Daxu Wu

Syntheses and electrochemistry of some transition metal complexes with 2-mercaptopyridine N-oxide and crystal structure of bis(2-mercaptopyridine N-oxide)nickel(II)

Abstract The complexes M(mpo)n (M = Mn, Ni, n = 2; M = Fe, Co, n = 3) (Hmpo = 2-mercaptopyridine N-oxide) were prepared by reacting the appropriate metal chloride with either Nampo or dtpo [2,2-dithiobis(pyridine N-oxide)] in the presence of sodium methoxide. The structure of the complex Ni(mpo)2 was determined by X-ray diffraction. The nickel atom is in a square planar environment of two mpo− ligands in the cis configuration. The four complexes were investigated by physicochemical methods especially by 1H NMR spectroscopy and cyclic voltammetry.

Syntheses, structures and spectroscopic properties of [Ag(dppm)(O2CCH2Ph)]2 and [Ag2(dppm)3](NO3)2·3H2O

The reaction of [Ag(dppm)(NO 3 ] 2 with sodium phenylacetate and dppm in THF at room temperature gave rise to the silver complexes [Ag(dppm)(O 2 CCH 2 Ph)] 2 ( 1 ) and [Ag 2 (dppm) 3 ](NO 3 ) 2 ( 2 ), respectively. Their crystal structures have been determined by single crystal X-ray diffraction analysis. Complex 1 is binuclear with a silver-silver separation of 3.080 A and bridged by two dppm ligands. The cation in complex 2 possesses a Ag 2 P 6 core with AgAg distance of 2.987 A and the silver atoms are each coordinated by three phosphorus atoms in an ideal trigonal-planar environment. Their IR, Raman, 1 H and 31 P NMR spectroscopic properties are also reported.

Palladium complexes with simultaneous O:S coordination, syntheses, structures and characterization of complexes with 2-mercaptophenol or 2-mercaptopyridine N-oxide

Abstract Complexes (Et4N)2[Pd2(mp)2(Hmp)2] (1) and [Pd(mpo)2] (2) synthesized from the reactions of palladium chloride with 2-mercaptophenol (H2mp) and 2-mercatopyridine N-oxide (Hmpo) or 2,2′-dithiobis(pyridine N-oxide) (dtpo), respectively, have been characterized by X-ray diffraction analyses and studied by IR, Raman, 1H and 13C NMR, and EI-MS techniques. The palladium atoms in the two compounds are in square planar environments. The average PdO distances are 2.009 A and 2.043 A for 1 and 2, respectively. The results of EHMO calculations show that the PdO bonds are weaker than the PdS bonds in both compounds and large delocalized π bonds extend in the (mp)2Pd2S2 plane in 1 and in the Pd(mpo)2 plane in 2. The reaction of [Ni(mpo)2] with [Pd(COD)Cl2] led to the formation of 2 also, which implies that the bidentate O:S ligand mpo readily transfers from the NiII to the PdII ion.

A tetranuclear silver complex with dppm and i-mnt ligands. Synthesis and structural characterization of [Ag4(μ-dppm)4(μ4 i-mnt)2] · 0.5 DMF (i-mnt 2,2-dicyano-1,1-ethylenedithiopate; dppm bis(diphenylphosphino)methane)

Abstract The reaction of [Ag(dppm) (NO3)]2 (1) with potassim i-mnt  2,2-dicyano-1,1-ethylenediothiolate; dppm  bis (diphenylphosphino)methane) in DMF at room temperature gave rise to the complex [Ag4(μ-dppm)4(μ4-S2C=C(CN)2)2] (2). The crystal structure of 2 has been determined by single crystal X-ray diffraction analysis. 2 is a tetranuclear complex with a silver-silver separation of 3.376(2) A and the four silver atoms form a distorted square plane bridged by four dppm and two i-mnt ligands. Each silver atom is coordinated by two phosphorus and two sulfur atoms in a distorted tetrahedral environment. The IR, 1H and 31P NMR spectroscopic properties of 2 have also been investigated.

