Hans‐Otto Fröhlich

Beiträge zur chemie organometallischer metallacyclischer nebengruppenmetallverbindungen: VI. Synthese und eigenschaften von zincacyclohexankomplexen des typs {Li(D)2}2Zn(CH2CH2CH2CH2CH2)2 (D (C2H5)2O; 2D (CH3)2NC2H4N(CH3)2); Molekülstruktur von {Li(CH3)2NC2H4N(CH3)2}2Zn(CH2CH2CH2CH2CH2)2☆

Abstract ClCH2(CH2)3CH2Cl reacts with lithium/sodium-alloy (1% sodium) and ZnCl2 in ether (Et2O) to give {Li(Et2O)2}2 Zn(CH 2 (CH 2 ) 3 C H2)2 (1) (yield 80%). DTA investigations showed that thermal decomposition of 1 takes place at 172°C. By addition of (CH3)2NC2H4N(CH3)2 (tmed) to 1 in ether, {Li(tmed)}2 Zn(CH 2 (CH 2 ) 3 C H2)2 (2) was formed. Both complexes were characterized by 1H and 13C NMR spectroscopy and 2 by X-ray diffraction methods.

Beiträge zur chemie organometallischer metallacyclischer nebengruppenmetallverbindungen

Abstract A new synthetic route to Li 2 Ni(C 4 H 8 ) 2 (Solv) x (Solv = diethylether, Et 2 O, x = 1 ( 1 ); tetramethylethylendiamin, TMED, x = 2 ( 2 ); tetrahydrofuran, THF, 4 ( 3 )) is described. (Li(THF) 2 ) 2 Ni(C 4 H 8 ) 2 ( 3 ) has been characterized by X-ray studies. The 1 H and 13 C NMR spectral properties of the metallacycles are reported.

Beiträge zur chemie organometallischer metallacyclischer nebengruppenmetallverbindungen XII. Synthese, NMR-spektroskopische untersuchung und kristallstruktur von 1—vergleichende DTA-untersuchungen von 1 und unsubstituierten nickelacyclopentan-komplexen der zusammensetzung (L = TMEDA, THF, d8-THF)

The complex 1 was synthesized with good yield by treatment of NiCp2 with the dilithium compound LiCH2CMe2CMe2CH2Li 2. It was characterized by elemental analysis, 1H and 13C NMR and X-ray spectroscopy. The crystal data and the final R values are as follows: crystal system: orthorhombic, space group Pnma (No. 62) with cell parameters a = 17.849(3) A, b = 13.138(2) A, c = 14.516(1) A, Z = 4 and R = 0.062, RW = 0.060. The average distance LiNi (2.506(7) A) is only little larger than the sum of the covalence radii of the two elements (2.38 A). According to DTA studies, the following decomposition temperatures of the complexes 1, 3, (L = THF 4, d8-THF 5) resulted: 1 (234°C), 3 (182°C), 4 (108°C), 5 (108°C). Surprisingly they vary considerably. After the DTA measurement, the gas phases above the solid decomposition residues were analyzed by gas chromatography and mass spectroscopy. The results of these investigations are reported.

Beiträdge zur chemie organometallischer metallacyclischer nebengruppenmetallverbindungen: VIII. Synthese und Eigenschaften von Li2Pd-(CH2(CH2)2CH2)2 (D)x - Molekülstruktur von [Li(THF)2]2Pd-(CH2(CH2)2CH2)2

[(Et2O)Li2Pd-(CH2(CH2)2CH2)2] (1) was prepared by treatment of (1,5-COD)PdCl2 with Li(C4H8)Li in diethyl ether. By substituting other n-donor for the diethyl ether in 1, derivatives of the composition [(D)xLi2Pd(CH2(CH2)2CH2)2] (D= N,N, N′,N′-tetramethylethylenediamine (TMEDA), x = 2 (2); N,N,N′,N′,N″-pentamethyldiethylenetriamine (PMDETA), x = 2 (3); tetrahydrofuran (THF), x = 4 (4)) are obtained. The complexes 1-4 have been characterized by elemental and DTA analysis, and complexes 2 and 3 by 1H and 13C NMR spectroscopy as well. The crystal structure of 4 has been determined by an X-ray diffraction study. The crystal data and the final R values are as follows: space group P1 (Z = 1) with cell parameters a = 9.060(7) A, b = 9.126(9) A, α = 9.723(6) A, α = 107.46(4)°, β = 91.20(4)°, γ = 116.23(3)°, R = 0.041, Rw = 0.050. The structural details are discussed. The first results of the reaction of 2 with CO are described, and IR investigation of the reaction mixture suggest that carbonyl cluster dianions of the composition [Pd3(CO)3(μ2-CO)3]n2− are present in solution. Other products of this reaction are 1-butyleyclopentanol, cyclopentanone and cyclopentanol.

