181-189

Synthesis of New Co(III) Hetero-Ligand
Complexes with Imidazole and 1-Methylimidazole
and Their ¹H, ¹³C and ⁵⁹Co NMR Spectra

by E. Danilczuk¹, A. Grzelakowska² and M. Michalska³

¹Faculty of Chemical Technology and Engineering, Department of Inorganic Chemistry
²Faculty of Agriculture, Department of Environmental Chemistry,
University of Technology and Agriculture, 85326 Bydgoszcz, Poland
³Department of Chemistry, Nicolaus Copernicus University, 87-100 Toruń, Poland

(Received July 5th, 1999; revised manuscript September 22nd, 1999)

cis-[Co(en)₂(1-MeIm)₂]Cl₃, fac-[Co(dien)(ImH)₃]X₃ (X = Cl^–, , ) and fac-[Co(dien)(1-MeIm)₃]Cl₃ complexes were prepared and characterized by absorption, ¹H NMR, ¹³C NMR and ⁵⁹Co NMR spectra, where en, dien, ImH and 1-MeIm denote ethylenediamine, diethylenetriamine, imidazole and 1-methylimidazole, respectively. Calculated coordination-induced shifts (d_complexed – d_free) ranged from +0.62 to –0.03 ppm for ¹H and +7.11 to –1.19 ppm for ¹³C nuclei of imidazole ligands. The influence of imidazole methylation on ⁵⁹Co NMR spectra was considered.

191-198

The Synthesis, Spectroscopic Characterization,
Crystal and Molecular Structure
of [ReBr₃(NO)(dppe)]_0.60[ReBr₄(dppe)]_0.40

by J.O. Dzięgielewski¹, B. Machura¹, J. Małecki¹,
T.J. Bartczak² and W. Czurak²

¹Department of Inorganic and Radiation Chemistry, Institute of Chemistry, University of Silesia,
Szkolna 9, 40-006 Katowice, Poland

²X-Ray Crystallography Laboratory, Institute of General and Ecological Chemistry,
Technical University of ŁódŸ, Żeromskiego 116, 90-924 ŁódŸ, Poland
e-mail: tadekbar@ck-sg.p.lodz.pl.

(Received September 3rd, 1999; revised manuscript October 29th, 1999)

[ReOBr₃(dppe)] (where dppe denotes Ph₂PCH₂CH₂PPh₂) reacts with gaseous nitric oxide in the presence of an excess of free PPh₃ to give [ReBr₃(NO)(dppe)]_0.60[ReBr₄(dppe)]_0.40, characterized by X-ray crystallography, IR, UV-Vis, and magnetochemical measurements. The complex is a paramagnetic compound with magnetic moment 2.54 MB.

199-206

Synthesis and Characterization of Thiocyanato-Bridged Heteropolynuclear Chromium(III)–Copper(II) Complexes

by L. Dobrzańska¹, G. Wrzeszcz¹, A. Grodzicki¹ and F. Rozpłoch²

¹Faculty of Chemistry, Gagarina 7 and ²Institute of Physics, Grudziądzka 5/7,
Nicholas Copernicus University, 87-100 Toruń, Poland

(Received October 4th, 1999; revised manuscript November 17th, 1999)

Heteropolynuclear thiocyanato-bridged complexes were prepared in the reactions of aqueous solutions of K₃[Cr(NCS)₆] with copper(II) complexes of the type [CuX₄]²⁺, where X = imidazole (imH), 4-methylimidazole (4-MeimH) and 2X = ethylenediamine (en). Solid products were formulated as (Cu(imH)₄)₃(Cr(NCS)₆)₂×2H₂O, (Cu(4-MeimH)₄)₃(Cr(NCS)₆)₂·3H₂O and (Cu(en)₂)₃(Cr(NCS)₆)₂·H₂O on the basis of elemental analysis and spectral data (IR, UV-VIS). EPR spectra, variable temperature magnetic susceptibility and thermal properties in air were investigated, indicating that all complexes are polynuclear with thiocyanate bridges, exhibiting Curie-Weiss behavior between 80–300 K. Thermal decomposition is multistage and yields CuO and CuCrO₂ as final products.

