Polar bonds in π-complexes. Preparation and crystal structures of cyclopentadienylcarbonyl iron(II) and ruthenium(II) benzoates andp-fluorobenzoates

Complexes of Fe(II) and Ru(II) of the general formula Cp(OC)₂MOC(O)C₆H₄X-p, where M=Fe, X=H, F (1, 2) or M=Ru, X=H, F (3, 4) have been prepared by reactingp-XC₆H₄COOAg with [CpFe(CO)₂]₂ or CpRu(CO)₂I. The crystal structures of complexes1–3 have been determined using X-ray diffraction. Compounds1 and3 are isomorphous. The COO group in1–3 is coordinated as a monodentate ligand. As the latter and the CO ligands are electronically non-equivalent, the coordination of the Cp ligand to the metal is slightly asymmetric.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 395–399, February, 1993.     

Dichlorobis(cycloalkylamine)platinum(II) complexes structure activity relationship on the human MDA-MB-231 breast cancer cell line

Summary The syntheses of dichlorobis(cycloalkylamine)platinum(II) complexes withcis andtrans cycloalkylamine ligands [cis-PtCl₂(C₃H₅NH₂)₂ tocis-PtCl₂(C₈H₁₅NH₂)₂ (3–8) andtrans-PtCl₂(C₇H₁₃NH₂)₂ (9) andtrans-PtCl₂(C₈H₁₅NH₂)₂ (10)] are described. The distinction betweencis andtrans isomers was achieved by¹H-NMR spectroscopy. The antitumor activity was determined on the cell proliferation of the human MDA-MB-231 breast cancer cell line during long-term drug exposure. The complexes with small cycloalkylamine ligands (3–6) were inferior, those with large cycloalkylamine ligands were comparable (7) or superior (8) to cisplatin. Surprisingly, thecis/trans isomers7/9 and8/10 were equally active. All cycloalkylamine ligands were inactive. IR-spectroscopic studies showed that the size of the cycloalkylamine ring does not lead to significant differences in the Pt-Cl binding strength. Therefore it is assumed that the markedly stronger antitumor activity of the higher homologues,7–10, is not the result of a faster reaction with bionucleophils such as DNA. A possible explanation of the high activity of7–10 is the strong lipophilicity of the complexes. This assumption was confirmed by toxicity tests against confluent cultures.In memory of Professor Dr. Günter Gliemann, late director of the Institut für Physikalische und Theoretische Chemie, Universität Regensburg.     

Preparation and characterization of Cu(II)-N-salicylideneanthranilic acids,their reduction products and hydrolysis of the Schiff base

Copper (II) complexes ofN-salicylideneanthranilic acid (I) and its derivatives (II, III) as well as their NaBH₄ reduction products, namelyN-(2-hydroxybenzyl) anthranilic acids (IV–VI) have been prepared and their structures have been determined analytically. Tetracoordinated planar structures of the Cu(II) complexes of the Schiff bases and distorted tetrahedral structures of the Cu(II) complexes of compoundsV–VI have been elucidated by ESR and other spectral methods. During the preparation of the complex the hydrolysis of the Schiff base often takes place in the presence of water giving anthranilates and salicylaldehydates of metals to some extent along with the complexes of the Schiff base. The kinetic data for the hydrolysis ofN-salicylideneanthranilic acid (I) in methanol-water solution also are reported.Presented at the Sixth International Seminar on Inclusion Compounds, Istanbul, Turkey, 27–31 August, 1995.     

