Ji-Cheng Shi

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.

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.

A novel network of bis(2-mercapto-3-pyridinol)oxovanadium(IV)_ based on hydrogenbond interactions: synthesis, structure and EPR spectroscopic properties

Abstract Reaction of VCl3 with 2-mercapto-3-pyridinol (H2mpp) in the presence of CH3ONa yields (VO(Hmpp)2 · CH3CN (1). The coordination geometry around the vanadium is square pyramidal, with a VO double bond of 1.602(6) A and average VS and VO distances of 2.392 and 1.943 A, respectively. The mpp ligands behave as the thione tautomer with the N atoms prontonated rather than the thiol alternative form. The intermolecular hydrogen bonding interactions between the protonated N atoms and the terminal O or the coordinated O atoms of mpp ligands result in an infinite two-dimensional network of VO(Hmpp)2. Complex (1) has been characterized by infrared, and EPR spectroscopic studies.

Chiral phosphine ligands derived from sugars.: 15. Synthesis, structure and spectroscopic studies of platinum(II) complexes with chiral phosphine substituted carbohydrate ligands

Abstract The reactions of chiral P,O-bidentate methyl 4,6-O-benzylidene-n-deoxyl-n-(diphenylphosphino)-α- d -altropyranoside (n-Hmbpa, n=2, 3) with [PtCl2(NCMe)2] gave the complexes trans-[PtCl2(n-Hmbpa)2] (1a: n=2; 1b: n=3). Treating the complexes 1a and 1b with NEt3 or NaOMe, only the corresponding mono(alkoxo)platinum(II) complex trans-[PtCl(3-mbpa)(3-Hmbpa)] (2b) can be isolated and characterized. The molecular structure of 1b has been determined by X-ray analysis and shows the pyrano-ring of the ligand 3-Hmbpa in a slightly distorted chair conformation. As the oxygen donor coordinating to the Pt(II) center to form the five-membered P:O chelating alkoxoplatinum(II) complex 2b, the pyrano-ring of the ligand 3-mbpa results in a boat conformation suggested by the NMR spectra.

CHIRAL PHOSPHINE LIGANDS DERIVED FROM SUGARS. 8. SYNTHESES OF GOLD(I) COMPLEXES CONTAINING CHIRAL SUGAR PHOSPHINES AND PYRIDINE-1-OXIDE-2-THIOLATE

Abstract Gold(I) compounds [Au(n-MBPA)(2-mpoS)] (2-mpoS=pyridine-1-oxide-2-thiolate; 1, n=2; 2, n=3) with a chiral phosphine derived from glucose (n-MBPA=methyl 4,6-O-benzylidene-n-deoxy-n-(diphenylphosphino)-α-D-altropyranoside, n=2, 3) have been prepared and characterized by 1H, 13C and 31P NMR and molecular vibration spectroscopy. The spectroscopic data suggest a monodentate mode of coordination for 2-mpoS ligand through the S donor.

Self-assembly of a chiral phosphinegold(I) building blockinto a two-dimensional netsheet based on a hydrogen bond between oneCl- anion and three hydroxy groups, co-ordination andaurophilicity interactions†

The trigold(I) complex [{Au(mbpa)} 3 S]Cl 2 [mbpa = methyl 4,6-O-benzylidene-3-deoxy-3-(diphenylphosphino)-α- D-altropyranoside] has been obtained from the compound [Au(mpba)Cl] 1 and L-cysteine. Complex 2 crystallizes in space group P6 6 with a = 15.165(2), c = 18.897(3) A and Z = 2, R = 0.030, R′ = 0.050. The crystal structure shows that the Au 3 S core is a perfect trigonal pyramid with angles Au–S–Au and P–Au–S of 88.7 and 179.6°, respectively, and that the chiral building blocks [{Au(mpba)} 3 S] + assemble through triple hydrogen bonding between one hydrogen-bond acceptor, Cl - , and three hydrogen-bond donors [Cl · · · O(2) 3.017(10) A], and form infinite two-dimensional netsheets. The netsheets align in the same direction. A relativistic interaction of the d 10 closed shell of gold(I) was revealed by NMR studies. Complex 2 displays a strong bright white emission at 495 nm when excited at 303 nm at room temperature, where the lowest-energy transition is of metal-to-ligand charge-transfer (Au→S) type.

