Synthesis and Structure of a New Bis[(trimethylphosphan)titanocene] Complex with a Bridging C₂ Unit

Abstract

Synthesis and Structure of a New Bis[(trimethylphosphane)titanocene] Complex with a Bridging Cz UnitBis(trimethy1phosphane)titanocene (I) reacts with 2-methylene-1,l-diphenylcyclopropane (2) to give red crystalline (q2-2-methylene-l,l-diphenylcyclopropane)(trimethylphosphane)ti-lysis. tanocene (3). In solution complex 3 degrades smoothly to. form the new CpzTi(PMe3) -Cz -Ti(PMe3)Cpz complex 4, the crystal structure of which has been elucidated by an X-ray anaLineare, durch eine C2-Brucke verbundene Dimetallsysteme haben in letzter Zeit zunehmend Interesse gefunden, da sie je nach Art und Oxidationsstufe des Metalls in den drei valenzisomeren Formen 1 -I11 auftreten konnen.Die Zuordnung zu den verschiedenen Erscheinungsformen erfolgt im allgemeinen iiber spektroskopische Daten (z. B. Signallagen und C -C-Kopplungen in den 13C-NMRSpektren) und vor allem durch lnterpretation der durch Kristallstrukturanalyse erhaltenen M -C-und C -C-Bindungslangen in der M -C2 -M-Einheit. Am zahlreichsten sind Ethindiyldimetallkomplexe des Typs I wie Cp-

Highlights in the Renaissance of Amidometal Chemistry

“…The reduction product is a dimetallacumulene. [116] Examples of metalcarbide systems with a C 2 bridge are rare and were hitherto mainly synthesized from alkynes. [117] Scheme 26.…”

What a Difference One Electron Makes! Generating Low‐Coordinate Ti–C and V–C Multiply Bonded Frameworks through One Electron Oxidatively Induced α‐Hydrogen Abstractions

“…Their seminal work was followed‐up by Bickelhaupt and co‐workers in 1986 15a. However, it was not until 1992 that Krüger and co‐workers structurally characterized the d 0 Ti=C bonded complex (PMe 3 )Cp 2 Ti=C=C=TiCp 2 (PMe 3 ) [Ti=C, 2.051(2) Å] 19. In 1993, Fryzuk and co‐workers20 reported the synthesis and structural elucidation of the first mononuclear and terminalalkylidene [η 5 ‐C 5 H 3 ‐1,3‐(SiMe 2 CH 2 P i Pr 2 ) 2 ]Zr=CHPh(Cl).…”

Interaction mode of bridging ‘C2’ units in dinuclear complexes of late transition metals in low oxidation states: a theoretical approach †

“…A first class, we called class I, is constituted by early transition metals (those of the titanium, vanadium and chromium triads) in high oxidation states with mainly π-donor ligands, like RO Ϫ , often in a pseudo-tetrahedral co-ordination. [3][4][5][6][7] For this class of complexes all three possible valence-bond structures have been found depending on the metal d configuration. A second class, we called class II, is constituted by midto-late transition metals (from the manganese triad to the right) in low oxidation states with mainly π-acceptor ligands (like carbonyl or phosphines), often in a pseudo-octahedral coordination.…”