,3-BDC)n] chains with titmb linkers, while compound 3 also has a 2D network formed by linking 24-membered [Zn2(bitmb)2] metallamacrocycles via 1,3-BDC bridges. The ligands titmb and bitmb in compounds 1–3 adopt less-common cis–trans–trans and cis–trans conformations, respectively. Their thermal and photoluminescent properties were also investigated.

Reaction of CuI with equimolar amount of 2,6-bis(1-methyl-1H-pyrazol-3-yl)pyridine (bmppy) in MeCN and CH2Cl2 yielded a binuclear complex [(bmppy)Cu(μ-I)]2 (1). It was characterized by elemental analysis, IR, 1H NMR and single crystal X-ray diffraction. Complex 1 possesses an iodide-bridged dimeric structure in which each Cu(I) center is tetrahedrally coordinated by two μ-I and two N atoms from one bmppy ligand. Complex 1 exhibited good catalytic performance in the polymerization of methyl methacrylate (MMA) in cyclohexanone. Even though the ratio of MMA to 1 was raised up to 1000:1 when the reaction time and temperature and the MMA concentration were fixed at 4 h and 80 °C and 3 mol/L, respectively, the polydispersity index (PDI) for the resulting PMMA is close to 1.36 and the conversion is up to 75%. In addition, the effects of solvents, reaction temperatures as well as the ratios of MMA to catalyst 1 were also investigated.

Hydrothermal reactions of CdSO4 with tetrakis(4-pyridyl)cyclobutane (tpcb) and 1,3-benzenedicarboxylic acid (1,3-H2BDC) or 5-nitro-1,3-benzenedicarboxylic acid (5-NO2-1,3-H2BDC) resulted in the formation of two coordination polymers [Cd(tpcb)0.5(1,3-BDC)]n (1) and {[Cd2(tpcb)(5-NO2-1,3-BDC)2(OH2)2] · 4H2O}n (2), respectively. Compounds 1 and 2 were characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. 1 and 2 exhibit two different types of two-fold interpenetrating 3D architectures with (66)2(64 · 82) and (52 · 8)(54 · 6∙8)(4 · 53 · 62 · 7 · 82 · 10) Schlafli symbols, respectively. Their thermal and photoluminescent properties were also investigated.

Reactions of PbI2 with KI, I2 and 1,2-bis(diphenylphosphino)ethane (dppe) (molar ratio = 1:5:3:4) in MeCN/EtOH under solvothermal conditions afforded a one-dimensional (1D) coordination polymer [(EP)(Pb2I6)]n (EP2 + = ethane-1,2-diylbis(ethyldiphenylphosphonium)) (1) and a three-dimensional (3D) coordination polymer [{(Pb3(μ-I)6)(dppeo)3}·EtOH]n (2) (by-product). Treatment of the same components with H2O2 under similar conditions produced another 3D coordination polymer [{Pb2(μ-I)2(μ3-I)2}(dppeo)]n (dppeo = ethane-1,2-diylbis(diphenylphosphine oxide)) (3). Compound 2 could also be prepared in a medium yield from solvothermal reactions of PbI2 with KI, I2 and dppeo (molar ratio = 1:5:3:4). Compounds 1–3 were characterized by elemental analysis, IR and single crystal X-ray diffraction. Compound 1 contains one 1D anionic [PbI3]nn − chain with EP2 + dications being embedded between chains. The EP2 + dication was in situ generated via the cleavage of C O bond of EtOH followed by alkylation of dppe. Compound 2 consists of trinuclear [Pb3(μ-I)6] fragments that are interlinked via dppeo bridges to form a 3D 6-connected net (a 41263 Schlafli symbol). Compound 3 has a 3D net (with a 66 Schlafli symbol) constructed from 1D [Pb2(μ-I)2(μ3-I)2]n chains linked by dppeo ligands. The dppeo ligand in 3 was formed in situ from the oxidation of dppe by H2O2. The optoelectronic properties of 1–3 were also investigated.

