Tricarbonyl rhenium complexes of bis(pyrazol-1-yl)methane and bis(3,5-dimethylpyrazol-1-yl)methane – Synthesis,spectroscopic characterization,X-ray structure and DFT calculations

Two novel tricarbonyl rhenium complexes based on the bidentate heterocyclic N–N ligands [bis(pyrazol-1-yl)methane(bpzm) and bis(3,5-dimethylpyrazol-1-yl)methane(bdmpzm)] have been synthesized by heating at reflux [Re(CO)₅Cl] with the appropriate N–N ligand in toluene. The compounds have been characterized by IR and UV–Vis spectroscopy and X-ray analysis. Density functional theory (DFT) and time-dependent (TD) DFT calculations have been carried out for the [Re(CO)₃(bdmpzm)Cl] complex.     

Copper(II) complexes of bis(pyrazol-1-yl)methane - Synthesis, spectroscopic characterization, X-ray structure and DFT calculations

Two novel copper(II) complexes incorporating bis(pyrazol-1-yl)methane ligand (bpzm) have been synthesized. The compounds [CuCl(bpzm)₂(H₂O)]Cl·H₂O (1) and [Cu(N₃)₂(bpzm)]_n (2) have been studied by IR, UV-Vis spectroscopy and X-ray crystallography. The experimental studies on the compounds 1 and 2 have been accompanied computationally by the density functional theory (DFT) calculations.     

Synthesis, spectroscopic characterization, X-ray structure and DFT calculations of rhenium(III) complex with bis(3,5-dimethylpyrazol-1-yl)methane

[ReCl₃(MeCN)(PPh₃)₂] reacts with bis(3,5-dimethypyrazol-1-yl)methane (bdmpzm) in acetone to give [ReCl₃(bdmpzm)(PPh₃)]. The compound has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The molecular orbital diagram of [ReCl₃(bdmpzm)(PPh₃)] has been calculated with the density functional theory (DFT) method.     

Synthesis,spectroscopic characterization,X-ray structure and DFT calculations of five-coordinated chlorocopper(II) complex with bis(3,5-dimethylpyrazol-1-yl)methane

The reaction of copper dichloride dihydrate and bis(3,5-dimethylpyrazol-1-yl)methane affords [Cu{H₂C(3,5-Me₂pz)₂}₂Cl]Cl · 3H₂O. The compound has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The electronic structure of the [Cu{H₂C(3,5-Me₂pz)₂}₂Cl]⁺ cation has been calculated with the density functional theory (DFT) method. The spin-allowed doublet–doublet electronic transitions of [Cu{H₂C(3,5-Me₂pz)₂}₂Cl]⁺ have been calculated with the time-dependent DFT method, and the UV–Vis spectrum of the title compound has been discussed on this basis.     

Synthesis and structure of 1-(4-chlorophenyl)-3-(5-methyl-1, 3-dioxan-5-yl)-(1,2),(3,4)-diepoxybutane

The synthesis and X-ray structural study of 1-(4-chlorophenyl)-3-(5-methyl-1,3-dioxan-5-yl)-(1,2), (3,4)-diepoxybutane are described.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 715–718, April, 1995.     

Prototropic tautomerism of 5‐aryloxy‐1(2)H‐tetrazoles

The structure of 5‐(2,6‐dimethylphenoxy)‐1H‐ and 2H‐tetrazoles together with those of 5‐(2,6‐diisopropyl‐phenoxy)‐1H and 2H‐tetrazoles have been theoretically studied including absolute shieldings and energies. The conclusion of these studies is that a slow tautomerism between 1H‐ and 2H‐tetrazoles cannot explain the experimental observations reported recently in the literature. Copyright © 2012 John Wiley & Sons, Ltd.     

The crystal structure and vibrational spectra of two molecules emitting dual fluorescence: 4-(1H-Pyrrol-1-yl)benzonitrile (PBN) and 5-cyano-2-(1pyrrolyl)-pyridine (CPP)

Crystal structures and vibrational spectra are reported for the two title molecules which exhibit dual fluorescence due to the existence of a low lying charge transfer excited state. The data show that in the ground state PBN is twisted whereas CPP is planar, and the crystal structures are quite different. The experimental spectra are in very good agreement with quantum mechanical calculations, which also predict considerable differences between the vibrational spectra of CPP in the ground state and in the charge transfer excited state.     