Synthese und Reaktionsverhalten von 3-(Bis(alkylthio)methylen)-3H-isobenzofuran-1-on-und 2-(Bis(alkylthio)methylen)-3(2H)-benzofuranon-Derivaten

Summary 3(Bis(alkylthio)methylene)-3H-isobenzofuran-1-ones2a–e and 2-(bis(alkylthio)methylene)-3(2H)-benzofuranone derivatives4a–c are obtained by reaction of phthalides1a–d or 3(2H)-benzofuranone (coumaranone3), respectively, with carbon disulfide under basic conditions followed by alkylation. The reaction behaviour of the new compounds2 and4 is investigated. 2-((2-Dimethylthio-1-oxo)ethyl)benzoic acid N,N-dimethylamide (7a) and 2-((2-dimethylthio-1-oxo)ethyl)-benzoic acid 2-methylpiperidide (7b) are surprisingly formed instead of the methylthio substitution products by treatment of2a with the corresponding amine in the presence of aluminum chloride.

Herrn Professor Dr. Dr. h. c.Waldemar Adam zum 60. Geburtstag gewidmet     

Interaction of decacarbonyldimanganese and decacarbonyldirhenium with 1-aryl-3-cyanoprop-2-en-1-ones

The reactions of M₂(CO)₁₀ (M = Mn, Re) withtrans-1-aryl-3-cyanoprop-2-en-1-ones in the presence of Me₃NO proceed with replacement of the CO ligand and lead to complexeseq-(1-aryl-3-cyanoprop-2-en-1-on)nonacarbonyldimanganese andeq-(1-aryl-3-cyanoprop-2-en-1-on)nonacarbonyldirhenium complexes where the metals are bonded with the ligand through the nitrogen atom of the cyanogroup. The treatment of (1-phenyl-3-cyanoprop-2-en-1-on)nonacarbonyldirhenium with a second equivalent of the ligand resulted in the disubstituted complex,eq,eq-bis(1-phenyl-3-cyanoprop-2-en-1-on)octacarbonyldirhenium in a good yield. The structures of the obtained complexes are discussed on the basis of¹³C,¹H NMR, and IR-spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1485–1487, August, 1994.This work was supported in part by the Russian Foundation for Basic Research (grant No 93-03-4028).     

Darstellung und Charakterisierung von Halogeno(diethyldithiocarbamato) (triethyl- und triphenylphosphin)palladium(II)-Komplexen

The Complexes [Pd(PEt ₃)₂ dtc]X (1) and Pd(PR ₃)Xdtc (2, 3) (dtc=S₂CNEt ₃;X=Cl, Br, I;R=Et, Ph) have been prepared. Conductivity, susceptibility, UV and IR measurements show that the cations [Pd(PEt ₃)₂ dtc]⁺ of1 and the complexes2, 3 have square-planar structure.

     

Synthesis and thermal transformations of molecular complexes of bis[tris(trifluoromethyl)germyl]mercury(ii witho-quinones

Stable molecular complexes of bis[tris(trifluoromethyl)germyl]mercury(II) Hg[(CF₃)₃Ge]₂ (1) witho-quinones (3,6-di-tert-butylbenzoquinone-1,2 (2), 3,6-di-tert-butyl-4,5-dimethoxybenzoquinone-1,2 (3), and 1,4,5,7-tetra-tert-butyldibenzo[1,4]dioxin-2,3-dione (4)) have been synthesized and characterized by elemental analysis and IR and electronic absorption spectroscopies. Depending on the ratio between the starting reactants, the reactions ofo-quinones with1 gave complexes of the composition R₂Hg · Q (5,7,9) or R₂Hg · Q₂ (6,8,10), where Q=2 (5,6),3 (7,8),4 (9,10); R=Ge(CF₃)₃. According to the spectral data, the molecule ofo-quinone in R₂Hg · Q acts as a neutral ligand, whereas the second molecule ofo-quinone in R₂Hg · Q₂ is not coordinated to1. It has been found by ESR that thermolysis of polycrystalline samples of complexes6 and10 involves intermediate formation of radical pairs and finally yields paramagnetico-semiquinone complexes, SQGe(CF₃)₃, which are typical products of one-electron oxidation of Organometallic compounds byo-quinones.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1568–1573, August, 1995.The authors wish to thank M. A. Lopatin for his help in recording the electronic absorption spectra.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No. 93-03-18369).     

