Tetramethyl(2-methylthioethyl)cyclopentadienyl complexes of zirconium(iv): synthesis, crystal structure, and dynamic behavior in solutions

Zirconium and titanium complexes with side-chain functionalized cyclopentadienyl ligands

“…25 Compared to bis(cyclopentadienyl) de rivatives 3 and 4, the δ( 1 H) and δ( 13 C) values for the CH 2 SCH 3 fragment in complex 2 are substantially shifted downfield (for CH 2 by ~0.7 and ~8 ppm, respectively), which is consistent with the presence of the S→Zr bond. The downfield shifts for both groups are observed along with a substantial (by 3-5 Hz) increase in the constants 1 J C,H associated with an increase in the s character of the C-H bonds adjacent to the sulfur atom due to its co ordination to the metal atom.…”

“…The reactions of 2 and Cp*ZrCl 3 with a small excess of Na 1 give homo and mixed ligand complexes 3 and 4, respectively. 25 Methoxyethyl substituted zirconium complexes (6-9) were synthesized 27 starting from the lithium salt of (2 methoxyethyl)tetramethylcyclopentadiene (Li 5) 26 (Scheme 3). It should be noted that the two step synthe sis, including the preparative isolation and purification of half sandwich complexes 2 and 6, is the method of choice for the preparation of homoligand complexes 3 and 7, respectively.…”

Mono- and bis-[2-(P,P-dimethylphosphanyl)ethyl]tetramethylcyclopentadienyl zirconium(IV) complexes: Synthesis and structural studies in crystalline state and in solutions

“…However, in this case the apical position opposite to the Cp-ring is occupied not by the bridging chlorine atom, as in 4a and 4b, or by oxygen atom, as in 4a-THF and 4b-THF, but by the phosphorous atom related to the sandwich moiety. In the half-sandwich subpart of 7, like it was observed for 4a and 4b and their O- [15], S- [16], and N- [13] counterparts the apical bond is considerably longer than the corresponding equatorial bond [compare Zr(1)-P(2) 2.8468(9) Å vs. Zr(1)-P(1) 2.7873-(9) Å ]. 1 H and 31 P NMR spectra of 7 in THF-d 8 present nearly a superposition of those for 4b and 6 in an equimolar ratio.…”

“…The cyclic fragment Zr(1)-Cl(1)-Zr(1a)-Cl(1a)-[Zr (1)] is a parallelogram, with the lengths of the ''covalent'' bonds Zr(1)-Cl(1) markedly shorter than those of ''coordination'' ones Zr(1)-Cl(1a) (2.5576(3) vs. 2.7893(3) Å , respectively). This structural motif is typical for MeOCH 2 CH 2 - [15], MeSCH 2 CH 2 - [16], and even for bulkier 8-quinolinyl substituted monocyclopentadienyl [17] complexes of Zr(IV). Of interest, this type of spatial organization was not observed for solvent-free [g 5 :g 1 -jN-C 5 H 4 CH 2 CH 2 NMe 2 ]ZrCl 3 (monomeric) [13] and [g 5 :g 1 -jP-C 5 H 4 CH 2 CH 2 PPh 2 ]ZrCl 3 (only complicated solvent-free ionic product corresponding to formula [{[g 5 :g 1 -jP-C 5 H 4 CH 2 CH 2 PPh 2 ] ZrCl} 2 (l-Cl) 3 ] 2 + [(ZrCl 3 ) 2 (l-Cl) 2 ] 2À was crystallographically characterized [14]).…”

“…The Zr-P distances in 78. 16(3) C(7)-P(1)-C (9) 103.44(18) C(7)-P(1)-C (8) 104.1(2) C(9)-P(1)-C (8) 105.0(2) C(7)-P(1)-Zr (1) 103.40(14) C(9)-P(1)-Zr (1) 121.46(15) C(8)-P(1)-Zr (1) 117.18 ( solvent-free complex 4a (2.7733(4) Å ) are nearly the same as in 4a-THF. The molecular structures of ring-permethylated complexes 4b-THF and 4b (see Figs.…”