PREPARATION, CHARACTERIZATION AND ELECTROCHEMISTRY OF BINUCLEAR COPPER(I) COMPLEXES Cu_2(dppm)Cl_2 AND Cu_2(dppe)Cl_2

Two binuclear copper(I) complexes with novel structures and novel bonding,Cu_2(Ph_2PCH_2PPh_2)Cl_2 (Ph_2PCH_2PPh_2=dppm) and Cu_2(Ph_2P-CH_2CH_2PPh_2)Cl_2 (Ph_2PCH_2CH_2PPh_2=dppe), were prepared and characterized through elemental analyses, ICP, IR(4000-200 cm~(-1), CsI disc.), ~(31)P-NMR spectra. Their electronic conductivities, oxidation and reduction potentials were measured. Preliminary studies show that both of the two complexes have chlorobridging and phosphorus-bridging structures.     

CRYSTAL STRUCTURE OF RhCl(dppm)_2·H_2O

<正> C50H46OP4ClRh, RhCl(dppm)2 · H2O, Mr = 922. 2, monoclinic, P21/2, a=10. 532(3), b=22.574(8), c=18. 641(8) A, β=93. 41(3)°, V = 4424 (3) A3, Z = 4, Dc=1. 386 g. cm-3, λ(MoKα) = 0. 71073A , F(000) = 1904. The structure was determined by direct methods and difference Fourier syntheses and refined by full-matrix least-squares to final R = 0. 037 and Rw = 0. 036 for 3432 (F> 6. 0σ(F) ) observed reflections. The structure of the title compound contains RhCl-(dppm)2 and non-coordinated H2O molecules. The rhodium atom is coordinated by one chlorine atom and four phosphorus atoms of two DPPM ligands forming a tetragonal pyramidal configuration.     

Syntheses, Structures, Bonding, and Optical Properties of Trinuclear Cluster Iodides: M3(μ3-I)2(μ-dppm)3·I (M=Cu, Ag), dppm=bis(diphenylphosphino)methane)

The title compounds were obtained from the reactions of copper or silver monohalides with the bidentate bis(diphenylphosphino)methane (dppm) ligand at room temperature in a mixed solvent. Single-crystal X-ray diffraction analyses indicate that both compounds crystallize in a monoclinic system but in different space groups. The structures are characterized by a trinuclear [M₃I₂(dppm)₃]⁺ cation with a trigonal-bipyramid [M₃( ₃-I)₂] core. In agreement with the geometric characteristics of the M₃ triangles, ³¹P NMR spectra exhibit a single peak for the [Cu₃] cluster but a double-peak for the [Ag₃] cluster. Preliminary optical studies by UV/Vis and emission techniques show major absorption shoulders at 286 nm for Cu₃I₂(dppm)₃·I and 254 nm for Ag₃I₂(dppm)₃·I, but no luminescence in the non-degassed MeCN solution at 298 K. The structures, bonding, electronic excitations and emissions are discussed based on relativistic density functional theory calculations.     

Reactions of the dirhenium(II) complexes Re2X4(dppm)2 (X= Cl,Br; dppm = Ph2PCH2PPh2) with isocyanides. Part IX. New isomeric forms of the mixed carbonyl-isocyanide dirhenium(II) Complexes Re2 Cl4(dppm)2(CO)(CNxyl) and [Re2Cl3(dppm)2(CO)(CNxyl)2]O3SCF3 The X-ray crystal structure of [(xyl NC)2ClRe(μ-dppm)2ReCl2(CO)] O3SCF3

The monocarbonyl complex Re₂Cl₄(µ-dppm)₂(CO) reacts with xylyl isocyanide in acetonitrile to afford the bioctahedral complex (CO)Cl₂Re(µ-dppm)₂ ReCl₂(CNxyl), 2b. This is a different structural isomer from the edge-sharing bioctahedral complex Cl₂Re(µ-Cl)(µ-dppm)₂ReCl(CNxyl) or this same stoichiometry which A formed when acetone is be reaction solvent. The complex2b reacts with a further equivalent of xylNC in the presence of TlO₃SCF₃ in dichloromethane to form a red complex of composition [Re₂Cl₃(µ-dppm)₂ (CO)(CNxyl)₂]O₃SCF₃. 3, which has the open bioctahedral structure [(xylNC)₂ClRe(µ-dppm)₂ReCl₂(CO)]O₃SCF₃. This is a third isomeric form of this dirhenium cation: the previously isolated green and yellow forms have edge-sharing bioctahedral structures. Crystal data for3 at 295 K: orthorhombic space group Pbca (No. 61) witha=22.654(5) Å,b=22.717(4) Å,c=27.324(4) A,V= 14061(7) ų, andZ = 8. The structure was refined to R = 0.059 (R, = 0.134 ) for 14164 data. The Re-Re distance is 2.3833(8) Å.     