Reaction of (C6F5)2HGeGeH(C6F5)2 with triethylbismuth: molecular structure of [(C6F5)2Ge]4Bi2

The reaction of (C₆F₅)₂HGeGeH(C₆F₅)₂ with triethylbismuth affords a new polynuclear germylbismuth derivative, [(C₆F₅Ge]₄Bi₂ (1). The metal framework of molecule1 has the form of a gable roof built by two central Bi atoms and four peripheral Ge atoms with covalent Bi-Bi bonds [3.045(3) Å], Bi-Ge [2.724(5)-2.755(4) Å] and Ge-Ge [2.444(6), 2.465(6) Å].Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 921–924, May, 1994.     

Photochemical study of tris(benzotriazol-1-yl)methane

Photodecomposition of tris(benzotrizol-1-yl)methane (1) in benzene gives [1-benzotryazol-1-yl-methylidene]-biphenyl-2-ylamine (2) resulting from the loss of the benzotriazolyl radical and nitrogen followed by addition of benzene. Elimination of the second benzotriazolyl radical from 2 provides the biphenyl-2-ylmethyleneamine radical, which affords phenantridine (3) after ring closure. In contrast, the photolysis of 1 in methanol gives a high yield of benzotriazole (4).     

Synthesis and crystal structure of triphenyl[tris(tetrahydrofuran)]ytterbium, Ph3Yb(THF)3

Triphenyl[tris(tetrahydrofuran)]ytterbium, Ph₃Yb(THF)₃ (1), was synthesized in high yields by the reaction of Yb with an excess of Ph₂Hg or Ph₃Bi in the presence of catalytic amounts of YbI₂(THF)₄ as well as by the reaction of Ph₂Yb(THF)₂ (2) with Ph₂Hg or Ph₃Bi. The crystal structure of complex1 was studied by X-ray structural analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 163–166, January, 1998.     

Synthesis and structures of tris(pentafluorophenyl)silylamines

Tris(pentafluorophenyl)silylamines were synthesized by silylation of amines and imines with (C₆F₅)₃SiCl or (C₆F₅)₃SiOTf in the presence of triethylamine. The crystal structures of the (C₆F₅)₃SiN(H)CH₂Ph and (C₆F₅)₃SiN(CH=CMe₂)CH₂Ph compounds were studied by X-ray diffraction. The crystal packings were analyzed by quantum chemical calculations in terms of the density functional theory (PBE exchange-correlation functional). Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1345–1352, July, 2007.     

Dinuclear copper(I) complexes of tris(3,5-dimethylpyrazol-1-yl)methane: Synthesis, structure, and reactivity

The reaction of [Cu(NCMe)₄](BF₄) with equimolar amounts of the tris(substituted-pyrazolyl)methane ligand HCPz₃ or HC(3,5-Me₂Pz)₃ yields the respective salts [Cu(HCPz₃)(NCMe)](BF₄) (1a) or [Cu(HC(3,5-Me₂Pz)₃)(NCMe)](BF₄) (1). The acetonitrile ligand of 1 can be replaced by prazine, 4,4′-dipyridine or 1,4-diisocyanobenzene to yield related mononuclear complexes [Cu(HC(3,5-Me₂Pz)₃)(pyrazine)](BF₄) (2), [Cu(HC(3,5-Me₂Pz)₃)(4,4′-bipyridine)] (BF₄) (3) or [Cu(HC(3,5-Me₂Pz)₃)(1,4- CNC₆H₄NC)](BF₄) (7), respectively. A series of binuclear copper(I) complexes {[Cu(HC(3,5-Me₂Pz)₃)]₂(μ -BL)}(BF₄)₂ (4, BL = pyrazine; 5, BL = 4,4′-dipyridine; 8, BL = 1,4-diisocyanobenzene) were prepared by treating equal molar ratio of 1 with related mononuclear complexes 2, 3 and 7. In addition, binuclear copper(I) complexes were also prepared from treatment of 2 equiv of 1 with the related bridge ligand. Both of 4 and 5 reformed mononuclear starting complex 1 in acetonitrile solution. However, the more robust complex 8 was stable in acetonitrile solutions. The structure of complexes 1a, 4, 5, and 7 were confirmed by X-ray crystallography. The redox properties of 4 and 8 were examined by cyclic voltammetry and exhibited two quasi-reversible waves suggesting that no significant structural reorganization occurs during the redox process on the electrochemical time scale.     

