Falk Olbrich

Novel 18-crown-6 organometallic rubidium and cesium complexes containing cyclopentadienyl, indenyl, pentamethylcyclopentadienyl, and fluorenyl as carbanions

Abstract The synthesis of base-free cyclopentadienyl-, indenyl-, pentamethylcyclopentadienyl-, and fluorenylrubidium and -cesium is described. Reactions of these compounds with the hexadentate Lewis base 18-crown-6 yielded new complexes of the type [MR(18-crown-6)] and [{RbFl(18-crown-6)}2(L)] (M=Rb, Cs; R=Cp, Ind, Cp*, Fl; L=dimethoxyethane, dioxane). All complexes were characterized by NMR spectroscopy and X-ray structure analysis. The dominating structure element in the investigated complexes is an [MR(18-crown-6)] unit in which the alkali metal ion is in close contact with the six oxygen atoms of the crown ether. In addition, a multihapto π-interaction between the cation and carbanion was found. For all isolated complexes containing the fluorenyl ligand, [MFl(18-crown-6)] and [{RbFl(18-crown-6)}2(L)], only a η2 coordination of the aromatic C–C bond between the C5- and C6-ring to the metal ions was observed.

Cyclopentadienyl, indenyl, fluorenyl, and pentamethylcyclopentadienyl complexes of potassium with 18-crown-6

Abstract The first 18-crown-6 Lewis base adducts of potassium organometallic compounds are described. The mononuclear complexes [KCp(18-crown-6)] (1), [KCp*(18-crown-6)] · 0.5THF (2a), [KInd(18-crown-6)] (3), [KFl(18-crown-6)] · 0.5toluene (4), and [{KFl(18-crown-6)}{KFl(18-crown-6)(THF)}] (5) and the binuclear complex [{KFl(18-crown-6)}2(DME)] (6) were synthesised and single-crystal X-ray diffraction analyses were carried out (Cp=cyclopentadienyl, Cp*=pentamethylcyclopentadienyl, Ind=Indenyl, Fl=Fluorenyl). The influence of the neutral ligand on the potassium–anion-interaction is discussed in a comparative study.

Ab initio structure determination of two polymorphs of cyclopentadienylrubidium in a single powder pattern

The structures of two polymorphic phases of solid RbCsH 5 have been solved ab initio by high-resolution powder X-ray diffraction measured in a single powder pattern. The compound crystallizes in space group Pbcm (phase I), Z--8, with unit-cell parameters a = 9.3396(1), b = 10.9666(1), c = 10.5490(1)A, and in space group Pnma, Z = 4 (phase II), with unitcell parameters a = 10.7990 (2), b = 8.6923 (2), c 5.7061(2)A. Both phases show polymeric zigzag chains, so-called bent-polydecker sandwich structures, with an .average Rb--Cpz (Cp-ring-centroid) distance of 2.97 A. Phase II contains a single chain along the a axis, whereas phase I contains two similar but crystallographically independent chains perpendicular to each other along the b axis and along the c axis, leading to a more complex coordination sphere around the Rb atoms. The chains are bent with Cpz--Rb--Cpz angles ranging from 123.5 to 136.5 ° .

Metallorganische verbindungen des kupfers: VII. Synthese und struktur von alkin-alkinyl-kupfer(I)-komplexen (alkin = 3,3,6,6-tetramethyl-1-thia-4-cycloheptin; alkinyl = CCC6H5, CCtC4H9)

Abstract The copper(I) complexes [CuX(tmtch)] 2 and [(CuX) 2 (dms)(tmtch)] n (X  Cl, Br; dms = dimethylsulfide; tmtch = 3,3,6,6-tetramethyl-1- thia-cyclohept-4-yne) react with ethynyllithium compounds (LiCCC 6 H 5 , LiCC t C 4 H 9 ) using halide substitution to form the previously unknown alkyne-alkynyl-copper(I)-complexes [CuCCC 6 H 5 (tmtch)] 2 ( 2 ) and [(CuCC t C 4 H 9 ) 4 (tmtch) 2 ] ( 3 ). Both novel complexes have been characterized by X-ray diffraction studies.

Metallorganische Verbindungen des Kupfers. Synthese und Struktur von komplexen des 3,3,6,6-Tetramethyl-1-thia-4-cycloheptins mit Kupfer(I)-Halogeniden

Abstract 3,3,6,6-Tetramethyl-1-thia-4-cycloheptyne (C 10 H 16 S) ( 1 ) reacts with copper(I)-halogenides-dimethylsulfid to give η 2 -(CC) coordinated copper complexes [(C 10 H 16 S) 2 CuX] 2 ( 2 ) (X = Cl, Br, I). Reaction of CuCl(dms) with 0.5 mol of C 10 H 16 S ( 1 ) in the presence of dimethylsulfide yields the polymeric complex [(C 10 H 16 S)Cu 2 Cl 2 (CH 3 SCH 3 )] n ( 3 ). X-ray diffraction studies of 2a (X = Cl) and 3 confirm the η 2 -(CC) coordination of the thiacycloheptyne ligand 1 in both complexes. Additional coordination of the sulphur atom to copper in complex 3 leads to a polymeric structure.