SYNTHESIS AND CRYSTAL STRUCTURE OF A PLATINUM (Ⅱ) COMPLEX WITH MIXED DIPHOSPHINE AND THIOLATE LIG-ANDS, Pt(dppm)(SPh)_2

<正> The reaction of H2PtC14, Ph2PCH2PPh2(dppm) , NaSPh, and element selenium in DMF gives rise to a mononuclear complex Pt (dppm ) (SPh)2, PtS2P2C37H32, Mr = 797. 83, triclinic, space group P1, a = 10. 051(2), b = 11. 805 (3), c=15. 499(4)(?). α=109.41(3), β=90. 94(3), γ=107. 80°, V = 1636.3 (?)3. Z = 2, Dc= 1. 619gcm-3, * = 45. 749cm-1, and F(000) = 788. The final structural refinement converged with unweighted and weighted R factors of 0. 029 and 0. 044, respectively, for 4832 observed unique reflections with I>3σ(I). The complex is an asymmetric molecule with a four-coordinated Pt atom. The average of Pt -S and Pt-P bond distances are 2. 334(3) and 2. 260(3) (?), respectively.     

Synthesis, structure and characterization of the trinuclear copper (Ⅰ) complex [Cu_3(μ_3Br)_2(dppm)_3]Br

The novel trinuelear copper(I) complex [Cu3(μ3-Br)2(dppm)3]Br has been obtained by reaction of bis(diphenyl-phosphino)methane (dppm) with cupric bromide. The title complex was characterized by single-crystal X-ray analysis, elemental analysis, molecular weight determination, 31P NMR and its conductivity was also measured. The [Cu3(dppm)3Br2] cation consists of a triangular array of copper atoms, with dppm ligands (Ph2PCH2PPh2) bridging each edge of the triangle and two triply bridging Br groups bound to the two faces of the Cu3 unit. Crystallographic data: monoclinic, space group P21/c, a = 1.4739(4) , b = 1.7708(5), c = 2.8395(8) nm, β= 97.16(3)°, V = 7.353nm3, Z = 4,F(000)= 3296, Dcalc = 1.472 g/cm3, μ= 26.478 cm-1, R = 0.06, Rw = 0.08, 4654 reflections observed with I > 3σ(I).     

双核银络合物[Ag_2(dppm)_2(Py)_2(μ-Cl)]ClO_4的合成与结构

二-(二苯基膦)甲烷(dppm)是一种易与金属形成多核络合物的有机膦配体。我们用dppm作为配体合成了一系列银的多核络合物,并对其结构进行了研究。本文报导了其中一个双核化合物[Ag_2(dppm)_2(Py)_2(μ-Cl)]ClO_4的合成及晶体结构、分子结构的测定。     

Photochemical reactions of [(η 5-C5H5)Mn(CO)3] with Ph2P(S)(CH2) n P(S)Ph2 [n=1, dppm(S)2; 2, dppe(S)2; 3, dppp(S)2]

