Huq, F. & Skapski, A.C. Journal of Crystal and Molecular Structure (1974) 4: 411. doi:10.1007/BF01220097
The structure of acetylacetonatodicarbonylrhodium(I), Rh(acac)(CO)2, has been refined from three-dimensional X-ray diffractometer data. The complex crystallises in the triclinic space groupP¯1 with two molecules in a unit cell of dimensionsa = 6.5189(5),b = 7.7614(8),c = 9.2049(12)Å, α = 106.04(1), β = 91.15(1), γ = 100.21(1) °. Full-matrix least-squares refinement, using 1456 independent reflections, has reachedR = 0.038.
The rhodium atom has a square-planar coordination with two Rh-O(acac) distances of 2.040 and 2.044Å, and two Rh-C(carbonyl) distances both equal to 1.831Å, the O-Rh-O angle is 90.8 ° and the C-Rh-C angle is 88.9 °. All twelve non-hydrogen atoms are closely planar, with an average deviation of 0.003Å, and a maximum deviation of 0.006Å, from the least-squares plane through the molecule. A second non-crystallographic plane of symmetry bisects the molecule, which therefore has essentiallymm2 (C2v) point symmetry. The molecules stack in such a way that the rhodium atoms of neighbouring molecules occupy the two remaining pseudo-octahedral positions, with Rh...Rh distances of 3.253 and 3.271Å.