Synthesis,characterization and crystal structure of one Mn(II) complex with 4,4′-bisimidazolylbiphenyl and 4,4′-sulfonyldibenzoic acid

One new title compound [Mn₃(BIBP)(sdb)(NO₂⁻)₂(H₂O)₂]_n·2DMF (1) (BIBP = 4,4′-bisimidazolylbiphenyl, sdb = 4,4′-sulfonyldibenzoic acid) has been synthesized under hydrothermal condition. The title compound was characterized by IR spectra, thermal analysis, single crystal and powder X-ray diffraction. Magnetic susceptibility measurements indicate that compound 1 exhibits antiferromagnetic coupling interaction.     

Synthesis and crystal structure of 1,4-diaminobutyl-N,N′-bis(cyanoborane): the first substituted-borane adduct of putrescine

The reaction of 1,4-diaminobutane (putrescine) with two molar equivalents of trimethylaminecyanoborane in anhydrous diethyl ether, produced an unprecedented cyanoborane species, 1,4-diaminobutyl-N,N^′-bis(cyanoborane) (1), in 78% yield, via a Lewis-base exchange reaction. The crystal structure showed the title compound (1) to be a zwitterionic species in which the two nitrogen atoms of a putrescine unit are coordinated to two cyanoborane units.     

Synthesis and crystal structure characterization of Cu ( Ⅰ ) coordinational polymer {Cu(4,4'-bipy)Br}n

利用溶剂热法合成了标题化合物,其结构经元素分析和X-射线单晶衍射表征.标题化合物属于四方晶系,I41/acd空间群,晶胞参数:a=1.4443(4)、b=1.444 3(4)、c=3.855 0(15) nm、V=8.042(4) nm3、Z =32、Mr=299.63 g/mol、Dc=1.980 g·cm-3、μ =6.10 mm-1、F(000) =4 672、R1 =0.029、wR2=0.079、S=1.05.标题化合物中Cu+分别与两个4,4'-联吡啶上一个N原子配位以及两个端基溴原子配位,形成了四面体配位几何构型.分子内Cu…Cu之间的距离为0.282 95 (13) nm.在a+c轴方向,通过4,4’-联吡啶桥联作用形成二维层状网格,层与层通过互穿插形成三维结构.     

Tricarbonyl rhenium complex of 2,2′-bis(4,5-dimethylimidazole) — Synthesis,spectroscopic characterization,X-ray structure and DFT calculations

The paper presents a combined experimental and computational study of the tricarbonyl rhenium(I) complex incorporating 2,2′-bis(4,5-dimethylimidazole) (tmbiimH₂). The complex has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The electronic structure of [Re(CO)₃(tmbiimH₂)Cl] has been calculated with the density functional theory (DFT) method, and the electronic spectrum of the complex was investigated at the TDDFT level employing B3LYP functional in combination with LANL2DZ.     

Synthesis,characterization, crystal structure and in vitro anticancer potentials of mono and bimetallic palladium(II)–N–heterocyclic carbene complexes

N–heterocyclic carbene (NHC) complexes of palladium(II) are generally active as catalysts toward various coupling reactions, while their pharmacological efficiencies are seldom explored. A new series of palladium(II) complexes of both, functionalized and non–functionalized NHCs that were active against the human colon cancer (HCT116) cells are reported. Complexes were prepared by the technique of transmetallation using palladium source and in situ prepared silver(I)–NHC complexes in acetonitrile, and all complexes are characterized using spectroscopic and analytical tools. Additionally, the structure of palladium complex 9 was elucidated using single crystal X–ray diffraction method. In vitro anticancer studies revealed that the palladium complexes, 9 and 10, having xylyl–spacers significantly inhibited the HCT116 cell growth, exhibiting IC₅₀ values in low micromolar range in MTT assay.     

Tricarbonyl rhenium complex of 2,6-bis(8′-quinolinyl)pyridine: Synthesis,spectroscopic characterization,X-ray structure and DFT calculations

2,6-Bis(8′-quinolinyl)pyridine (bqp) reacts with pentacarbonyl rhenium chloride in toluene to give fac,fac-[Re(bqp-κ³N)(CO)₃](Cl). X-ray crystallographic data on fac,fac-[Re(bqp-κ³N)(CO)₃](Cl) show that the bqp ligand and carbonyl ligands achieve a mutually facial arrangement. A mix of MLCT and π–π* ligand centered transitions is observed for the low energy UV–vis absorption bands. The complex is emissive in solution and appears to be dominated by a MLCT-based process. Electronic and structural characteristics are supported by DFT calculations.     