Preparation of samarimm(ii) sulfide by the reaction of samarium(II) bis[bis(trimethylsilyl)amide] with hydrogen sulfide

X-ray amorphous samarium(II) sulfide was prepared by the reaction of H₂S with samarium(II) bis[bis(trimethylsilyl)amide] (1) in THF at 10^–2 Torr. Compound1 was prepared by two methods: 1) the reaction of SmI₂ with lithium bis(trimethylsilyl)amide and 2) the reaction of samarium naphthalide with bis(trimethylsilyl)amine. SmS was transformed to the polycrystalline state with the lattice parametera = 5.92 Å by annealing at 400–500 °C.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 241–243, February, 1995.     

Ligational behaviour of thiosemicarbazide and thiosemicarbazone-(III): Tetragonal complexes of cobalt(II) derived from 4-benzylamidothiosemicarbazide and 1-(α-) furyl-4-benzylamidothiosemicarbazone

Zusammenfassung Es wurden eine Anzahl von neuen Kobalt(II)-Komplexen von 4-Benzylamidothiosemicarbazid (BTSC) und 1-(-)Furyl-4-benzylamidothiosemicarbazon (FBTS) von der allgemeinen Zusammensetzung CoL ₂ X ₂ (L=BTSC, FBTS;X=Cl, Br, I, NO₃ and NCS) synthetisiert. Die Untersuchugen erfolgten mittels Elementaranalyse, magnetischer Messungen, Elektronenanregungsspektroskopie und IR-Spektroskopie (einschließlich des fernen IR); aus diesen Messungen ließ sich eine im wesentlichen tetragonale Symmetrie für alle Komplexe dieser Reihe ableiten.

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Ligational behaviour of thiosemicarbazide and thiosemicarbazone-(III): Tetragonal complexes of cobalt(II) derived from 4-benzylamidothiosemicarbazide and 1-(-) furyl-4-benzylamidothiosemicarbazone

A number of new complexes of cobalt(II) have been prepared with 4-benzylamidothiosemicarbazide (BTSC) and 1-(-)furyl-4-benzylamidothiosemicarbazone (FBTS) which conform to the general formula CoL ₂ X ₂ (whereL=BTSC andFBTS andX=Cl, Br, I, NO₃ and NCS). These have been characterized by chemical analyses and physical measurements. The tetragonal symmetry has been proposed on the basis of electronic spectral studies for all these complexes. The explanation for the slightly lower magnetic moments for cobalt(II) complexes has been sought in the possible presence of low symmetry component. The tetragonal radial parametersDq(E),Dq(A),Dt andDs and molecular orbital parameters d and d have been evaluated. The S–N, bidentate nature of the ligands and the presence of the various anions in the coordination sphere have been confirmed on the basis of additional Co–N, Co–S and Co–X frequencies in the far infrared spectra of the complexes. The nitrato and thiocyanato groups act as monodentate and are coordinated through oxygen and nitrogen atoms, respectively.

     

(N-methyl-N-alkoxymethylaminomethyl)dialkoxysilanes and bis[N-methyl-N-(dialkoxysilylmethyl)amino]methanes

(N-methyl-N-alkoxymethylaminomethyl)-dialkoxysilanes and bis[N-methyl-N-(dialkoxymethyl)amino]methanes were first obtained by the interaction of (N-methylaminomethyl) dialkoxy-R-silanes with chloromethyl alkyl ethers in yields of 40–67% and 10–25 %, respectively.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 382–383, February, 1995.     

