Bildung von Chelat-Liganden aus Pseudohalogenid und Pyrazol in der Koordinationssphäre von PdII und PtII

Formation of Chelate Ligands from Pseudohalide and Pyrazole in the Coordination Sphere of Pd^II and Pt^II New Pd^II and Pt^II complexes of the composition M(L · X)₂ were prepared (X = NCO^?), N(CN), C(CN), L = pyrazole (Pz), 3, 5-dimethylpyrazole (Dmpz) and studied applying IR spectroscopy. The complexes are obtained by nucleophilic addition of imine nitrogen from the pyrazole ring to the carbon from the pseudohalide anion. When the neutral ligand was Dmpz the reaction ran partially anly. With NCS^? and pz only the complex Cu(NCS)₂(Pz)₂ is yield.     

Der Einfluß der Koordinationssphäre von Samarocenen auf die Synthese von flüssigkristallinen Polymethacrylaten

The Influence of the Coordination Sphere of Samarocenes on the Synthesis of Liquid Crystalline Polymethacrylates (C₅Me₅)₂Sm(THF)₂ ( 1 ) reacts with 1,3‐Diisopropyl‐4,5‐dimethylimidazoline‐2‐ylidene C₃N₂Me₂iPr₂ (iPr‐carben) with formation of (C₅Me₅)₂Sm(iPr‐carben) ( 3 ). The reaction of (C₅Me₄Et)₂Sm(THF)₂ ( 2 ) with Al₂Me₆ in toluene yields [(C₅Me₄Et)₂Sm(CH₃)Al(CH₃)₃]₂ ( 6 ). 3 and 6 were characterized by single crystal X‐ray structure analysis. Via living polymerization of mesogenic methacrylates with the organosamarium complexes 1 , 2 , 3 , (C₅Me₅)₂Sm(C₃H₅) ( 4 ), (C₅Me₅)₂Sm(CH₃)(THF) ( 5 ), 6 , and (C₅Me₄Et)₂SmCH(SiMe₃)₂ ( 7 ), liquid crystalline homo‐ and blockcopolymers were obtained with narrow molecular mass distribution indexes in high yield. Partial competitive mechanisms are observed dependend of the structure of the catalyst and the polarity of the solvents.     

Dichlorphosphatokomplexe der Nitridchloride von Molybdän und Wolfram

Dichlorophosphate Complexes of the Nitrido Chlorides of Molybdenum and Tungsten Tetraphenylarsonium dichlorophosphate AsPh₄[PO₂Cl₂], is prepared by the reaction of AsPh₄Cl with P₂O₃Cl₄. The vibrational spectrum is reported as well as the valence force constants of the [PO₂Cl₂]^? ion. The f-values are clearly smaller than those of the isoelectronic SO₂Cl₂ molecule. The dichlorophosphate ion forms complexes with the nitride chlorides MNCl₃ (M ? Mo, W) of the type [MNCl₃(PO₂Cl₂)]₂^2?, which are characterized by their i.r. spectra.     

Untersuchungen zur Sb–Sb‐Bindungsknüpfung in der Koordinationssphäre von Übergangsmetallen

Investigations of Sb–Sb Bond Formation Reactions in the Coordination Sphere of Transition Metals The reaction of SbCl₃ with various transition metal metalates of the type K[ML_n] [ML_n = Ni(CO)Cp*, Fe(CO)Cp′, Co(CO)₄; Cp* = η⁵‐C₅Me₅, Cp′ = η⁵‐C₅H₄Me] in the presence of [Cr(CO)₅thf] have been studied. With K[Ni(CO)Cp*] and K[Fe(CO)₂Cp′] the trigonal‐pyramidal complexes [(μ₃‐Sb){Ni(CO)Cp*}₃] ( 1 ) and [(μ₃‐Sb){Fe · (CO)₂Cp′}₃] ( 2 ), respectively, are obtained. The reaction with K[Co(CO)₄] leads to the tetrahedral cluster [Co₃(CO)₉(μ₃‐Sb{Cr(CO)₅})] ( 3 ) and the butterfly cluster [Co₂(CO)₆(μ‐SbCl)(μ‐SbCl{Cr(CO)₅})] ( 4 ). All products are characterised by X‐ray crystal structure determination. In contrast to the corresponding [(CO)₅CrPCl₃] system forming P–P bonds, starting from SbCl₃/[Cr(CO)₅thf] does not cause a Sb–Sb bond formation.     

Untersuchungen zur P–P‐Bindungsknüpfung in der Koordinationssphäre von Übergangsmetallen

Investigations of P–P Bond Formation Reactions in the Coordination Sphere of Transition Metals The reaction of [CpW(CO)₃]^– with PCl₃ leads to the transition metal substituted dichlorphosphines [{CpW(CO)₃}PCl₂] ( 1 ) and [{Cp(CO)₃W}PCl₂{WCl(CO)₂Cp}] ( 2 ). The X‐ray structure of 2 reveals the Lewis acid/base character of this compound. Reactions of 1 and [Cr(CO)₅Cp*PCl₂], respectively, with metalates of the type [M(CO)₃Cp′]^– (M′ = Mo, W; Cp′ = η⁵‐C₅H₄tBu) afford the cyclo‐P₃ complexes [(η³‐P₃)MCp′(CO)₃] ( 3 ) (M = W) and ( 4 ) (M = Mo) and the compounds [(μ,η²‐P₂{Cr(CO)₅}₂){Mo(CO)₂Cp}₂] ( 5 ) and [{μ₃‐PW(CO)₃Cp′}{W(CO)₂Cp′}₂] ( 6 ), respectively. Complex 6 possesses a planar homoleptic W₃P moiety revealing delocalised multiple bonds within the W₂P‐subunit. Reducing [(CO)₅WPCl₃] with magnesium leads to the formation of the phosphinidene complex [{(CO)₅W}₂PCl], whereas the reduction of [CpW(CO)₃PCl₂] ( 1 ) with magnesium yields the cyclo‐P₃ complex 3 together with P₄ phosphorus.