Stable gold(iii) complexes with thiosemicarbazone derivatives

Journal of Organometallic Chemistry, 1997

The reaction of [AuCl(L)] (L = AsPh3 or PPh3) with Mg(CH2SiMe3)Cl gives the neutral complexes [Au(CH2SiMe3)L] [L = ASPh3 (1) or PPh3 (2)]. Complex 1 undergoes substitution reactions with monodentate ligands to afford mononuclear complexes [Au(CH2SiMe3)PPh3] or [Au(CH2SiMe3)L′]ClO4 [L′ = PPh2CH2PPh2Me (3) or PPh2CH2PPh2CH2C6F5 (4)]. If a potentially bidentate ligand is used, the latter reaction gives mononuclear or dinuclear complexes, [Au(CH2SiMe3)dppe] (dppe = PPh2CH2CH2PPh2) (5) or [(Me3SiCH2)Au(L-L)Au(CH2SiMe3)] [L-L = dppm (6) or dppe (7)] (dppm = PPh2CH2PPh2), depending on the molar ratio. The structure of [Au(CH2SiMe3)PPh2CH2PPh2Me]ClO4 has been established by an X-ray diffraction study.

Chemical Communications, 2006

Inorganic Chemistry, 1984

angle (1 16O in la,b; 109.3' in 9) accompanying Ir-Ir bond formation to force the N atoms somewhat toward tetrahedral geometry. Intramolecular contacts are significant (-3.2 A) Registry No. la, . Supplementary Material Available: Listings of thermal parameters, anisotropic and isotropic temperature factors, least-squares planes, bond lengths and bond angles, and observed and calculated structure factors for compounds la, lb, and 9 (51 pages). Ordering information is given on any current masthead page. A series of heterotrimetallic Au(1) anionic complexes of the general formula [M'-Au-M']-with M' = Mn(CO)5 (l), CO(CO)~ (2), Cr(CO)$p (3), M o ( C O )~C~ (4), W(CO)$p (5), and Fe(CO)&p (6) have been prepared and characterized. The linear coordination about the gold atom is evidenced by infrared spectroscopy, particularly in the metal-metal stretching region where a strong absorption between 150 and 200 cm-I is typical for the v,,(Au-M') vibration. The corresponding approximate force constants are compared with those of other related linear trimetallic complexes. It is found that metal-metal bond strength increases in the M'-M-M' systems in the following sequence of M = Pd < Pt < Au < Hg. The same trend is observed for the covalency of these complexes as deduced from their u(C0) frequencies. The molecular structure of [n-Bu4N] [Au[Cr(CO),Cplz] (3) has been determined by X-ray diffraction: P 2 , / c with a = 11 10.6 (6) pm, b = 1690.5 (14) pm, c = 2209.2 (8) pm, p = 122.46 (3)O, and Z = 4. The complex anion has approximate C, symmetry. The Cr(l)-Au-Cr angle is 162.2 (3)', and the Au-Cr distances are 264.1 (9) and 263.5 (8) pm. The coordination about the Cr atoms is of the "four-legged piano-stool" type. The 1 9 7 A~ Mossbauer parameters of 1,4, and 6 have been measured and are compared with those obtained for AuC12-and Ad,. Considering the linearity of these molecules, the IS and QS values are consistent with complexes in which the Au(1) center has a sp, hybridization. They furthermore confirm the bonding scheme deduced from infrared spectroscopy, in which u bonding between the metals is predominant and x effects will arise from x donation into the gold 6p, and 6py orbitals. Braunstein, P.; Keller, E.; Vahrenkamp, H. J . Organomet. Chem. 1979, 165, 233. (a) Bender, R.; Braunstein, P.; Jud, J. M.; Dusausoy, Y. Inorg. Chem. 1983, 22, 3394. (b) Ibid., in press. Braunstein, P.; Matt, D.; Bars, 0.; Grandjean, D. Angew. Chem., Inz. Ed. Engl. 1979, 18, 797. Fusi, A,; Ugo, R.; Psaro, R.; Braunstein, P.; Dehand, J. Plenum Press: New York, 1969; p 31 1 . Braunstein, P. Thbe de Doctorat t s Sciences Physiques, Universite Louis Pasteur, Strasbourg, 1974; Archives CNRS A 0 10.814. Braunstein, P.; Dehand, J.