Synthesis,structure and characterization of neat Zn2(OH)2 diamond-core chains linked through 2,2′,4,4′-biphenyl-tetracarboxylate

Reaction of 2,2′,4,4′-biphenyltetracarboxylic acid (2,4-H₄bptc), Zn(NO₃)₂ · 6H₂O in the presence of NaOH hydrothermally at 180 °C affords the first 2,4-H₄bptc complex [Zn₃(μ₃-OH)₂(2,4-bptc)]_n · 2nH₂O (1). Crystal structure indicates that 1 is Zn₂(OH)₂ diamond-core chains linked through 2,2′,4,4′-biphenyltetracarboxylate. 1 was characterized by TG, IR and fluorescence spectra. 1 is the first example of 2,4-H₄bptc complex and also first neat Zn₂(OH)₂ diamond-core chains.     

Synthesis,crystal structure and second harmonic generation of (DMAPM+)[Cd(DMAP)I3]−

A new inorganic–organic hybrid, (DMAPM⁺)[Cd(DMAP)I₃]⁻, (DMAPM⁺I⁻=4-N,N-dimethylamino-1-methyl-pyridinium iodide, DMAP = 4-N,N-dimethylamino- pyridine) 1, has been prepared, showing a moderate second harmonic generation (SHG) of about three times as strong as that of potassium dihydrogen phosphate (KDP).     

Synthesis,characterization, and platinum-catalyzed cross-linking of 1,4-bis(1-methyl-1-silacyclobutyl) benzene,co-oligo(1-silacyclobut-1-ylidene-1,4-phenylene), and co-oligo(1-silacyclobut-1-ylidene-4,4′-diphenylene)

1,4-bis(1-Methyl-1-silacyclobutyl)benzene (I) has been prepared by the reaction of 1-chloro-1-methyl-1-silacyclobutane with the di-Grignard reagent prepared fromp-dibromobenzene. In a similar manner, co-oligo(1-silacyclobut-1-ylidene-1,4-phenylene) (II) and co-oligo(1-silacyclobut-1-ylidene-4,4′-biphenylene) (III) have been prepared by condensation oligomerization between 1,1-dichloro-1-silacyclobutane and the di-Grignard reagents prepared fromp-dibromobenzene and 4,4′-dibromobiphenyl, respectively. These have been characterized by¹H,¹³C, and²⁹Si NMR as well as FT-IR and UV spectroscopy. The molecular weight distributions of these co-oligomers have been determined by GPC. Their thermal stabilities have been evaluated by TGA. Thermal degradation of these co-oligomers in nitrogen gives high (60%) char yields. The stability of these chars in air has been determined. TheT _g's of these co-oligomers have been measured by DSC. Platinum-catalyzed ring opening of the silacyclobutane rings ofI,II, andIII cross-links these to thermoset materials. The bending moduli (logE′), tan δ, andT _g's of these materials have been determined by DMTA. The dielectric constant and dissipation factor of cross-linkedII are reported.     

Synthesis and characterization of iron(II) and iron(III) complexes with a tridentate O,N,O′-ligand

The coordination chemistry of the ligand precursor 1-benzoyl-4,5-dihydro-3,5-bis(trifluoromethyl)-1H-pyrazol-5-ol (1a) to iron(II) acetate was studied. In dependence of the added co-ligand different complex geometries were observed. In case of 4-dimethylaminopyridine (DMAP) as co-ligand an octahedral iron(II) complex was found with an O,N,O′-coordination of the tridentate ligand (1a-2H), in which the ligand is planar, the oxygen donors are trans to each other, and the nitrogen donor is in a cis position. The other coordination sites on the iron center are occupied by DMAP ligands. In contrast to that, with triphenylphosphane as the co-ligand an oxidation process took place, which revealed an octahedral iron(III) complex with a comparable geometry for the tridentate ligand (O,N,O′-coordination, 1a-2H) demonstrating the usefulness of 1a-2H to stabilize different oxidation states. The additional coordination sites are occupied by one triphenylphosphane oxide and ethoxide ligands. Interestingly, the ethoxide ligands act as bridging ligands to form a bimetallic complex.     

