Characterization and crystallography of trans-azulenedimanganese hexacarbonyl

Abstract

Observed and calculated densities are 1.75 ± 0.01 and 1.765 g cm-3, respectively. A single-crystal X-ray diffraction study has been completed. Data out to sin = 0.38 (Mo Ku radiation) were collected with a 0.01 "-incrementing Buerger automated diffractometer, and the structure was solved by a combination of Patterson, Fourier, and least-squares refinement techniques. All atoms (including hydrogens) have been located, the final discrepancy index being Rp = 8.12% for 1683 independent, nonzero reflections. The crystal is composed of discrete molecular units of ¿ra»s-CioH8Mn2(CO)6, separated by normal van der Waals contacts.The molecule consists of two Mn(CO)i groups bonded (with an over-all ¿raros configuration) to an azulene ligand. One Mn(CO)3 group interacts with the atoms of the five-membered ring and participates in a -cyclopentadienyl-*• metal bond, while the other Mn(CO)3 group is associated with the remaining five atoms of the azulene nucleus via a noncyclic -pentadienyl->metal linkage.(1958).

Transition Metal Complexes of Azulene and Related Ligands

“…Churchill and Bird (72,76), however, have reexamined the reaction of azulene with dimanganese decacarbonyl and have been able to isolate only a single complex, of stoichiometry cloH,Mn,(cO)~. The formulation of this species has been confirmed by mass spectrometric studies, which show the parent ion peak at m/e 406 (corresponding to C,,H,Mn,(CO),+) along with peaks corresponding to the stepwise loss of carbonyl ligands, i.e.,CloH,Mnz(CO),-,+ (n = 1 to 6).…”

“…The molecular stereochemistry of azulenedimanganese hexacarbonyl showing metal-to-carbon distances(72,76).…”

Effect of Spectator Ligands on Haptotropic Rearrangements of Metal‐Azulene Complexes

“…[15] Since the 1960s, dinuclear Az complexes have been synthesised with several transition metals such as Mo, Fe, and Mn. [17][18][19][20][21][22][23][24][25][26][27][28] However, only a few crystallographic structures of mononuclear azulene complexes have been reported so far, one chromium (Scheme 1a), [29] one molybdenum (Scheme 1b) [30] and two rhodium cationic complexes (Scheme 1c and d). [31][32][33] The coordination preference in these complexes is to the 5MR, but they exhibit a difference in their connectivity in solid-state.…”

“…Concerning the dinuclear complexes, one metal centre interacts with all five carbons of the cyclopentadienyl moiety, but the other can bind to the 7MR with different hapticities, mainly η 3 [21,[23][24][25] and η 5 , [17][18][19][20]22,27] that resemble more a metal-allyl and a metal-pentadienyl (M-Pdl) bonds, respectively, than a metal-aryl bond. Theoretical studies have shown that the coordination in the Az complexes is very diverse.…”

Unsaturation and variable hapticity in binuclear azulene manganese carbonyl complexes

“…3) in which each azulene ring is bonded to an Mn(CO) 3 unit as a pentahapto ligand. 4 No manganese-manganese bond is required to give each manganese atom the favored 18-electron configuration. Therefore, both the cis and trans isomers are feasible; the trans isomer is the one found experimentally.…”