B. Ribár

TRANSITION METAL COMPLEXES WITH THIOSEMICARBAZIDE-BASED LIGANDS. PART 28. SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF THE FIRST PHOSPHORUS-BONDED THIOSEMICARBAZIDE COMPLEX: [2-(DIPHENYLPHOSPHINO) BENZALDEHYDE THIOSEMICARBAZONATO(1-)] PYRIDINENICKEL(II)-NITRATE

Abstract The synthesis and crystal structure analysis of the diamagnetic complex [Ni(L)Py]NO3 (L = the monoanion of the newly synthesized ligand 2-(diphenylphosphino)benzaldehyde thiosemicarbazone) are reported. The complex crystallizes in the space group P21/n (No. 14) with a = 8.533(1), b = 29.123(3), c = 10.627(a) A, β = 100.36(1)°, V = 2597.8(5) A3. As revealed by X-ray analysis, the 2-(diphenylphosphino)benzaldehyde thiosemicarbazone ligand deprotonated at N(3) acts as a monoanionic tridentate donor, coordinating through SNP. The core of the bulky {Ni[(C6H5)2P-(C6H4CH=N-N=CS-NH2)·]}+ cation is a slightly puckered quadrangle formed around Ni2+ by SNP accompanied by a pyridine nitrogen. The dihedral angle of the atomic triangles S/N(4)/N(41) and P(2)/N(4)/N(41) is 18.0(4)°. The NO3 − anions are well separated from the cations which may account for the observed disorder of the oxygen atoms.

TRANSITION METAL COMPLEXES WITH THIOSEMICARBAZIDE-BASED LIGANDS. PART 25. SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF CIS-DIOXO [(SALICYLALDEHYDE THIOSEMICARBAZONATO(1-))] AQUOMOLYBDENUM (VI)CHLORIDE MONOHYDRATE, [MoO2(HL)H2O]Cl·H2O

Abstract The synthesis and crystal structure analysis of the diamagnetic complex [MoO2(HL)H2O]Cl·H2O(HL = monoanion of salicylaldehyde thiosemicarbazone) are reported. The complex crystallizes in the space group P21/a (No. 14) with a = 11.003(1), b = 8.444(1), c = 15.364(1) A, β = 104.96(1)°, V = 1379.1(2) A3. X-ray structure determination revealed that the complex possesses the usual cis-MoO2 2+ core and that the thiosemicarbazide ligand is present as a monoanionic tridentate donor coordinating through ONS. According to a search in the Cambridge Structural Database (state April 1994) this complex is the first in which the sixth coordination site at Mo(VI) is occupied by a water molecule forming a distorted octahedral coordination geometry together with the tridentate ligand.

TRANSITION METAL COMPLEXES WITH THIOSEMICARBAZIDE-BASED LIGANDS. PART 24.1 SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF [PENTANE-2,4-DIONEBIS(THIOSEMICARBAZONATO(1-)]NICKEL(II) THIOCYANATE

Abstract The syntheses of dark-green diamagnetic complexes [Ni(H2L)]X (H2L = the monoanion of pentane-2,4-dionebis(thiosemicarbazone) and X is either NO3 or NCS) and the crystal structure of the NCS complex is described. Crystals of the NCS complex are monoclinic, space group C2/c, with a = 11.867(1), b = 10.715(1), c = 22.319(1)A, β = 90.11(1)°, V = 2838.0(4) A3, Z = 8. The crystal structure was refined using 2491 independent reflections to R = 0.051. The structure consists of well separated [Ni(H2L)]+ cations and NCS− anions. NiII has a slightly distorted square-planar geometry formed with two nitrogen (Ni-N = 1.863(4) and 1.856(4) A) and two sulphur atoms (Ni-S = 2.153(2) and 2.163(1) A) of the monodeprotonated tetradentate ligand.

Synthesis, structural and spectral investigations of new types of dioxovanadium(V) complexes withS-methylthiosemicarbazones derived from salicyl and 2,4-dihydroxybenzaldehydes. X-ray structure of ammonium(salicylaldehydeS-methylthiosemicarbazonato) dioxovanadate(V) monohydrate

SummaryThe x-ray crystal structure of [VO2(HL1)] (where L1 denotes the dianion of theS-methylthiosemicarbazone of salicylaldehyde) has been determined and refined to R=0.058 (Rw=0.063) for 3377 observed reflections.There are two symmetrically independent molecules in the asymmetric unit, showing no significant differences in their geometries. The vanadium atom is pentacoordinated in a distorted square-pyramidal arrangement.Absorption spectra of [VO2(HL1)] and [VO2(HL2)], in the 10000–45000 cm−1 range, were calculated from the measured reflectance spectra, applying Kubelka-Munks theory. The extinction coefficients were determined from the absorption spectra of the solutions of these complexes in methanol. The observed maxima are interpreted on the basis of intraligand transition and charge-transfer spectra on the basis of the presence of approximate groupC2v for both complexes.

