Two- and three-dimensional photoluminescent Cd(II)-carboxylate coordination frameworks bridged by benzenepentacarboxylate and N-donor ligands

Reactions of Cd(OAc)₂·H₂O, benzenepentacarboxylic acid (H₅bpc), 2,2′-bpy/4,4′-bpy, and Et₃N yield two new coordination polymers [Cd₅(bpc)₂(2,2′-bpy)₄(H₂O)₄] (1) and [Cd₅(bpc)₂(4,4′-bpy)₂(H₂O)₄]·3H₂O (2). Complex 1 is a 2-D structure based on six-connected Cd-carboxylate layers. Adjacent layers are linked by π–π interactions and hydrogen bonds to generate a layered supramolecular network. Complex 2 is a 3-D coordination framework. The bpc ligands adopting μ ₇-bridging mode connect Cd(II) ions to form a 3-D open framework with elliptic channels, in which the coordinated 4,4′-bpy ligands fill to support the whole framework. Complex 2 exhibits strong photoluminescence at room temperature.     

Two 2-dimensional cadmium(II) coordination polymers with 3-amino-5-methylthio-1,2,4-triazolate ligand

Reactions of cadmium(II) salts with 3-amino-5-methylthio-1H-1,2,4-triazole (Hamstz) afforded two cadmium(II) coordination polymers, [Cd₂(amstz)₂Cl₂]_n (1) and [Cd₂(amstz)₂(NO₃)₂]_n (2). Compounds 1 and 2 feature 2-D layered structures based on the dinuclear [Cd₂(amstz)₂] subunits. The cadmium coordination polyhedra are tetrahedral and tetragonal pyramidal in 1 and 2, respectively, due to the presence of different coordinated anions, Cl^? and NO₃^?. Compounds 1 and 2 exhibit photoluminescence emission with maxima at 620 and 621 nm upon excitation at 470 and 472 nm, respectively, which can be attributed to the ligand-to-metal charge transfer emssion.     

Construction of three new metal-organic frameworks with distinct SBUs: trinuclear {Cd3(COO)6} clusters,inorganic -Cd-O-Cd- chains,and heterometallic trinuclear {Cd2Ba(COO)4} clusters

Three metal-organic frameworks (MOFs), [Cd₃(OABDC)₂(e-urea)₄]_n (1), [Cd₃(OABDC)₂(H₂O)₅)]_n (2) and [Cd₂Ba(OABDC)₂(H₂O)₇]_n (3) (H₃OABDC = 5-oxyacetate isophthalic acid, e-urea = 2-imidazolidinone), were prepared using H₃OABDC and metal salts. Single-crystal X-ray diffraction analyses reveal that 1 features a 2-D layered structure constructed from trinuclear {Cd₃(COO)₆} SBUs and represents a (3,6)-connected kgd topology. Compounds 2 and 3 are 3-D inorganic–organic hybrid frameworks; 2 employs infinite inorganic –Cd–O–Cd– chains as SBUs, whereas (3,6)-connected ant-type 3 employs heterometallic trinuclear {Cd₂Ba(COO)₄} clusters as SBUs. The structures of these three compounds indicate that the SBUs play an important role in the construction of MOFs. Moreover, the thermal stabilities and solid-state photoluminescent properties of these three compounds have also been investigated.     

A mesitylene-bridged bis-benzimidazolyl ligand and six metal coordination compounds

The mesitylene-bridged bis-benzimidazolyl ligand 1,3-bis(benzimidazol-1′-yl-methyl)mesitylene (L) and six metal complexes, [Cu₉L₆(OH)₇Cl₈] (1), [Co₂L₄(NO₃)(H₂O)₂](NO₃)₃ (2), [Zn₂L₂Cl₄] (3), [CdL₂(NO₃)₂]_n (4), [MnL(L_A)(CH₃OH)]_n (5), and [CoLCl₂]_n (6) (L_A = terephthalate), have been prepared and characterized. Complex 1 is a football-like cluster formed by six Ls, nine Cu(II) ions, eight chlorides, and seven hydroxides, in which the size of the football is about 13.9 × 15.4 Å. Complex 2 contains a cage-like ball formed by four Ls and two Co(II) ions, in which the external and internal sizes of the ball are about 12.2 × 14.6 Å and 6.5 × 10.7 Å, respectively. In this complex, one nitrate is fixed in the middle of the cage through two Co–O bonds. The 24-membered metallomacrocycle of 3 is formed by two Ls and two Zn(II) ions. In 4, 2-D layers with 48-membered metallomacrocycles are formed via Ls and Cd(II) ions. In 5, L and terephthalate ions (L_A) participate in coordination with Mn(II) to afford 2-D network layers. The 1-D polymeric chain of 6 is formed via L and Co(II) chloride moieties. In the crystal packing of 1–6, 2-D supramolecular layers and 3-D supramolecular frameworks are formed via intermolecular weak interactions, including hydrogen bonds, π–π interactions, and C–H?π contacts. The conformations of metal complexes from L are described. Additionally, the fluorescence emission spectra of L and 1–6 are reported.     