Synthesis,characterization, and structure-property relationships of aromatic polyimides containing 4,4′-diaminotriphenylmethane

This work reports two series of structurally different aromatic polyimides based on 4,4´-diaminodiphenylmethane (DPM) and 4,4´-diaminotriphenylmethane (TPM) and three commercial dianhydrides. All TPM-based polyimides formed membranes due to their high molecular weight (inherent viscosities ~0.93–1.14 dl/g), they exhibited high thermal stability (5 %: 490–544 °C), glass transition temperatures between 269 and 293 °C, and reasonable mechanical properties. The incorporation of pendant phenyl moieties in the TPM-based polyimides has a strong effect producing an improvement in solubility, thermal stability, density and gas permeability coefficient in comparison with DPM-based polyimides. The most interesting polyimide TPM-6FDA, containing phenyl and trifluoromethyl as bulky pendant groups, showed higher gas permeability coefficient for CO₂ (23.73 Barrer) and the best ideal selectivity to the gas pair CO₂/CH₄ (α = 28.93).     

Synthesis and characterization of poly(11-(4′-cyano-trans-4-stilbenyloxy)undecanyl vinyl ether)

Summary Polymers based on 11-(4-cyano-trans-4-stilbenyloxy)undecanyl vinyl ether have been synthesized by living cationic polymerization, photo-initiated cationic polymerization using onium salts and thermal initiated cationic polymerization using onium salts. The polymers have been characterized by size exclusion chromatography, nuclear magnetic resonance spectroscopy, differential scanning calorimetry and polarized light microscopy. Living cationic polymerization resulted in a polymer of low molecular mass M_n3 600, with a uniformity index (D) of 1.2 displaying a focal conic texture indicative of smectic A (s_A) phase with preserved cyanogroup and trans-configuration. Photo-initiation using 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide and diphenyliodonium hexafluorophosphate resulted in an insoluble polymer exhibiting only vague liquid crystalline textures. Initiation with phenothiazine and phenacyltetramethylenesulfonium hexafluoroantimonate also yielded a partly insoluble polymer with a disturbed s_A phase. It is suggested that the monomer and polymer are sensitive towards radicals leading to cross-linking and branching. The thermal initiation on systems with -methylbenzyltetramethylenesulfonium hexafluorophosphate and p-methoxybenzyltetramethylenesulfonium hexafluorophosphate resulted in completely soluble mesomorphic polymers of M_n13 000, D=1.7 and M_n26 000, D=2.8 respectively, in both cases with a preserved cyanogroup and a transconfiguration. Polarized light microscopy revealed a distinct focal conic structure indicative of s_A in both cases.     

A spin-crossover catecholato–iron(III) system: Synthesis,crystal structure and magnetic properties

A new mononuclear Fe(III)–catecholate complex, which exhibits an incomplete spin transition without hysteresis, had been synthesized and structurally characterized. Analyzed from the structural characteristics, the tripodal ligand must play the important role in affecting the spin crossover (SCO) behavior. The larger steric strain effect and weak cooperativity existed in the crystal lattice are inclined to favor the incomplete transition.     

Synthesis and crystal structure of the bi-metallic hybrid compound {Mn4(2,2′-bipyridine)2Sb4S10}

The new bi-metallic inorganic–organic hybrid compound {Mn₄(2,2′-bipyridine)₂Sb₄S₁₀} was synthesized under solvothermal conditions. Its 2D-layered network contains distinct heterocubanes constructed by SbS₃ pyramids, MnS₆ and MnN₂S₄ octahedra. The interconnection of these units leads to a layered structure with ellipsoidal rings with pores of dimension 7.8 Å · 8.8 Å.     

Synthesis,crystal structure and magnetic properties of a new 2D cyanide-bridged heterobimetallic Cr(I)–Mn(III) complex

A new two-dimensional cyanide-bridged Cr(I)–Mn(III) coordination polymer {K[Mn(L)]₂[Cr(CN)₅NO]}·CH₃CN (1) (L = N,N-ethylene-bis(3-methoxysalicylideneiminate)) has been successfully synthesized by the reaction of K₃[Cr(CN)₅NO] with [Mn(L)(H₂O)₂]ClO₄ and characterized by elemental analysis, FT-IR and X-ray structure determination. Investigation systematic over magnetic susceptibility of the complex reveals the overall antiferromagnetic interaction between the cyanide-bridged Cr(I) ion and Mn(III) ion and its 3D antiferromagnetic ordering behavior with typical metamagnetic character below 12.5 K.     