Beiträge zur chemie organometallischer metallacyclischer nebengruppenmetallverbindungen: IX. Eine ungewöhnliche koordinationsgeometrie des platin(II) in dem homoleptischen metallacyclopentankomplex [Li(PMDETA)]2Pt(CH2CH2CH2CH2)2☆

Abstract Reaction of [Li2(Et2O)]P t(CH 2 CH 2 CH 2 C H2)2 (1) with N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) in diethylether (Et2O) gives [Li(PMDETA)]2P t(CH 2 CH 2 CH 2 C H2)2 (2). The complex has been characterized by DTA analysis, 1H and 13C NMR spectroscopy and X-ray crystallography. The thermal properties and the structures of 2 and [Li(TMEDA)]2P t(CH 2 CH 2 CH 2 C H2)2 (3) indicate the significant difference of the influence of PMDETA and N,N,N′,N′-tetramethylethylenediamine (TMEDA) on the platinacyclopentane system.

XIII. Synthese und Eigenschaften von [Li(TMEDA)]2Pt(CH2CMe2CMe2CH2 )2(1) ; Vergleich der Zersetzungstemperaturen von Metallacyclopentan-Komplexen des Pt(II) und Ni(II) des Typs (1) mit und ohne β-Wasserstoff; Kristallstruktur von (COD) PtCH2SiMe2SiMe2CH2 (8)☆

Abstract The air-sensitive complex [Li(TMEDA)]2 Pt(CH 2 CMe 2 CMe 2 C H 2 (1) was synthesized in 50% yield by treatment of (COD)PtCl 2 with LiCH 2 CMe 2 CMe 2 CH 2 Li. This “at-complex” was characterized by elementary analysis as well as by 1H and 13C NMR spectroscopy. DTA investigations showed the following thermal decomposition temperature: Tdec. = 163°C. This decomposition temperature is significantly lower than those of the complexes [Li(TMEDA)]2 Pt(CH 2 CHRCHRC H 2 ) 2 (R=H (5), (R = HTdec. = 249°C; R = CH3 (6), [Li(TMEDA)]2 Ni(CH 2 CMe 2 CMe 2 C H2)2 (R = H (3), Tdec. = 182°C; R = CH3 (4), Tdec. = 172°C). Attempts to prepare an “at-complex” containing heteroatoms in the metallacyclic ring adding diethyl ether solution of LiCh2SMe2SMe2CH2Li (7) to CODPtCl2 unsuccessful. The reaction gave (COD) PtCH 2 SiMe 2 PtCH 2 SiMe 2 C 2 (8) (yield: 80%). The complex was characterized by mass spectroscopy and X-ray diffraction. The crystal data and the final R values are as follows: crystal system: monoclinic, space group P21/n with cell parameters a = 6.369(1) A , b = 20.016(2) A , c = 12.913(2) A , β = 94.42(1)°, Z = 4, R = 0.039, Rw = 0.047. The average distance PtC (in the 1-platina-3,4-disilacyclopentane ring) is 2.063(7) A and the angle CH2PtCH2 is 86.2(3)°.

Beiträge zur chemie organometallischer metallacyclischer nebengruppemetallverbindungen XI. Synthese und charakterisierung von und seine umsetzung mit CH3I und einem C22-steroidiodid

Abstract reacts with 2 mol of CO 2 to form a seven-membered cyclic nickel compound of the type I . No ring contraction has been observed in this complex. Acidolysis of the product of the cross-coupling reaction of I with CH 3 I gives caproic acid. The reaction of I with the C 22 -steroid iodid V can be used for the formation of the C 27 -steroid carboxylic acid VI .