Carsten Thöne

Synthesis and Structural Studies of Pyridine‐2‐selenolates − Reactions with Electrophilic Phosphorus(III) Compounds and Related Complex Chemistry

The reaction intermediates in the synthesis of 2,2′-bis(pyridyl) diselenide (2,2′-Py2Se2) have been determined. The reaction of Na2Se2 with 2-BrC5H4N (2-BrPy) leads to a tautomeric mixture of pyridine-2-selenol (2-PySeH) and pyridine-2(1H)-selone (2-PyHSe), which have been investigated by spectroscopic means. Additionally, the crystal structure of the latter has been determined. Reductive cleavage of the Se−Se bond in 2,2′-Py2Se2 with KBsBu3H leads to K-2-SePy, which was trapped, either as [(18-crown-6)K]+[2-PySe]−, whose structure contains polymeric cation−anion chains, or as [Et4N]+[2-PySe]−. Reactions of K-2-SePy or [Et4N]+[2-PySe]− with Ph2PCl, tBu2PCl, or tBuPBr2 lead to the corresponding, extremely air-sensitive (pyridyl)selenophosphanes Ph2P-2-SePy, tBu2P-2-SePy, and tBuP(2-SePy)2. The latter was trapped as tBuP(O)(2-SePy)2, whose crystal structure has been determined. Metal complexes of these (pyridyl)selenophosphanes have been prepared starting from the phosphane and CuBr, AgBr, (tht)AuCl (tht = tetrahydrothiophene), or [(η6-C7H8)Mo(CO)3], in one-pot syntheses. All crystal structures of the resulting metallacycles [({(C5H4N-2-Se)tBu2P}-N,P)Cu(µ-Br)]2, [({(C5H4N-2-Se)tBu2P}-N,P)Ag(µ-Br)]2, [({(C5H4N-2-Se)tBu2P}-P)AuCl], and [({(C5H4N-2-Se)2tBuP}-N,N′,P)Mo(CO)3], were determined. Additionally, comprehensive spectroscopic investigations are presented.

Mono- and binuclear copper(II) complexes of saccharin with 2-pyridinepropanol synthesis, spectral, thermal and structural characterization

Mono- and binuclear copper(II) saccharinate (sac) complexes containing 2-pyridinepropanol (pypr) have been prepared and characterized by elemental analyses, i.r., u.v.–vis., magnetic measurements and single crystal X-ray diffraction. The copper(II) ion in trans-[Cu(pypr)2(sac)2] has −1 site symmetry and is octahedrally coordinated by two bidentate neutral pypr (N, O) and two sac (O) ligands. The binuclear copper(II) complex, [Cu2(μ-pypr)2(sac)2], is built up around a centre of symmetry and contains two strongly distorted square–planar coordinated copper(II) ions bridged by two alkoxo groups of the deprotonated pypr ligand, which also coordinates to the copper(II) ions through its nitrogen. In contrast to the mononuclear complex, the sac ligands in the binuclear complex is N-coordinated. The binuclear complex exhibits diamagnetic behaviour. The i.r. spectra and thermal decompositions of both complexes are described.

Different Coordination Modes of Saccharin in the Complexes of Lead(II) with 2-Pyridylmethanol and Pyridine-2, 6-dimethanol — Synthesis, Spectral and Structural Characterization

New lead(II)-saccharin complexes, [Pb(sac)2(pym)] (1) and [Pb(sac)2(pydm)] (2) (sac = saccharinate anion; pym = 2-pyridylmethanol; pydm = pyridine-2, 6-dimethanol) were synthesized and characterized by IR spectroscopy and single crystal X-ray diffractometry. Complex 1 crystallizes in the monoclinic P21/c space group with Z = 4, while the crystals of complex 2 are extremely X-ray sensitive and decompose by the X-ray beam within one day. Pym and pydm act as bi- and tridentate ligands, respectively. Most important feature of the complexes is non-equivalent coordination of the sac ligands to the lead(II) atom. In the complex 1, the sac ligands coordinate to the lead(II) ion in two distinct manners. One sac ligand behaves as a bridge between the lead(II) atoms through its N and carbonyl O atoms, whereas the other sac ligand acts as a bidentate chelating ligand through its N and carbonyl O atoms which is bicoordinating and also bridges the metal atoms to achieve the seven-coordination. The structure is built up of three-dimensional chains formed by the bridging of the PbN3O2 units and also held intermolecular hydrogen bonds. The IR spectra of the complexes were discussed in detail. Unterschiedliche Koordination von Saccharin in den Komplexen von Blei(II) mit 2-Pyridylmethanol und Pyridin-2, 6-dimethanol — Synthese, spektroskopische und strukturelle Charakterisierung Neue Blei(II)-Saccharin-Komplexe, [Pb(sac)2(pym)] (1) und [Pb(sac)2(pydm)] (2) (sac = Saccharinat-Anion; pym = 2-Pyridylmethanol; pydm = Pyridin-2, 6-dimethanol) wurden synthetisiert und durch IR-Spektroskopie und Einkristall-Rontgenanalyse charakterisiert. 1 kristallisiert monoklin, Raumgruppe P21/c mit Z = 4, wahrend die Kristalle von 2 extrem rontgenempfindlich sind und im Rontgenstrahl innerhalb eines Tages zerfallen. Pym und pydm sind zwei- bzw. dreizahnige Liganden. Die wichtigste Besonderheit der Komplexe ist die unterschiedliche Koordination der Saccharinat-Liganden am Bleiatom. Im Komplex 1 koordinieren die Saccharinat-Liganden in zwei unterschiedlichen Weisen. Ein sac-Ligand bildet eine Brucke zwischen den Blei(II)-Atomen uber seine N- und Carbonyl-O-Atome, wahrend der andere sac-Ligand als zweizahniger Chelatligand uber seine N- und Carbonyl-O-Atome die Metallatome zweifach koordiniert und verbruckt, die dadurch Siebenerkoordination erreichen. Die Struktur ist aus dreidimensionalen Ketten aufgebaut durch die Verbruckung der PbN3O2-Einheiten und wird uber zwischenmolekulare Wasserstoffbruckenbindungen zusammengehalten. Die IR-Spektren werden im einzelnen diskutiert.

