J. Macicek

Mechanochemical synthesis of soluble complexes containing M3S74+ and M3Se74+ fragments from polymeric M3Y7Br4 (M Mo, W; Y S, Se). The crystal structure of (PPN)2W3S7Cl6

Abstract The interaction of solid W3S7Br4 or W3Se7Br4 with Et4NBr under vibrational mill conditions followed by extraction with acetonitrile resulted in the isolation of (Et4N)2W3S7Br6 (1) and (Et4N)2W3Se7Br6 (2) salts. Treatment of the product of the analogous reaction of Mo3Se7Br4 and Et4NBr with sodium diethyldithiocarbamate (Nadtc) resulted in [Mo3Se7(dtc)3]dtc (4). The M3Y74+ (Y = S, Se) cluster fragments are retained in all of these reactions. By dissolving 1 in conc. hydrochloric acid and adding PPNCl, the (PPN)2W3S7Cl6 salt (5) was obtained, for which an X-ray study has been performed. Selected distances for the cluster anion W3(μ3-S)(μ2-S2)3Cl62− are 2.7270(7)-2.7445(6) A for WW, 2.360(3)-2.361(3) A for W—(μ3,-S), 2.032(4)–2.052(4) A for SS, 2.429(3)- 2.459(2) and 2.493(4)–2.519(3) A for WCl (for cis and trans positions with respect to μ3-S, respectively). Rather short distances (3.17–3.21 A) between the chlorine atoms and sulphur atoms of the μ2-S2 ligands of the adjacent anions were noted. The interaction of 2 with 1,2-bisdiphenylphosphine ethane (dppe) is accompanied by elimination of selenium to produce W3Se4Br3(dppe)3]Br (6).

Monomeric Pt(II) and Pd(II) complexes with Creatinine. Crystal structure of tetrakis-(Creatinine) platinum(II) diperchlorate

Abstract Pt(II) and Pd(II) complexes with creatinine, C3H2N2(O)(CH3)NH2, were synthesized. Potentiometric and IR spectroscopic analyses were carried out. A model for the coordination of the ligands to the central atoms was confirmed by X-ray structural investigation of Pt(creat)4(ClO4)2. The compound [Pt(C4H7N3O)(ClO4)2] crystallizes in the monoclinic crystal system, space group C2/c, a = 15.748(5), b = 15.763(7), c = 24.843(8) A, β = 106.84(4)°, V = 5902 A3, Z = 8. The refinement of the structure by the least-squares method gave R = 0.051 and Rw = 0.054 for 1527 observed reflections with I > 2σ(I). The structure consists of Pt(creat)42+ complex cations, possessing approximate D2 symmetry and rotationally disordered perchlorate anions. The Pt atom is square-planarly coordinated by the endocyclic N atoms of four creatinine ligands. The PtN bond lengths range from 2.00(2) to 2.03(1) A and the NPtN angles from 88.4(9) to 91.8(8)°. The ligands are almost planar and tilted towards the PtN4-plane by 82.1(8)–93.5(9)°.

Studies on intermolecular interactions of metal chelate complexes. V. copper(ii) dithiophosphate complexes: an example of an inner self-redox reaction

SummaryStudies of copper dithiophosphate (dtp) complexes by various physical methods, in the solid and the molten state as well as in solution, are reported. In the solid state all the complexes of dithiophosphate (RO)2PS2− [R = CnH2n+1 (n=1–4), Ph, orcyclo-C6H11] are diamagnetic but in the molten state and in solution they are paramagnetic. Interconversions were found to be reversible, and the effect was ascribed to an inner self-redox reaction. Only the bulkyo-tolyl derivative is paramagnetic in the solid and molten states and in solution. It is proposed that the self-redox reaction involves association between two molecules of CuII(dtp)2 during crystallization, followed by formation of [CuI(dtp)]2, and (RO)2P(S)S-S(S)P(OR)2, and then [CuI(dtp)]4. The molecular structures of complexes with R = isopropyl ando-tolyl confirm these inferences.

Reactions of α-chloroimines with homophthalic anhydrides. Synthesis and molecular structure of 3,3a-dihydrofuro[3,4-c] isoquinoline-1,5(4h,9bh)-diones, furo[3′, 4′:9,9α]-8,9,16,16a-tetrahydro-1h,3h,11h-dibenzo[a,g]quinolizine-1,11-diones and related compounds

Abstract The reaction of α-chloroimines 1 - 3 , resp. 11 with homophthalic anhydrides 4 leads to the formation of the isoguinoline ring system incorporated in furo[3,4-c]isoquinolinediones 8 - 10 , resp. 13a-(chloromethyl)-8H- dibenzo[a,g]-quinolizine-8-one-13-carboxylic acids 12 . The latter compounds were converted into furo[3′ 4′:9,9a]dibenzoquinolizinediones 13 under basic conditions. NMR studies provided information concerning the relative configuration and the solution conformation of the various heterocycles obtained. The molecular structure of 8b and 12b was determined by X-ray analysis.

Absolute structure of a new paramagnetic platinum(II)-creatinine complex with a columnar structure

Abstract A new platinum complex with creatinine [C3H2 N2(O)(CH3)NH2] exhibiting paramagnetic properties was synthesized fully characterized by crystallographic, spectral magnetic measurements. The compound [AsPh4]+[Pt(creatinine)Cl3]− crystallizes to give a columnar honeycomb motif of tetraphenylarsonium cations with the channels occupied by creatinine anions. The shortest Pt-Pt distance is 7.622(1). A remarkable feature of the structure is the formation of short Ptμ H intermolecular bonds of 2.73(2) A. The temperature dependence of both μeff and EPR parameters of the complex has been studied.