Reactions of an organometallic precursor cluster [PPh4][Cp∗MoS3(CuSCN)3] (Cp∗ = η5-C5Me5) (1) with three ditopic ligands with different spacer lengths including 4,4′-bipyridine (4,4′-bipy), 1,2-bis(4-pyridyl)ethylene (bpee) and 1,2-bis(4-pyridyl)ethane (bpe) in DMF/MeCN gave rise to three unique [MoS3Cu3]-based coordination polymers {[Cp∗MoS3Cu3(4,4′-bipy)1.5(μ-SCN)(SCN)]·DMF·MeCN}n (2), {[Cp∗MoS3Cu3(bpee)1.5(μ-SCN)(SCN)]·0.5(bpee)·2(DMF)}n (3) and {[Cp∗MoS3Cu3(bpe)1.5(μ-SCN)(SCN)]·0.5(bpe)·0.25(DMF)}n (4), respectively. Compounds 2–4 were characterized by elemental analysis, IR, UV–Vis, 1H NMR and single-crystal X-ray crystallography. For 2, each [Cp∗MoS3Cu3] cluster core, serving as a unique seesaw-shaped four-connecting node, is interlinked by single SCN bridges, single and double 4,4′-bipy bridges to form a 2D (4,4) corrugated network. For 3 or 4, each [Cp∗MoS3Cu3] cluster core, acting as a uncommon piano-stool-shaped three-connecting node, is interconnected by double SCN bridges, single and double bpee (or bpe) bridges to yield a 2D (6,3) latticed network. These results provided an interesting insight into the spacer length-controlled assembly of [MoS3Cu3]-based coordination polymers.

The solvothermal reactions of Zn(NO3)2∙6H2O with 1,4-benzenedicarboxylic acid (1,4-H2bdc) and 1,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)butane (dmpzb) or 1,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)hexane (dmpzh) afforded two three-dimensional coordination polymers [Zn3(1,4-bdc)3(dmpzb)]n (1) and [Zn2(1,4-bdc)2(dmpzh)]n (2), respectively. Compounds 1 and 2 were characterized by elemental analysis, IR, powder X-ray diffraction, and single crystal X-ray diffraction. Compound 1 has an 8-connected 3D net (a 364185262 Schlafli symbol) assembled from trinuclear [Zn3(1,4-bdc)3] units and 1,4-bdc and dmpzb bridges. Compound 2 has a 6-connected 3D net (with a 485463 Schlafli symbol) constructed from binuclear [Zn2(1,4-bdc)2] units and 1,4-bdc and dmpzh linkers. The solid state luminescent and thermal stability properties of 1 and 2 at ambient temperature were also investigated. The results showed that the spacer lengths of bipyrazol-based ligands did affect the topological structures of zinc(II) coordination polymers.

We report a one-pot route to the formation of free-standing, large-area CNTs/TiO 2 nanofiber membrane with enhanced photocatalytic activity. Tetra- n -butyl titanate was reacted with NaOH to form high-quality titanate nanofibers with diameters below 200 nm and longitudinal dimensions of several tens of micrometers. CNTs were condensed with the as-prepared nanofibers and enabled the nanofibers to assemble into a free-standing membrane. It is proposed that the CNTs act as linkers between the nanofibers, and it is crucial for the formation of the membrane under the hydrothermal conditions. Benefiting from the introduction of CNTs, the as-prepared nanofiber membrane exhibited higher photocatalytic activity than pure TiO 2 nanofibers.

Reactions of PdCl 2 ·2H 2 O with 2 equiv. of 4-(trimethylammonio)benzenethiolate (Tab) (prepared in situ from a mixture of TabHPF 6 and Et 3 N in MeOH) and seven phosphine ligands: PPh 3 , 1,1-bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,4-bis(diphenylphosphino)butane (dppb), N , N , N ′, N ′-tetra(diphenylphosphanylmethyl)ethylene diamine (dppeda), and 1,4- N , N , N ′, N ′-tetra(diphenylphosphanylmethyl)benzene diamine (dpppda), afforded a family of mononuclear and dinuclear Pd(II)/Tab/phosphine complexes, [Pd 2 (PPh 3 ) 2 (Tab) 2 ( μ -Tab) 2 ](PF 6 ) 4 ( 1 ), [Pd 2 (dppm) 2 (Tab) 2 ( μ -Tab)](PF 6 ) 4 ( 2 ), [Pd 2 (dppb)(Tab) 2 ( μ -Tab) 2 ]Cl 4 ( 3 ), [PdL(Tab) 2 ](PF 6 ) 2 ( 4 : L = dppe; 5 : L = dppp) and {[PdL(Tab) 2 ] 2 }Cl 4 ( 6 : L = dppeda; 7 : L = dpppda). These compounds were characterized by elemental analysis, IR spectra, UV–Vis spectra, 1 H and 31 P{ 1 H} NMR, electrospray ionization (ESI) mass spectra and single-crystal X-ray diffraction. In the structure of 1 – 7 , each Pd(II) adopt an approximate square planar coordination geometry. The results provide an interesting insight into the chemistry of palladium(II)/thiolate/phosphine complexes.

