Synthesis of (3R,4S,5S,9S)-3,5,9-trihydroxy-4-methylundecanoic acid δ-lactone

Radical-mediated opening of a chiral trisubstituted epoxy alcohol using cp₂TiCl furnished the ‘2-methyl-1,3-diol’ moiety with the desired stereochemistry, which led to a total synthesis of (3R,4S,5S,9S)-3,5,9-trihydroxy-4-methylundecanoic acid δ-lactone 1.     

First platinum(ii)–alkaline-earth acetate-bridged complexes Ptii(m-OAc)4Mii(AcOH)4 (M = Ca,Sr, Ba)

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Phase formation in Li2MoO4-Rb2MoO4-MMoO4 (M = Ca, Sr, Ba, Pb) systems and the crystal structure of α-Rb2Pb(MoO4)2

A subsolidus triangulation of Li₂MoO₄-Rb₂MoO₄-MMoO₄ (M = Ca, Sr, Pb, Ba) systems is performed. The RbLiMoO₄-Rb₂M(MoO₄)₂ (M = Pb, Ba) joins, where 11 mol.% long Rb₂M(MoO₄)₂-based solid solutions are found, are studied in most detail. Ternary molybdates do not form in the systems, which is confirmed by spontaneous flux crystallization. The α-Rb₂Pb(MoO₄)₂ crystals are obtained and their crystal structure is solved (a = 20.9724(15) ?, b = 12.1261(8) ?, c = 16.1171(10) ?, β = 115.728(13)°, C2/m space group, R = 0.0695, Z = 16), which is a monoclinic superstructure of the palmierite type and has the largest cell volume and the most complex structure among lead-containing palmierites. One of the MoO₆ tetrahedra is orientationally disordered over two sites; lead atoms are shifted from the centers of their coordination polyhedra to one of their faces and have cn = 6–8; for rubidium cations cn = 10–12.     

C4H4Y (Y＝O, S, Se)与BX3 (X＝H, F, Cl)作用的计算化学研究

采用量子化学的密度泛函B3LYP和二阶微扰MP2(full)方法对C₄H₄Y (Y＝O, S, Se)与BX₃ (X＝H, F, Cl)形成的电子授受型复合物进行了研究, 所得18个复合物的构型包括BX₃位于C＝C双键上方的π-p作用型和B与O, S, Se直接作用的n-p作用型. 体系C₄H₄Y-BH₃以n-p作用型较为稳定, 体系C₄H₄Y-BF₃, C₄H₄Y-BCl₃的π-p和n-p作用型复合物稳定性相当. 对各复合物的几何构型、振动频率和自然键轨道分析表明, 复合物的形成过程中均存在几何构型的改变、电荷的转移和振动频率的变化, 它们的变化规律与复合物稳定性的变化规律基本一致, 即按H, F, Cl的顺序依次降低.     

Synthesis, structure, and properties of M[VO2(XO4)(H2O)2] · H2O (X = S, M = K, Rb, NH4, Tl; X = Se, M = K, Rb, NH4)

Keeping of MVO(XO₄)₂ under saturated vapor pressure at room temperature resulted in the synthesis of a number of isostructural complexes M[VO₂(XO₄)(H₂O)₂] · H₂O, where X = S, M = K, Rb, NH₄, Tl and X = Se, M = K, Rb, NH₄. The conclusion about the isostructural nature of the synthesized sulfate and selenate compounds was based on X-ray diffraction and vibrational spectroscopy data. Characteristic features of the thermal decomposition of M[VO₂(XO₄)(H₂O)₂] · H₂O on heating in air were identified. It was shown that K[VO₂(SeO₄)(H₂O)₂] · H₂O tends to undergo spontaneous dehydration under ambient conditions to give the monohydrate K[VO₂(SeO₄)(H₂O)].     

Complex salts trans-[Rh(β-Pic)4Cl2]X (X = Cl?, ReO 4? , and ClO 4? ): Synthesis, crystal structures, and thermal properties

Three novel complex salts containing the cation trans-[Rh(β-Pic)₄Cl₂]⁺ with the anions Cl⁻ (I), ReO₄⁻ (II), and ClO₄⁻ (III) were obtained and characterized by elemental analysis, X-ray diffraction, NMR spectroscopy, and IR spectroscopy. The complex trans-[Rh(β-Pic)₄Cl₂]ReO₄ crystallizes from DMF as a solvate in which solvent molecules fill the channels formed by the cations and anions. The thermal properties of complexes I, II, and II · DMF were examined by DTA. Final and some intermediate products of the thermolysis were isolated and characterized by physicochemical methods.     