Synthesis,structures and properties of two carboxylate-bridged coordination polymers with linear and ladder chain motifs

Two cadmium(II) compounds, [Cd(nip)(phen)₂] _n (1) and [Cd₂(nip)₂(phen)₂] _n (2) [nip = 5-nitroisophthalate, phen = 1,10-phenanthroline], have been synthesized under hydro (or solvo) thermal conditions and characterized by single-crystal X-ray diffraction. Compound 1 exhibits a 1-D linear chain structure adopting the coordination mode in which one Cd is coordinated to two phen ligands. The formation of 1 was favored by selecting Cd(phen)₂(NO₃)₂ as metal source in ethanol-water. Compound 2 displays a 1-D ladder-like chain structure featuring di-cadmium units. Both 1 and 2 are further assembled into 3-D supramolecular frameworks through interchain hydrogen bonding.     

Cyanuric chloride reagent as a chloride ion donor: synthesis,crystal structure,and magnetic properties of [Cu2(2-APM)2(μ-Cl)2(μ-OCH3)2]n coordination polymer

A new chloro- and methoxo-bridged Cu(II) coordination polymer, [Cu₂(2-APM)₂(μ-Cl)₂(μ-OCH₃)₂]_n·CH₃OH (1), was prepared using in situ formed chloride by the decomposition of cyanuric chloride and 2-aminopyrimidine (2-APM) as a ligand in methanol. Its solid-state structure has been characterized by elemental analysis and single crystal X-ray diffraction. X-ray crystallographic studies reveal that this compound has an extended 2-D supramolecular architecture directed by strong hydrogen bonds and aromatic π–π stacking interactions. Compound 1 shows an antiferromagnetic coupling exchange with coupling constants of ?58.2 and ?41.4 cm^?1 between adjacent copper(II) ions, in agreement with the intermetallic distances of 3.0405(5) and 3.6073(5)?Å found in the crystal structure.     

Syntheses,crystal structures,and fluorescent properties of 2-D Cd(II) complexes based on 2-(1H-imidazol-1-methyl)-1H-benzimidazole and 1,2,4,5-benzenetetracarboxylate ligands

Two new complexes, {[Cd(btec)_0.5(imb)(CH₃OH)]·CH₃OH}_n (1) and {[Cd(btec)_0.5(H₂btec)]·(H₂imb)·2H₂O}_n (2) (H₄btec = 1,2,4,5-benzenetetracarboxylic acid, imb = 2-(1H-imidazol-1-methyl)-1H-benzimidazole), have been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. Both complexes exhibit 2-D network structures. In 1, each 1,2,4,5-benzenetetracarboxylate links four Cd²⁺ cations, and each Cd²⁺ cation connects two 1,2,4,5-benzenetetracarboxylates, to form a 2-D layer, with the imb ligands located on each side of the 2-D layer. In 2, there are two kinds of 1,2,4,5-benzenetetracarboxylates in the structure. One kind is completely deprotonated and acts as hexadentate linkers, leading to a 2-D layer. The other kind is only doubly deprotonated and decorates each side of the 2-D layer. In 2, imb is protonated, forming (H₂imb)²⁺ cations that only cocrystallize with the negatively charged Cd coordination polymer ({[Cd(btec)_0.5(H₂btec)]^2?}_n), but does not coordinate to the Cd²⁺ cations. IR spectra, PXRD patterns, thermogravimetric analyses, and fluorescent properties of 1 and 2 have also been determined.     

Crystal structure and characterization of two cadmium(II) coordination polymers with a multidentate N-donor tecton 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole

Two new cadmium(II) complexes [Cd_1.5(L)Cl₂(H₂O)]_{2 n} (1) and [CdL₂] _n (2) with a multidentate N-donor building block 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (HL) have been prepared and characterized by elemental analysis, infra-red spectra, powder X-ray diffraction (XRD), and single-crystal XRD. 1 is a 2-D layered coordination polymer constructed from linkage of [Cd₃(μ-Cl)₄] trinuclear units with HL spacers, while 2 shows a 2-D layer structure. 3-D supramolecular architectures are further assembled in 1 and 2 via hydrogen-bonding contacts. Both 1 and 2 are thermally stable to 450?°C, and 2 showed strong fluorescent emission bands.     

