Ct. Eagle et al., PI-BACK-BONDING IN BIS(ISONITRILE) COMPLEXES OF RHODIUM(II) ACETATE -STRUCTURAL ANALOGS FOR RHODIUM CARBENOIDS, Organometallics, 17(20), 1998, pp. 4523-4526
Rh-2(O2CCH3)(4). 2C=NC6H4R (R = (CH3)(2)N-(1), -H (2), -CF3 (3)) were
synthesized and characterized by X-ray crystallography. The structures
exhibited several common features: (i) a relatively short Rh-C bond (
2.148(4) Angstrom (1), 2.133(4) Angstrom (2), and 2.122(4) Angstrom (3
)), (ii) an inversion center between the two rhodium atoms, (iii) copl
anar aryl rings, and (iv) a significant deviation from linearity in th
e Rh-C-N bond angle. Comparison to other rhodium carboxylate complexes
indicates the presence of pi-back-bonding and by extension, pi-back-b
onding in rhodium-carbenoid systems.