Six new complexes, Mn(CO)( ⁵-C₅H₅){Ph₂P(S)(CH₂) _n P(S)Ph₂}] (1a–3a) [(1a), n=1; (2a), n=2; (3a), n=3] and [Mn₂(CO)₄( ⁵-C₅H₅)₂(cis--Ph₂P(S)(CH₂) _n P(S)Ph₂)] (1b–3b) [(1b), n=1; (2b), n=2; (3b), n=3] have been synthesized by the photochemical reaction of [( ⁵-C₅H₅)Mn(CO)₃] with Ph₂P(S)(CH₂) _n P(S)Ph₂ [n=1, dppm(S)₂; 2, dppe(S)₂; 3, dppp(S)₂]. The complexes have been characterized by elemental analysis, mass spectroscopy, f.t.-i.r. and ³¹P–[¹H]-n.m.r. spectroscopy. The spectroscopic studies reveal that coordination of the ligand iscis-chelate bidentate in [Mn(CO)( ⁵-C₅H₅){Ph₂P(S)(CH₂) _n P(S)Ph₂}] (1a–3a) and cis-bridging bidentate between two metals in [Mn₂(CO)₄( ⁵-C₅H₅)₂(cis--Ph₂P(S)(CH₂) _n P(S)Ph₂)] (1b–3b).     

Facile Syntheses of (±)-Curcuphenol, (±)-Curcudiol, (±)-Curcuhydroquinone,and (±)-Curcuquinone

The syntheses of (±)-curcuphenol 1, (±)-curcudiol 2, (±)-curcuhydroquinone 3, and (±)-curcuquinone 4 have been achieved. The key steps involved in the syntheses were the Reformatsky reaction and hydrogenation reaction.     

Reactions of cationic vinylidene complexes [Fe{=C=C(R1)R2}(η-C5H5)(dppm)]+[dppm = bis(diphenylphosphino)methane] with nucleophiles: stereoselective synthesis and crystal structure of the alkenyl complex (E)-[Fe{C(H)=C(Me)Ph}(η-C5H5)(dppm)]

The reactivity of the cationic vinylidene complexes [Fe{CC(R¹)R²}(η-C₅H₅(dppm)]⁺ toward different nucleophiles has been investigated. Whereas the disubstituted complexes (R¹ = Me; R² = Ph or ^tBu) are unreactive with water and methanol, the addition of the anion hydride proceeds stereoselectively to give the alkenyl E isomers. The structure of (E)-[Fe{C(H)C(Me)Ph}(η-C₅H₅(dppm)] has been determined by an X-ray diffraction study. Nucleophilic additions to the unsubstituted complex (R¹ = R² = H) have also been examined.     

[Cu3(dppm)3(μ 3-I)2][(0.5TCNQ)], a radical salt derived from a donor with a copper(I) trimer

A radical salt 1, [Cu₃(dppm)₃(μ ₃-I)₂][(0.5TCNQ)], has been prepared by reaction of CuI, dppm (diphenylphosphinomethane) and TCNQ (7,7′,8,8′-tetracyanoquinodimethane) with a molar ratio of 1 : 1 : 0.5 and characterized by IR, UV–Vis and solid-emission spectroscopy. Its structure was determined by X-ray crystallography. 1 also has photoluminescence (λ _max = 653 nm) at room temperature. Magnetic properties indicate that TCNQ is in the reduced state (TCNQ^2?).     

簇合物[MoS4Cu4(dppm)4](NCS)2·4(CH3)2CHOH的合成与晶体结构

合成了一个五核簇合物[MoS4CU4(dppm)4](NCS)2·4(CH3)2CHOH,用单晶X-射线衍射方法测得该晶体属于单斜晶系,空间群P21/a,晶胞参数a＝2.0536(2),b＝1.8095(2),c＝3.1951(4)nm,β＝100.220(4)°,V＝11.6846(23)nm3,Z＝4,Dc＝1.349g/cm3,μ＝10.87cm-1,F(000)＝4896,R＝0.085,Rw＝0.089.其二价簇阳离子是一个MoS4单元被一个十六原子环[-Cu-P-C-P-]4包围在中心的"主客体"结构.     

膦桥双核银配合物[Ag(dppm)NO3]2的合成与结构

[Ag(dppm)NO3]2晶体属单斜晶系, 空间群Cc。单胞参数: a=1.2704(1),b=1.7028(2), c=2.2634(5)nm; β=100.66(1)°; Z=4; V=4.8117nm^3; Dc=1.530g·cm^-^3。两个双齿膦配体dppm连续两个银离子形成一个扭曲八元环。Ag-Ag间距离为0.3089nm, 硝酸根以不对称配位方式与银离子配位, 结构测定的最后偏离因子R=0.050。     