A copper(II) complex of benzimidazole-based ligand: synthesis,structure, redox aspects and fluorescence properties

Employing 1-(2-methoxybenzyl)-2-(2-methoxyphenyl)-1H-benzimidazole (bpb) as a monodentate ligand, a new greenish-blue copper(II) complex, [Cu(bpb)₂(NO₃)₂] (1a), has been synthesized. 1a has been characterized analytically and spectroscopically. The X-ray crystal structure of 1a reveals that it adopts a cis disposition with respect to the ligands. The solid state structure of 1a is stabilized by intramolecular offset face-to-face π–π stacking. Non-covalent supramolecular edge-to-face C–H?π interactions with neighboring molecules give 1-D supramolecular chains that further lead to the formation of an assembled 3-D supramolecular metal-organic framework via hydrogen bonding interactions. 1a shows blue fluorescence most likely due to intramolecular offset face-to-face π–π stacking. At room temperature, 1a is one-electron paramagnetic. It shows a rhombic EPR spectrum with g₁ = 2.12, g₂ = 2.42, and g₃ = 2.52 in the solid state at liquid nitrogen temperature. In cyclic voltammetry, 1a displays a one-electron oxidative Cu(II)/Cu(III) couple. Our DFT calculations, corroborate the observed experimental results of 1a.     

Lead(II) coordination frameworks with 3-fluorophthalic acid: hydrothermal synthesis,crystal structure,and luminescence

Hydrothermal reactions of Pb(NO₃)₂ and 3-fluorophthalic acid (H₂Fpht) in the absence or presence of 2,2′-bipyridine (bpy) gave two coordination polymers: Pb₅(Fpht)₄(Fba)₂ (1) and [Pb₂(Fpht)₂(bpy)(H₂O)]·3H₂O (2). The 3-fluorobenzoic acid (HFba) results from an in situ decarboxylation of H₂Fpht. Solid 1 displays a 2-D structure, comprising center-related hexanuclear [Pb₃(COO)₆]₂ units. There are three crystallographically different Pb(II) ions and two different ligands, Fpht and Fba. The Fpht ligands adopt μ_6?:?η⁵η³ and μ_6?:?η³η⁴ unusual bridging coordination modes. A 3-D supramolecular architecture is formed via C–H?F hydrogen bonds. Solid 2 possesses a 1-D chain structure, comprising center-related tetranuclear [Pb₂(COO)₄]₂ units. There are two crystallographically different Pb(II) ions. The Fpht ligands adopt μ_3?:?η²η³ and μ_4?:?η³η³ bridging coordination. The free water molecules form (H₂O)₃ clusters to link the 1-D chain by hydrogen bonds. A 3-D supramolecular assembly is constructed via hydrogen bonds between the free water and the F of Fpht ligands. Fluorescence of the complexes originates from π*–π transitions of the ligands.     

Hydrothermal synthesis and crystal structures of two new divalent metal phosphonates with layered structure

Two divalent metal phosphonates with a layered structure, Zn(H₂L) (1) and Cd₂L (2) (H₄L?=?CH₃CH₂CH₂N(CH₂PO₃H₂)₂), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The structure of 1 shows a layered structure in which the 1D zinc(II) phosphonate chains are interconnected by bridging organic groups to form 2D layers. In 2, the interconnection of [CdO₅N] and [CdO₅] polyhedra via edge-sharing forms a dimer. The dimers are interconected by [CPO₃] tetrahedra via corner-sharing to form 2D double layers in the bc-plane.     

Syntheses,crystal structures,and luminescent properties of three metal coordination polymers based on adipic acid and 2-(pyridine-3-yl)-(1H)-benzimidazole

Three new metal coordination polymers constructed from adipic acid and 2-(pyridin-3-yl)-(1H)-benzimidazole ligands, [M(ADP)(3PBI)₂(H₂O)₂]·2H₂O (M = Ni and Co for 1 and 2, respectively) and [Cd(ADP)(3PBI)(H₂O)] (3) [ADP = adipic acid dianion; 3PBI = 2-(pyridin-3-yl)-(1H)-benzimidazole], have been synthesized by hydrothermal reactions and were characterized by X-ray single-crystal diffraction, elemental analyses, IR, powder X-ray diffraction, and thermogravimetry. Complexes 1 and 2 are isostructural. Both form a 1-D linear chain structure, which is further assembled into a 3-D supramolecular framework by π?π stacking and hydrogen bonding interactions. Complex 3 possesses a binuclear unit and displays a 2-D layer which is further extended to a 3-D supramolecular architecture via hydrogen bonding and other weak packing interactions. The luminescent properties of 3 were investigated in the solid state at room temperature.     