Dalton Transactions, 2009

The reaction of pyridil bis{3-hexamethylene-iminylthiosemicarbazone} (H 2 Plhexim) with dichloro[2-(dimethylaminomethyl)phenyl-C 1 ,N]-gold(III) ([Au(damp-C 1 ,N)Cl 2 ]) led to the isolation of the complexes [Au 2 (H 2 Plhexim)(Hdamp-C 1) 2 Cl 4 ]Cl 2 •2H 2 O (1) and [Au(H 2 Plhexim)] 2 Cl 2 •S 8 •6H 2 O (2). The spectroscopic data for 1 suggests that the bisthiosemicarbazone is coordinated to two different Au(III) atoms through the sulfur atoms. The fourfold coordination of the gold atoms is completed by one protonated Hdamp ligand, with the corresponding cleavage of an Au-N bond, and by two chloro ligands. The coordination mode and structure has been rationalized by means of DFT calculations. The crystal structure of 2 shows the neutral bisthiosemicarbazone coordinated through the sulfur atoms in a linear S-Au-S geometry. Gold-gold interactions are not observed and this is due to the steric hindrance of the bulky groups present in the ligand, which prevent the approach of two neighboring gold atoms. During the reaction, the reduction of Au(III) to Au(I) takes place with the bisthiosemicarbazone oxidized to the elemental sulfur, S 8 , which is present in the complex. (H 2 O) 12 clusters are also located in the void spaces. The in vitro antitumor activity against the HeLa-299 cell line was also investigated. The IC 50 values are slightly higher than that of cisplatin. In comparison to the value for cisplatin, the maximum antiproliferative activity is higher in the Au(I) complex and similar in Au(III) complex, thus, the Au(I) complex exhibits greater activity against the human cervix carcinoma cell line.

Journal of Organometallic Chemistry, 1997

The reaction of [AuCI(L)] (L = AsPh 3 or PPh 3) with Mg(CH2SiMe3)CI gives the neutral complexes [Au(CHeSiMe 0L] [L = ASPh 3 (1) or PPh 3 (2)]. Complex 1 undergoes substitution reactions with monodentate ligands to afford mononuclear complexes [Au(CH2SiMe3)PPh3] or [Au(CH2SiMe3)U]C104 [L' = PPh2CH2PPh2Me (3) or PPh2CH2PPh2CH2C6F5 ]. If a potentially bidentate ligand is used, the latter reaction gives mononuclear or dinuclear complexes, [Au(CH2SiMe3)dppe] (dppe = PPh2CH2CH?PPh 2) (5) or [(Me3SiCH2)Au(L-L)Au(CH2SiMe3)] [L-L = dppm (6) or dppe ] (dppm = PPh2CH2PPh2), depending on the molar ratio. The structure of [Au(CH~SiMe3)PPh,CH.PPh2Me]CIO4 has been established by an X-ray diffraction study. © 1997 Elsevier Science S.A.

Inorganic Chemistry, 2000

It has been found that several trinuclear complexes of Au I interact with silver and thallium salts to intercalate Ag + and Tl + cations, thereby forming chains. The resulting sandwich clusters center the cations between the planar trinuclear moieties producing structures in which six Au I atoms interact with each cation in a distorted trigonal prismatic coordination. The resultant (B 3 AB 3 B 3 AB 3 ) ∞ pattern of metal atoms also shows short (∼3.0 Å) aurophilic interactions between BAB molecular centers. These compounds display a strong visible luminescence, under UV excitation, which is sensitive to temperature and the metal ion interacting with the gold. X-ray crystal structures are reported for Ag([Au(µ-C 2 ,N 3 -bzim)] 3 ) 2 BF 4 ‚CH 2 Cl 2 (P1, Z ) 2, a ) 14.4505 Å; b ) 15.098(2)Å; c ) 15.957(1)Å; R ) 106.189(3)°; ) 103.551(5)°; γ ) 101.310(5)°); Tl([Au(µ-C 2 ,N 3 -bzim)] 3 ) 2 PF 6 ‚0.5C 4 H 8 O (P1, Z ) 2, a ) 15.2093(1)Å; b )15.3931(4)Å; c ) 16.1599(4)Å; R ) 106.018(1)°; ) 101.585(2)°; γ)102.068(2)°); and Tl([Au(µ-C(OEt)dNC 6 H 4 CH 3 )] 3 ) 2 PF 6 ‚C 4 H 8 O (P2(1)/n, Z ) 4, a ) 16.4136(3)Å; b ) 27.6277(4)Å; c ) 16.7182(1)Å; ) 105.644 °). Each compound shows that the intercalated cation, Ag + or Tl + , coordinates to a distorted trigonal prism of six Au I atoms. The counteranions reside well apart from the cations between the cluster chains.