Reaction of silver nitrate with N,N,N′,N′-tetra(diphenylphosphanylmethyl)ethylenediamine (dppeda) in the presence of aminothiocarbamide in CH2Cl2/MeOH afforded an unexpected and low-yield binuclear complex [Ag2(dppatc)2](NO3)2·2MeOH (dppatc = N,N-bis(diphenylphosphanylmethyl)aminothiocarbamide) (1). An X-ray analysis revealed that the [Ag2(dppatc)2]2+ dication of 1 contains a centrosymmetric double half-open cage structure in which two Ag centers are bridged by a pair of the heteroscopionate dppatc ligands via four Ag-μ-S and four Ag P bonds. The in situ-formed dppatc ligand in 1 could be readily generated by one-pot and high-yield reaction of diphenylphosphine with formaldehyde and aminothiocarbamide. Further reaction of AgNO3 with dppatc could produce 1 in a relatively high yield. The results provided an efficient route to the synthesis of dppatc and also an interesting insight into its coordination chemistry.

Solvothermal reactions of Cu2(OH)2CO3 with 1,2-bis(4-pyridyl)ethane (bpe) and iodobenzene or 4-iodotoluene in acetonitrile and aqueous ammonia afforded two arylamine-solvated [Cu2I2]-based coordination polymers {[Cu2I2(bpe)2]∙Am}n (1: Am = aniline; 2: Am = p-toluidine). Compounds 1 and 2 were characterized by elemental analysis, IR spectra, and powder X-ray diffraction (PXRD). Compounds 1 and 2 have a two-dimensional (4,4) topological network in which every rhombic [Cu2I2] dimer acts as a planar four-connected node to link other four equivalent ones by four bpe bridges. Each layer is further stacked via π–π interactions to form a 3D structure with 1D rhombic channels occupied by the guest aniline or p-toluidine molecules. These guest molecules were in situ generated through Ullmann coupling reactions of iodobenzene or 4-iodotoluene with ammonia. The thermal and photoluminescent properties of 1 and 2 were also investigated.

In the absence of any additional ligands, the efficient N-arylation of nitrogen-containing heterocycles with aryl iodides catalyzed by relative low catalyst amount of Cu(OAc)2·H2O was developed. This simple catalytic system is involved in the C–N cross-coupling reaction and works for a variety of pyrazole, pyrrole, imidazole, triazole, indole, benzoimidazole, benzotriazole, carbazole, and anilines as well as aryl iodides with different electronic properties. Highly efficient copper(II)-catalyzed N-arylation protocol was established.

Solvothermal reactions of CuX (X = Cl, Br, I, CN) with bis(4-bromo-3,5-dimethylpyrazol-1-yl)methane (brdmpzm) in MeCN gave rise to four one-dimensional coordination polymers [Cu(μ-X)(brdmpzm)]n (X = Cl (1), Br (2), I (3), CN (4)). Compounds 1–4 were characterized by elemental analysis, IR spectra and X-ray crystallography. X-ray analysis revealed that 1–3 have a 1D split-stair chain derived from connecting [Cu(brdmpzm)] fragments via μ-X bridges, while 4 consists of a zigzag chain formed by linking [Cu(brdmpzm)] fragments via μ-CN bridges. The luminescence properties of 1–4 along with free brdmpzm ligand at ambient temperature were also investigated.

