Indenyl and fluorenyl transition element complexes

Exocyclic coordination of the η3-fluorenyl, η3-cyclopenta[def]phenanthrenyl and η3-8,9-dihydrocyclopenta[def]phenanthrenyl anions: X-ray crystal structures, NMR fluxionality and theoretical studies

“…The group 6 metal fragments of the general type Cp 0 ML 2 (M ¼ Cr, Mo, W; Cp 0 ¼ Cp, Cp*, Ind; L ¼ 2e donors) have proven to be particularly able to stabilize ring-slipped cyclopentadienyl-like ligands coordinated in a trihapto (Z 3 -Cp 0 ) fashion. The earliest example of a de bona fide bent (Z 3 -Cp) ligand structurally characterized, in CpW(Z 3 -Cp)(CO) 2 , 1 the related Z 3 -Cp* in Cp*Cr(Z 3 -Cp*)(CO) 2 , 2 and the first Z 3 -Ind ligand in IndW(Z 3 -Ind)(CO) 2 3 all confirm this fact. Our recent studies of a series of Ind(Cp 0 )ML 2 metallocenes (M ¼ Mo, W; Cp 0 ¼ Cp, Ind) 4 produced several additional examples of Z 3 -Cp 0 derivatives of the type Cp 0 M(Z 3 -Cp 0 )L 2 as well as deep insight into the factors that control Z 5 !…”

The hapticity of η-indenyl complexes: molecular structures of [(η5-C9R7)Rh(η4-cod)](R = H, Me)(cod = cyclo-octa-5-diene)

“…For comparison, consider the values of A = 0.79(1), 0.689 (7), and 0.72(2) 8, respectively for complexes (4) ,8 ( 5 ) ,9 and (6). 10 Although hinge angles were not reported for (4--6), the fold angles are 28, 22, and 26" for the +indeny1 ligands. Thus, both the slip and fold distortions are extremely large for (4)(5)(6) and there is clearly no bonding between the metal atom and C(3a) or C(7a), as required to attain an 18e configuration at the metal.…”

Bis-indenyl molybdenum(iv) halide complexes: synthesis and X-ray studies

“…16 The fluorine atoms of the BF 4 anion in 8 were disordered over two positions. Thus, the counter-ion was introduced in the process refinement in two tetrahedral sites with refined population parameters of x and 1 Ϫ 0.41, being equal to 0.59 (2).…”

“…In contrast to the well developed chemistry of bis-cyclopentadienyl complexes of Group 6 metals, the number of their bis-indenyl counterparts is very small, reflecting difficulties found in their synthesis. The early examples reported are (C 9 H 7 ) 2 Cr, 1 (η 5 -Ind)W(η 3 -Ind)(CO) 2 2 and (η 5 -Ind)Mo(η 3 -Ind)-(dppe). 3 Recent investigations in our laboratory have focused on the chemistry of mixed ring (Cp)(indenyl)molybdenum() complexes 4 but a simple route into the bis-indenyl complexes, namely (η 5 -Ind)Mo(η 3 -Ind)(CO) 2 has only recently been achieved.…”