13C and1H NMR spectroscopic characterization of titanium(IV) alkylperoxo complexes Ti(OOtBu)n(OiPr)4?n with n=1, 2, 3, 4

Using¹³C and¹H NMR spectroscopy, titanium(IV) alkylperoxo complexes Ti(OOtBu)_n(OiPr)_4−n with n=1, 2, 3 and 4 were characterized in the reaction of Ti(OiPr)₄ withtBuOOH in CH₂Cl₂ and CDCl₃.     

呋喃同系物C4H4X(X=O,S,Se,Te)非线性光学性质的TDDFT-SOS理论研究

用含时密度泛函理论(TD-DFT)组合态求和(SOS)方法计算了呋喃同系物[呋喃(C4H4O)、噻吩(C4H4S)、硒吩(C4H4Se)、碲吩(C4H4Te)]的非线性光学性质.计算结果表明,体系的三阶NLO系数(γ)随着杂原子被重原子的取代而逐步增大,B3LYP等4种势函数计算的NLO系数基本一致.计算的色散关系曲线表明,标题化合物在宽频区存在小的色散作用,是一类具有应用前景的NLO材料.     

Crystal Structure of Loliolide (5, 6,7a-Tetrahydro-6-hydroxy-4, 4, 7a-trimethyl-2 (4H)-benzofuranones)

1INTRODUCTIONThetitlecompound,C,,H,,O,(mp:146～148'C),forthefirsttime,wasiso-latedfromClinopodiumpolycephalum(Vant-)byC.Y.WuetHsuancalled"DuanXueliu"inChinesethatisusedinfolkmedicineforthetreatmentofhaemorrhagiadisease[1i.Itsstructurehasalreadybeendeterminedt2ibymeansofUV,lR,NMRandchemicalsynthesis.Sinceloliolideappearedtohaveantitumoractivity"'andim-munosuppressiveactivity'#'inrecentyears,weaffirmedthestructurebyX-raydiffractionanalysis.2EXPERIMENTALApaleyellowtransparentcry…     

五配位铁硫化合物(Et4N)4〔Fe2(S,X-C6H4-o)4〕的合成与晶体结构

利用无水FeCl与双齿配体Na_2BDT或Na_2MP(Na_2S,X-C,H_4-o_2:X=S,BDT;X=O,MP)在乙醇溶液中反应,然后加入沉淀剂Et_4NBr,可以得到双核铁硫化合物(Et_4N)_2[Fe_(S,X-CH_4-o)_4](1,X=S;2,X=0)。它们分别具有以双硫或双氧桥联起来的五配位扭曲三角双锥构型的铁原子。分子为心对称,核心Fe_2X_2~(2+)为平面。每个铁原子上的二个苯环平面A和B相互近于平行(1,二面角10.1°)或近于垂直(2,二面角100.2°);但铁原子与XSCC平面非共面。Fe原子离平面0.05～0.5A。2是第一个以双齿配位的双氧桥铁硫化合物,它既含有桥基氧原子又具有端基氧原子,对研究含氧配位的铁原子周围环境,为模拟固氧酶中的“P簇”,有一定意义。     

Unexpected complexation of allylpseudothiohydantoin hydrochlorides towards CuX (X = Cl,NO3, ClO4, BF4, 1/2SiF6). The first known examples of joint CuI(Cl,ClO4) and CuI(Cl,BF4) π-complexes

By means of alternating current-electrochemical synthesis starting from a mixture of 2-imino-3-(prop-2-en-1-yl)-1,3-thiazolidin-4-one (3-allylpseudothiohydantoin, napt) and 2-allylamino-1,3-thiazol-4(5H)-one (allylaminopseudothiohydantoin, aapt) hydrochlorides and corresponding copper(II) salts five new π-complexes, [Cu(napt)Cl] (1), [Cu₂(aapt)₂Cl]NO₃ (2), [Cu₂(aapt)₂Cl]BF₄ (3), [Cu₂(aapt)₂Cl]ClO₄ (4) and [Cu₂(aapt)₂Cl]₂SiF₆·2H₂O (5), were obtained and studied by X-ray single crystal diffraction and IR-spectroscopy. Napt and aapt molecules are selectively coordinated to Cu⁺ depending on the anion type. In crystals of 1 and 5, the organic ligands are attached to the metal in a chelating N,(C=C)-bidentate mode. The aapt molecule in 2-4 acts as a tridentate chelating ligand, being coordinated to the copper(I) ion through the heterocyclic N atom, carbonyl O atom, and C=C bond of allyl group, forming an original cationic [Cu₂(aapt)₂Cl]⁺ fragment with both a bridging Cl^– ion and O atom of the C=O group. In the presence of the doubly charged SiF₆^2– anion, Cu(I) in 5 prefers to be bonded with two bridging Cl^– ions, rather than the C=O group, causing [Cu₂(aapt)₂Cl]⁺ units to associate into the infinite cationic chains. Crystals of 3 and 4 are the first known examples of the simultaneous BF₄^–/Cl^– or ClO₄^–/Cl^– participation in copper(I) π-complex formation.     

