Hartmut Wunderlich

Synthesis, properties and structure of bis(dialkyldithiophosphinato)manganese(II) complexes

Abstract Reaction of Mn 2 (CO) 10 or powdered manganese with bis(diorganothiophosphoryl)disulfanes, R 2 P(S)- S 2 P(S)R 2 (R= Et, n -Pr) gives tetrahedral Mn(II)- dithiophosphinates, (R 2 PS 2 ) 2 Mn, which are dimerized in solution and in the solid state via ligand bridges. The crystal structure of the ethylcomplex is reported. Crystals are orthorhombic, space group Pbca with cell dimensions a = 20.164(4), b = 13.837(3) and c = 11.960(2) A.

Ionic cluster dithiophosphinates [Mo3S4(R2PS2)3py3]+[MI3]−(M=Zn·py, Cd·py, Hg)

Abstract Reactions of clusters Mo 3 S 4 L 4 ( 2 ) (L=R 2 P(S)S − ; R=Et ( a ), Pr ( b )) with MI 2 (M=Zn, Cd, Hg) in the presence of pyridine yieided ionic clusters [Mo 3 S 4 L 3 py 3 ] + [MI 3 py] − (M=Zn ( 9 ), Cd ( 10 ); R=Et ( a ), Pr ( b )) and [Mo 3 S 4 L 3 py 3 ] + [HgI 3 ] − ( 11 ) (L=Pr 2 P(S)S − ), respectively. The cluster cations consist of a triangular array of Mo atoms which are bridged by three S atoms and capped by the fourth S atom. Each of the Mo atoms is chelated by one L and coordinated by one pyridine. 9a crystallizes in the monoclinic space group P 2 1 with Z =2 formula units in the unit cell of dimensions a =1120.9(2), b =1756.3(3), c =1447.3(2) pm, β=105.31(1)°, D c =1.98 mg/ mm 3 . The crystal structure was refined to R = 0.04 using 5599 observed reflections and consists of [Mo 3 S 4 (Et 2 PS) 3 py 3 ] + [ZnI 3 py] − . The coordination number of the Mo atoms is 8. The average distance MoMo is 276.6(2) pm. The Zn atom is coordinated tetrahedrally with average distance ZnI of 259.0(2) and ZnN of 208.8(11) pm.

Protonation sites of organic bases with several nitrogen functions: crystal structures of salts of chlordiazepoxide, dihydralazine, and phenformin

The crystal structures of 7-chloro-2-methylamino-5-phenyl-3H-1,4-benzodiazepine 4-oxide (chlordiazepoxide) hydrochloride (1), 1,4-dihydrazinophthalazine (dihydralazine) hydrosulphate trihydrate (2), and 1-(2-phenylethyl)biguanide (phenformin) hydrochloride (3) have been determined by X-ray diffraction. All have space group P21/c, and for (1): a= 13.120(5), b= 8.439(3), c= 15.070(6)A, β= 107.81(3)°, Z= 4; for (2)a= 6.966(3), b= 11.099(4), c= 19.005(5)A, β= 104.72(3)°, Z= 4; and for (3)a= 14.947(5), b= 9.396(3), c= 20.345(7)A, β= 116.73(3), Z= 8. In (1) and (2) protonation occurs at a ring nitrogen atom, leading to amidinium systems. The second proton in (2) is attached to a terminal hydrazine nitrogen. The two independent cations in (3) have the same tautomeric form RHN·C(NH2)NC(NH2)2. The structure of (1) was determined by direct methods, those of (2) and (3) by the heavy-atom method. The structures were refined to R 0.059, 0.076, and 0.082 for 2 967, 2 015, and 4 672 observed intensities.