Synthesis,characterization and properties of polyimides from 3,3′,4,4′-benzophenonetetracarboxylic dianhydride and imidazole-blocked 2,5-bis[(n-alkyloxy)methyl]-1,4-benzenediisocyanates

Summary By the solution condensation of 3,3,4,4-benzophenonetetracarboxylic dianhydride (BTDA) with imidazole-blocked 2,5-bis[(n-alkyloxy)methyl]-1,4-benzenediisocyanates (C_m-BDIs) a series of aromatic polyimides (C_m-BP-PIs) having flexible (n-alkyoxy)methyl (-CH₂O-n-C_mH_2m+1, m=4, 6, 8) side chains were prepared and characterized by IR- and ¹H-NMR spectroscopy and their properties were measured and discussed in respect to the effects of side chains. Inherent viscosities of the polymers were in the 0.23–0.34 dL/g range. All the polymers were highly soluble in N,N-dimethylpropyleneura(DMPU) and C₆- and C₈-BP-PIs even in CHCl₃ at room temperature. UV-VIS spectra showed that the -electrons are delocalized along the main chain. TGA studies showed a two-step pyrolysis behavior and in DSC Tg's of C₄-, C₆- and C₈-BP-PIs were determined to be 184, 135 and 127 °C, respectively. Wide-angle X-ray diffractometry for as-polymerized samples revealed a quite low crystallinity with only loosely developed layered structure.     

Synthesis,crystal structure and luminescent properties of new tris-β-diketonate Eu(III) complex with thiadiazolophenanthroline derivative ligand

Herein we describe the synthesis, characterization and spectroscopic properties of the complex tris-(thenoyltrifluoroacetonate)([1, 2, 5]thiadiazolo[3, 4-f][1,10]phenanthroline) europium(III) acetonitrile solvate, [Eu(TTA)₃ TDPHEN] 1.5CH₃CN, where TTA = 2-thenoyl trifluoroacetone and TDPHEN = [1, 2, 5]thiadiazolo[3, 4-f][1, 10] phenanthroline. X-ray crystallography reveals that it is an eight-coordinate Eu(III) complex containing three β-diketonate chelates and one N,N′-bidentate ligand, [1, 2, 5] thiadiazolo[3, 4-f][1, 10] phenanthroline. The excitation at 340 nm of the europium complex in a solution of acetonitrile, and at room-temperature, showed the typical Eu(III) red emission as a sharp band at 611 nm, characteristic of Eu(III) due to the transition ⁵D₀ → ⁷F₂. This complex also showed red emission in the solid state phase (λ_em = 612 nm).     

Preparation and characterization of three types of dinuclear iron(III) complexes with H2salbn,N,N′-disalicylidene-1,4-diaminobutane

By the reaction of the tetradentate Schiff base ligand H₂salbn, N,N^′-disalicylidene-1,4-diaminobutane with Fe^IIICl₃·6H₂O in the presence of Et₃N in MeOH a dinuclear iron(III) complex, [Fe^III(salbn)(μ-OMe)]₂ (1), has been obtained, whereas in EtOH, dinuclear complexes, [Fe^III(μ-salbn)]₂(μ-O) (2) and [Fe^III(salbn)]₂(μ-salbn) (3), are obtained. The structure of the complex 1 consists of two Fe(III) centers with one tetradentate salbn ligand (N₂O₂) which are bridged by two methoxo groups to yield a planar Fe₂O₂ core. On the other hand, in the complex 2, each of the two Fe(III) ions has a five-coordinate structure in which both salbn ligands act as a bridging didentate ligand and one oxygen atom bridges two Fe(III) ions to form a μ-oxo structure. The structure of the complex 3, which was obtained by accompanying with complex 2, consists of two six-coordinate Fe(III) centers in which each Fe(III) ion is coordinated by a tetradentate salbn ligand (N₂O₂) and one bridging salbn ligand (NO).     

4′-(Oxodiphenylphosphino)-2,2′:6′,2′′-terpyridine – crystal structure and complexes of cobalt(II) and cobalt(III)

The complex [Co(2)₂]²⁺ (2 = 4^′-(oxodiphenylphosphino)-2,2^′:6^′,2^′′-terpyridine) has been prepared either by the direct reaction of 2 with Co(II) or by careful oxidation of [Co(1)₂]²⁺(1 = 4^′-(diphenylphosphino)-2,2^′:6^′,2^′′-terpyridine). Further oxidation with H₂O₂ leads to [Co(2)₂]³⁺. The ¹H NMR spectra of the paramagnetic and diamagnetic [Co(2)₂]²⁺ and [Co(2)₂]³⁺ are reported. The crystal structure of ligand 1 has been determined; in the solid-state, 1 exhibits extensive intermolecular π–π stacking.