{[Cu4(nip)4(4，4′-bipy)4(DMF)4]·CH3OH}n配合物的合成与晶体结构

A coordination polymer, {[Cu₄(nip)₄(4，4′-bipy)₄(DMF)₄]·CH₃OH}_n, have been synthesized by the layer method using 5-nitroisophthalic acid (H₂nip), Cu(CH₃COOH)₂ and 4,4′-bipyridine(4,4′-bipy) with three solutions in a marrow tube and structurally characterized by X-ray single-crystal structure analysis. The results indicated that the nip ligand has a μ₂ mono-atomic bridging-monodentate coordination mode and the structure is a two-dimensional network. CCDC: 623420.     

Structural variations of nickel complexes in NiS4 and NiS2PN coordination environments: spectral and single-crystal X-ray structural studies on bis(4-methylpiperidinecarbodithioato-S,S′)nickel(II) and (4-methylpiperidinecarbodithioato-S,S′)(thiocyanato-N)(triphenylphosphine)nickel(II)

Abstract  

[Ni(4-mpipdtc)₂] and [Ni(4-mpipdtc)(PPh₃)(NCS)] (4-mpipdtc = 4-methylpiperidinecarbodithioate anion) have been characterized by electronic, IR, and NMR spectroscopy, single crystal X-ray analysis, and cyclic voltammetry. IR spectra of the complexes show the contribution of the thioureide form to the structures. ¹H NMR spectra show the deshielding of α-CH₂ protons on complexation. ¹³C NMR spectra shows interesting differences between the N¹³CS₂ carbon signals of the parent complex [Ni(4-mpipdtc)₂] and the mixed ligand complex [Ni(4-mpipdtc)(PPh₃)(NCS)]. The N¹³CS₂ carbon signal for [Ni(4-mpipdtc)(PPh₃)(NCS)] is observed at 204.85 ppm with an upfield shift of about 3.8 ppm compared with that found in [Ni(4-mpipdtc)₂] (201.06 ppm). The observed shielding in [Ni(4-mpipdtc)(PPh₃)(NCS)] indicates the effect of PPh₃ on the mesomeric drift of electron density toward nickel through the thioureide C–N bond. Single crystal X-ray analysis of [Ni(4-mpipdtc)₂] and [Ni(4-mpipdtc)(PPh₃)(NCS)] confirms the presence of four-coordinated nickel in a distorted square-planar arrangement with the NiS₄ and NiS₂PN chromophores, respectively. The C–N (thioureide) bond lengths of [Ni(4-mpipdtc)(PPh₃)(NCS)] are shorter than those found in [Ni(4-mpipdtc)₂], because of the presence of the π-acid (triphenylphosphine) in [Ni(4-mpipdtc)(PPh₃)(NCS)]. Significant asymmetry in Ni–S bond distances was observed in Ni(4-mpipdtc)(PPh₃)(NCS)] (2.162(2) and 2.211(2) ?). This observation clearly supports the less effective trans effect of SCN^– over PPh₃. The piperidine ring in the dithiocarbamate fragment is in the normal chair conformation.     

K2NiF4型结构的A2－xSrxBO4(A＝La, Dy, B＝Mn, Fe, Co, Ni)希土复合氧化物的合成

以典型的轻希土镧和重希土镝及碱土金属锶作为Ａ位离子，以过渡金属锰、铁、钴、镍作为Ｂ位离子，合成了Ｋ２ＮｉＦ４型结构的Ａ２－ｘＳｒｘＢＯ４希土复合氧化物，采用粉末Ｘ射线衍射技术考察了反应条件等因素对生成Ｋ２ＮｉＦ４型四方（Ｔ）结构上析影响，实现结果表明，四方结构的形成不仅与几何因素有关，而且与各组分的物理化学性质有关。各个不同的组成，生成四方相的温度范围也有所不同。适当地提高反应温度以及延长灼烧时间     

RBa2Cu4O8(R=Dy,Ho,Er,Tm,Yb)和Y2Ba4Cu7O14.3的化学键参数计算

使用复杂晶体上化学键理论计算了RBa     

Exchange coupling in alkoxy-polyoxovanadates [VIVnVV6?nO7(OR)12]4?n (n = 4, 3, 2)