A titanium(IV) dimer complex containing tris(2-mercaptophenolato)titanium(IV) fragments linked by sodium ions Synthesis, structure and characterization of (Et4N)(2) Ti(mp)(3)Na(MeOH)(2) (2) (H(2)mp = 2-mercaptophenol)

Abstract The dimeric complex (Et4N)2[Ti(mp)3Na(MeOH)2]2 (1) was prepared by reaction of Cp2TiCl2, —(H2mp = 2-mercaptophenol) and CH3ONa in methanol and structurally characterized by X-ray diffraction methods. The compound crystallizes in the monoclinic space group P21lc with a = 12.425(6), b = 17.404(4), c= 18.256(7) A, (β = 126.00(5)°, V= 3193.6 A3, and Z = 2. The stnructure was refined to R (RK) = 0.050 (0.064) for 3701 reflections (I>3σ;(7)). The anion contains two [Ti(mp)2]2- fragments linked by sodium ions through the μ2-O and μ3-O bridges to form a Ti2Na2O6 core which can be interpreted as two comer-voided oxocubane-like TiNa2O4 subunits sharing the Na2O2 face. The structure of the symmetric heterometallic tetranuclear [Ti(mp)3Na(MeOH)2]2 2-anion possesses a crystallographic inversion centre. Each Ti(IV) atom in a distorted octahedral coordination geometry is chelated by three mp ligands with StOb-D and StOb-T coordination modes. Complex (1) was also investigated by infrared, electronic, 1H NMR and ...

CHIRAL PHOSPHINE LIGANDS DERIVED FROM SUGARS-6. SYNTHESES AND SPECTROSCOPIC STUDIES ON RHODIUM COMPLEXES WITH A NEW TYPE OF CHIRAL PHOSPHINES

Abstract Methyl 4,6- O -benzylidene-3-deoxy-3-(diphenylphosphino)-α-D-altropyranoside (1) and methyl 4,6- O -benzylidene-2-deoxy-2-(diphenylphosphino)-α-D-altropyranoside (bd2) were prepared from methyl 2,3-anhydro-4,6- O -benzylidene-α-D-mannopyranoside and methyl 2,3-anhydro-4,6- O -benzylidene-α-D-allopyranoside, respectively, via regioselective and stereospecific ring-opening reactions in high yields. Ligands 1 and 2 reacted with [{Rh(CO) 2 Cl} 2 ] to give trans -[(P′) 2 Rh(CO)Cl] (3, P′ = 1 ; 4, P′ = 2). Compounds 1–4 have been characterized by elemental analyses, multinuclear NMR, IR and Raman, mass spectroscopic investigations. Copyright

Chelate-stabilized alkoxopalladium(II) complexes with chiral phosphine-substituted carbohydrate ligands

The reactions of chiral P,O-bidentate methyl 4,6-O-benzylidene-2-deoxy-2-(diphenylphosphino)-α-D-altropyranoside (HL1) and methyl 4,6-O-benzylidene-3-deoxy-3-(diphenylphosphino)-α-D-altropyranoside (HL2) with [PdCl2(cod)](cod = cycloocta-1,5-diene) or [PdCl2(NCMe)2] gave the complexes trans-[PdCl2(HL)2](L = L11a or L21b). Complex 1b crystallizes in the tetragonal space group P41212, with a= 12.326(2), c= 32.649(8)A and Z= 4, R= 0.023 for 2502 reflections having I 3σ(I). The large deviation (14.6°) of the angle P–Pd–P′ from 180° may be ascribed to the overcrowding of the bulky phosphine ligands. Treatments of 1a and 1b with NaOMe in methanol gave the corresponding bis(alkoxo) complexes cis-[PdL2]2a and 2b. The compounds have been characterized by infrared, Raman, 1H, 13C and 31P NMR spectroscopy. The Pd–O absorption appears at 388 cm–1 for 2a and 366 cm–1 for 2b. The cis and trans geometries have been assigned by Raman spectroscopic studies.