Preparation, characterization and reactivity of Cp2M(PMe3)2 complexes (M = Ti, Zr): the molecular structure of Cp2Zr(PMe3)2

Cationic complexes of titanium(III); phosphine substitution reactions

“…Reduction of 4 yields the known compound C P~T~( P M~~)~, 6, (33). Rausch et al have described the equilibrium in which dissociation of PMe3 from 6 occurs (reaction [4]) (34). Presumably the addition of excess PMe3 inhibits the dissociation of phosphine from the electrochemically generated 6.…”

Reduction of 2-(N,N-dimethylamino)ethyl substituted zirconocene dichlorides: Intramolecular activation of NCH2–H bond. The crystal structures of [η5:η2(C,N)-C5(CH3)4CH2CH2N(CH3)CH2][η5-C5(CH3)5]ZrX (X=Cl, H)

“…However, in absence of such stabilizer and even in case of its low concentration, complexes of the divalent metal eagerly convert to the M(III) compounds [3,4,21]. This conversion usually occurs as an insertion of the coordination-deficient metal center into a C-H [15,17,20,22] or C-heteroelement bond [2] (i.e., oxidative addition reaction) and may process in both inter-or intramolecular fusion.…”

“…of the subunit 3 in co-crystallized 2 and 3, Zr-Cl distance is somewhat longer than observed for the pure 3 (vide supra) due to the disordering of the chlorine atom in the crystal of the co-crystallized 2 and 3. It is a known fact that the Group 4 metallocene dihalides, if treated with an appropriate reagent in presence of a side ligand that exhibits both n-donor and, at least weak, p-acidic properties (CO, tertiary phosphanes or even N 2 ) can be reduced to the divalent metal complexes [15][16][17][18][19][20]. However, in absence of such stabilizer and even in case of its low concentration, complexes of the divalent metal eagerly convert to the M(III) compounds [3,4,21].…”

Experimental and Theoretical Studies of Unusual Four‐Membered Metallacycles from Reactions of Group 4 Metallocene Bis(trimethylsilyl)acetylene Complexes with the Sulfurdiimide Me3SiN=S=NSiMe3

“…How-ever, the product obtained was only characterised spectroscopically. [9] In this paper we report on an alternative synthesis of this compound as well as on its X-ray crystalstructure determination and a detailed theoretical study of its structure and bonding. Scheme 1.…”