Gold(I) Pyrazolate Clusters: The Structure and Luminescence of the Tetranuclear, Base-Stabilized [(dppm)2Au4(3,5-Ph2Pz)2](NO3)2 ⋅ H2O

The tetranuclear Au(I) pyrazolate complex, [(dppm)₂Au₄(3,5-Ph₂Pz)₂](NO₃)₂  H₂O, 1, has been synthesized and structurally characterized. It is the first tetranuclear pyrazolate of Au(I) to have been found, although the trinuclear pyrazolates of Au(I) are well known. Complex 1 exhibits luminescence at 77 K when excited at 333 nm with an emission maximum at 454 nm. The emission has been assigned to ligand to metal charge transfer, LMCT, based upon the vibronic structure that is observed. The complex crystallizes in the monoclinic space group P2₁/c, with a=19.33(3) Å, b=20.26(3) Å, c=19.80(3) Å, =106.74(2)°, V=7425(17) ų, Z=8, and R=0.058. The Au    Au distances are Au(1)    Au(4)=3.185(3) Å, Au(1)    Au(2)=3.230(3) Å, Au(2)    Au(3)=3.079(3) Å, and Au(3)    Au(4)=3.280(3) Å.     

Density functional study of S(N) 2 substitution reactions for CH(3) Cl + CX(1) X(2•-) (X(1) X(2) = HH, HF, HCl, HBr, HI, FF, ClCl, BrBr, and II)

A systematic investigation on the S_N2 displacement reactions of nine carbene radical anions toward the substrate CH₃Cl has been theoretically carried out using the popular density functional theory functional BHandHLYP level with different basis sets 6‐31+G (d, p)/relativistic effective core potential (RECP), 6‐311++G (d, p)/RECP, and aug‐cc‐pVTZ/RECP. The studied models are CX¹X^2?? + CH₃Cl → X²X¹CH₃C^? + Cl^?, with CX¹X^2?? = CH₂^??, CHF^??, CHCl^??, CHBr^??, CHI^??, CF₂^??, CCl₂^??, CBr₂^??, and CI₂^??. The main results are proposed as follows: (a) Based on natural bond orbital (NBO), proton affinity (PA), and ionization energy (IE) analysis, reactant CH₂^?? should be a strongest base among the anion‐containing species (CX¹X^2??) and so more favorable nucleophile. (b) Regardless of frontside attacking pathway or backside one, the S_N2 reaction starts at an identical precomplex whose formation with no barrier. (c) The back‐S_N2 pathway is much more preferred than the front‐S_N2 one in terms of the energy gaps [ΔE(front)?ΔE(back)], steric demand, NBO population analysis. Thus, the back‐S_N2 reaction was discussed in detail. On the one hand, based on the energy barriers (ΔE and ΔE) analysis, we have strongly affirmed that the stabilization of back attacking transition states (b‐TSs) presents increase in the order: b‐TS‐CI₂ < b‐TS‐CBr₂ < b‐TS‐CCl₂ < b‐TS‐CHI < b‐TS‐CHBr < b‐TS‐CHCl < b‐TS‐CF₂ < b‐TS‐CHF < b‐TS‐CH₂. On the other hand, depended on discussions of the correlations of ΔE with influence factors (PA, IE, bond order, and ΔE), we have explored how and to what extent they affect the reactions. Moreover, we have predicted that the less size of substitution (α‐atom) required for the gas‐phase reaction with α‐nucleophile is related to the α‐effect and estimated that the reaction with the stronger PA nucleophile, holding the lighter substituted atom, corresponds to the greater exothermicity given out from reactants to products. © 2012 Wiley Periodicals, Inc. J Comput Chem, 2012     

Synthesis and Crystal Structure of a Heterotrinuclear Compound [PdCu2(tdt)((μ-dppm)2(MeCN)4]-(ClO4)2·2/3H2O (tdt = 3,4-Toluenedithiolate,dppm = Bis(diphenylphosphino)methane)