[(C5H5)Co{P(O)(OH)2}3H]: A novel organometallic tris-phosphonic acid that dissolves glass to form a six-coordinate silicon complex

The sodium salt of the tripodal oxygen ligand Na[(C5H5)Co(P(O)(OMe)2)3] (1) reacts with gaseous hydrogen chloride in dichloromethane to give sodium chloride and [(C5H5)Co(P(O)(OMe)2)3H2]Cl (2). Addition of an equimolar amount of 1 leads to precipitation of sodium chloride again to yield the acid form of the ligand [(C5H5)Co(P(O)(OMe)2)3H] (3). Its solid-state structure contains a very short intramolecular OH.O hydrogen bond. The compound hydrolyses in boiling water to give methanol and the title complex [(C5H5)Co(P(O)(OH)2)3H] (4). This complex is a rather strong tris-phosphonic acid (pK(a1) 2.0, pK(a2) 4.0, pK(a3) 6.3, and pK(a4) 9.6). Attempts to grow single crystals of this highly water-soluble yellow crystalline compound lead to the silicon complex [((C5H5)Co[P(O)(OH)2]2[P(O)2(OH)])(2)Si].8 H2O (5). The crystal structure determination shows that it is a molecular complex of two tris-phosphonic acids that each act as a tris-chelating ligand. Additional water molecules form a complex net of hydrogen bonds between the complexes of 5. The SiO6 octahedron is only insignificantly distorted with Si-O bond lengths of 1.78 A. Complex 4 reacts with stoichiometric amounts of potassium carbonate to yield the potassium salt K[(C5H5)Co(P(O)(OH)2)3] (6). The crystal structure of 6 has also been determined. In the solid state it is a two-dimensional coordination polymer with each potassium ion being coordinated by twelve oxygen atoms of six tris-phosphonic acids.

Die Kristallstruktur des 1:1-Komplexes von Antimontrichlorid und 2.2′-Bipyridin / The Crystal Structure of the 1:1 Complex of Antimony Trichloride and 2,2′-Bipyridine

The crystal structure of the complex compound of SbCl3 with a chelating bipyridyl group was determined. Sb(C10H8N2)Cl3 crystallizes in the space group P21/c with a = 818.9(4), b = 695.8(7), c = 2331.3(12) pm, β = 103.59(4)° and Z = 4 molecules per unit cell. The SbCl3 fragment is T-shaped with at 254.7 pm. Taking into account also the N atoms of the chelating 2,2′-bipyridyl group ( = 228.1 pm) and an intermolecular Sb···Cl contact at 334.0 pm the Sb coordination is distorted octahedral.

Vierkernige Molybdän-Schwefel-Cluster mit Dithiophosphinatoliganden / Tetranuclear Molybdenum-Sulfur-Clusters with Dithiophosphinato Ligands

Tetranuclear clusters Mo4S4(R2PS2)6 (4) (a: R = Et, b: R = Pr) with cubane-like cores are conveniently obtained by reacting equimolar quantities of Mo3S4(Et2PS2)4, Mo(CO)6 and R2P(S)-S-S-P(S)R2. 31P NMR and MS data of 4 are reported and the magnetic properties are discussed. 4a crystallizes triclinically with a = 1159.41(6), b = 1162.77(7), c = 2228.54(14) pm, α = 102.660(3), β = 98.382(4), γ = 98.546(5)°. P1̅, Z = 2. The molecule consists of a distorted Mo4S4 cubane. Each Mo atom is coordinated by six S atoms: three within the cubane, two from a bidentate and one from a chelating dithiophosphinato ligand. Two Mo -Mo distances are short- ened by the chelate to an av. of 278.6 pm, while the av. of the remaining four Mo -Mo distances is 287.9 pm.