3,6-Di-tert-butyl-o-benzosemiquinone complexes of copper(1) with bidentate bis(diphenylphosphine) ligands. Synthesis, structures, and properties

New mononuclear 3,6-di-tert-butyl-o-benzosemiquinone complexes of copper(1) with bis(diphenylphosphine) ligands were synthesized: (DBSQ)Cu(dppe) (1) (DBSQ=3,6-di-tert-butyl-o-benzosemiquinone and dppe=1,2-bis(diphenylphosphino)ethane), (DBSQ)Cu(dppp) (2) (dppp=1,3-bis(diphenylphosphino)propane), (DBSQ)Cu(dppn) (3) (dppn=2,2′-bis(diphenylphosphino)-1,1′-binaphthyl), and (DBSQ)Cu(dppfc) (4) (dppfc=1,1′-bis(diphenylphosphino)ferrocene). The compositions and structures of complexes1–4 were characterized by elemental analysis and electronic absorption, IR, and ESR spectroscopy. The molecular structures of complexes3 and4 were established by X-ray diffraction analysis. The reactions of elimination and replacement of neutral ligands in the coordination sphere of the complexes were studied by ESR spectroscopy. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2333–2340, November, 1998.     

Benign synthesis of the unsymmetrical ligand N-(quinolin-8-yl)pyrazine-2-carboxamide. Preparation,electrochemistry, antibacterial activity,and crystal structures of Cu(II) and Zn(II) complexes

Hqpzc has been synthesized by a highly efficient procedure using the ionic liquid TBAB as an environmentally benign reaction medium. [Cu(qpzc)(OAc)]·H₂O (1) and [Zn(qpzc)(OAc)(H₂O)] (2), complexes of the deprotonated ligand, qpzc¯ [qpzc¯ = N-(quinolin-8-yl)pyrazine-2-carboxamide], have been synthesized and characterized by elemental analyses, spectroscopic methods, and X-ray crystallography. The coordination geometry around the metal ions in both complexes is distorted square pyramidal. The mono-anionic qpzc¯ is a tridentate unsymmetrical ligand furnishing an N3 set, occupying three of the four basal positions. Acetate is a bidentate ligand in 1 and unidentate in 2. The apical position in 2 is occupied by water. Quite strong O-H…O hydrogen bonds create columns of complexes [rod group p21(11)] in the copper complex, but in conjunction with π-π interactions, a 3D edifice in the zinc complex. The electrochemical behavior of the ligand and its copper and zinc complexes shows that the quinoline ring reduces at more positive potentials in these complexes relative to the free ligand. The in vitro antibacterial activities of these complexes were tested against Escherichia Coli and Staphylococcus Aureus.     

Zn(II), Cd(II) and Hg(II) complexes with 1-(p-methoxybenzyl)-2-(p-methoxyphenyl)benzimidazole: Syntheses, structures and luminescence

Five coordination compounds Zn(mbmpbi)₂Cl₂ (1), Zn(mbmpbi)₂Br₂ (2), Cd(mbmpbi)₂Cl₂ (3), Hg(mbmpbi)₂Cl₂ (4) and Hg(mbmpbi)₂Br₂ (5) were synthesized by the reaction of 1-(p-methoxybenzyl)-2-(p-methoxyphenyl)benzimidazole (mbmpbi) with the corresponding metal halides. The complexes have been characterized by elemental analysis, conductance measurements, FT-IR, ¹H NMR and photoluminescence spectral studies. The ligand mbmpbi exhibits the N-benzimidazole coordination. The structures of 3-5 have been determined by single crystal X-ray diffraction. These three complexes are isostructural, crystallizing in the monoclinic system, P2/n space group with a distorted tetrahedral geometry around the metal ion. Zn(II) and Cd(II) complexes show strong blue emission in solid state at room temperature.     