207-217

Furo[2,3-b]pyrrole Derivatives.
Syntheses and Reactions in the Furan and Pyrrole Ring

by R. Sleziak¹, A. Krutošíková¹, M.K. Cyrański² and T.M. Krygowski²

¹Department of Organic Chemistry, Faculty of Chemical Technology, Slovak University of Technology, SK 812 37 Bratislava, Slovak Republic
²Department of Chemistry, University of Warsaw, L. Pasteura 1, 02-093 Warsaw, Poland

(Received June 7th, 1999; revised manuscript October 25th, 1999)

6-Substituted furo[2,3-b]pyrrole-5-carboxylic acids 2b–d as well as their 2-formyl- substituted derivatives 4a–d have been prepared by alkaline hydrolysis of the corresponding esters 1b–d and 3a–d, respectively. A different behaviour of methyl 6H-furo[2,3-b]pyrrole-5-carboxylate 1a in comparison with the 4H-furo[3,2-b]pyrrole isomer has been discussed in a framework of different acidity of proton of NH group. The hypothesis has been supported by ab initio B3LYP/6-311+G** DFT calculations. The 2-formylated derivatives 3b–d were used for synthesis the propenoic acids 5b–d, the corresponding acid azides 6b–d, new disubstituted ureas 9 or 10, 2-cyano-derivatives 11a–d, which were transformed into the corresponding amidines 12 and substituted arylureas 13 as well as to 5¢-tetrazolyl derivative 14. Further methyl 2-triphenylmethyl-6H-furo[2,3-b]pyrrole-5-carboxylate 15 and its Michael addition product 16 were prepared.

219-225

Fragments of a Proline-Rich Polypeptide Settled
on a Hexapeptide Carcass Constructed of Glycine and
L-Lysine Residues. Synthesis and Biological Properties

by I. Wirkus-Romanowska¹, H. Miecznikowska¹, A. Zabłocka²,
K. Rybka², W. Fortuna², R. Międzybrodzki², S. Szymaniec²,
M. Janusz², J. Lisowski² and G. Kupryszewski¹

¹Faculty of Chemistry, University of Gdańsk, 80-952 Gdańsk, Sobieskiego 18, Poland
²Institute of Immunology and Experimental Therapy, Polish Academy of Sciences,
53-114 Wrocław, Rudolfa Weigla 12, Poland

(Received September 17th, 1999; revised manuscript October 25th, 1999)

Proline-rich polypeptide fragments settled on a hexapeptide constructed of L-lysine and glycine residues were synthesized by the solid phase method: X–Lys(X)-Gly–Lys(X)-Gly–Lys(X)-Gly–OH, X = Tyr-Val-Pro-Leu-Phe-Pro and Y–Lys(Y)-Gly–Lys(Y)-Gly–Lys(Y)-Gly–OH, Y = Val-Glu-Ser-Tyr-Val-Pro-Leu-Phe-Pro. Immunotropic activity of the analogues was determined in a murine system using resistance to hydrocortisone and in human cell cultures using induction of cytokines as indicators.

227-230

Simple Synthesis of 2-Thioglycosyl Derivatives
of Pyridine N-Oxide

by G. Pastuch and W. Szeja

Silesian Technical University, Department of Chemistry, ul. Krzywoustego 8, 44-100 Gliwice, Poland

(Received July 26th, 1999; revised manuscript November 4th, 1999)

A new class of “latent” glycosyl donors, 2-thioglycosyl pyridine N-oxides was synthesized from 1-thiosugar and 2-bromopyridine N-oxide in the reaction of aromatic nucleophilic substitution of halogen.