Das dynamische Verhalten des Hydridotris(3,5-dimethylpyrazolyl)borat-Liganden in Organopalladium(II)-Komplexen

Die neuen Organopalladium(II)-Komplexe [PdTp*(R)(PPh3)] (R = Me (1), C(O)Me (1 a), p-tol (2), C(O)p-tol (2 a)) des dreizahnigen Stickstoffliganden Tp* = [HB(3,5-Me2pz)3]– sind bei Raumtemperatur nicht-starre Molekule auf der NMR-Zeitskala. Die 1H-NMR-Spektren zeigen bei tiefer Temperatur fur 1 Cs-Symmetrie wahrend 1 a, 2, 2 a symmetrielos sind (C1). Die unterschiedlichen Temperaturabhangigkeiten der 1H-NMR-Spektren konnen auf den gleichen Austauschmechanismus, namlich intramolekulare Substitution von koordinierten Pyrazolylringen durch den nicht-koordinierten Pyrazolylring, zuruckgefuhrt werden. Eine rasche Turnstile-Rotation eines trigonal-bipyramidalen Intermediates wird nicht beobachtet. Die Kristallstrukturanalyse ergab fur das Palladiumatom im Komplex 1 planare Koordination. The Dynamic Behaviour of Hydridotris(3,5-dimethylpyrazolyl)borate Ligand in Organopalladium(II) Complexes The new palladium(II) complexes [PdTp*(R)(PPh3)] (R = Me (1), C(O)Me (1 a), p-tol (2), C(O)p-tol (2 a)) of the tridentate nitrogen ligand Tp* = [HB(3,5-Me2pz)3]– are non-rigid molecules on the NMR time scale at room temperature. The 1H-NMR spectra at low temperature indicate Cs-symmetry for 1 whereas 1 a, 2, 2 a are symmetryless (C1). The difference in temperature dependence of the 1H-NMR spectra is not indicative of a different exchange mechanism. We postulate that in all cases an intramolecular substitution of coordinated and non-coordinated pyrazolyl substituents takes place. We do not observe a rapid Turnstile rotation of a trigonal bipyramidal intermediate. The crystal structure analysis shows that the coordination of the palladium atom in complex 1 is planar.

(R)-5-[(1R,2R)-1-Ethyl-2- (4-oxocyclohexyl)butyl]oxepan-2-one, an Enantiopure ‘Pseudosteroid′

The title compound C18H30O3 represents an optically pure member of a class of ‘pseudosteroids’, i. e. perhydrostilbene derivatives which mimic steroidal androgens (in the way like hexestrols or stilbestrols serve to substitute natural estrogens). The molecule 2 is characterized by three consecutive chiral centers leading to eight possible stereoisomers including four diastereomers. All enantiomers have been separated and their biological profile has been determined. As the result of the crystal structure presented here the two symmetry independent molecules display the configuration R,R,R at the centers of chirality.

1,2-deoxygenation of vic-dihydroxyindenoimidazoles: Optimization of a novel deoxygenation reagent

Abstract Treatment of vic-dihydroxyindeno[1,2-d]imidazoles with N,N,N’,N’-tetraalkyl sulfurous diamides yields indeno[1,2-d]imidazoles by deoxygenation. Isochromeno[3,4-d]imidazoles are formed as byproducts. An X-ray crystal structure analysis confirmed the structure of deoxygenated products. The ratio of products depending on the reaction conditions was analyzed. A mechanism of the reaction is discussed.

Amidinadditionsprodukte des 1,2,3-Indantrionhydrats: Synthese und Strukturzuordnung durch Kristallstrukturanalyse, spektrale Daten und Blei(IV)acetatoxidation / Products of Amidinaddition to 1,2,3-Triketohydrindenhydrat: Synthesis and Determination by Crystal Structure, Spectral Data and Oxidation with Lead(IV)acetate

The addition of amidines to 1,2,3-triketohydrindenhydrat gives cyclic dihydroxyindenoimidazoles. From N-substituted amidines mixtures of regioisomeric derivatives were obtained. Analysis of crystals revealed the major product of 2k to be 4k. They belong to the monoclinic space group P21/c (a = 889.1(2); b = 1186.6(3); c = 2783.5(7) pm; β = 91.26(2)°) with Ζ = 8 molecules including four molecules of ethanole per unit cell. These results were confirmed by oxidation with lead(IV)acetate, which lead to derivatives of isoindols.