Organometallic selenolates. Part 2. A new synthesis of dimeric (selenolato) tetracarbonylmanganese(I) complexes. Crystal structures of [Mn(CO)4SeR]2; R = CH2 Ph, C(O) Ph and CO2Me

Abstract Dimeric selenolato-carbonyl manganese(I) complexes [Mn(CO) 4 SeR] 2 (R = CH 2 Ph, C(O)Ph, CO 2 Ph, CO 2 Me) have been synthesised via reaction of elemental selenium with NaMn(CO) 5 and subsequent reaction with the corresponding organohalides in one-pot syntheses. They have been characterised by spectroscopic methods ( 1 H, 13 C, 77 Se) and the chemical shifts have been compared with the assumed reaction intermediate [Mn(CO) 4 Se] 2 Na 2 . Additionally, X-ray crystal structure analyses have been performed for [Mn(CO) 4 (SeR)] 2 (R = CH 2 Ph, C(O)Ph, CO 2 Me).

Synthesis, Crystal and Molecular Structure of 2‐Pyridylethanolbis(saccharinato)mercury(II)

2-Pyridylethanolbis(saccharinato)mercury(II), [Hg(sac) 2 (pyet)], where sac and pyet are the saccharinate anion and the 2-pyridylethanol molecule, respectively, crystallizes in the triclinic space group P1 (No. 2) with a = 10.4518(6), b = 11.3796(6) (5), c = 19.9945(12) A, a = 102.758(3)° β = 98.146(3)°, γ = 104.751(3)°, Z = 4, V = 2193.0(2) A 3 . The unit cell contains two crystallographically independent [Hg(sac) 2 (pyet)] units in which the mercury(II) ion is tetrahedrally coordinated by two nitrogen atoms of two sac ligands, and one nitrogen and one oxygen atoms of one neutral pyet ligands. The pyet acts as a bidentate N- and O-donor ligand forming a six-membered chelate ring, while sac behaves as a monodentate N-donor ligand. The average bite angle of the pyet ligand is 75.8(5)°. The Hg-N sac bond distances are in the range 2.0874(18) and 2.1931(18) A, whereas the Hg-N pyet and Hg-O pyet bond distances are 2.2452(19)-2.3202(19) and 2.6036(17)-2.5902(16) A, respectively. The crystal exhibits two strong hydrogen bonds between the hydroxyl O atom of pyet and sulfonyl O atoms of sac and the C-H...O type weak hydrogen bonds between H atoms of the aromatic rings of the pyet and the sulfonyl O atoms of the sac ligands. Furthermore, packing of the molecules in the solid-state results in aromatic π-π interactions associated with the aromatic rings of sac-sac and py-py.

Syntheses, spectroscopic and structural studies of indenyl ruthenium complexes incorporating amine and nitrile ligands: molecular structures of [(η5-C9H7) Ru(η2-dppe)(CH3CN)]PF6 and [(η5-C9H7)Ru(η2-dppe)(NH3)]PF6

The reaction of [(η5-C9H7)Ru(η2-dppe)Cl] (1) with monodentate nitriles, (L) in the presence of NH4PF6 afforded the complexes [(η5-C9H7)Ru(η2-dppe)(L)]PF6, with L = CH3CN (2a), CH3CH=CHCN (2b), NCC6H4CN (2c), C6H5CH2CN (2d), respectively. However, reaction of 1 with NH4PF6 in methanol yielded an amine complex of the type [(η5-C9H7) Ru(η2-dppe)(NH3)]PF6 (3a). The complexes were fully characterized by spectroscopy and analytical data. The molecular structures of the complexes [(η5-C9H7)Ru(η2-dppe) (CH3CN)]PF6 (2a) and [(η5-C9H7)Ru(η2-dppe)(NH3)]PF6 (3a) have been determined by single crystal X-ray analyses.