Reactions of 25,26,27,28-tetrahydroxy-calix[4]arene (1) with 4 equiv. of m-carboxybenzenediazonium chloride in the presence of NaOAc∙3H2O in DMF produced a new azo calix[4]arene [H4L] (2) (H4L = 5,11,17,23-tetrakis[(m-carboxyphenyl)azo]-25,26,27,28-tetrahydroxycalix[4]arene) in 96% yield. Hydrothermal reactions of Cd(NO3)2·4H2O with H4L at 90 °C under pH = 5.0–6.0 gave rise to a coordination polymer {[H3O]2[Cd7L4(DMF)4(EtOH)2(H2O)2]·5DMF·11.5EtOH·H2O}n (3). Compound 3 was characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. Compound 3 consists of a 3D framework with an unprecedented (3346526371)(364135861) topology. The thermal properties of 2 and 3 were also investigated.

The cyclotrimerization of aryl isocyanates and the cyclodimerization of alkyl isocyanates initiated by one praseodymium benzenethiolate complex [Pr(SPh) 3 (THF) 3 ] were investigated. Comparative runs with [Pr(SPh) 3 (THF) 3 ] and its precursor Pr[(Me 3 Si) 2 N] 3 showed that the former has the advantages of a higher selectivity toward isocyanates, easy preparation, low catalyst loading, high conversion as well as mild reaction conditions.

Solvothermal reactions of CdSO4·8/3H2O with 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (titmb) and HCl in H2O, MeOH or EtOH afforded three coordination complexes [Cd5Cl2(μ-Cl)4(μ3-Cl)2(η,η,η-μ3-SO4)2(H2O)2(Htitmb)2]n (1), [Cd4Cl2(μ-Cl)2(η,η,η-μ3-SO4)2(MeOH)2(titmb)2]n (2) and [Cd4Cl2(μ-Cl)2(η,η,η-μ3-SO4)2] (3), respectively. All the compounds were characterized by elemental analysis, IR and single crystal X-ray diffraction. Compound 1 has a 1D chain in which each centrosymmetric double butterfly-shaped [Cd5Cl2(μ-Cl)4(μ3-Cl)2(H2O)2] unit interlinks with its equivalent ones via two couples of η,η,η-μ3-SO4 anions and two pairs of the Htitmb ligands. Compound 2 consists of one centrosymmetric [Cd5Cl2(μ-Cl)2(η,η,η-μ3-SO4)2(MeOH)4(titmb)2] unit that interconnects with equivalent ones via sharing Cd3 and its symmetry-related ones, forming a 1D zigzag chain. Compound 3 consists of a [Cd4Cl2(μ-Cl)2(η,η,η-μ3-SO4)2] unit linked by a pair of titmb ligands. The results may provide some insight into solvent effects on the formation of different coordination compounds from the same components.

The hydrothermal reactions of CuCl with 1,3-bis(4-pyridyl)propane (bpp), 1,3-benzenedicarboxylic acid (1,3-H2bdc), and KOH in water afforded {[Cu8Cl4(bpp)8][(1,3-Hbdc)4(H2O)9.5]}n (1). Single-crystal X-ray diffraction revealed that 1 has anionic [(1,3-Hbdc)4(H2O)9.5]n4n− water cluster chains that are encapsulated into the 1D channels of a 3-D [Cu8Cl4(bpp)8]n4n+ cationic framework. The thermal and luminescent properties of 1 in the solid state were also investigated.

Diffusion reactions of CuI with N,N,N′,N′-tetra(diphenylphosphanylmethyl)ethylene diamine) (dppeda) and 1,4-N,N,N′,N′-tetra(diphenylphosphanylmethyl)benzene diamine (dpppda) in MeCN/toluene in a zigzag glass tube or solvothermal reactions of CuI and dppeda or dpppda in MeCN produced two [CuxIx]-based coordination polymers, [Cu2I2(dppeda)]·2MeCN (1·2MeCN) and [Cu4I4(dpppda)]·MeCN (2·MeCN), respectively. Both compounds were characterized by elemental analysis, IR spectroscopy, 1H and 31P{1H} NMR, ESI-MS and thermogravimetric analysis, and their structures were determined by single crystal X-ray diffraction. In 1, [Cu2I2] cores are interconnected by dppeda ligands in a μ-η2:η2 end-to-end mode to form a 1D chain, while in 2 stair-like [Cu4I4] cores are linked by dpppda ligands in a unique Z-shaped μ-η2:η2 side-by-side mode to produce the other kind of 1D chain.