Features of the reaction of 3(5)-methyl-5(3)-trifluoromethylpyrazole with chloroform. Synthesis and structure of fluorinated analogs of tris(pyrazol-1-yl)methane

Reaction of 3(5)-methyl-5(3)-trifluoromethylpyrazole (I) with chloroform leads to a complex mixture of compounds. The main components are {bis[(5-methyl-3-trifluoromethyl)pyrazol-1-yl](3-methyl-5-trifluoromethyl)pyrazol-1-yl}methane, bis{[(3-methyl-5-trifluoromethyl)pyrazol-1-yl](5-methyl-3-trifluoromethyl)-pyrazol-1-yl}methane, and tris[(3-methyl-5-trifluoro-methyl)pyrazol-1-yl]methane. The structure of isomeric substances was proved by XRD method.     

4-(5-喹啉-3-基-四氮唑-2-基)丁胺的合成

三苯基膦钯催化3-溴喹啉完成氰化取代制得3-氰喹啉(1);1与叠氮化钠经[2+3]环加成合成了3-(2H-四氮唑-5-基)喹啉(2);2与N-(4-溴丁基)邻苯二甲酰亚胺反应制得2-[4-(5-喹啉-3-基-四氮唑-2-基)丁基]异吲哚-1,3-二酮(3);3经肼解合成了4-(5-喹啉-3-基-四氮唑-2-基)丁胺(4...     

Synthesis and crystal structure of tris(ethylenediamine)cobalt(III) bis(tetrachloroaurate(III)) chloride

The binary complex salt [Co(N₂C₂H₈)₃][AuCl₄]₂Cl has been synthesized. Its crystal structure has been determined. Crystal data for C₆H₂₄N₆Cl₉AuCo: a = 20.8976(14) Å, b = 14.4773(9) Å, c = 7.9944(5) Å; β = 110.809(2)°; V = 2260.9(3) ų, space group C2/c, Z = 4, d _calc = 2.798 g/cm³. The plane square environment of the gold atom of the complex anion is completed to a tetragonal pyramid by the chlorine atom of the neighboring complex anion (Au…Cl 3.538 Å). The structure is layered. Layers of complex cations and complex anions alternate along the X axis.     

芳醛-N-(1-苯基-1H-四唑-5-巯基)乙酰腙的微波合成及其晶体结构

在微波辐射下快速、高产率地合成了一系列含有四唑环的酰腙类化合物, 并对其进行了元素分析、红外以及核磁共振氢谱和碳谱表征. 对化合物4a的无色晶体进行了X射线晶体衍射. 结果表明, 该晶体属三斜晶系, 空间群P-1, V＝0.80070(38) nm³, Z＝2, D_c＝1.404 g•cm^－3, a＝0.7382(1) nm, b＝0.9992(2) nm, c＝1.1535(2) nm, α＝81.41(2)°, β＝85.72(2)°, γ＝72.21(2)°, 分子结构呈反式构型, 通过分子间氢键组装成二聚体. 生物活性测试发现部分化合物具有抗菌活性.     