Syntheses of phenoxo-bridged Zn(II) and metallamacrocyclic Hg(II) complexes of organochalcogen (Se,Te) substituted Schiff-bases: structure and DNA-binding studies of Zn(II) complexes

The coordination of organochalcogen (especially Se and Te) substituted Schiff-bases L¹H, L²H, L³H, and L⁴H toward Zn(II) and Hg(II) has been studied. Reactions of these ligands with ZnCl₂ in 1?:?1 molar ratio gave binuclear complexes [{2-[PhX(CH₂) _n N?=?C(Ph)]-6-[PhCO]-4-MeC₆H₂O}₂Zn₂Cl₂] (where X?=?Se, n?=?2 (1); X?=?Se, n?=?3 (2); X?=?Te, n?=?2 (3); and X?=?Te, n?=?3 (4)) with partial hydrolytic cleavage of proligands. In these complexes, two partially hydrolyzed ligand fragments coordinate tridentate (NOO) with two Zn's. Reaction of HgBr₂ with L¹H and L²H in 1?:?1 molar ratio gave monometallic complexes [C₆H₂(4-Me)(OH)[2,6-{C(Ph)?=?N(CH₂) _n Se(Ph)}₂HgBr₂]] (n?=?2 (5) or 3 (6)) and under similar conditions with L³H and L⁴H gave bimetallic complexes [C₆H₂(4-Me)(OH)[2,6-{C(Ph)?=?N(CH₂) _n Te(Ph)}₂Hg₂Br₄]] (n?=?2?(7) or 3 (8)) in which the ligands coordinate with metal through selenium or tellurium, leaving the imino nitrogen and phenolic oxygen uncoordinated. The proligands L¹H, L²H give 14- or 16-membered metallamacrocycles through Se–Hg–Se linkages and L³H, L⁴H give 16- or 18-membered metallamacrocycles through Te–Hg–Br–Hg–Te linkages. All the complexes were characterized by elemental analyses, ESIMS, FTIR, multinuclear NMR, UV-Vis, and conductance measurements. The redox properties of the complexes were investigated by cyclic voltammetry (CV). Complexes 1–4 exhibited ligand-centered irreversible oxidation processes. Complexes 5 and 6 showed metal-centered quasi-reversible single electron transfer, whereas dinuclear complexes 7 and 8 displayed two quasi-reversible, one-electron transfer steps. A single-crystal X-ray structure determination of 1 showed that the coordination unit is centrosymmetric with Zn(II) in square-pyramidal coordination geometry and the two square pyramids sharing an edge. The Zn?···?Zn separation is 3.232?Å. The DNA-binding properties of 1 and 3 with calf thymus DNA were explored by a spectrophotometric method and CV.     

Syntheses based on (N,N-difluoroamino)dinitroacetonitrile

High reactivity of the nitrite group in (NN-difluoroamino)dinitroacetonitrile was demonstrated. Based on its reaction with HN₃, a new preparative method for the synthesis of 5-[(N,N-difluoroamino)dinitromethylltetrazole was developed; some derivatives of the latter compound have been obtained.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8. pp. 2056–2058, August, 1996.     

Crystalline β Modification of (BEDT-TTF)<Subscript>2</Subscript>Br<Subscript>0.12</Subscript>Cl<Subscript>1.88</Subscript>I

The structure of the crystalline β’ modification of a radical cation salt of bis(ethylenedithio)tetrathiafulvalene with mixed dihalogen iodide (BEDT-TTF)₂Br_0.12Cl_1.88I (I) was investigated by single crystal X-ray diffraction. Triclinic structure of I (space group , a = 6.638 Å, b = 9.779 Å, c = 12.920 Å; α = 87.24°, β = 79.10°, γ = 81.37°) was solved by direct methods and refined in a full-matrix anisotropic approximation to R = 0.030 using all 3897 measured independent reflections (CAD-4 automatic diffractometer, λMoK _α). In the crystal structure of I the mixed Cl*-I-Cl* anion occupies the inversion center i(000), its terminal atom having a composition Cl* = Cl_0.94Br_0.06. The semi-radical cation (C₁₀H₈S₈)^1/2+ has one of two ethylene groups disordered.Original Russian Text Copyright © 2004 by A. N. Chekhlov__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 5, pp. 960–965, September–October, 2004.     