231-238

Iodide Ion-Selective PVC Membrane Electrode Based
on a Recently Synthesized Salen–Mn(II) Complex

by M. Shamsipur¹, S. Sadeghi², H. Naeimi³ and H. Sharghi³

¹Department of Chemistry, Razi University, Kermanshah, Iran
²Department of Chemistry, Shahid Beheshti University, Tehran, Iran
³Department of Chemistry, Shiraz University, Shiraz, Iran

(Received June 7th, 1999; revised manuscript September 6th, 1999)

A new PVC membrane electrode for iodide ions based on a recently synthesized salen–Mn(II) complex as membrane carrier was prepared. The electrode exhibits a Nernstian slope of 59.0±0.4 mV per decade for I^– over a wide concentration range (1.0×10^–1–3.4×10^–5 M). It has a relatively fast response time of about 20 s and can be used for at least three months without any divergence in potential. The proposed sensor shows a fairly good discriminating ability towards I^– ion in comparison to other common anions. The electrode can be used in the pH range 3.5–8.5. It was used as an indicator electrode in potentiometric titration of iodide ion.

239-244

Thermodynamics of Substituted Pyrazolone. VI. Potentiometric and Conductometric Studies
of Complexes of Some Transition Metals
with 4-(4-Acetophenyl)hydrazono-3-methyl-1-
-phenyl-2-pyrazolin-5-one

by A.A. El-Bindary, A.Z. El-Sonbati and H.M. Kera

Chemistry Department, Faculty of Science (Demiatta), Mansoura University, Demiatta, Egypt

(Received August 24th, 1999; revised manuscript November 16th, 1999)

The dissociation constant of 4-(4-acetophenyl)hydrazono-3-methyl-1-phenyl-2-pyra- zolin-5-one (AHMPP) has been determined potentiometrically in 0.1 M KCl and 50% (v/v) ethanol-water mixture. Also, the stepwise stability constants of the formed complexes of , Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, La³⁺, Ce³⁺, and Th⁴⁺ with AHMPP have been determined. The stability of the formed complexes follow the sequence:

Th⁴⁺ > > Ce³⁺ > La³⁺ > Mn²⁺ < Co²⁺ < Ni²⁺ < Cu²⁺ > Zn²⁺

The thermodynamic parameters (DG, DH and DS) for AHMPP and its complexes were evaluated and discussed. The dissociation process is nonspontaneous, endothermic and entropically unfavourable. The formation of the metal complexes has been found to be spontaneous, exothermic or endothermic (depends on the metal) and entropically favourable. The stoichiometries of these complexes were determined conductometrically indicating the formation of 1:1 and 1:2 (metal:ligand) complexes.

245-256

Ab Initio Calculations of the Pairing of Four Canonical DNA Bases with Three Thymine Derivatives Generated by Hydroxyl Radical in Anaerobic Conditions

by P. Cysewski

L. Rydygier Medical University in Bydgoszcz, Department of Physical Chemistry,
Skłodowskiej-Curie 9, 85-094 Bydgoszcz, Poland

(Received February 12th, 1999; revised manuscript September 22nd, 1999)

The coding properties of three hydroxyl radical induced thymine derivatives: 5-hydroxy-6-hydrothymine (1), 5,6-dihydrothymine (2) and 6-hydroxy-5,6-dihydrothymine (3) were characterized by ab initio HF/6-31G, HF/6-31G**//HF/6-31G and SCI-PCM/6-31G**//HF/6-31G quantum chemistry calculations. All studied derivatives may have potential miscoding character, which strongly depends on the polarity of the environment. Under non-polar conditions all analyzed thymine derivatives are able to pair with guanine, what may result in the T ® C transition. Additionally, 1 is able to form stable pairs with cytosine and adenine. Compound 3 is capable to pair with all four canonical DNA bases. All these pairs are more stable than standard AT pair. In polar environment the pairing potential of studied thymine derivatives is significantly reduced. However, the mispairing potential is usually the same and remained significant, especially for 6-hydroxy-6-hydrothymine.