Cobalt complexes with pnicogen (phosphine or pyridine) and thiolato ligands. Syntheses, X-ray crystal structures and spectroscopic characterization

Abstract Mixed pnicogen and thiolato mononuclear cobalt complexes, Co(SR)2(PBun3)2 [R = Ph (1); R = Stolyl-p (2)] and Co(mpo)2L [L = PBun3 (3); L = Py (4)], have been synthesized and studied spectroscopically. The complexes 1 and 2 are tetrahedral, as determined by magnetic susceptibility studies. The structures of 3 and 4 were determined by X-ray diffraction. The cobalt(II) ions in both 3 and 4 are in a square-pyramidal environment with the two trans-oriented mpo ligands in the basal plane and the pnicogen group in the axial position.

Chiral phosphine ligands derived from sugars 10. Syntheses, structure, characterization, and antitumor activity of the gold(I) complexes with sugar-substructure phosphine ligands

Abstract Gold(I) complexes with sugar-substructure phosphine ligands [Au(n-MBPA)l][n-MBPA = methyl 4,6-O-benzylidene-n-deoxy-n-(diphenylphosphino)-α- d -altropyranoside, HL = I H-pyrimidine-2-thione (2-pymSH), 3,5-dimethyl-1 H-pyrimidine-2-thione (2-pymmSH). 1, n = 2, L = 2-pymS; 2, n = 3, L = 2-pymS; 3, n = 2, L = 2-pymmS; 4, n = 3, L = 2-pymmS]have been prepared and characterized by 1H, 13C and 31P NMR and molecular vibration spectra. Compound 2 crystallizes in the orthorhombic space group P212121, with a = 9.917(4), b = 14.418(6), c = 20.048(7) A, and Z = 4, R = 0.031 for 2493 reflections with I ≥ 3σ(I). The mononuclear compound features a linear geometry for the gold atom defined by important parameters: Au-P 2.256(3) A, Au-S 2.306(3) A and P-Au-S 178.5(1)°. The altropyranose ring in 2 exhibits a distorted chair conformation. The preliminary experiment reveals that the gold(I) complexes with sugar-substructure phosphine ligands possess antitumor activity against P388 leukemia.

The synthesis and crystal structures of the first species of monocubane type clusters [Mo3PbS4]6+ and [Mo3BiS4]7+

The synthesis and crystal structure of two heteronuclear transition metal-main group metal cubane-like cluster compounds [Mo 3 (PbI 3 )S 4 (dtp) 3 (py) 3 ] ( I ) and [Mo 3 (BiI 3 )S 4 (μ-OAc)(dtp) 3 ·(py)]·(CH 3 ) 2 CO( II ) (dtp=S 2 P(OC 2 H 5 ) 2 − ;OAc=(OOCCH 3 ) − ) are reported. They resulted from the reaction of trinuclear Mo 3 S 4 (dtp) 4 ·H 2 O with PbI 3 − and BiI 3 , respectively. Both of the molecular structures have an [Mo 3 MS 4 ] core (MPb, Bi) but their molecular configurations are different. The electron transfer of a lone pair electrons of M metals occurs in the additive clusters I and II , thus enhancing the MoMo bonding. Evidence for this is seen in the 95 Mo NMR spectrum before and after the addition reaction. Crystal data: I : triclinic, P l, a = 11.087(2), b = 12.760(5), c = 19.358(4), A, α = 94.37(3), β = 92.39(2), γ = 99.46(2)°, V = 2689(2), A 3 , Z = 2. Least-squares refinement of 4462 reflections gave a final agreement factor of R = 0.052 ( Rw = 0.058); II : triclinic, P l, a = 11.696(4), b = 13.044(4), c = 18.241(6), A, α = 74.90(3), β = 75.96(3), γ = 88.06(3)°, V = 2605(3)A 3 , Z = 2. Least-squares refinement of 5913 reflectioins gave a final agreement factor of R = 0.054 ( Rw = 0.061).

Syntheses and spectroscopic characterizations of the compounds containing univalent coinage metal and tetraselenomolybdate. Crystal structure of [MoSe4(AuPPh3)2]