Low-temperature X-ray study of benzoid-quinoid tautomerism in crystals of 2-(N,N-diphenylhydrazinoethylidene)-3(2H)-benzo[b]thiophenone

An X-ray investigation of 2-(N,N-diphenylhydrazinoethylidene)-3(2H)-benzo[b]thiophenone was performed at room and low (–80 °C) temperatures. It was established that the structure of this compound in the crystalline state at R-20 °C is intermediate between the ketoenehydrazine and hydroxyhydrazone forms, while at –80 °C the molecular structure is completely transformed to the hydroxyhydrazone form. This confirms the dynamic nature of hydrogen atom disordering in the molecule at 20 °C.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 104–106, January, 1995.This work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-04355).     

Concentration-controlled Zn(II) compounds constructed from N-tosyl-L-glutamic acid and 1,10-phenanthroline

By controlling the concentration of the reaction system, two zinc(II) complexes, [Zn₂(tsgluO)₂(phen)₂]_n (1) and [Zn₂(tsgluO)₂(phen)₂(H₂O)₂] (2) (H₂tsgluO = N-tosyl-L-glutamic acid, phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions and characterized by elemental analysis, infrared spectra, thermogravimetric analysis, and single-crystal X-ray diffraction. Complexes 1 and 2 both crystallize in the triclinic space group P-1. Complex 1 exhibits a 1-D double-chain structure. Complex 2 has a dinuclear structure which is extended by hydrogen-bonding interactions to form a 2-D supramolecular network. The structural difference indicates that the concentration plays a crucial role in modulating structures of coordination complexes. The two compounds also show intense fluorescence at room temperature.     

Reductivetrans-2,6-diallylation of pyridines with allylboranes. Synthesis oftrans- andcis-2,6-diallyl-1,2,5,6-tetrahydropyridines and their deuterated derivatives

The reductivetrans-2,6-diallylation of pyridines with triallyl- and allyl(dialkyl)boranes has been discovered. Heating (40–100 °C) of pyridine, deuteropyridine, or 3-bromopyridine complexes with triallylborane in the presence of alcohols (ROH or CH₃OD), water, or Et₂NH results in the respectivetrans-2,6-diaIlyl-1,2,5,6-tetrahydropyridines (2,3,22, or25) in 20–97 % yields. A preparative method for the isomerization oftrans-2,6-diallyl compounds2 and25 into the respectivecis-isomers4 and28 by heating them with triallyl- or allyl(dialkyl)boranes (125–150 °C) has been suggested. The hydrogenation oftrans- orcis-2,6-diallyl-1,2,5,6-tetrahydropyridines gavetrans- orcis-2,6-dipropylpiperidines, respectively. Thecis- andtrans-configurations of compounds2 and4 were established by analyzing the NMR spectra ofN-benzyl (7 and13) andN,N-dimethyl (6 and 14) derivatives of piperidine derivatives5 and8. A possible mechanism for the reductive diallylation of pyridines has been discussed.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 693–704, April, 1994.This study was financially supported by the Russian Foundation for Basic Research (Project 93-03-18193).     

Synthesis,structure and properties of three one-dimensional coordination polymers {[M(II)L(NCS)2](DMF)2} n (M(II)=cadmium(II), zinc(II), manganese(II); L=1,4-bis[2-(2-pyridyl)benzimidazolato]butane)

A tetradentate N-donor ligand 1,4-bis[2-(2-pyridyl)benzimidazolato]butane (L) was prepared for construction of a coordination framework. Three one-dimensional coordination polymers {[M(II)L(NCS)₂](DMF)₂} _n (M(II) = cadmium(II), 1, zinc(II), 2, manganese(II), 3) were obtained by reaction of metal ions and L in the presence of KSCN in DMF/water. The complexes are isostructural and consist of 1D zigzag [M(II)L(NCS)₂] _n chains and DMF molecules. Within the chains, the metal atoms are each octahedrally coordinated by four N atoms of L and two N atoms of the SCN^? anions. Complexes 1 and 2 in the solid state at room temperature exhibit intense photoluminescence at 453 and 433 nm, respectively.