Insertion of carbon monoxide into metal-nitrogen bonds. Synthesis, chemistry, structures, and structural dynamics of bis(pentamethylcyclopentadienyl) organoactinide dialkylamides and eta/sup 2/-carbamoyls
This paper reports the synthesis and characterization of chlorobis(pentamethylcyclopentadienyl)thorium and -uranium dialkylamides, M(eta-(CH/sub 3/)/sub 5/C/sub 5/)/sub 2/(NR/sub 2/)Cl (M = Th, U; R = CH/sub 3/, C/sub 2/H/sub 5/), and bis(dialkylamides), M(eta-(CH/sub 3/)/sub 5/C/sub 5/)/sub 2/(NR/sub 2/)/sub 2/ (M = Th, U, R = CH/sub 3/; M = U, R = C/sub 2/H/sub 5/). The amide compounds undergo facile migratory insertion of carbon monoxide to produce the corresponding eta/sup 2/-carbamoyl complexes M(eta-(CH/sub 3/)/sub 5/C/sub 5/)/sub 2/(eta/sup 2/-CONR/sub 2/)Cl, M(eta-(CH/sub 3/)/sub 5/C/sub 5/)/sub 2/(eta/sup 2/-CONR/sub 2/)NR/sub 2/, and M(eta-(CH/sub 3/)/sub 5/C/sub 5/)/sub 2/(eta/sup 2/-CONR/sub 2/)/sub 2/ which were characterized by a variety of chemical and physicochemical methods. The infrared spectra of these compounds exhibit unusually low C-O stretching frequencies (1490 to 1560 cm/sup -1/) for carbamoyl complexes, indicative of strong metal-oxygen bonding. The molecular structures of Th(eta-(CH/sub 3/)/sub 5/C/sub 5/)/sub 2/(eta/sup 2/-CON(C/sub 2/H/sub 5/)/sub 2/)Cl and U(eta-(CH/sub 3/)/sub 5/C/sub 5/)/sub 2/(eta/sub 2/-CON(CH/sub 3/)/sub 2/)/sub 2/ have been determined by single-crystal x-ray diffraction techniques. For the chloro complex, least-squares refinement led to a value for the conventional R index (on F) of 0.080 for 3156 independent reflections having 2theta/sub MoK..cap alpha../ < 55/sup 0/ and I > 3sigma(I), while for the bis(carbamoyl), least-squares refinement led to a conventional R (on F) of 0.036 for 3689 independent reflections having 2 theta/sub MoK..cap alpha../ < 55/sup 0/ and I > 3sigma(I). The M((CH/sub 3/)/sub 5/C/sub 5/)/sub 2/ fragments of both molecules are of the bent sandwich M(C/sub 5/H/sub 5/)/sub 2/X/sub 2/ configuration, with the carbamoyl ligands bound in a eta/sup 2/ fashion. In the bis(carbamoyl), the U-O distances are 2.370 (5) and 2.342 (7) A, the corresponding U-C distances 2.405 (8) and 2.402 (9) A, and the corresponding U-C-O angles 73.0 (4) and 71.8 (5)/sup 0/. The structural and spectral data evidence dative nitrogen lone-pair donation to the carbenoid carbamoyl carbon atom. 6 figures, 8 tables.
- Research Organization:
- Northwestern Univ., Evanston, IL
- OSTI ID:
- 6454344
- Journal Information:
- J. Am. Chem. Soc.; (United States), Vol. 103:9
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
THORIUM COMPLEXES
MOLECULAR STRUCTURE
SYNTHESIS
URANIUM COMPLEXES
BINDING ENERGY
CARBON MONOXIDE
CHEMISTRY
EXPERIMENTAL DATA
INFRARED SPECTRA
NITROGEN
NUCLEAR MAGNETIC RESONANCE
ORGANIC COMPOUNDS
ROTATIONAL STATES
STRUCTURAL CHEMICAL ANALYSIS
X-RAY DIFFRACTION
ACTINIDE COMPLEXES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COMPLEXES
DATA
DIFFRACTION
ELEMENTS
ENERGY
ENERGY LEVELS
EXCITED STATES
INFORMATION
MAGNETIC RESONANCE
NONMETALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
RESONANCE
SCATTERING
SPECTRA
400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials