Unexpected formation of chiral single crystals of {NH(n-C3H7)3[MnIICrIII(C2O4)3]}, A 2D oxalate-based material

In an attempt to obtain chiral single crystals of a two-dimensional (2D) bimetallic oxalate-based material by enantioselective auto-assembling of Mn²⁺ and (rac)-[Cr(C₂O₄)₃]^3? templated by the optically active complex (+)-(Rp)-[1-CH₂(n-C₃H₇)₃-2-CH₃(C₅H₃)Fe(C₅H₅)]⁺, we obtained the unexpected 2D network species {NH(n-C₃H₇)₃[MnCr(C₂O₄)₃]}. X-ray diffraction determination of the structure reveals that the complex crystallizes in the enantiomorphous space group P6₃. The interlayer spacing of 7.93?Å?is the lowest found so far for 2D, bimetallic, oxalate-bridged compounds.     

A Variable-Pressure 2D 1H-NMR Study of the Mechanism of Trimethyl Phosphate Intermolecular Exchange and cis/trains-Isomerisation of Tetrachlorobis(trimethyl phosphate)zirconium(IV)

In chloroform, [ZrCl₄·2(MeO)₃PO] exists in both cis- and trans-isomeric forms. Three reactions can be envisaged in the presence of excess (MeO)₃PO = L: (1) cis-[ZrCl₄·2L] + *L?cis-[ZrCl₄·L*L]+ L; (2) trans-[ZrCl₄·2L] + *L ? trans-[ZrCl₄·L*L] + L; (3) cis-[ZrCl₄·2L]? trans-[ZrCl₄·2L]. To distinguish between these possible reaction pathways, we have used 2D ₁H-NMR spectroscopy. For the first time, variable-pressure 2D exchange spectra were used for mechanistic assignments. cis/trans-Isomerisation was found to be the fastest reaction (in CHCl₃/CDCl₃), with a small acceleration at higher pressure: it is concluded to be an intramolecular process with a slightly contracted six-coordinate transition state. The intermolecular (MeO)₃PO exchange on the cis- and trans-isomer are second-order processes and are strongly accelerated by increased pressure: I_a mechanisms are suggested without ruling out limiting A mechanisms.     

A linear trinuclear cobalt(II) complex with 4-(2-pyridine)-1,2,4-triazole: synthesis,structure and characterization

The linear trinuclear cobalt(II) complex [Co₃(pytrz)₆(H₂O)₆](NO₃)₆ (1) with pytrz = 4-(2-pyridine)-1,2,4-triazole has been prepared and characterized. It crystallizes in the rhombohedral R-3 space group with Z = 3, a = 13.955(2), b = 13.955(2), c = 28.942(9) Å, γ = 120°, V = 4881.2(18) ų. The structure of 1 comprises the cation [Co₃(pytrz)₆(H₂O)₆]⁶⁺, in which linear trinuclear Co(II) units are bridged by six L ligands and have six aqua molecules as terminal ligands. The six free nitrates link the terminal aqua ligands through N–H ··· O hydrogen bonds with C₃ symmetry. 1 was characterized by FT-IR, electronic spectra and magnetic measurements. The variable-temperature magnetic measurements reveal weak anti-ferromagnetic interactions in 1.     

Supramolecular complexes constructed with carboxylate Cu(II) and 2-(2-pyridyl)-benzimidazole via hydrogen bonding

Four copper(II) supramolecular complexes, {[Cu(Hpb)(mal)]·H₂O} _n (1), (Hpb?=?2-(2-pyridyl)-benzimidazole, mal?=?maleate), [Cu₄(pb)₄(cro)₄(MeOH)₂]·2MeOH (2) (cro?=?crotonate), [Cu₂(pb)(Hpb)(mac)₃(MeOH)] (3) (mac?=?α-methacrylate) and [Cu(Hpb)(acr)₂(H₂O)] (4) (acr?=?acrylate), based on carboxylate copper(II)-aromatic ligand systems which are assembled by combination of metal coordination, hydrogen-bond and π–π interactions, have been rationally designed and synthesized. Complex 1 forms a 3D supramolecular network with open channels by extending 2D undulating sheets constructed from 1D helical chains. Complex 2 generates a 2D grid-like sheet via unusual finite-chain tetranuclear molecules, with four copper atoms arranged in a line; the unit does not extend further due to the capping effect of the terminal methanol. Complexes 3 and 4 present a 1D sinusoidal structure and a 3D columnar network with 1D ladder-shaped double chains, respectively. Interestingly, coligand Hpb, deprotonated or/and neutral in different supramolecular complexes, provides hydrogen bonding and π–π stacking interactions. In complexes 2, 3 and 4, carboxylate anions show various bridging modes, which are reflected in their magnetic properties. Weak ferromagnetic coupling (syn-anti µ-OCO) exists in 1, antiferromagnetic (syn-syn µ-OCO) and weak ferromagnetic coupling (µ-O of the??COO group) in 2 and antiferromagnetic coupling (syn-syn µ-OCO) in 3.     

Syntheses,structures, and luminescence of two Zn(II) coordination polymers based on 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole and carboxylates

Reactions of Zn(II) salts, 5-(4-(1H-imidazol-1-yl)phenyl)-1H-tetrazolate (HIPT) and 2-mercaptobenzoic acid or 2-propyl-1H-imidazole-4,5-dicarboxylic acid (H₃PrIDC), result in two mixed-ligand coordination polymers (CPs), [Zn₂(IPT)(DSDB)(OH)]_n (H₂DSDB = 2,2′-disulfanediyldibenzoic acid, 1) and [Zn₂(IPT)(PrIDC)(H₂O)]_n (H₃PrIDC = 2-propyl-1H-imidazole-4,5-dicarboxylic acid, 2). Compound 1 possesses a 2-D structure built by 1-D [Zn(IPT)]_n chains and DSDB^2? connectors, in which the DSDB^2? is generated via in situ reaction from 2-mercaptobenzoic acid. It displays a new intricate 4-nodal {3·4·6·7·8·9}{3·6·7·8·9·10}{3·8·9}{4·6·8} topology. Compound 2 displays a 3-D framework with new 3-connected topology with Schläfli symbol of (4·8·10) (8·12²), in which the 1-D Zn-carboxylate chains were bridged by 3-connected IPT^? ligands. The thermal stabilities and luminescence properties of 1 and 2 have also been studied. The compounds exhibit intense solid-state fluorescent emissions at room temperature.     

Synthesis,structure, spectroscopic,and DNA binding properties of Co(III) and Ni(II) complexes with ((E)-2-(amino((pyridin-2-ylmethylene)amino)methylene)maleonitrile)

Two new complexes, [Co(L)₂]Cl·(MeOH)₂ (1) and [Ni(L)₂]₄·EtOH (2) (L?=?(E)-2-(amino((pyridin-2-ylmethylene)amino)methylene)maleonitrile), were synthesized and characterized by X-ray crystallography, IR, UV, and fluorescence spectroscopy. According to X-ray crystallographic studies, each metal was six-coordinate with six nitrogens from two ligands. Both complexes form two-dimensional supramolecular networks via hydrogen bonding and π–π interactions. Ultraviolet and visible spectra showed that absorptions arise from π–π ^?, MLCT, and d–d electron transitions. Fluorescence spectroscopy revealed moderate intercalative binding of these two complexes with EB–DNA, with apparent binding constant (K _app) values of 9.14?×?10⁵ and 3.20?×?10^5?M^?1 for Co(III) and Ni(II) complexes, respectively. UV–visible absorption spectra showed that the absorption of DNA at 260?nm was quenched for 2 but quenched then improved for 1 with addition of complexes, tentatively attributed to the effect of the combined intercalative binding and electrostatic interaction for 1.     

4-(2-(4-咪唑)苯乙烯基)吡啶和三种芳香二羧酸的Cd(Ⅱ)配位聚合物的合成、结构及荧光性质

以4-(2-(4-咪唑)苯乙烯基)吡啶(ISPE)为配体,分别与间苯二甲酸(1,3-H_2BDC)、4,4′-联苯二甲酸(4,4′-H_2BPDC)和4,4′-二苯乙烯二甲酸(4,4′-H_2STDC)及过渡金属盐Cd(NO3)2·4H_2O通过溶剂热自组装形成了3种配位聚合物晶体{[Cd_2(ISPE)_2(1,3-BDC)_2]·DMF}_n(1)、[Cd(ISPE)(4,4′-BPDC)]_n(2)和[Cd(ISPE)_2(4,4′-STDC)(H_2O)_2]_n(3)。并用单晶X射线衍射、PXRD、红外光谱、元素分析、热重等对其进行了表征。单晶解析结果表明:配位聚合物1是二维层状网格结构,配位聚合物2是一个六重穿插的类金刚烷三维网格结构,配位聚合物3是由一维网格结构通过氢键和分子间作用力堆积形成的三维网格结构。另外还研究了它们的室温固态荧光性能。     

Cobalt(II) complexes with pyridine and 5-[(E)-2-(aryl)-1-diazenyl]-quinolin-8-olates: synthesis,electrochemistry and X-ray structural characterization

Abstract

Nine new cobalt(II) compounds, trans-[Co(L^PAQ)₂(Py)₂] (1), trans-[Co(L^PAQ)₂(3-MePy)₂] (2), trans-[Co(L^MeAQ)₂(Py)₂] (3), trans-[Co(L^OMeAQ)₂(Py)₂] (4), trans-[Co(L^OEtAQ)₂(Py)₂]·2(H₂O) (5), trans-[Co(L^CAQ)₂(Py)₂] (6), trans-[Co(L^BAQ)₂(Py)₂] (7), cis-[Co(L^BAQ)₂(3-MePy)₂] (8a) and trans-[Co(L^BAQ)₂(3-MePy)₂]·2(3-MePy) (8b) (primary ligand: L^XAQ?=?substituted 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-olate; secondary ligands: Py?=?pyridine, 3-MePy = 3-methylpyridine), have been synthesized and characterized by elemental analysis, IR and UV-vis spectroscopy. Magnetic measurements of the cobalt compounds were performed in solution by ¹H NMR spectroscopy using the Evans’ method while their redox properties were studied by cyclic voltammetry. Single-crystal X-ray diffraction analysis of the compounds revealed their octahedral geometries and trans configuration, except for 8a, which has a cis configuration. Intermolecular noncovalent interactions were detected, π···π interactions in 5, C?–?H···π interactions in 2 and C?–?H···π edge-to-face (T-shaped) arrangements in 3, 4, 6, and 7.     

Synthesis,properties, and X-ray crystal structures of two Ag(I) complexes with 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid

Two 1-D and 3-D Ag(I) complexes involving 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid (H₃PIDC) have been characterized by infrared spectrum, elemental analysis, and single-crystal X-ray diffraction. [Ag₂(HPIDC)]_n (1), synthesized under hydrothermal conditions, gave a 3-D framework; [Ag₂(HPIDC)(MBI)]_n (2) (MBI?=?2-methyl-1H-benzo[d]imidazole), with MBI as the second ligand, gave a 1-D zigzag chain and further formed a 3-D supramolecular structure through π···π interactions. The most interesting structural features of these complexes are the presence of C–H···Ag hydrogen bonding interactions and Ag···C weak interactions between the Ag centers and H₃PIDC. Luminescence indicates that 2 has significantly stronger fluorescent emissions than 1 in the solid state at room temperature.     

Copper(II) complex with 6-(3,5-dimethyl-1H-pyrazol-1-yl)-2-(pyridin-2-yl)pyrimidin-4-amine: synthesis,crystal structure,and electronic spectroscopy

A copper(II) complex with 6-(3,5-dimethyl-1H-pyrazol-1-yl)-2-(pyridin-2-yl)pyrimidin-4-amine (L), [CuLCl₂], has been synthesized. This compound is formed irrespective of the Cu?:?L molar ratio (Cu?:?L?=?1?:?1, 2?:?1, and 20?:?1) in the MeOH/H₂O/DMF mixture as a single product. ESI-MS data demonstrate that the additional amount of CuCl₂ above the Cu?:?L?=?1?:?1 molar ratio, is effectively solvated, and high-nuclearity species are formed in trace amounts in the solution. The complex adopts a distorted square-pyramidal geometry with two chlorides and three nitrogen atoms from L. The electronic spectrum of the complex contains a broad band with a maximum at 12,820?cm^?1 within the region characteristic for square-pyramidal chromophores CuA₅ (A?=?Cl, N). Due to Cu?···?Cl contacts, the molecules of [CuLCl₂] form the dinuclear [CuLCl₂]₂ unit. Surprisingly, the NH₂-group participates in the formation of NH?···?Cl hydrogen bonds instead of the formation of (NH?···?N3_(pyrimidine))₂ synthon, which is common for N-heteroaromatic compounds containing the NH₂-group in the α-position to aza-atom. These hydrogen bonds together with Cu?···?Cl contacts result in the formation of a 3-D-structure.     

Synthesis and characterization of cerium,thorium, and uranyl complexes with ( E )-4-(4-methoxyphenoxy)-4- oxobut-2-enoic acid

(E)-4-(4-Methoxyphenoxy)-4-oxobut-2-enoic acid and its Ce(IV), Th(IV), and UO₂(II) complexes were synthesized and characterized by MS, elemental analysis, IR, UV, TG-DTA, and NMR. The complexes have composition [CeL₂(OH)₂ · 2H₂O] · H₂O, [ThL₂(OH)₂ · 2H₂O] · H₂O, and [UO₂L₂ · 2H₂O] · H₂O. Molar conductance data confirm that the three complexes are nonelectrolytes. The IR and NMR results show that the carboxylates coordinate to the metal ions bidentate, and the ester carboxylic groups do not take part in coordination. Luminescence spectra of the ligand and complexes in DMSO at room temperature were also studied showing strong luminescence of the metal ions.     

Synthesis and anticancer property of one Ce(III) compound based on 5-(2-pyrazinyl)tetrazole-2-acetic acid

Mononuclear [Ce(pztza)₂(H₂O)₆](pztza)·H₂O (1) (pztza = 5-(2-pyrazinyl)tetrazole-2-acetato) has been prepared and characterized by IR, elemental analysis and single-crystal X-ray diffraction. PEG_-5000 (poly(ethyleneglycol_-5000)) coated [Ce(pztza)₂(H₂O)₆](pztza)·H₂O nanoparticles (NPs) can disperse into distilled water. In vitro study on Hela cells shows that Hpztza is nontoxic while [Ce(pztza)₂(H₂O)₆](pztza)·H₂O NPs show high toxicity with half-maximal inhibitory concentration (IC₅₀) of 17 μg/mL (1.93 × 10^?5 M). In addition, such NPs can inhibit the migration of Hela cells effectively.     

Synthesis and anticancer property of one Fe(II) compound based on 5-(3-pyridyl)tetrazole-2-acetic acid

Abstract

Tetrazole-carboxylate ligands are universally considered as multi-functional candidates for the construction of coordination architectures. A 1-D [Fe(pytza)₂(H₂O)₂]_n·2nH₂O (pytza = 5-(3-pyridyl)tetrazole-acetato) has been prepared. In vitro study on Hela cells show that Hpytza is naturally nontoxic while [Fe(pytza)₂(H₂O)₂]_n·2nH₂O shows high toxicity with a half-maximal inhibitory concentration (IC₅₀) of 6.3?×?10^?5 M. In addition, the compound can effectively inhibit the migration of Hela cells.     

Reaktionen des [η2-{P–PtBu2}Pt(PPh3)2] und [η2-{P–PtBu2}Pt(dppe)] mit Metallcarbonylen. Bildung von [η2-{(CO)5M · PPtBu2}Pt(PPh3)2] (M = Cr,W) und [η2-{(CO)5Cr · PPtBu2}Pt(dppe)]

Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XVI [1] Reactions of [g²-{P–P^tBu₂}Pt(PPh₃)₂] and [g²-{P–P^tBu₂}Pt(dppe)] with Metal Carbonyls. Formation of [g²-{(CO)₅M · PP^tBu₂}Pt(PPh₃)₂] (M = Cr, W) and [g²-{(CO)₅Cr · PP^tBu₂}Pt(dppe)] [η²-{P–P^tBu₂}Pt(PPh₃)₂] 4 reacts with M(CO)₅ · THF (M = Cr, W) by adding the M(CO)₅ group to the phosphinophosphinidene ligand yielding [η²-{(CO)₅Cr · PP^tBu₂}Pt(PPh₃)₂] 1 , or [η²-{(CO)₅W · PP^tBu₂}Pt(PPh₃)₂] 2 , respectively. Similarly, [η²-{P–P^tBu₂}Pt(dppe)] 5 yields [η²-{(CO)₅Cr · PP^tBu₂}Pt(dppe)] 3 . Compounds 1 , 2 and 3 are characterized by their ¹H- and ³¹P-NMR spectra, for 2 and 3 also crystal structure determinations were performed. 2 crystallizes in the monoclinic space group P2₁/n (no. 14) with a = 1422.7(1) pm, b = 1509.3(1) pm, c = 2262.4(2) pm, β = 103.669(9)°. 3 crystallizes in the triclinic space group P1 (no. 2) with a = 1064.55(9) pm, b = 1149.9(1) pm, c = 1693.2(1) pm, α = 88.020(8)°, β = 72.524(7)°, γ = 85.850(8)°.     

A 2-D nickel coordination polymer with an unsymmetric ligand, 5-(3-pyridyl)-1,3,4-oxadiazole-2-thione

A new nickel coordination polymer was obtained from an unsymmetric building block 5-(3-pyridyl)-1,3,4-oxadiazole-2-thione (HL6) and Ni(NO₃)₂ · 6H₂O-afforded [Ni(L6)₂(H₂O)₂] _n (1) with a (4,4) network. Complex 1 exhibits moderate antimicrobial activity against Bacillus subtilis ATCC 6633 and Candida albicans ATCC 90028. Thermogravimetric data and magnetic moments for 1 have been investigated.     

Kristallstruktur von Tetraphenylphosphonium-Monothiocyanatohydro-closo-Decaborat, [P(C6H5)4]2[2-(SCN)B10H9] · CH3CN

Crystal Structure of Tetraphenylphosphonium Monothiocyanatohydro-closo-Decaborate, [P(C₆H₅)₄]₂[2-(SCN)B₁₀H₉] · CH₃CN The X-ray structure determination of [P(C₆H₅)₄]₂[2-(SCN)B₁₀H₉] · CH₃CN (monoclinic, space group P2₁/n, a = 10.6040(10), b = 13.8880(9), c = 33.888(3) Å, β = 94.095(8)°, Z = 4) reveals the S coordination of the SCN substituent with a B? S distance of 1.913(6) Å and a B? S? C angle of 105.3(3)°. The SCN group is nearly linear (178.2(7)°).     

Synthesis,structure and magnetic properties of Ni2(NO3)4(APTY)4 (APTY=1,5-dimethyl-2-phenyl-4-{[(1 E )-pyridine-4-ylmethylene]amino}-1,2-dihydro-3 H -pyrazol-3-one)

A novel dinuclear nickel(II) complex Ni₂(NO₃)₄(APTY)₄ (1) (APTY?=?1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one), was synthesized by solvothermal reaction of Ni(NO₃)₂?·?6H₂O with APTY in methanol at 353?K. The structure consists of centrosymmetric dimers resulting from octahedrally coordinated Ni atoms bridged by APTY ligands. Weak intermolecular interactions (C–H?···?N, C–H?···?O hydrogen bonding, C–H?···?π and π–π stacking interactions) are responsible for a supramolecular assembly of molecules in the lattice. Magnetic measurements over 1.8–300?K show weak antiferromagnetic coupling between Ni(II) ions with J?=?2.969?cm^?1, g?=?2.280, θ?=??5.903.     

Synthesis,structures and characterization of two new supramolecular coordination complexes with the ambidentate ligand 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione (Hpot)

Two new coordination supramolecular complexes based on a versatile and unsymmetrical 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione (Hpot) and Mn^II and Ni^II have been synthesized and structurally characterized by single-crystal X-ray diffraction analysis. Reaction of MnCl₂?· 4H₂O with Hpot afforded a neutral mononuclear complex [Mn(pot)₂(H₂O)₄]?·?2H₂O (1), which exhibits a three-dimensional (3-D) supramolecule through versatile intermolecular O–H?···?X (X=O, N and S) hydrogen bond interactions. When using NiCl₂?·?6H₂O instead of MnCl₂?· 4H₂O under similar reaction conditions, a neutral mononuclear complex [Ni(pot)₂(H₂O)₄] (2) is also obtained, which does not exhibit intermolecular hydrogen bonds and π–π stacking interactions. It is very interesting that the pot anion exhibits different coordination modes in complexes 1 and 2. The IR spectra and the TGA for 1 and 2 have been investigated and discussed in detail.     

Syntheses,crystal structures,and fluorescent properties of two d10 metal complexes based on 2-(benzoimidazol-yl)methyl)-1H-1,2,4-triazole and 1,3,5-benzenetricarboxylate

Two d¹⁰ metal complexes, {[Zn(Hbtc)(bmt)]·DMF·5H₂O} _n (1) and {[Cd(Hbtc)(bmt)]·0.5DMF·0.5H₂O} _n (2) (H₃btc?=?1,3,5-benzenetricarboxylic acid, bmt?=?2-((benzoimidazol-yl)methyl)-1H-1,2,4-triazole), have been synthesized under solvothermal conditions by employing bmt and H₃btc. Single-crystal X-ray diffraction shows that Zn(II) ions are connected by bmt with bidentate-bridging coordination and by 1,3,5-benzenetricarboxylate with bis-monodentate coordination leading to the 2D structure of 1. Complex 2 exhibits a 2D layer structure, in which bmt coordinate tridentate-bridging to Cd(II) and 1,3,5-benzenetricarboxylates coordinate to Cd(II) unidentate/chelating. Photoluminescence and thermogravimetric analyses of the two complexes are investigated.