A. Kowalczyk

Bio: A. Kowalczyk is an academic researcher from Polish Academy of Sciences. The author has contributed to research in topics: Sparteine & Copper(II) sulfate. The author has an hindex of 1, co-authored 1 publications receiving 5 citations.

Synthesis and spectral characterization of sparteine and α -isosparteine complexes with copper(II) sulfate

Abstract: Complexes of CuSO4 of the general formula [Cu(C15H26N2)SO4] where [C15H26N2] is sparteine or α-isosparteine have been obtained from copper(II) and an appropriate alkaloid. The 1 : 1 (metal : alkaloid) stoichiometry was confirmed by elemental analysis. The compounds have been characterized by mass spectrometry, IR, and UV–Vis spectroscopy. The magnetic properties were also determined; no anti-ferromagnetic behavior was observed. Information on the geometry of newly obtained compounds was obtained using quantum-chemical calculations.

NMR Spectra of Sparteine N1-oxide and α-Isosparteine N-oxide

Abstract: Sparteine N1-oxide and α-isosparteine N-oxide were prepared and their structures determined for the first time by 1 H- and 13 C-NMR spectroscopy using two-dimensional techniques. The N-oxide effects were also calculated. Keywords: Sparteine, α-isosparteine, N-oxides, NMR spectroscopy, DFT calculations. Introduction The wide use of quinolizidine alkaloids in chemistry is related first of all with a possibility of configurational-conformational changes that could take place in the bis-quinolizidine skeleton. Naturally occurring (–)-sparteine is an equilibrium mixture in which the conformer possessing a boat ring C and trans junction of rings C/D predominates [1-4]. On the other hand, the less stable all-chair conformer participates in complex formation [5-7]. The compound α-isosparteine, consisting of two trans-quinolizidine systems, exists solely in an all-chair conformation, and similarly in the free base form [8] and in metal complexes [5-7,9,10]. As a continuation of our study on the complex forming ability of bis-quinolizidine alkaloids [6,7,9,10], the choice of N-oxides as ligands was made. We have already obtained the complexes of sparteine N16-oxides with lithium [11] and zinc [12] salts. This time the subject of our study was the synthesis of the complexes of sparteine N1-oxide, sparteine epi-N-oxide and α-isosparteine N-oxide. NMR spectroscopy is known to permit observation of conformational changes taking place in the structure of the ligands during complexation reactions. Moreover, a comparison of the chemical shifts of carbon atoms and protons of the initial alkaloid and the complex formed, enables determination of the effects of complexation. The present work is a continuation of our studies on the structural investigation of bis-quinolizidine alkaloids [13-17]. The NMR data of sparteine N16-oxide and

Crystal structure of sparteinium tetrachlorocuprate monohydrate-packing polymorph

Abstract: A new polymorph of sparteinium tetrachlorocuprate monohydrate [(C15H28N2)CuCl4·H2O] is reported. The structure of the analyzed crystal was solved in the orthorhombic P212121 space group with the following unit cell parameters at 295 K: a = 9.7722(2) A; b = 13.4582(3) A; c = 15.1582(3) A. The various types of hydrogen bonding interactions existing in the crystal structure of this salt were compared with the data of the previously reported polymorph. XRPD measurement proved that our salt consists of a pure phase of the new polymorph. Cooling down the salt to ca. 230 K caused its color to change from orange-brown to yellow. DSC experiments revealed that during the cooling an endothermic process takes place corresponding to the mentioned color change of the salt.