2003

A square-planar [AuL 2 ] + gold (III) complex (L 2 = 6.13-dichloro-5,7,12,14-tetramethyl-1,4,8,11-tetraaza-4,6,11,13-tetraenato(2-)) containing two chlorine atoms in the β-position of the ligand hexacyclic ring was first synthesized by the reaction of a tetraiminate complex of [AuL 1 ] + (L 1 = 5,7,12,14-tetramethyl-1,4,8,11-tetraaza-4,6,11,13-tetraenato(2-)) with HAuCl 4 in an acetone-DMFA solution. The complex was isolated in the form of dichloroaurite (I), perchlorate (II), and tetrachloroaurate (III). Compounds I-III were studied by elemental and X-ray diffraction analyses and IR and NMR spectroscopies. Single crystals of [AuL 2 ]ClO 4 were obtained, and its crystal structure was determined from X-ray diffraction patterns. The crystals are monoclinic: a = 10.147(2)Å, b = 7.260(1)Å, c = 12.519(2)Å, β = 96.70(1) • , V = 915.9(3)Å 3 , Z = 2, space group P 2/c, d calc = 2.218, d meas = 2.209 g/cm 3. The crystal structure is built from nearly planar [Au(C 14 H 20 N 4 Cl 2)] + cations and [ClO 4 ] − anions. Introduction of chlorine atoms into the β-positions of the hexacyclic rings of the tetraazamacrocycle hardly changes the lengths of the delocalized C. .. N and C. . .

Zeitschrift für Naturforschung B, 2009

The P∩N-ligands Ph2Pqn, 1, Ph2 Piqn, 2, Ph2 Ppym, 3, and the As∩N-ligands Ph2Asqn, 4, Ph2Asiqn, 5, (Ph = phenyl, qn = 8-quinoline, iqn = 1-isoquinoline, pym = 2-pyrimidine) have been synthesized, the ligands 2 and 5 for the first time. Their ligand properties were probed by the synthesis of gold(I) complexes. Reaction with (tht)AuCl (tht = tetrahydrothiophene) yielded the chlorogold complexes Ph2RP-Au-Cl (R = qn, 6; iqn, 7; pym, 8) and Ph2RAs-Au-Cl (R = qn, 9; iqn, 10) in high yields. Further treatment of 7 and 8 with one equivalent of AgBF4 provided the complexes [(Ph2Piqn)Au]BF4, 11, [(Ph2Ppym)Au]BF4, 12, and [(Ph2Piqn)Au(tht)]BF4, 14. For comparison, the previously reported complex [(Ph2Ppy)Au]BF4 (py = pyridine), 13, was re-investigated. The compounds were characterized by elemental analyses, mass spectrometry and NMR spectroscopy. In addition, the solid-state structures of 2, 3, 6, 7, 9 - 14 have been determined by X-ray crystallography. The chloro-gold compounds crystallize in...

Crystal Growth & Design, 2012

Reaction of the thiosemicarbazone ligands 2-pyridineformamide thiosemicarbazone (HAm4DH) or 2-pyridineformamide 3-hexamethyleneiminylthiosemicarbazone (HAm4hexim) with the gold(I) compound [AuCl(tdg)] (tdg = thiodiglycol = 2,2′-thiodiethanol) gives the complexes [Au(H 2 Am4DH) 2 ]Cl 3 ·H 2 O (1) and [Au(HAm4hexim) 2 ]Cl (2). The room temperature oxidation of solutions of 2 in water/methanol leads to the crystallization of a gold(III) complex of formula [Au(Am4hexim)Cl]Cl·2H 2 O (3). Single-crystal X-ray diffraction analysis revealed that in compounds 1 and 2 gold(I) is linearly coordinated to sulfur atoms from two monodentate thiosemicarbazone molecules. Packing architectures and hydrogen bonding networks obtained using graph set notations are discussed for all complexes. Weak agostic interactions exist in both 1 [(N−H)···Au; H···Au = 2.70 and 2.82 Å] and 2 [(C−H)···Au; H···Au = 2.79 Å], and gold−gold contacts are present in the solid state in 1 (Au···Au = 3.83 Å) but not in 2 (Au···Au = 5.46 Å). The fluorescence of the ligands and complexes of gold(I) was studied. In addition, elemental analysis data and spectroscopic properties in the solid state and in solution are also described for complexes 1 and 2.

A polynomial function is a type of mathematical function that is built from variables (usually denoted as "x") and constants, combined using addition, subtraction, and multiplication, but not division by a variable.