X-Ray Crystal Structure of 10β-Hydroxy-4β,5β-epoxyestr-1-en-3,17-dione and Antitumor Activity of its Congeners

Based on the biological properties of epoxyquinols from natural sources, the title compound was synthesised as a potential antitumor agent. Its molecular structure was partially confirmed by NMR studies. The detailed structure was established by X-ray analysis revealing two symmetry independent molecules in the asymmetric unit each consisting of four fused rings with the C(10) β-oriented hydroxy group and β-oriented O atom bridging C(4) and C(5). The conformation of A ring in both conformers A and B is boat (B3,6), while rings B and C are chairs (1C4) and the five-membered D ring is in an envelope (E2) conformation. The in vitro antitumor activity of title compound and its 17b-acetoxy analogue against HeLa and Fem-x cells revealed IC50 values of 5.7 and 7.1 mM, and 2.25 and 1.58 mM, respectively. Corresponding quinols were tested on 47 cell lines with 10b-hydroxy-17β-acetoxyestra-1,4-dien-3-one being most active against leukemia SR cells (GI50 = 0.17 mM).

Synthesis, reactions and stereochemistry of 3-hydroxymethyl-2,3-dihydro-4H-1,3-benzoxazin-4-one and some perhydrogenated derivatives

Abstract 3-Hydroxymethyl-2,3-dihydro-4H-1,3-benzoxazin-4-one and a number of its perhydrogenated derivatives were prepared from the corresponding 2-hydroxycarboxamides by treatment with a formaldehyde/formic acid mixture. Thermal decomposition of the 3-hydroxymethyl derivatives led to the previously unknown parent compounds. With one exception (14), both in the N-unsubstituted (16–18) and in the N-substituted (7–15) cyclopentane- and cyclohexane-fused derivatives the oxazinone ring predominantly attains a single half-chair conformation.

CRYSTAL STRUCTURE OF A MIXTURE OF LUPEOL-ACETATE TAUTOMERS ISOLATED FROM HIERACIUM PLUMULOSUM A. KERNER, ASTERACEAE

Abstract Transparent single crystals obtained from the purified extract of the plant Hieracium plumulosum A. Kerner, Asteraceae were submitted to spectroscopic and X-ray studies. The spectroscopic (infra-red, mass spectrometry, 1H and 13C nuclear magnetic resonance) investigations suggested the presence of two isomers of lupeol acetate (C32H52O2) with tautomeric relationship. Their mixture crystallizes in the monoclinic system with space group P21: a = 19.170(2) A , b = 8.128(1) A , c = 21.832(2) A , β = 90.24(1)°, V = 3401.7(6) A 3 , Z = 4 (two molecules in the asymmetric unit), Dx = 1.095 g cm−3, μ(CuKα) = 0.488 mm−1. The structure was solved by direct methods and refined to a final R = 0.071 for 6636 reflections with I > 2σ(I). The bond lengths around C 20 ( C 60) are between single and double bonds indicating the superposition of the tautomers, i.e., lup-20(29)-en-3β-ol and lup-19(20)-en-3β-ol acetates. They are distributed with different ratio in the symmetry-independent positions. In addition, the difference maps revealed that toluene solvent molecules are also captured in the lattice. They substantially hindered the refinement of atomic positions in particular for the C 19 ( C 59) functions.

Ozonation of 3β-acetoxy-5α-chloro-cholestane in solution. X-ray study of 3β-acetoxy-5α-chloro-14-cholestene-ozonide.

Abstract A selected saturated steroid derivative has been subjected to ozonation in solution. As the main reaction product 14,15-ozonide has been isolated in crystalline form whose structure has been unambiguously confirmed by the X-ray difraction method.

TRANSITION METAL COMPLEXES WITH HYDRAZIDES AND HYDRAZONES. PART 81. X-RAY CRYSTAL STRUCTURE OF A CATENA-POLYBROMO (ACETONE-1-NAPHTHOYLHYDRAZONE) COPPER(II)-COPPER(I) COMPLEX

Abstract The title compound [Cu3Br4C28H28N4O2] is a type of polymeric three-centre octahedral-trigonal planar coordination complex. The copper(II) atom located at a centre of symmetry is six-coordinate with two bidentate (N3, O1) ligands of acetone-1-naphthoylhydrazone forming the equatorial plane and two bromine ions in axial positions (Cul-Brl = 2.946(1)A). The ligands are in trans positions. The Cu(I) atoms are in trigonal planar coordination by two bridging Br− ions (Cu2-Br2 = 2.412(1)A, Cu2-Br2∗ = 2.407(2)A) which connect two Cu(I) atoms and a third bromine ion shared with the octahedral Cu(II) ion (Cu2-Br1 = 2.304(1)A). The arrangement forms an infinite chain along the b axis.

Crystal structure of usnic acid sodium salt 2 1/2 hydrate

Usnic acid, 1,3(2H,9bH)-dibenzofurandione-2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl, (1) was isolated from the lichenUsnea barbata by supercritical CO2 extraction. The corresponding sodium salt 2 1/2 hydrate was obtained by reacting the acid with sodium carbonate. (C18H15O7Na·2.5 H2O) × 2,Mr=822.68, triclinic,P1,a=14.179(8),b=7.369(4),c=9.109(6)Å,α=88.47(2),β=105.35(2),γ=92.27(2)°,V=917(2)Å3,Z=1,Dx=1.490 g cm−3, λ(MoKα)=0.71073 Å,μ=1.32 cm−1,F(000)=430,T=293(2)K. The structure was solved by direct methods and refined toR=0.038 for 3229 observed reflections. Both Na ions are pentacoordinated. Their coordination polyhedra are distorted square pyramids bound together by a common water molecule (OW1). The molecules are also joined together by a common water oxygen (OW2) in an infinite chain which lies parallel to theb-axis. The chains are held together by hydrogen bonds. The conformation of usnic acid in the complex differs from that found previously by a rotation of the acetyl group bound to the cyclohexadienone ring.