A novel rhenium(III) complex with bis(pyrazol-1-yl)methane: X-ray structure and DFT calculations for [ReCl3(bpzm)(PPh3)]

The [ReCl₃(MeCN)(PPh₃)₂] complex reacts with bis(pyrazol-1-yl)methane (bpzm) to give [ReCl₃(bpzm)(PPh₃)]. This compound has been studied by IR, UV–Vis spectroscopy, magnetic measurement and X-ray crystallography. The molecular orbital diagram of [ReCl₃(bpzm)(PPh₃)] has been calculated with the density functional theory (DFT) method. The spin-allowed triplet–triplet electronic transitions of [ReCl₃(bpzm)(PPh₃)] have been calculated with the time-dependent DFT method, and the UV–Vis spectrum of the title compound has been discussed on this basis. The magnetic behavior is characteristic of a mononuclear d⁴ low-spin octahedral Re(III) complex (³T_1g ground state) and arises because of the large spin–orbit coupling (ζ = 2500 cm⁻¹), which gives a diamagnetic ground state.     

Structure of the Ligated Ag60 Nanoparticle [{Cl@Ag12}@Ag48(dppm)12] (where dppm=bis(diphenylphosphino)methane)

A novel bisphosphine ligated Ag₆₀ nanocluster, [{Cl@Ag₁₂}@Ag₄₈(dppm)₁₂], has been dis-covered and characterized by X-ray crystallography. It consists of a central chloride located inside an icosahedral silver core layer, which is further encased by a second shell of 48 silver atoms/ions, which are capped with 12 bis(diphenylphosphino)methane (dppm) ligands. Due to lack of sufficient material the cluster could not be further characterized by other methods. DFT calculations were carried out on the cation [{Cl@Ag₁₂}@Ag₄₈(dppm)₁₂]⁺ to determine if it corresponds to a superatom with a core count of n=58. The DFT optimized structure is in agreement with X-ray ndings, but the low value of the HOMO-LUMO gap does not support superatom stability.     

不对称取代双(吡唑)甲烷VIB羰基金属化合物的合成及表征

3-苯基吡唑与二溴甲烷在相转移催化下反应,得到(3-苯基吡唑-5'-苯基吡唑)甲烷(1)和双(3-苯基吡唑)甲烷(2)的混合物.当该混合配体与M(CO)₆(M=Cr,Mo,W)在光照下反应时,分离得到了不对称取代的(3-苯基吡唑-5'-苯基吡唑)甲烷四羰基铬(3),钼⑷和钨(5).用X-射线衍射测定了化合物5的晶体结构.结果表明,该晶体属于单斜晶系,P2(1)/n空间群,a=1.7976(7) rnn,b=1.3210(5) nm, c=1.8681(7) nm;β=98.293(8)°, V=4.390(3) nm³, Z=8,最终结构偏离因子[I>2σ(I)]=0.0516, Rw=0.0898, GOF=0.879.两个苯基分别处于两个吡唑的3位及5'位.     

Synthesis and special characterization through X-ray analysis of 1,8-dioxooctahydroxanthenes

Pyran moiety containing heterocyclic compounds have the capability for binding to either side to cyclohex-2-enone rings and to form xanthene derivatives (1,8-dioxooctahydroxanthenes also known as xanthenodiones). These xanthene derivatives display a wide range of biological activities and find applications in laser technologies and photodynamic therapy. This paper describes the preparation, X-ray structural analysis, and theoretical investigation of a series of 1,8-dioxooctahydroxanthenes. The compounds were synthesized via Knoevenagel condensation between different aldehydes and β-diketones. The reactions were performed free of solvents and the 1,8-dioxooctahydroxanthenes were obtained in good yields (70−92%). All the compounds were fully characterized by NMR and IR spectroscopy as well as mass spectrometry. Among the synthesized compounds, seven had their crystal structures elucidated for the first time. In all the new crystal structures, the three fused rings did form an almost completely planar xanthenodione core, except for the side rings that adopt half-chair conformation with both carbons at the flaps oriented toward to the aromatic substituent, or with one of the two carbons pointing opposite to the substituent. Another conformational difference among the new compounds investigated by X-ray diffraction resides in the rotation around the bond axis connecting the xanthenodione core to its aromatic substituent. It was found that different bent levels resulted from weak intermolecular contact patterns. In addition, theoretical calculations for single molecule and dimmers have provided insights into the balance between intramolecular and intermolecular forces driving both conformational features.