Abstract From the reactions of [Et 4 N] 2 MoSe 4 and M(PPh 3 ) n L(M = Cu, Ag, Au: L = Cl, NO 3 : n = 1−2)in univalent comage metal and an MoSe 4 2 unit, [MoSe 4 (CuPPh 3 )PPh 3 ) 2 ] ( 1 ), [MoSe 4 (AgPPh 3 ) Ag(PPh 3 ) 2 ] ( 2 ), [MoSe 4 (Ag-PPh 3 ) 2 ] ( 3 ), [MoSe 4 (AuPPh 3 ) 2 ] ( 4 ), [MoSe 3 )Set(CuPPh 3 ) 3 Cl] ( 6 ), have been isolated and characterized by 93 Mo NMR, IR and Raman spctra. The 93 Mo chemical shifts are mainly dependent upon the shielding effects from the number of the coinage metal atoms around the Mo atom and the geometric structure of the molecule. The shielding order is Au > Cu > Ag. The crystal structure of 4 has been determined by X-ray single-crystal diffraction analysis. It crystallizes in the triclinic space group P -1 with cell constants a = 9.570(2), b = 10.755(2), c = 19.837(4) A : α = 89.59(3), β = 80.37(3), γ = 68.33(3)° and Z = 2 . The molecule has a linear structure with an average Mo distance of 2.846(2) A.

COPPER COMPLEXES DERIVED FROM 1-(2-CARBOXYBENZOYL)THIOSEMICARBAZIDE (H3L) : SYNTHESES, CHARACTERIZATION AND CRYSTAL STRUCTURE OF CU3L2(PY)6(HIM)(H2O)2

Abstract The reaction of CuCl2·2H2O with 1-(2-carboxybenzoyl)thiosemicarbazide (H3L) and imidazole (HIm) in NaOH gave a CuII complex, which was crystallized from pyridine (Py) to give complex 1, [Cu3L2(Py)6(HIm)](H2O)2. The complex molecule contains a linear Cu3 array in which the central copper atom at the crystallographic inversion centre has an octahedral environment and the other two Cu atoms are square pyramidal, each bridged to the central Cu atom via the L group, with the atoms O(1) and N(2) chelating to Cu(1), and the atoms N(1), S and O(2) to Cu(2). The carboxylate groups coordinate to the metal atoms in a unidentate fashion. Complex 2, [Cu2(H3L)2Cl2](H2O)3, obtained by the reaction of CuCl2·2H2O with H3L has been characterized by IR, UV, NMR (1H and 13C) spectra, and TGA and molar conductance measurements. The ESR and magnetic moment measurements show that the Cu atoms in complex 2 are in the Cu1 oxidation state.

Syntheses, reactions and spectroscopic properties of Mo(W)CuS cluster compounds, and crystal structure of (Et4N)4[WS4Cu10Br12]

The synthetic reactions and spectroscopic studies of molybdenum(tungsten)-copper-sulfur cluster compounds, which can be prepared by the stepwise or unit construction reactions through the successive addition of CuL (L = Cl, Br, R 2 dtc) across six edges or four faces of MS 4 (M = Mo, W) tetrahedra, are described. A series of Mo(W)CuS cluster compounds, (Et 4 N) 2 [MoCu 2 S 4 (S 2 CNEt 2 ) 2 ] ( 1 ) (Et 4 N) 2 - [MoCu 2 S 3 O(S 2 CNC 4 H 8 ) 2 ( 2 ), [MoCu 2 S 4 (dppe) 2 ] ( 3 ) (dppe = bis(diphenylphosphine ethane, (Et 4 N) 2 [MoCu 3 S 4 (S 2 CNEt 2 ) 3 ] ( 4 ), (Et 4 N) 2 [Mo 2 Cu 4 S 8 (S 2 CNEt 2 ) 2 ] ( 5 ), (Et 4 N) 2 [Mo 2 Cu 4 S 6 O 2 (S 2 CNC 4 H 8 ) 2 ] ( 6 ), [Mo 2 Cu 4 S 8 (dppm) 2 ] ( 7 ), [Mo 2 Cu 4 S 6 O 2 (dppm) 2 ] ( 8 ) (dppm = bis(diphenylphosphine)methane), (Et 4 N) 4 [MoS 4 Cu 10 Br 12 ] ( 9 ), (Et 4 N) 4 [WS 4 Cu 10 Br 12 ] ( 10 ), have been prepared and characterized by IR and 95 Mo NMR spectra. The polynuclear WCu cluster compound (Et 4 N) 4 [WS 4 Cu 10 Br 12 ] ( 10 ) is characterized by single crystal X-ray diffraction analysis. The anion structure consists of a central WS 4 moiety, an octahedral Cu 6 and a tetrahedral Cu 4 array. The average WCu and WS distances are 2.726(8) and 2.247(7) A and the average angles of SWS, SCuS and SCuBr are 109.5(3), 104.1(4) and 112.6(3)°, respectively.