The heterotrinuclear compound [PdCu2(tdt)((-dppm)2(MeCN)4](ClO4)2(2/3H2O 1 (tdt = 3,4-toluenedithiolate, dppm = bis(diphenylphosphino)methane) has been prepared and characterized by X-ray structural analysis. Compound 1 crystallizes in trigonal system, space group R3c with a = b = 34.4275(3), c = 32.6700(5) (A), V = 33534.4(7) (A)3, Mr = 1527.21, Z = 18, Dc = 1.361 g/cm3, F(000) = 13974, μ(MoKα) = 1.069 mm-1, the final R = 0.0703 and wR = 0.1389 for 8375 observed reflections with I>2σ(I). The dithiolate tdt displays a chelating and bridging coordination mode, which chelates a PdII and bridges two Cu Ⅰ atoms. The PdⅡ center is located in an approximate square-planar environment with S2P2 donors, and each CuⅠ center exhibits a tetrahedral geometry.     

Total synthesis of (±)-maistemonine, (±)-stemonamide, and (±)-isomaistemonine

A full account of the total synthesis of (±)-maistemonine, (±)-stemonamide, and (±)-isomaistemonine is presented. Two approaches have been developed to construct the basic pyrrolo[1,2-a]azepine core of the Stemona alkaloids, featuring a tandem semipinacol/Schmidt rearrangement of a secondary azide and a highly stereoselectively desymmetrizing intramolecular Schmidt reaction, respectively. To build the common spiro-γ-butyrolactone, a new protocol was carried out by utilizing an intramolecular ketone-ester condensation as the key transformation. The vicinal butyrolactone moiety of (±)-maistemonine was stereoselectively introduced via a one-pot procedure involving the epimerization at C-3 and carbonyl allylation/lactonization. Moreover, (±)-stemonamide was divergently synthesized from a common intermediate, and (±)-isomaistemonine was obtained via the epimerization of (±)-maistemonine at C-12.     

Ion-Exchange Processes M(II) → Fe(III) and Fe(III) → M(II) in Metal Hexacyanoferrate(II) Gelatin-Immobilized Matrices (M = Mn,Co, Ni,Cu, Zn,Cd)

Ion-exchange reactions M²⁺ Fe³⁺ and Fe³⁺ M²⁺ (M = Mn, Co, Ni, Cu, Zn, Cd) were studied in metal(II) hexacyanoferrate(II) gelatin-immobilized matrices M₂[Fe(CN)₆] in contact with aqueous FeCl₃ solutions and Fe₄[Fe(CN)₆]₃ in contact with aqueous MCl₂ solutions. It was shown that in both cases, M²⁺ was replaced by Fe³⁺ and Fe³⁺ was replaced by M²⁺ to some extent, but no complete replacement was observed in the M₂[Fe(CN)₆]–FeCl₃ or Fe₄[Fe(CN)₆]₃–MCl₂ systems under study. No electrophilic substitution Fe³⁺ Mn²⁺ was found to occur in any noticeable degree during the contact of Fe₄[Fe(CN)₆]₃ with aqueous MnCl₂ solutions even when this contact occurred for 1 h and longer.     

Synthesis and Crystal Structure of a Heterotrinuclear Compound [PdCu_2(tdt)(μ-dppm)_2(MeCN)_4]-(ClO_4)_2·2/3H_2O (tdt = 3,4-Toluenedithiolate, dppm =Bis(diphenylphosphino)methane)

1 INTRODUCTION Great attention has been attracted to design novel heterometallic molecular materials with phosphorus- and sulfur-containing ligands, owing to their abundant optical and opto-electronic properties[1～4]. Self-assembly is an efficient ap- proach to obtain heterometallic assembly by the Incorporation of two different metal components[5, 6]. We are interested in investigating the reaction between Pd(diimine)(dithiolate) and metal dip- hosphine Cu2(μ-dppm)2(MeCN)42 , the fo…     

Synthesis, Crystal Structure and Luminescence Property of [Ag_2(dppm)_2(NMP)_2](SbF_6)_2·4H_2O·3CH_2Cl_2

1 INTRODUCTION cited state by the intense spin-obital coupling of Ag?, and the energy gap between triplet excited state and The study of photoluminescent properties of d10 singlet ground state is very small, which causes lu- metal complexes has been receiving current atten- minescence quenching of Ag? complex[15, 16 ] . tion. A number of polynuclear complexes of Au, Ag, In this paper, we report the synthesis and struc- and Cu containing bridging phosphine ligands have tural characterizat…