Synthesis, spectra, thermal analysis and crystal structure of a mononuclear oxalato-copper(II) complex with monoethanolamine, [Cu(mea)2(ox)]

cis-bis(Monoethanolamine)oxalatocopper(II), cis-[Cu(mea)2(ox)], has been prepared and characterized by elemental analyses, IR, UV–Vis, thermal analysis and single crystal X-ray diffraction. The title complex crystallizes in the triclinic form with space group. The copper(II) ion lies on a center of symmetry and is octahedrally coordinated by two bidentate neutral mea (N,O) and one bidentate ox (O,O′) ligands. The individual molecules are held together by an extensive three-dimensional network of O–H···O, N–H···O and C–H···O type intermolecular hydrogen bonds. The IR spectrum and thermal decomposition of the title complex are described.

Dalton communications. A new route to organometallic selenolate complexes of tungsten(II) and molybdenum(II). Crystal structure of [W(η5-C5H5)(CO)3(SeCH2Ph)]

Molybdenum(II) and tungsten(II) organoselenolate complexes were synthesised via selenium insertion into the corresponding metal–lithium bonds and subsequent reactions with organohalides.

Synthesis and Properties of Organogermanium and Organotin Dithiophosphonate Complexes; Crystal Structures of (C6H5)2Sn(Cl)[(p-MeOC6H4)(EtO)PS2−S, S′], Me2Sn[(p-MeOC6H4)(MeO)PS2-S]2, Me2Sn[(p-MeOC6H4)( i PrO)PS2-S]2, and Me2Ge{[(C6H5)3SiO](p-MeOC6H4)PS2-S}2

2,4–Bis-(4-methoxyphenyl)-1,3,2λ5,4λ5-dithiadiphosphetane-2,4-disulfide (Lawessons reagent) reacts with a variety of alcohols and silanols to form dithiophosphonic acids in a facile manner. Their lithium salts react with organotin- and organogermanium chlorides to produce organometallic dithiophosphonate complexes of the type A R3“M[S(S)P(R)(OR′)] (M = Ge, Sn; R = 4-MeOC6H4; R′ = Me, SiPh3, GePh3, SnPh3; R″ = Me, Ph) and B R2”M[S(S)P(R)(OR′)]2 (M = Ge, Sn; R = 4-MeOC6H4; R′ = Me, Et, i Pr, tBu, SiPh3; R″ = Me, Ph). The ligands in the new organometallic compounds are bound in an asymmetric fashion as revealed by four X-ray structure determinations, containing one representative example of type A and three examples of type B . All new compounds are fully characterized by analytical and spectroscopic methods.

Zur Koordinationschemie des 2,2′-Dipyridyldiselenids (PySeSePy), Teil 2 [1] Komplexe mit Mangan, Kupfer und Zink/ The Coordination Chemistry of 2,2′-Dipyridyldiselenide (PySeSePy), Part 2. Complexes with Manganese, Copper and Zinc

Abstract The coordination chemistry of 2,2′-dipyridyldiselenide (PySeSePy) towards manganese, copper and zinc centres has been studied. The complexes [MnBr2-N,N′-(PySeSePy)] (1), [CuBr2-N,N′-(PySeSePy)] (2), [Cu-(μ-Br)-N,N′-(PySeSePy)]2 (3), [Cu-(μ-Br)-{μ-N,N′-(PySeSePy)}]n (4), [Cu-(μ-Cl)-N,N′-(PySeSePy)]2 (5), [Zn(OOCC6F5)2-N,N′-(PySeSePy)] (6) and [Zn (OSO2CF3)2-N,N′-(PySeSePy)] (7) have been synthesised and the crystal structures of 1, 3, 4 and 6 determined. 1, 3 and 6 display seven-membered metallacycles with tetrahedral coordination of the metal centres. In these cases 2,2′-dipyridyldiselenide acts as a chelating ligand. In the polymeric complex 4, 2,2′-dipyridyldiselenide acts as a bridging ligand. All com plexes display selenium-selenium single bonds with an average length of 232 pm. In contrast to the analogous chloro and nitrato complexes, the zinc complexes 6 and 7 are not dissociated in solution, as evidenced by 77Se NMR experiments. The corresponding resonances are shifted downfield in comparison with the ligand.