Architectural diversity of six coordination compounds based on (S)-(+)-mandelic acid and different N-donor auxiliary ligands: syntheses,structures, and luminescent properties

Six transition metal coordination compounds with H₂mand and different N-donor ligands, [Co(Hmand)₂(2,2′-bipy)]·H₂O (1), [Ni(Hmand)₂(2,2′-bipy)]·H₂O (2), [Ni(Hmand)₂(bpe)] (3), [Zn(Hmand)₂(2,4′-bipy)(H₂O)]·2H₂O (4), [Zn(Hmand)(bpe)(H₂O)]_n[(ClO₄)]_n·nH₂O (5), and [Zn(Hmand)(4,4′-bipy)(H₂O)]_n[(ClO₄)]_n (6), were synthesized under different conditions (H₂mand = (S)-(+)-mandelic acid, bpe = 1,2-di(4-pyridyl)ethane, 4,4′-bipy = 4,4′-bipyridine, 2,4′-bipy = 2,4′-bipyridine, 2,2′-bipy = 2,2′-bipyridine). Their structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, infrared spectra, thermogravimetric analysis, powder X-ray diffraction, and circular dichroism. Compounds 1 and 2 are isostructural (0-D structures), which are extended to supramolecular 1-D chains by hydrogen bonding. Compound 3 exhibits 1-D straight chain structures, which are further linked via hydrogen bond interactions to generate a 3-D supramolecular architecture. Compound 4 displays a discrete molecular unit. Neighboring units are further linked by hydrogen bonds and π–π interactions to form a 3-D supramolecular architecture. Compound 5 displays a 2-D undulated network, further extended into a 3-D supramolecular architecture through hydrogen bond interactions. Compound 6 possesses a 2-D sheet structure. Auxiliary ligands and counteranions play an important role in the formation of final frameworks, and the hydrogen-bonding interactions and π–π stacking interactions contributed to the formation of the diverse supramolecular architectures. Compounds 1, 2, 4, 5, and 6 crystallize in chiral space groups, with the circular dichroism spectra exhibiting positive cotton effects. Furthermore, the luminescent properties of 4–6 have been examined in the solid state at room temperature, and the different crystal structures influence emission spectra significantly.     

Syntheses and structures of three coordination polymers based on 4-methylbenzenethiolates of Zn(II) and Cd(II) and bipyridine

Using 4-methylbenzenethiolates of Zn or Cd as precursors and 4,4′-bipyridine (4,4′-bpy) as bridges, we have synthesized three new Zn(II)/Cd(II) coordination polymers, {[Cd(4,4′-bpy)₂(NCS)₂] · 2(SC₆H₄CH₃-4)₂} _n (1), {[Zn(4,4′-bpy)(SC₆H₄CH₃-4)₂] · DMF} _n (2) and {[Zn(4,4′-bpy)(SC₆H₄CH₃-4)₂] · H₂O · 0.5CH₃OH} _n (3). Compound 1 is a 2-D sheet-like square polymer in which four 4,4′-bpy ligands and two isothiocyanate ligands complete the octahedral Cd(II) coordination sphere. Compounds 2 and 3 have similar coordination around Zn(II), but have different polymer structures. In 2, Zn(II) centers are linked via a bidentate 4,4′-bipyridine to form 1-D twisted arched chains, which is a new structural type for Zn(II). Compound 3 has 1-D zigzag chains. The 2-D sheets in 1 and 1-D chains in 2 and 3 are assembled via intermolecular C–H ··· π and C–H ··· S interactions into 3-D supramolecular networks. C–H ··· S interactions are a vital factor in constructing the sulfur-containing coordination polymers. Different coordination modes and packing schemes in 1–3 show that the guest molecule has a critical influence on formation of polymers.     