The molecular structure and magnetic properties of alkoxy-polyoxovanadates [V^IV _n V^V _6−n O₇(OR)₁₂]⁴⁻ⁿ (n = 4, 3, 2) were studied within the framework of the DFT approach. The equilibrium geometric configurations of all complexes studied in this work are characterized by a distorted octahedral hexavanadate core; the unpaired d-electrons are localized on the metal centers (V^IV). The localized spin density distribution is also retained in the low-temperature crystal structures of the compounds whose magnetic properties are described by the Heisenberg-Dirac-van Vleck exchange spin Hamiltonian. The exchange parameters calculated using the broken symmetry formalism suggest predominance of ferromagnetic coupling between vanadium(IV) ions in the μ-OR bridged dimeric units {V^IVO(OR)V^IV} and in the diagonal pairs {V^IVOV^IV} (n = 4). The results obtained indicate that the magnitude and sign of the exchange parameters in the isostructural dimeric units within the hexavanadate core depend on the total number of unpaired electrons in the system.     

Tetragonal cubanoid Cu4X4 in the isostructural π-complexes with divinyltetramethyldisiloxane: [Cu4X4(C8H18OSi2) (X = Cl, Br)

The formation of the heterocubanoid fragmen Cu₄Y₄(Y = Cl, Br, I, O, S) in the structure of the Cu(I) complexes is often associated with the appearance of valuable properties (catalytic, thermal, chemiluminescence, and others) of these compounds. The Cu₄X₄ cluster (X = Cl, Br) found in the isostructural π-complexes with divinyltetramethyldisiloxane (DVTMSO) (space group P , Z = 1, a = 10.2330(2) ?, c = 7.6877(3) ? for [Cu₄Cl₄(DVTMSO)₂] and a = 10.2633(1) ?, c = 7.9514(3) ? for [Cu₄Br₄(DVTMSO)₂]) makes it possible to discuss the homological chain of the Cu₄X₄ cuprohalide fragments from the viewpoint of steric (conformational, symmetric) and electronic (d _Cu → π*(C=C)) properties of an organic ligand. Original Russian Text ? T. Dużak, V.V. Olijnyk, B. Zarychta, J. Zaleski, 2009, published in Koordinatsionnaya Khimiya, 2009, vol. 35, No. 6, pp. 425–430.     

Chloroaqua Complexes [M3S4(H2O)9?xClx](4?x)+ (M = Mo, W; x = 4, 6, 7) and Their Supramolecular Compounds with Cucur[8]uril

Compounds of trigonal cluster chloroaqua complexes with cucurbit[8]uril were synthesized by slowly evaporating HCl solutions of chalcogenides heterometallic cubane cluster complexes of molybdenum and tungsten with cucurbit[8]uril in air; the complexes were characterized by X-ray diffraction analysis: (H₃O)₈[Mo₃S₄(H₂O)_2.5Cl_6.5]₂Cl(PdCl₄)·(C₄₈H₄₈N₃₂O₁₆)· 29H₂O (a = 13.3183(17) Å, b = 13.7104(18) Å, c = 18.225(3) Å; α = 80.263(3)°, β = 77. 958(3)°, γ = 87.149(4)°, V = 3207.4(7) ų, space group P , Z = 1, ρ(calc) = 1.900 g/cm³), (H₃O)₄ [Mo₃S₄(H₂O)₃Cl₆]₂·(C₄₈H₄₈N₃₂O₁₆)₃·68H₂O (a = 21.413(6) Å, c = 49.832(10) Å; γ = 120°, V = 19788(8) ų, space group R , Z = 3, ρ(calc) = 1.695 g/cm³), (H₃O)₆ [Mo₃S₄(H₂O)₃Cl₆]₂Cl₂·(C₄₈H₄₈N₃₂O₁₆)·12H₂O (a = 15.881(2) Å, b = 17.191(2) Å, c = 23.276(4) Å; β = 98.865(15)°, V = 6278.7(15) ų, space group P2₁/c, Z = 2, ρ(calc) = 1.638 g/cm³), [W₃S₄(H₂O)₅Cl₄]₂·(C₄₈H₄₈N₃₂O₁₆)₃·35H₂O (a = 21.038(3) Å; α = 61.20(1)°, V = 6762.0(14) ų, space group R , Z = 1, ρ(calc) = 1.582 g/cm³). The [Mo₃S₄(H₂O)₃Cl₆]²⁻ anion complex was isolated as three geometrical isomers.Original Russian Text Copyright © 2004 by E. V. Chubarova, D. G. Samsonenko, H. G. Platas, F. M. Dolgushin, A. V. Gerasimenko, M. N. Sokolov, Z. A. Starikova, M. Yu. Antipin, and V. P. Fedin__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 1049–1058, November–December, 2004.