FAR IR SPECTRA AND STRUCTURES OF Zn(II) COMPLEXES OF 2-AMINOTHIAZOLES

Abstract IR spectra and molecular structures of ZnL2X2 (L = 2-NH2-4-R-thiazole, R = H (at), CH3; 2-NH2-6-R1 -benzothiazole, R1 = H (abt), CH3, OCH3, OC2H5 or 2-NH2-tetrahydrobenzothiazole; X = Cl, Br, I) have been studied. It was found that the complex character of the far IR spectra and difficulties in v(NH2) interpretation make conclusions regarding structure based only on IR data ambiguous, and in some cases discrepant. Single crystal X-ray data for the complexes with L = at, X = Br, I and L = abt, X = Br show that structures are built up of discrete tetrahedral ZnL2X2 molecules with monodentate ligands coordinated via endo-N atoms. It was found that in the coordination tetrahedra MN2Cl2 (M = Co2+, Zn2+) the central atom redistributes electron density between the thiazole ligands and the terminal Cl atoms.

Synthesis, structural, spectral and EPR studies on the copper(II) complex of 5-(aminosulphonyl)-4-chloro-2-[(2-furanylmethyl)amino]benzoic acid (Furosemide)

Abstract The copper(II) complexes of Furosemide (Fu) widely used as a diuretic were synthesized and isolated from aqueous and methanol solutions as CuFu2 · 2Solv and characterized by elemental analysis, single crystal X-ray diffraction, UV—vis and IR spectroscopy, EPR and magnetic susceptibility measurements. The complex CuFu2 · 2MeOH was isolated from methanol solutions as green crystals. Its structure consists of flattened molecules arranged in stacks. A centrosymmetric CuO6 elongated bipyramid is formed around copper(II) by four oxygens from the COO− groups and two from the MeOH. The COO− groups act as bridges between the copper(II) atoms with two oxygens in the equatorial plane (CuO distance of 1.924 A) and the other two in apical positions at 2.720 A. The methanol oxygens are at an intermediate distance of 1.941 A. The CuCu separation is 4.749 A. Hydrogen bonding occurs within and between the molecules.

Preparation, Thermal Behaviour, and Structure of Calcium Trifluoroacetate Monohydrate

Summary. Calcium trifluoroacetate was prepared as its monohydrate Ca(CF3COO)2ċH2O by reaction of CaCO3 with an aqueous solution of CF3COOH. It has been established by thermogravimetry and differential thermal analysis that this salt possesses a low thermal stability. When heated in air, decomposition starts already at 106°C, yielding the final product CaF2. Single crystals of Ca(CF3COO)2ċH2O were obtained and found to be monoclinic (space group P21/n); unit cell parameters: a=9.465(2), b=9.360(3), c=16.565(7) Å.Zusammenfassung. Calciumtrifluoracetat wurde durch Reaktion von CaCO3 mit einer wäßrigen Lösung von CF3COOH als sein Monohydrat Ca(CF3COO)2ċH2O erhalten. Thermogravimetrische und differentialthermoanalytische Untersuchungen zeigen, daß dieses Salz eine geringe thermische Beständigkeit besitzt. Bei Erhitzen in Gegenwart von Luft beginnt die Zersetzung des Salzes bereits bei 106°C, wobei das Endprodukt CaF2 entsteht. Einkristalle von Ca(CF3COO)2ċH2O wurden hergestellt; sie sind monoklin (Raumgruppe P21/n). Parameter der Elementarzelle: a=9.465(2), b=9.360(3), c=16.565(7) Å.

EPR studies on bis(diisopropyldithiophosphato)copper(II) magnetically diluted in the corresponding palladium(II) and platinum(II) single crystals and crystal and molecular structure of bis(diisopropyldithiophosphato)palladium(II) host lattice

Abstract The EPR spectra of single-crystal samples of 63Cu[(Pri2O)2PS2]2 magnetically diluted in the corresponding palladium(II) and platinum(II) host lattices were studied at room temperature and eigen-values of the A and g tensors evaluated. The results obtained show that both the samples have approximately axial symmetry (ΔA = Ax - Ay ⪕ 3 G; Δg = gx - gy ⪕ 0.03) with one molecule per unit cell in both host lattices. It is found that gz coincides with Az whereas the angle between gx and Ax (gy and Ay) is 27° and 11° for 63Cu/Pt[(Pri2O)2PS2]2 and 63Cu/Pd[(Pri2O)2PS2]2, respectively. The data about a quadrupole interaction obtained was considered with special attention, because their values are close to the experimental error. In view of this, the possibility for determining Q values from simulated powdered EPR spectra was explored. The results show, however, inapplicability of this approach too. The crystal and molecular structure of bis(diisopropyldithiophosphato)palladium(II) was determined.

Structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid and (±)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid

The crystal structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid (1) and of (±)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid (2) have been solved by X-ray methods. They are built up in a similar way to centrosymmetric dimers of hydrogen-bonded molecules. The orientation of the substituents around the central C-C bond in both molecules fulfills the requirement for the least spatial hindrance. The observed shift of theυoh stretching frequencies from 3312(1), 3346 (2) cm−1 in solid to 3408(1), 3450(2), in diluted (10−3M) tetrachloromethane solution, indicates the formation of intramolecular hydrogen-bonded species.