Metallorganische Verbindungen des Kupfers. V: Synthese und Struktur von Komplexen des 3,3,6,6-tetramethyl-1-thia-4-cycloheptins mit Kupfer(I)-Bromid, -Iodid und -Cyanid

Abstract Due to ring strain in the cycloalkyne 3,3,6,6-tetramethyl-1-thia-4-cycloheptyne (TMTCH, C10H16S), the CC group shows unusual coordinating properties towards CuI. Thus copper(I)bromidedimethylsulfide reacts with half a mole of TMTCH in dimethylsulfide (DMS/THF) with formation of the polymeric complex [(CuBr)2(dms)(η2-tmtch)]n (2b). Using [Cul(dms)] an analogous iodo compound was not obtained. However, [CuI(η2-tmtch)]2 (1c) reacts with dimethylsulfide under formation of monomeric [CuI(dms)(η2-tmtch)] (3). The reaction of coppercyanide with an excess of TMTCH yields the first example of an alkyne cyano copper complex [CuCN(η2-tmtch)]4 (4); it contains a slightly puckered Cu4(CN)4 ring. Hitherto no structures of (η2-alkyne)CuX complexes with X = I or CN have been described.

Über metallalkyl- und arylverbindungen LV. Cyclopentadienyl- und indenyl-verbindungen des kaliums und natriums☆

Abstract The syntheses and crystal structures of the following solvated compounds are described: [cyclopentadienyl potassium(Et 2 O)] n ( 1 ) (multidecker structure), [indenyl sodium(PMDTA)] ( 2 ) (PMDTA = N,N,N′,N″N″-pentamethyldiethylenetriamine) (monomeric), [indenyl potassium(TMEDA)] n ( 3 ) (TMEDA = N,N,N′,N′-tetramethylenediamine) (monomeric), [indenyl potassium(PMDTA)] n ( 4 ) (polymeric, zig-zag chain). The different coordination modes are the combined result of electrostatic and steric effects.

Novel fluorenyl alkali metal DIGLYME complexes: synthesis and solid state structures

Abstract The reaction of the fluorenyl alkali metals with the tridentate Lewis base diethyleneglycol–dimethylether (DIGLYME) yielded the compounds [Li(DIGLYME)2]Fl (1, Fl=fluorenide anion), [Na(DIGLYME)2]Fl (2), [KFl(DIGLYME)]3 (3), [RbFl(DIGLYME)]9 (4), [CsFl(DIGLYME)]9 (5), [NaFl(DIGLYME)]2 (6), and [(KFl)2DIGLYME]n (7). The solid state structures of all complexes were determined by X-ray single crystal structure analysis. According to the X-ray analyses, the compounds 1 and 2 crystallize as solvent separated ion pairs, the complexes 3, 4, 5, and 6 as aggregates built up by two, three, or nine MFl(DIGLYME) units, and compound 7 as a polymeric band.

Kristall‐ und Molekülstrukturen von Lithium‐ und Natrium‐tert‐butoxid

Die Kristall- und Molekulstruktur von Lithium-tert-butoxid und die deutlich verbesserte Strukturbestimmung von Natrium-tert-butoxid werden mitgeteilt. LiOtBu (1) kristallisiert in Form von hexameren Einheiten (1)6 in der monoklinen Raumgruppe C2/m mit a = 2953, 5, b = 1752, 1, c = 1008, 9 pm, s = 92, 95°, Z = 36. Die Struktur weist eine Fehlordnung der Lithiumatome auf. Die Li—O-Bindungslangen liegen zwischen 186, 1 und 198, 4 pm. NaOtBu (2) kristallisiert in der trigonalen Raumgruppe R3¯ mit a = 1919, 8, c = 4261, 2 pm, Z = 90. Hier werden sowohl hexamere (2)6 als auch nonamere (2)9 Aggregate im festen Zustand gefunden. Die Na—O-Bindungslangen liegen zwischen 222, 6 und 231, 3 pm. Crystal and Molecular Structures of Lithium and Sodium tert-Butoxide The crystal and molecular structure of lithium tert-butoxide and the markedly improved structure analysis of sodium tert-butoxide are reported. LiOtBu (1) crystallizes in form of hexameric units (1)6 the monoclinic space group C2/m with a = 2953.5, b = 1752.1, c = 1008.9 pm, s = 92.95°, Z = 36. The structure shows disorder of the lithium atoms. The Li—O bond lengths are between 186.1 and 198.4 pm. NaOtBu (2) crystallizes in the trigonal space group R3¯ with a = 1919.8, c = 4261.2 pm, Z = 90. Here both hexameric (2)6 and nonameric (2)9 units are found in the solid state. The Na—O bond lengths are between 222.6 and 231.3 pm.

Metallorganische verbindungen des Kupfers: IV. Synthese und Struktur von Alkin-Komplexen des Typs [(Alkin)CuR] (R =icr; Cyclopentadienyl, Benzamidinat)

Abstract The monuclear copper complexes[Cu(C5H5)(C10H16S)] (3) (C5H5 = cyclopentadienyl; C10H16S = 3,3,6,6-tetramethyl-1-thia-4-cycloheptyne) and [Cu(C13H23N2Si2)(C10H16S)] (4) (C13H23N2Si2 = N,N′-bis(trimethylsilyl)benzamidinate) were synthesized from [CuCl(C10H16S]2 (2a) and C5H5⊝Li⊕ and C13H23N2Si2⊝Li⊛ respectively. The structures of both new compounds 3 and 4 were determined by X-ray diffraction studies.