The crystal and molecular structure of acetylcyclopentadienyl-manganese and -rhenium tricarbonyls

Synthesis, characterization, X-ray crystallography, and cytotoxicity of a cymantrene keto carboxylic acid for IR labelling of bioactive peptides on a solid support

“…1 usual geometrical parameters with a C-O bond length of 1.223(4) Å and is essentially in plane with the neighboring cyclopentadienyl ring (6.7°angle between the keto group and Cp plane). These and the other metrical parameters agree very well with the data reported for (C 5 H 4 COCH 3 )Mn(CO) 3 in the literature [32]. In the crystal lattice, additional intermolecular hydrogen bonds are observed which lead to carboxylate-bridged dimers (Fig.…”

Formation of a Dirhenium Carbene Complex from Reaction of (η5-C5H4Li)Re(CO)3with (η5-C5H5)Re(CO)3

“…The Cp cent 1 −Re1−C3 angle of 126.3° is that expected for a normal three-legged piano-stool complex. The carbene carbon atom is nearly coplanar with the cyclopentadienyl ligand (Cp cent 2 −C12−C3 = 183.7°), as expected for cyclopentadienyl substituents in an unstrained complex …”

Ring Strain Perturbation of the Equilibria between Hydroxycarbene Complexes and Metal Acyl Hydride Complexes

“…The X-ray crystal structure of tethered methoxycarbene complex 9 (Figure , top) shows that ring closure produces a moderately strained CpReL 3 system in comparison with untethered carbene complexes such as (C 5 H 5 )(CO) 2 ReC(OH)CH 3 ( 1 ). The alkyl tether of the cyclopentadienyl ring of 9 is bent down 9° toward Re [Cp(cent)−C(5)−C(6) = 171°], while in untethered systems the alkyl groups bend up away from the metal center . Ring strain also narrows the angle between the Cp centroid, rhenium, and the carbene carbon atom to 112° from the 126° ideal angle for a three-legged piano stool CpReL 3 system.…”