Complexes of nickel(II) carboxylates with pyridine and cyclam: crystal structures,mesomorphisms, and thermoelectrical properties

Nickel(II) carboxylates [Ni(CH₃(CH₂)₁₄COO)₂(H₂O)₂] (1) and [Ni(C₆H₅COO)₂(H₂O)₂] (2) were obtained from reactions of NiCl₂·6H₂O with CH₃(CH₂)₁₄COONa and C₆H₅COONa, respectively. Complex 1 reacted with pyridine (pyr) to form [Ni(CH₃(CH₂)₁₄COO)₂(pyr)₂(H₂O)₂] (3) and [Ni₂(μ₂-H₂O)(CH₃(CH₂)₁₄COO)₄(pyr)₄] (4) in the same reaction mixture, and reacted with cyclam to form an ionic complex, [Ni(CH₃(CH₂)₁₄COO)(cyclam)(H₂O)]CH₃(CH₂)₁₄COO·4H₂O (5). In contrast, 2 reacted with cyclam to form [Ni(C₆H₅COO)₂(cyclam)] (6). Finally, 6 reacted with p-(hexadecyloxy)pyridine (L) to form an ionic complex, [Ni(cyclam)(L)₂](C₆H₅COO)₂ (7). Complexes 3–6 were single crystals. All complexes have octahedral Ni(II) center(s) and were magnetic. Complexes with cyclam as co-ligand were more thermally stable than those with pyridine and its derivative, L. Complexes 3 and 4 were mesomorphic after partial loss of water and/or pyridine ligands on heating. The ionic complexes 5 and 7 were not mesomorphic, but showed good thermoelectrical behavior with negative S_e values in CHCl₃ (?0.28 mV K^?1 for 5; -0.39 mV K^?1 for 7) and positive S_e values in C₂H₅OH (+0.25 mV K^?1 for 5; +0.20 mV K^?1 for 7).     

Structures and fluorescent properties of picolinato zinc(II) and cadmium(II) complexes based on tridentate and tetradentate benzimidazole ligands

Five picolinato zinc(II) and cadmium(II) complexes, [Zn(ntb)(pic)]ClO₄·CH₃OH·2H₂O (1), [Zn(bbma)(pic)]NO₃·2CH₃OH (2), [Cd(ntb)(pic)]ClO₄·0.75CH₃OH·H₂O (3), [Cd₂(bbma)₂(pic)₂](ClO₄)₂ (4), and [Cd₂(bbp)(bbp_-H)(pic)₂(C₂H₅OH)]ClO₄ (5), have been synthesized, where pic is the anion of picolinic acid, ntb is tris(2-benzimidazolylmethyl)amine, bbma is bis(benzimidazol-2-yl-methyl)amine, and bbp is 2,6-bis(benzimidazol-2-yl)pyridine. All the complexes were characterized by X-ray single-crystal diffraction, elemental analysis, IR, fluorescence spectroscopy, and thermal gravimetric analysis. 1–3 are mononuclear complexes in which picolinate adopts a N,O-chelating mode. 4 is a symmetrical dinuclear complex bridged by two anti-parallel picolinates in a N,O,O-coordination mode. 5 is also a dinuclear complex in which only one picolinate is a bridge. A 1-D double chain is formed by extensive H-bonds and π–π stacking in 1, while single zigzag chains are formed in 5. Complexes 2–4 all exhibit 6³-hcb 2-D frameworks. They extend to form four-connected 6⁶-dia 3-D topological nets for 2 and 4 and five-connected 4⁶·6⁴-bnn 3-D topological nets for 3. The five complexes show emission maxima in the blue region in the solid state.     

Three-pillared layer metal–organic frameworks assembled by imidazole-4,5-dicarboxylate and rigid bisimidazole ligands: synthesis,crystal structure,and sensing nitroaromatics

Three-pillared layer metal–organic frameworks based on 1H-imidazole-4,5-dicarboxylate and linear bis(imidazole) ligands generally formulated as {[Co₃(idc)₂(bib)₃]·8H₂O}_n (1), {[Cd(Hidc)(bib)_0.5]}_n (2) and {[Cd(Hidc)(bibp)]}_n (3), where H₃idc = 1H-imidazole-4,5-dicarboxylate, bib = 1,4-bis(1-imidazolyl)benzene and bibp = 4,4′-bis(1-imidazolyl)biphenyl, have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Compound 1 features a 3-D-pillared layer structure with 1-D channels, generated by honeycomb-like 2-D layer linked by bib ligands. Compound 2 consists of 2-D lumpy layers of [Cd₄(Hidc)₄], which are further connected by bridging ligands of bib to generate a pillared layer 3-D framework with 1-D channels. In 3, the 2-D corrugated honeycomb networks, structurally analogous to CFx, are pillared by bibp ligands to form a 3-D architecture with 1-D channels. Through selecting different metal ions and the length of pillared ligands, the pore sizes are adjusted in the three complexes. The potential of 2 and 3 for nitro explosive sensing is investigated through luminescence quenching experiments, which show that 3 can be applied as a fluorescent sensor for nitro compounds.     