257-263

Gas-Liquid Chromatographic Interactions
for Twelve Benzene-Derived Chemical Functions
on Twelve Polar Stationary Phases

by J.M. Santiuste

Institute of Physical Chemistry “Rocasolano”, CSIC, Department of Structure and Molecular Dynamics, C. Serrano, 119, 28006-Madrid, Spain

(Received November 16th, 1998; revised manuscript October 25th, 1999)

Linear solvation energy relationship (LSER) was used to describe the solute–solvent interactions of benzene and twelve derivatives on 12 stationary phases taken from literature. The hydrogen-bond interactions between the basic solute and the acid solvent were negligible, the more relevant interactions being cavity-formation/dispersion and the dipolar interactions. The effect of the polarity of both the stationary phase (solvent) and the solute (chemical function) on interactions has been investigated. The dipolar interaction increases for each solute with increasing phase polarity and for each phase with increasing solute polarity, whereas the cavity-formation/dispersion interaction decreases with increasing stationary phase polarity. The plots of the cavity-formation/dispersion and of dipolar interaction increments between chemical functions and parent benzene molecule versus stationary phase polarity confirm the above trends.

265-273

The Crystal, Molecular and Electronic Structure
of [ReBr₂(NO)(CO)(PPh₃)₂]×NO Complex

by T.J. Bartczak¹, W. Czurak¹, J.O. Dzięgielewski²,
B. Machura², J. Kusz³ and J. Warczewski³

¹X-Ray Crystallography Laboratory, Institute of General and Ecological Chemistry,
Technical University of ŁódŸ, Żeromskiego 116, 90-924 ŁódŸ, Poland
e-mail: tadekbar@ck-sg.p.lodz.pl

²Department of Inorganic and Radiation Chemistry, Institute of Chemistry and
³Institute of Physics, University of Silesia, Uniwersytecka 4, 40-006 Katowice, Poland

(Received September 3rd, 1999; revised manuscript October 29th, 1999)

A new rhenium nitrosyl complex [ReBr₂(NO)(CO)(PPh₃)₂]×NO has been synthesized and characterized by X-ray diffraction, IR, UV-Vis and magnetochemical measurements. The Re atom is of six-coordinate distorted octahedral configuration and linear nitrosyl ligand is trans towards the bromine ligand and cis towards CO molecule.

275-280

Synthesis and Structure
of [NH₂(C₂H₅)₂]₄[O₄₂(H₂O)]×2H₂O

by Q.X. Zeng¹, J.Q. Xu¹, G.Y. Yang¹, Y.J. Song¹, Y.S. Pak³, Y.H. Xing¹,
R.Z. Wang¹, D.M. Li¹, Y. Xing², Y.H. Lin² and H.Q. Jia²

¹Department of Chemistry, Jilin University, Changchun 130023, P.R. China

²Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China

³Ham Hung Chemical Industrial University, D. PR. K

(Received May 20th, 1999; revised manuscript August 30th, 1999)

281-283

A New Lupane-Type Triterpenoid
from Taraxacum officinale

by W. Kisiel¹, B. Barszcz¹ and E. Szneler²

¹Department of Phytochemistry, Institute of Pharmacology, Polish Academy of Sciences,
 12 Smętna Street, 31-343 Kraków, Poland
²Department of Chemistry, Jagiellonian University, 3 Ingardena Street, 30-060 Kraków, Poland

(Received November 2nd, 1999)

285-287

Synthesis and Crystal Structure of Tetrakis(trifluoroacetato) Bis(acetone) Dirhodium(II)

by Q.-H. Zhao¹, W.-M. Bu², D.-Z. Liao¹, Z.-H. Jiang¹ and S.-P. Yan¹

¹Department of Chemistry, Nankai University, Tianjin, 300071, P. R. China
²Key Laboratory for Supramolecular Structure and Spectroscopy, Jilin University,
Changchun, 130023, P. R. China

(Received October 20th, 1999; revised manuscript November 24th, 1999)