Lesław Sieroń

New unsymmetrical Schiff base Ni(II) complexes as scaffolds for dendritic and amino acid superstructures

An efficient stepwise template approach has been developed that leads to a novel Ni(II) complex of an unsymmetrical 1∶1∶1 Schiff base derived from o-phenylenediamine, benzoylacetone and salicylic aldehyde [abbreviated as salophbac Ni(II)]. The 3- and 5-hydroxysubstituted salicylic aldehydes lead to complexes containing reactive OH groups that were further employed as points of attachment for the ligand superstructures. A range of new O-substituted derivatives of salophbac Ni(II) complexes have been synthesized bearing N-protected (L)-amino acid moieties as well as poly(arylether) and poly(arylester) dendrons. New products have been characterized by means of 1H and 13C NMR, MS and IR data. The crystal structures of the 3-Boc–(L)-phenylalanyloxy, 3-Ac–(D,L)-alanyloxy and (3′,5′-dibenzyloxy)-3-benzyloxy derivatives of salophbac Ni(II) complexes have been determined. The supramolecular C–H⋯π, π⋯π interactions and hydrogen bonds are discussed on the basis of the crystallographic data.

Synthesis, crystal structure, spectroscopic study, and magnetic behavior of the first dinuclear Mn(II) complex of hydrazone-based ligand-containing dicyanamide bridging groups

A new dinuclear complex of manganese(II), [Mn(L)(μ1,5-dca)(CH3OH)]2 (1), with dicyanamide anion and (E)-3-hydroxy-N′-(pyridin-2-ylmethylene)-2-naphthohydrazide (HL) was synthesized. The complex was characterized by elemental analyzes, spectroscopic methods, X-ray diffraction, and magnetic susceptibility studies. Two manganese ions in the complex were connected by two bridging dicyanamide ligands in a symmetric end-to-end (μ1,5-dca) fashion. The presence of intramolecular hydrogen bonding in the mononegative naphthohydrazone (L−) affects keto-enol tautomerism and the ligand coordinates to manganese(II) in the keto-form. Magnetic measurements showed an antiferromagnetic interaction between adjacent manganese ions in the dimer.

X-ray structure of poly[aquabis(benzimidazole-N3)copper(II)-μ-trans-2-butene-1,4-dicarboxylato-O,O′:O″,O‴] (I) and magnetic and spectroscopic characterization of I and the isostructural copper(II)-μ-adipato complex II

Abstract The title compounds [Cu(H2O)(C7H6N2)2(C6H6O4)] (I) and isostructural [Cu(H2O)(C7H6N2)2(C6H8O4)] (II) are the rarely observed seven-coordinate Cu(II) complexes of C2 elongated square-pyramidal geometry with a double-capped base by two very long CuO(carboxylate) bonds. The valences of CuN and CuO bonds in I and II have been computed to confirm the assumed Cu(II) coordination number. The hydrogen bond system and Cu⋯Cu intra- and interpolymeric chain spacing in I and II have been analyzed to explain their magnetic properties. The magnetic susceptibility measurements of I and II in the range 1.7–300 K suggest weak antiferromagnetic interaction between Cu(II) centres. The EPR and d–d spectra of both complexes have been measured and analyzed.

catena-Poly[aqua(benzimidazole-N3)-copper(II)-μ-malonato-O,O'':O']

The title compound forms a polymeric chain, [Cu(C 3 H 2 O 4 )(C 7 H 6 N 2 )(H 2 O)]∞. A malonate ion adopts a bridging position between two Cu atoms, coordinating via three of its O atoms. Two form a six-membered chelate ring, the third coordinates to the neighbouring Cu atom. The square-pyramidal Cu II coordination comprises one N and three O atoms as the base, and an H 2 O molecule in the apical position. The equalization of C-O bonds of both carboxylate groups and a differentiation of Cu-O bond lengths is observed.

New enantiomeric fluorine-containing derivatives of sulforaphane: Synthesis, absolute configurations and biological activity

Three pairs of enantiomers of the unknown sulforaphane analogs bearing organofluorine substituents bonded to the sulfinyl sulfur atom and having different number of methylene groups in the central carbon chain were synthesized and fully characterized, including determination of their absolute configurations. All the new compounds were tested in vitro for their cytotoxicity against melanoma cells to show increased activity in comparison with the natural sulforaphane. The influence of the particular structural changes in the molecule on the cytotoxicity is discussed.

Crystal structure of (3,3′,4,4′-tetramethyl-1,1′-diphosphaferrocen-2-yl) carboxylic acid and its bis-[W(CO)5] complex·0.5C5H12: Conformation of 1,1′-diphosphaferrocenes

AbstractThe structures of (3,3′,4,4′-tetramethyl-1,1′-diphosphaferrocen-2-yl)carboxylic acid (1) and its bis-[W(CO)5] pentane solvate complex (2) have been determined by X-ray analysis. The compound 1 crystallizes in the monoclinic P21/n space group with Z = 4; a = 7.8404(9), b = 14.9441(16), c = 11.7730(14) Å, β = 92.773(10)°, V = 1377.8(3) Å3, and Dcalc = 1.553 g cm−3. The compound 2 crystallizes in the triclinic

X-ray crystal structures of [Bi(C2H2N2S3)(Scn)3] (1) and Cs2K[Bi(Scn)6] (2). an unusual pentagonal-pyramidal coordination of biIII in (1)

P\bar 1

Three new olanzapine structures: the acetic acid monosolvate, and the propan-2-ol and propan-2-one hemisolvate monohydrates

space group with two complex molecules and one pentane molecule in the unit cell. Cell parameters: a = 10.7070(2), b = 12.577(2), c = 13.239(3) Å, α = 84.00(2), β = 77.58(1), γ = 66.06(1)°, V = 1591.0(5) Å3, and Dcalc = 2.100 g cm−3 .The fully eclipsed conformation of the phospholyl rings with P···P secondary bonding of 3.353(1) Å is observed in 1 and a partially eclipsed conformation is found in 2. The 10 possible conformations of 1,1′-diphosphaferrocenes were described as the function of conformational parameter θ and observed geometry of the phospholyl rings.7 We suppose that the earlier conclusions concerning the destabilizing nature of 1,1′-diphosphaferrocene conformations with θ < 100° cannot be considered as general. The mode of W – P coordination, the structural changes of 1 by W(CO)5 coordination, the structural effect of phospholyl rings substitution by the –COOH group, and hydrogen bonds are analyzed.