Syntheses,structures, and properties of two coordination polymers based on 5-methoxyisophthalate and flexible dipyridines

Hydrothermal reactions of 5-methoxyisophthalic acid (MeO-H₂ip), 1,3-di(4-pyridyl)propane (bpp) with Cd(NO₃)₂·4H₂O and Ni(NO₃)₂·6H₂O produced [Cd₂(MeO-ip)₂(bpp)₂]_n·nH₂O (1) and [Ni(MeO-ip)(bpp)(H2O)]_n·nH₂O (2), respectively. Complex 1 is a 2-D layer consisting of dinuclear Cd(II)-carboxylate units, two carboxylates of MeO-ip adopt μ₂,η²-bridging and chelating modes. MeO-ip bridges three Cd(II) ions to form a 1-D [Cd₂(MeO-ip)₂]_n chain, which is further extended into a 2-D layer by bpp in a trans,trans-conformation. However, two carboxylates of MeO-ip in 2 are monodentate and chelating to link Ni(II) into a 1-D [Ni(MeO-ip)]_n chain with bpp in a trans-gauche conformation connecting [Ni(MeO-ip)]_n chains into a two-fold interpenetrating 3-D network. Coordinated water and carboxylate oxygen from different MeO-ip form strong hydrogen bonds. The frameworks of 1 and 2 are stable below 250 and 300?°C, respectively. Luminescence indicates that 1 shows maximum emission at 375 and 450 nm upon excitation at 320 nm. Magnetic measurement of 2 suggests the presence of ferromagnetic interactions in 2.     

Dinuclear cadmium indomethacin and Lawsone complexes: synthesis,crystal structures,antiproliferative and biological evaluations

The synthesis and structural characterizations of Cd(II) indomethacin (Indo) and Lawsone (Law) complexes, K₂[Cd₂(Indo)₄(SCN)₂], 1 and [Cd₂(Law)₄(phen)₂]·4CH₃OH, 2 (SCN = thiocyanate, phen = 1,10-phenanthroline), have been studied. The complexes are dimeric, structurally characterized by spectral (IR, TOF-Mass) and X-ray crystallography. The interaction of indomethacin and Lawsone ligands, 1 and 2 with calf thymus DNA and bovine serum albumin were investigated using UV–visible and fluorescence spectrophotometric methods. The in vitro cytotoxicity of 1 and 2 was examined against promyelocytic leukemia (HL-60), colon (HCT-8), brain (SF-295), and melanoma (MDA-MB-435) cancer cell lines. Moreover, the antimicrobial activity of 1 and 2 against different strains of pathogenic bacteria were tested.     

The rigid isomeric 5-(x-pyridyl)-1H-tetrazole ligands-directed various isopolymolybdate-based compounds: assembly,structures, and properties

Two new isopolymolybdate-based metal–organic complexes, [Cu₂(2-ptz)₂(Mo₄O₁₄)_0.5] (1) and [Cu₃(OH)₂(3-ptz)₄(γ-H₄Mo₈O₂₆)(H₂O)₄]·10H₂O (2) (2-ptzH = 5-(2-pyridyl)-1H-tetrazole, 3-ptzH = 5-(3-pyridyl)-1H-tetrazole), constructed from isomeric ligands with different N-donor sites were synthesized under hydrothermal conditions. In 1, each [Mo₄O₁₄]^4? cluster connected with six neighboring [Mo₄O₁₄]^4? clusters through six binuclear [Cu₂(2-ptz)₂]²⁺ subunits to yield a 2-D layer. In 2, bidentate inorganic [Mo₈O₂₆]^4? anions link the trinuclear [Cu₃(OH)₂(3-ptz)₄] clusters to construct a 1-D chain. Adjacent chains connect through Mo–N bonds between the [Mo₈O₂₆]^4? anions and pyridyl groups from the trinuclear clusters to form a 2-D layer. The effect of the N-donor sites of the rigid isomeric ligands on the structures of 1 and 2 was discussed. The electrochemical properties and photocatalytic activities of 1 and 2 have also been studied.